Sample records for defocused optical system

  1. Motionless active depth from defocus system using smart optics for camera autofocus applications (United States)

    Amin, M. Junaid; Riza, Nabeel A.


    This paper describes a motionless active Depth from Defocus (DFD) system design suited for long working range camera autofocus applications. The design consists of an active illumination module that projects a scene illuminating coherent conditioned optical radiation pattern which maintains its sharpness over multiple axial distances allowing an increased DFD working distance range. The imager module of the system responsible for the actual DFD operation deploys an electronically controlled variable focus lens (ECVFL) as a smart optic to enable a motionless imager design capable of effective DFD operation. An experimental demonstration is conducted in the laboratory which compares the effectiveness of the coherent conditioned radiation module versus a conventional incoherent active light source, and demonstrates the applicability of the presented motionless DFD imager design. The fast response and no-moving-parts features of the DFD imager design are especially suited for camera scenarios where mechanical motion of lenses to achieve autofocus action is challenging, for example, in the tiny camera housings in smartphones and tablets. Applications for the proposed system include autofocus in modern day digital cameras.

  2. Optical switch phenomenon in a self-defocusing medium

    Institute of Scientific and Technical Information of China (English)

    Huagang Li; Zhihua Luo


    A spatial optical switch phenomenon caused by the induced focusing of a weak probe beam occurring in self-defocusing nonlinear media is discussed theoretically.A weak beam is induced to focus when it copropagates with an intense pump beam under the conditions that the probe and pump beams peak at different positions and propagate in different directions.Due to the effect of cross-phase modulation,the weak beam can not only be focused but also be deflected.The phenomenon is discussed by numerically solving the coupled amplitude equations.

  3. Optical dispersive shock waves in defocusing colloidal media (United States)

    An, X.; Marchant, T. R.; Smyth, N. F.


    The propagation of an optical dispersive shock wave, generated from a jump discontinuity in light intensity, in a defocusing colloidal medium is analysed. The equations governing nonlinear light propagation in a colloidal medium consist of a nonlinear Schrödinger equation for the beam and an algebraic equation for the medium response. In the limit of low light intensity, these equations reduce to a perturbed higher order nonlinear Schrödinger equation. Solutions for the leading and trailing edges of the colloidal dispersive shock wave are found using modulation theory. This is done for both the perturbed nonlinear Schrödinger equation and the full colloid equations for arbitrary light intensity. These results are compared with numerical solutions of the colloid equations.

  4. An approach to remove defocused aberration on array confocal microscope (United States)

    Huang, Xiangdong; Zhou, Tong; Jia, Jingguo


    In order to obtain a high resolution image required for ultra-precision measurement of microstructural object, a new approach is proposed for 3D microstructures. It uses the modulation transfer function with defocus aberration based on the ambiguity function and stable phase principle to achieve an optical phase filter, and utilizes generalized a spheric phase optical element to encode defocus images, and uses deconvolution technology to recover the images. In comparison with conventional optical system, the phase filter used in the optical system can make focal spot smaller when measure object defocusing, eliminates the effect of the defocus aberration, and improves the defocused property. Numerical results indicate the designed phase filter can improve lateral resolution of optical system, and the axial resolution of the optical system is not affect by the filter and defocus aberration. For different defocus plate, the phase filter can make character of modulation transfer function of lateral direction uniform approximation.

  5. Simultaneous defocusing of the aperture and medium on a spectroholographic storage system. (United States)

    Wang, Zhuo; Jin, Guofan; He, Qingsheng; Wu, Minxian


    In a spectroholographic storage system the defocusing method is often used to obtain spectrum uniformity and improve the quality of the recorded information. However, defocusing introduces vignette and stronger interpixel cross talk in the marginal field of view. We report a method that defocuses the aperture and medium together. Based on the pixel spread function, two inequalities are introduced to estimate the upper and lower bounds of the energy received at the CCD. We balance the spectrum uniformity with interpixel cross talk and vignette and then allow the designer to select optimal structure values of the defocusing spectroholographic storage system, i.e., the defocusing value, aperture size, and fill factors for the spatial light modulator and CCD.

  6. Expression of pax-6 in rhesus monkey of optical defocus induced myopia and form deprivation myopia

    Institute of Scientific and Technical Information of China (English)

    钟兴武; 葛坚; 邓文国; 陈晓莲; 黄娟


    Background Pax-6 gene plays an important role in the process of eye development. This study was to determine the role of pax-6 in the axial myopia produced by hyperopic optical defocus and form deprivation in infant monkeys. Methods Among seven normal infant rhesus monkeys (aged 1 to 1.5 months), five wore -3.00 D spectacle lenses over their right eyes and zero-powered lenses over their left eyes. Monocular form deprivation was produced by eyelid fusion in two monkeys. Ten weeks later, the monkeys were sacrificed by an overdose of barbiturates and their eyes were removed immediately. A 5 mm×5 mm button of retina and sclera was taken from the posterior poles along with a 4-mm optic nerve. RNA was isolated separately from each of these three types of tissues. After that, reverse transcription polymerase chain reaction (RT-PCR) was used for determining gene expression in the retina, sclera and optic nerve. Semi-quantitative analyses were performed on the PCR products. Results As expected, the optically induced hyperopic defocus and the form deprivation produced myopic growth. For the lens-treatment monkeys, pax-6 gene expression in the retinas of the defocused eyes was significantly higher than in the retinas of the left eyes (t=5.703, P=0.005). However, there were no analogous significant differences between pax-6 expression in the scleras or the optic nerves. For the two form-deprived monkeys, there were no obvious differences in pax-6 gene expression in the retinas or the optic nerves. Conclusion The result that the expression of pax-6 was enhanced by hyperopic defocus in the infant monkey retina suggests that pax-6 may be involved in vision-dependent eye growth and emmetropization.


    Directory of Open Access Journals (Sweden)

    Stepan E. Ivanov


    Full Text Available Subject of Research. Traditionally, afocal compensators, located in parallel or in converging beams, are used to correct the aberrations of mirror systems. The additional property of afocality gives the possibility to ignore practically the selection of materials in the design, since, in this case, the achromatic correction is achieved automatically. A change in the ambient temperature leads to a change in the shape of the mirrors and their mutual arrangement, in addition, the optical characteristics of the compensator material change that leads to defocusing. Main Results. Based on the analysis of paraxial formulas valid for the correction of chromatic aberrations and thermal defocusing, we have obtained formulas that enable to evaluate the characteristics of the materials necessary for passive athermalization, that is, to keep image quality when the ambient temperature changes without using a mechanical offset of the sensor. It is shown that in a two-lens compensator used to correct aberrations of two-mirror lens in a converging beam of rays, it is necessary to use a combination of optical glasses and polymer materials for passive athermalization. Practical Relevance. Based on the theoretical correlations obtained, a two-mirror system with an afocal compensator is calculated with a high image quality maintained over a wide temperature range. The use of obtained formulas in practice made it possible to demonstrate the possibility of creation of athermalized catadioptric lens involving combinations of conventional glasses with modern polymeric materials. The method presented is not universal, but it gives the possibility to select materials for calculating the afocal two-lens systems, compensating the thermal defocusing of the image without active correction methods (mechanical shifts.

  8. Three-Wave Resonant Interactions in Self-Defocusing Optical Media

    Institute of Scientific and Technical Information of China (English)

    崔维娜; 黄国翔; 孙春柳


    A three-wave resonant interaction for nonlinear excitations created from a continuous-wave background is shown to be possible in an isotropic optical medium with a self-defocusing cubic nonlinearity. Under suitable phasematching conditions the nonlinear envelope equations for the resonant interaction are derived by using a method of multiple-scales. Some explicit three-wave solitary wave and lump solutions are discussed.

  9. High-precision photometry by telescope defocusing - I. The transiting planetary system WASP-5

    DEFF Research Database (Denmark)

    Southworth, J.; Hinse, T. C.; Jørgensen, U. G.;


    We present high-precision photometry of two transit events of the extrasolar planetary system WASP-5, obtained with the Danish 1.54-m telescope at European Southern Obseratory La Silla. In order to minimize both random and flat-fielding errors, we defocused the telescope so its point spread...

  10. Transparent aluminium nanowire electrodes with optical and electrical anisotropic response fabricated by defocused ion beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, Diego, E-mail:; Giordano, Maria Caterina, E-mail:; Martella, Christian, E-mail:; Buatier de Mongeot, Francesco, E-mail:


    Highlights: • Self-organized Al nanowires were grown on glass substrates by ion beam sputtering. • Al nanowire pattern exhibit electrical and optical anisotropy. • Al NW pattern can be used as transparent electrodes for optoelectronic devices. - Abstract: Self-organized Al nanowire (NW) electrodes have been obtained by defocused Ion Beam Sputtering (IBS) of polycrystalline Al films grown by sputter deposition. The electrical sheet resistance of the electrode has been acquired in situ during ion bombardment of the samples, evidencing an increase of the electronic transport anisotropy as a function of ion fluence between the two directions parallel and orthogonal to the NWs axis. Optical spectra in transmission also show a large dichroism between the two directions, suggesting the role of localized plasmons in the UV spectral range. The results show that Al NW electrodes, prepared under experimental conditions which are compatible with those of conventional industrial coaters and implanters, could represent a low cost alternative to the transparent conductive oxides employed in optoelectronic devices.

  11. Three-dimensional surface measurement based on the projected defocused pattern technique using imaging fiber optics (United States)

    Parra Escamilla, Geliztle A.; Kobayashi, Fumio; Otani, Yukitoshi


    We present a three-dimensional surface measurement system using imaging fiber endoscope and the measurement is based on the focus technique in uniaxial configuration. The surface height variation of the sample is retrieved by taking into account the contrast modulation change obtained from a projected fringe pattern on the sample. The technique takes into account the defocus change of the fringe pattern due to the height variation of the sample and by a Gaussian fitting process the height reconstruction can be retrieved. A baseline signal procedure was implemented to remove back reflection light coming from the two fiber-surfaces (inlet and outlet) and also a Fourier transform filter was used to remove the pixelated appearance of the images. The depth range of the system is 1.1 mm and a lateral range of 2 mm by 2 mm. The novelties of the implementation are that the system uses the same imaging fiber as illumination and measurement and offers the advantage of the transportability to the measurement to a confined space having potential application on medical or industrial endoscopes systems. We demonstrate the technique by showing the surface profile of a measured object.

  12. Windowed defocused photographic speckle vibration measurement

    CERN Document Server

    Diazdelacruz, Jose M


    The out-of-plane vibration of a rough surface causes an in-plane vibration of its speckle pattern when observed with a defocused optical photographic system. If the frequency of the oscillations is high enough, a time-averaged specklegram is recorded from which the amplitude of the vibration can be estimated. The statistical character of speckle distributions along with the pixel sampling and intensity analog-to-digital conversion inherent to electronic cameras degrade the accuracy of the amplitude measurement to an extent that is analyzed and experimentally tested in this paper. The relations limiting the mutually competing metrological features of a defocused speckle system are also deduced mathematically.

  13. Accelerating defocus blur magnification (United States)

    Kriener, Florian; Binder, Thomas; Wille, Manuel


    A shallow depth-of-field is often used as a creative element in photographs. This, however, comes at the cost of expensive and heavy camera equipment, such as large sensor DSLR bodies and fast lenses. In contrast, cheap small-sensor cameras with fixed lenses usually exhibit a larger depth-of-field than desirable. In this case a computational solution is suggesting, since a shallow depth-of-field cannot be achieved by optical means. One possibility is to algorithmically increase the defocus blur already present in the image. Yet, existing algorithmic solutions tackling this problem suffer from poor performance due to the ill-posedness of the problem: The amount of defocus blur can be estimated at edges only; homogeneous areas do not contain such information. However, to magnify the defocus blur we need to know the amount of blur at every pixel position. Estimating it requires solving an optimization problem with many unknowns. We propose a faster way to propagate the amount of blur from the edges to the entire image by solving the optimization problem on a small scale, followed by edge-aware upsampling using the original image as guide. The resulting approximate defocus map can be used to synthesize images with shallow depth-of-field with quality comparable to the original approach. This is demonstrated by experimental results.

  14. Low-energy Self-defocusing Soliton Compression at Optical Communication Wavelengths in Unpoled Lithium Niobate Ridge Waveguide

    DEFF Research Database (Denmark)

    Guo, Hairun; Zeng, Xianglong; Zhou, Binbin;


    Self-defocusing soliton compression supported by the cascaded phase-mismatched second-harmonic generation process is numerically demonstrated in unpoled lithium niobate ridge waveguides where nano-joule pulses are operated and quasi-phase-matching is unnecessary. The soliton range is 1100-1800 nm....

  15. Parameter Estimation for Blur Image Combining Defocus and Motion Blur using Cepstrum Analysis

    Institute of Scientific and Technical Information of China (English)


    The degraded parameters recognition is very important for the restoration of blurred images. There are two common types of blurs for most camera systems. One is the defocus blur due to the optical system's defocus phenomenon and the other is the motion blur due to the relative movement between the objectives and the camera.Compared with the recognition for the blurred image with only one blur model, the parameter estimation for the picture combining defocus and motion blur models is a more complicated mission. A method was proposed for computer to estimate the parameters of defocus blur and motion blur in cepstrum area simultaneously. According to characters of both blur models in the frequency domain, an adjustment approach was suggested in the frequency area and then convert to the cepstrum field to increase the accuracy of measurement.

  16. Transition between self-focusing and self-defocusing in nonlocally nonlinear media

    CERN Document Server

    Liang, Guo; Hu, Yahong; Wang, Jing; Wang, Zhuo; Li, Yingbing; Guo, Qi; Hu, Wei; Lou, Senyue; Christodoulides, Demetrios N


    We reveal the relevance between the nonlocality and the focusing/defocusing states in nonlocally nonlinear media, and predict a novel phenomenon that the self-focusing/self-defocusing property of the optical beam in the nonlocally nonlinear medium with a sine-oscillation response function depends on its degree of nonlocality. The transition from the focusing nonlinearity to the defocusing nonlinearity of the nonlinear refractive index will happen when the degree of nonlocality of the system goes cross a critical value, and vise verse. Bright and dark soliton solutions are obtained, respectively, in the focusing state and in the defocusing state, and their stabilities are also discussed. It is mentioned that such a phenomenon might be experimentally realized in the nematic liquid crystal with negative dielectric anisotropy or in the quadratic nonlinear medium.

  17. Discrete solitons in self-defocusing systems with $\\mathcal{PT}$-symmetric defects

    CERN Document Server

    Chen, Zhiqiang; Chai, Jinglei; Zhang, Xiangyu; Li, Yongyao; Malomed, Boris A


    We construct families of discrete solitons (DSs) in an array of self-defocusing waveguides with an embedded $\\mathcal{PT}$ (parity-time)-symmetric dimer, which is represented by a pair of waveguides carrying mutually balanced gain and loss. Four types of states attached to the embedded defect are found, namely, staggered and unstaggered bright localized modes and gray or anti-gray DSs. Their existence and stability regions expand with the increase of the strength of the coupling between the dimer-forming sites. The existence of the gray and staggered bright DSs is qualitatively explained by dint of the continuum limit. All the gray and anti-gray DSs are stable (some of them are unstable if the dimer carries the nonlinear $\\mathcal{PT}$ symmetry, represented by balanced nonlinear gain and loss; in that case, the instability does not lead to a blowup, but rather creates oscillatory dynamical states). The boundary between the gray and anti-gray DSs is predicted in an approximate analytical form.

  18. Edge detector tolerant to object defocusing (United States)

    Mazzaferri, Javier; Campos, Juan; Escalera, Juan C.; Sheppard, Colin J. R.; Ledesma, Silvia


    Different methods for edge extraction have been studied in the past years. In a recent paper we have presented a rotation-invariant edge extractor based on a spiral phase filter placed in the frequency plane of a convergent correlator. In this architecture, the axial position of the output plane strongly depends on the axial position of the object. This condition limits the processing of three dimensional objects, because only a narrow axial region of the object would be correctly imaged to the output. The other axial regions of the target yield defocused results. Likewise, a rather small axial misalignment of planar scenes could produce completely inaccurate correlations. Besides, annular pupils have been widely used to regulate the depth of focus (DOF) and the transversal resolution of optical systems. In this paper we present a novel filter that combines the advantages of a spiral phase-based edge extractor and those of an axial-apodizing annular pupil. This design allows edge extraction of objects in a widened axial range. Numerical simulations and experimental results that demonstrate edge extraction with improved tolerance to defocusing are presented.

  19. Tunable nonlinear beam defocusing in infiltrated photonic crystal fibers

    DEFF Research Database (Denmark)

    Rosberg, Christian Romer; Bennet, Francis H; Neshev, Dragomir N.;


    We demonstrate a novel experimental platform for discrete nonlinear optics based on infiltrated photonic crystal fibers. We observe tunable discrete diffraction and nonlinear self-defocusing, and apply the effects to realize a compact all-optical power limiter....

  20. Design optical antenna and fiber coupling system based on the vector theory of reflection and refraction. (United States)

    Jiang, Ping; Yang, Huajun; Mao, Shengqian


    A Cassegrain antenna system and an optical fiber coupling system which consists of a plano-concave lens and a plano-convex lens are designed based on the vector theory of reflection and refraction, so as to improve the transmission performance of the optical antenna and fiber coupling system. Three-dimensional ray tracing simulation are performed and results of the optical aberrations calculation and the experimental test show that the aberrations caused by on-axial defocusing, off-axial defocusing and deflection of receiving antenna can be well corrected by the optical fiber coupling system.

  1. The generalized Toda lattices and the Whitham averaged system for the defocusing nonlinear Schrodinger equation (United States)

    Ye, Jian

    In Part I, we first study an iso-spectral deformation of general matrix which is a natural generalization of the nonperiodic Toda lattice equation. This deformation is equivalent to the Cholesky flow. We prove the integrability of the deformation, and give an explicit formula for the solution to the initial value problem. The formula is obtained by generalizing the orthogonalization procedure of Szego. Using the formula, the solution to the LU factorization can be constructed explicitly. Based on the root spaces for simple Lie algebras, we consider several reductions of the equation. This leads to generalized Toda equations related to other classical semi-simple Lie algebra which include the integrable systems studied by Bogoyavlensky and Kostant. We show these systems can be solved explicitly in a unified way. Based on the explicit solutions, we then consider the iso-spectral real manifolds of tridiagonal Hessenberg matrices with distinct real eigenvalues. The manifolds are described by the iso-spectral flows of indefinite Toda lattice equations introduced by Kodama and Ye. These Toda lattices consist of 2N-1 different systems with hamiltonians H = [[1]/over[2

  2. Removing harmonic distortion of measurements of a defocusing three-step phase-shifting digital fringe projection system (United States)

    XU, Zi-Xin; Chan, Yuk-Hee


    Binary defocusing method was adopted in 3D profilometry as it allows real-time measurement and does not need to handle the luminance nonlinearity of a projector. Current patch-based binary fringe patterns are periodic and carry strong harmonic distortion as compared with the ideal sinusoidal fringe patterns, which affects the measuring performance remarkably. In this paper, we propose a framework for generating aperiodic fringe patterns based on optimized patches. The produced fringe patterns can significantly lower the noise floor and suppress the harmonic distortion in the constructed phase map. Accordingly, the achieved depth measuring performance can be significantly improved. Special care is also taken during the optimization of the patches in our framework such that the depth measuring performance is robust to fringe period and defocusing extent.

  3. LBP-Based Segmentation of Defocus Blur. (United States)

    Xin Yi; Eramian, Mark


    Defocus blur is extremely common in images captured using optical imaging systems. It may be undesirable, but may also be an intentional artistic effect, thus it can either enhance or inhibit our visual perception of the image scene. For tasks, such as image restoration and object recognition, one might want to segment a partially blurred image into blurred and non-blurred regions. In this paper, we propose a sharpness metric based on local binary patterns and a robust segmentation algorithm to separate in- and out-of-focus image regions. The proposed sharpness metric exploits the observation that most local image patches in blurry regions have significantly fewer of certain local binary patterns compared with those in sharp regions. Using this metric together with image matting and multi-scale inference, we obtained high-quality sharpness maps. Tests on hundreds of partially blurred images were used to evaluate our blur segmentation algorithm and six comparator methods. The results show that our algorithm achieves comparative segmentation results with the state of the art and have big speed advantage over the others.

  4. The influence of the positive and negative defocusing on lensless ghost imaging (United States)

    Zeng, Xue; Bai, Yanfeng; Shi, Xiaohui; Gao, Yang; Fu, Xiquan


    Lensless ghost imaging with fully spatially incoherent source is investigated theoretically and experimentally. The effects of positive and negative defocusing on lensless ghost imaging are studied by using classical optical theory and a fully spatially incoherent source. Based on the numerical calculation and experimental results, we find that the negative defocusing has a stronger influence on imaging resolution when compared with that from the positive defocusing. To explain this phenomenon, the analytical expression of point spread function with the positive and negative defocusing is presented.

  5. The effect of defocus on edge contrast sensitivity

    NARCIS (Netherlands)

    Jansonius, NM; Kooijman, AC

    The effect of optical blur (defocus) on edge contrast sensitivity was studied. Edge contrast sensitivity detoriates with fairly small amounts of blur (similar to 0.5 D) and is roughly reduced by half for each dioptre of blur. The effect of blur on edge contrast sensitivity equals the effect of blur

  6. Double shock dynamics induced by the saturation of defocusing nonlinearities

    KAUST Repository

    Crosta, Matteo


    We show that the saturation of defocusing nonlinearities leads to qualitative changes in the onset of wave breaking, determining double shock formation whose regularization occurs in terms of antidark solitons. In a given material, the crossover between different regimes can be controlled by changing the input intensity. © 2012 Optical Society of America.

  7. Compensating focusing for space hyper spectral imager's fore optical system

    Institute of Scientific and Technical Information of China (English)

    Yicha Zhang; Wei Liu


    @@ The performance of space hyper spectral imager is severely affected by turbulent orbit temperature. Turbulence results in a defocus in the fore optical system of the imager. To address this problem, a focusing system is added. A number of simulation methods are applied on the fore optical system to study the relationship between temperature and focusing. In addition, this process is conducted to obtain a practical reference for focusing while the imager is flying on orbit. The obtained correlation between focusing and temperature is proven effective based on ground imaging and simulation testing.%The performance of space hyper spectral imager is severely affected by turbulent orbit temperature. Turbulence results in a defocus in the fore optical system of the imager. To address this problem, a focusing system is added. A number of simulation methods are applied on the fore optical system to study the relationship between temperature and focusing. In addition, this process is conducted to obtain a practical reference for focusing while the imager is flying on orbit. The obtained correlation between focusing and temperature is proven effective based on ground imaging and simulation testing.

  8. A Unified Approach for Registration and Depth in Depth from Defocus. (United States)

    Ben-Ari, Rami


    Depth from Defocus (DFD) suggests a simple optical set-up to recover the shape of a scene through imaging with shallow depth of field. Although numerous methods have been proposed for DFD, less attention has been paid to the particular problem of alignment between the captured images. The inherent shift-variant defocus often prevents standard registration techniques from achieving the accuracy needed for successful shape reconstruction. In this paper, we address the DFD and registration problem in a unified framework, exploiting their mutual relation to reach a better solution for both cues. We draw a formal connection between registration and defocus blur, find its limitations and reveal the weakness of the standard isolated approaches of registration and depth estimation. The solution is approached by energy minimization. The efficiency of the associated numerical scheme is justified by showing its equivalence to the celebrated Newton-Raphson method and proof of convergence of the emerged linear system. The computationally intensive approach of DFD, newly combined with simultaneous registration, is handled by GPU computing. Experimental results demonstrate the high sensitivity of the recovered shapes to slight errors in registration and validate the superior performance of the suggested approach over two, separately applying registration and DFD alternatives.

  9. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.


    : The observations are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period...

  10. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.;


    Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period...

  11. Lensless Ghost Diffraction with Partially Coherent Sources:Effects of the Source Size,Transverse Coherence,Detector Size and Defocusing Length

    Institute of Scientific and Technical Information of China (English)

    LIN Jie; CHENG Jing


    @@ Lensless ghost diffraction with partially coherent sources is investigated theoretically and numerically.Based on the classical optical coherent theory and the Gauss-Shell model of the partially coherent sources,we derive an analytical imaging formula of lensless ghost diffraction(LGD).Using this formula,we can see the effects of the transverse size and coherence of the sources,the detector size and defocusing length on the quality of LGD.Numerical results are presented to show that for different detector sizes and defocusing lengths,high quality LGD can be realized by using sources with appropriate transverse sizes and coherent widths.These findings can be used to choose the optimal parameters in the design of a realistic LGD system.%Lensless ghost diffraction with partially coherent sources is investigated theoretically and numerically. Based on the classical optical coherent theory and the Gauss-Shell model of the partially coherent sources, we derive an analytical imaging formula of lensless ghost diffraction (LGD). Using this formula, we can see the effects of the transverse size and coherence of the sources, the detector size and defocusing length on the quality of LGD. Numerical results are presented to show that for different detector sizes and defocusing lengths, high quality LGD can be realized by using sources with appropriate transverse sizes and coherent widths. These findings can be used to choose the optimal parameters in the design of a realistic LGD system.

  12. Phase imaging from defocus information in a light field

    CERN Document Server

    Davis, Quintin Tyrell


    Optical microscopy is without a doubt an essential component of life science research, but many objects of interest in biology are transparent. Chemical or immunological dyes, which can often be toxic, fluorescent transgenes, which require a protocol for transformation of exogenous DNA, and phase contrast, which inextricably combines phase information with amplitude, all serve to increase the contrast of transparent objects. Transparent objects of non-uniform refractive index and/or thickness are phase objects and phase can be extracted from defocus information above and below the object. The light microscopist will recognize this in that object contrast can vary as the stage is moved around an object's focal plane. This phase information can be quantitatively retrieved from a set of defocused images, but this has the disadvantage of decreasing temporal resolution, as the microscope stage has to be moved between image captures. By incorporating additional optics in the form of an array of pinholes or microlen...

  13. High-precision photometry by telescope defocusing - IV

    DEFF Research Database (Denmark)

    Southworth, John; Hinse, T. C.; Dominik, M.


    We present photometric observations of four transits in the WASP-17 planetary system, obtained using telescope defocusing techniques and with scatters reaching 0.5 mmag per point. Our revised orbital period is 4.0 ± 0.6 s longer than previous measurements, a difference of 6.6σ, and does not suppo...

  14. Lensless Ghost Diffraction with Partially Coherent Sources: Effects of the Source Size, Transverse Coherence, Detector Size and Defocusing Length (United States)

    Lin, Jie; Cheng, Jing


    Lensless ghost diffraction with partially coherent sources is investigated theoretically and numerically. Based on the classical optical coherent theory and the Gauss-Shell model of the partially coherent sources, we derive an analytical imaging formula of lensless ghost diffraction (LGD). Using this formula, we can see the effects of the transverse size and coherence of the sources, the detector size and defocusing length on the quality of LGD. Numerical results are presented to show that for different detector sizes and defocusing lengths, high quality LGD can be realized by using sources with appropriate transverse sizes and coherent widths. These findings can be used to choose the optimal parameters in the design of a realistic LGD system.

  15. Active optical zoom system (United States)

    Wick, David V.


    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  16. Microscopic structured light 3D profilometry: Binary defocusing technique vs. sinusoidal fringe projection (United States)

    Li, Beiwen; Zhang, Song


    This paper compares the binary defocusing technique with conventional sinusoidal fringe projection under two different 3D microscopic profilometry systems: (1) both camera and projector use telecentric lenses and (2) only camera uses a telecentric lens. Our simulation and experiments found that the binary defocusing technique is superior to the traditional sinusoidal fringe projection method by improving the measurement resolution approximately 19%. Finally, by taking the speed advantage of the binary defocusing technique, we presented a high-speed (500 Hz) and high-resolution (1600×1200) 3D microscopic profilometry system that could reach kHz.

  17. Defocus cue and saliency preserving video compression (United States)

    Khanna, Meera Thapar; Chaudhury, Santanu; Lall, Brejesh


    There are monocular depth cues present in images or videos that aid in depth perception in two-dimensional images or videos. Our objective is to preserve the defocus depth cue present in the videos along with the salient regions during compression application. A method is provided for opportunistic bit allocation during the video compression using visual saliency information comprising both the image features, such as color and contrast, and the defocus-based depth cue. The method is divided into two steps: saliency computation followed by compression. A nonlinear method is used to combine pure and defocus saliency maps to form the final saliency map. Then quantization values are assigned on the basis of these saliency values over a frame. The experimental results show that the proposed scheme yields good results over standard H.264 compression as well as pure and defocus saliency methods.

  18. Optical system design

    CERN Document Server

    Fischer, Robert F


    Honed for more than 20 years in an SPIE professional course taught by renowned optical systems designer Robert E. Fischer, Optical System Design, Second Edition brings you the latest cutting-edge design techniques and more than 400 detailed diagrams that clearly illustrate every major procedure in optical design. This thoroughly updated resource helps you work better and faster with computer-aided optical design techniques, diffractive optics, and the latest applications, including digital imaging, telecommunications, and machine vision. No need for complex, unnecessary mathematical derivations-instead, you get hundreds of examples that break the techniques down into understandable steps. For twenty-first century optical design without the mystery, the authoritative Optical Systems Design, Second Edition features: Computer-aided design use explained through sample problems Case studies of third-millennium applications in digital imaging, sensors, lasers, machine vision, and more New chapters on optomechanic...

  19. Nonlinear optical systems

    CERN Document Server

    Lugiato, Luigi; Brambilla, Massimo


    Guiding graduate students and researchers through the complex world of laser physics and nonlinear optics, this book provides an in-depth exploration of the dynamics of lasers and other relevant optical systems, under the umbrella of a unitary spatio-temporal vision. Adopting a balanced approach, the book covers traditional as well as special topics in laser physics, quantum electronics and nonlinear optics, treating them from the viewpoint of nonlinear dynamical systems. These include laser emission, frequency generation, solitons, optically bistable systems, pulsations and chaos and optical pattern formation. It also provides a coherent and up-to-date treatment of the hierarchy of nonlinear optical models and of the rich variety of phenomena they describe, helping readers to understand the limits of validity of each model and the connections among the phenomena. It is ideal for graduate students and researchers in nonlinear optics, quantum electronics, laser physics and photonics.

  20. Brain refractive index measured in vivo with high-NA defocus-corrected full-field OCT and consequences for two-photon microscopy. (United States)

    Binding, Jonas; Ben Arous, Juliette; Léger, Jean-François; Gigan, Sylvain; Boccara, Claude; Bourdieu, Laurent


    Two-photon laser scanning microscopy (2PLSM) is an important tool for in vivo tissue imaging with sub-cellular resolution, but the penetration depth of current systems is potentially limited by sample-induced optical aberrations. To quantify these, we measured the refractive index n' in the somatosensory cortex of 7 rats in vivo using defocus optimization in full-field optical coherence tomography (ff-OCT). We found n' to be independent of imaging depth or rat age. From these measurements, we calculated that two-photon imaging beyond 200 µm into the cortex is limited by spherical aberration, indicating that adaptive optics will improve imaging depth.

  1. Optical vortex solitons in self-defocusing Kerr-type nonlocal medium∗%自散焦非局域非线性材料中的光学涡旋孤子

    Institute of Scientific and Technical Information of China (English)



      通过数值模拟的方法对非局域非线性自散焦材料中的光学涡旋孤子的传输特性以及相互作用特性进行了研究。研究表明,拓扑荷|m|=1的非局域涡旋孤子是稳定的,而拓扑荷|m|>1的非局域涡旋孤子均具有拓扑不稳定性。在微扰存在的情况下以及在近距离相互作用的过程中,|m|>1的涡旋孤子会分裂成一系列的|m|=1的涡旋孤子。非局域涡旋孤子与局域涡旋孤子具有相同的长距离相互作用模式,即点涡旋相互作用模式。但两者的短距离相互作用存在一些差别,在相同的距离下,两涡旋间的相互绕转的周期随着材料的非局域响应长度增大而增大。%The propagation and interaction properties of optical vortex solitons in a self-defocusing Kerr-type nonlocal medium are investi-gated by the numerical simulation method. It is indicated that the singly charged vortices are stable and the multicharged vortices are topologically unstable in both the nonlocal and local cases. And in the nonlocal and local cases the point vortices model is applicable for describing the interactions of vortices provided that the interval distances between vortices are much larger than the size of the core of the vortices. However, vortices interact differently in short distance, depending on the nonlocality, and the larger the characteristic nonlocal respond length, the larger the rotating period of two singly charged vortices.

  2. Stereoscopic optical viewing system (United States)

    Tallman, Clifford S.


    An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  3. Optical controlled keyboard system (United States)

    Budzyński, Łukasz; Długosz, Dariusz; Niewiarowski, Bartosz; Zajkowski, Maciej


    Control systems of our computers are common devices, based on the manipulation of keys or a moving ball. Completely healthy people have no problems with the operation of such devices. Human disability makes everyday activities become a challenge and create trouble. When a man can not move his hands, the work becomes difficult or often impossible. Controlled optical keyboard is a modern device that allows to bypass the limitations of disability limbs. The use of wireless optical transmission allows to control computer using a laser beam, which cooperates with the photodetectors. The article presents the construction and operation of non-contact optical keyboard for people with disabilities.

  4. Digital Optical Control System (United States)

    Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.


    We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.

  5. Three-dimensional Orientation Sensors by Defocused Imaging of Gold Nanorods through an Ordinary Wide-Field Microscope

    CERN Document Server

    Li, Tao; Chen, Xiao-Jun; Xu, Yi; Dai, Qiaofeng; Liu, Hai-Ying; Lan, Sheng; Wu, Li-Jun


    Gold (Au) nanoparticles particularly nanorods are actively exploited as imaging probes because of their special nonblinking and nonbleaching absorption, scattering and emitting properties that arise from the excitation of surface plasmons. Herein, we report a novel orientation sensor at nanoscale by defocused imaging of single Au nanorods (AuNRs) through an ordinary wide-field optical microscope. By simultaneously recording defocused images and two-photon luminescence intensities for a large number of single AuNRs, we correlate their defocused images with their three-dimensional spatial orientations. As many AuNRs can be monitored in parallel, defocused imaging of single AuNRs is a high throughput sensing technique that allows us to obtain their spatial orientations within one frame in situ and real-time. The probe size can be down to several nanometers, which is highly desirable in order to minimize any potential interference from the probe itself. Furthermore, the sensing property is insensitive to the exci...

  6. Optical Complex Systems 2008 (United States)

    Brun, Guillaume

    The Optical Complex Systems are more and more in the heart of various systems that industrial applications bring to everyday life. From environment up to spatial applications, OCS is also relevant in monitoring, transportation, robotics, life sciences, sub-marine, and even for agricultural purposes.

  7. Optics Supply Planning System

    Energy Technology Data Exchange (ETDEWEB)

    Gaylord, J


    The purpose of this study is to specify the design for an initial optics supply planning system for NIF, and to present quality assurance and test plans for the construction of the system as specified. The National Ignition Facility (NIF) is a large laser facility that is just starting operations. Thousands of specialized optics are required to operate the laser, and must be exchanged over time based on the laser shot plan and predictions of damage. Careful planning and tracking of optic exchanges is necessary because of the tight inventory of spare optics, and the long lead times for optics procurements and production changes. Automated inventory forecasting and production planning tools are required to replace existing manual processes. The optics groups members who are expected to use the supply planning system are the stakeholders for this project, and are divided into three groups. Each of these groups participated in a requirements specification that was used to develop this design. (1) Optics Management--These are the top level stakeholdersk, and the final decision makers. This group is the interface to shot operations, is ultimately responsible for optics supply, and decides which exchanges will be made. (2) Work Center Managers--This group manages the on site optics processing work centers. They schedule the daily work center operations, and are responsible for developing long term processing, equipment, and staffing plans. (3) Component Engineers--This group manages the vendor contracts for the manufacture of new optics and the off site rework of existing optics. They are responsible for sourcing vendors, negotiating contracts, and managing vendor processes. The scope of this analysis is to describe the structure and design details of a system that will meet all requirements that were described by stakeholders and documented in the analysis model for this project. The design specifies the architecture, components, interfaces, and data stores of the system

  8. Effect of retinal image defocus on the thickness of the human choroid. (United States)

    Chiang, Samuel T-H; Phillips, John R; Backhouse, Simon


    To describe the time-course and amplitude of changes to sub-foveal choroidal thickness (SFCT) induced by imposed hyperopic and myopic retinal defocus and to compare the responses in emmetropic and myopic subjects. Twelve East Asian subjects (age: 18-34 years; six were emmetropic and six had myopia between -2.00 and -5.00 dioptres (D)) viewed a distant target (video movie at 6 m) for 60 min on two separate occasions while optical coherence tomography (OCT) images of the choroid were taken in both eyes every 5 min to monitor SFCT. On each occasion, one eye was optimally corrected for distance with a contact lens while the other eye wore a contact lens imposing either 2.00 D hyperopic or 2.00 D myopic retinal defocus. Baseline SFCT in myopic eyes (mean ± S.D.): 256 ± 42 μm was significantly less than in emmetropic eyes (423 ± 62 μm; p < 0.01) and was correlated with magnitude of myopia (-39 μm per dioptre of myopia, R(2) = 0.67: p < 0.01). Repeated measures anova (General Linear Model) analysis revealed that in both subject groups, 2.00 D of myopic defocus caused a rapid increase in SFCT in the defocussed eye (significant by 10 min, increasing to approximately 20 μm within 60 min: p < 0.01), with little change in the control eye. In contrast, 2.00 D of hyperopic defocus caused a decrease in SFCT in the experimental eye (significant by 20-35 min. SFCT decreased by approximately 20 μm within 60 min: p < 0.01) with little change in the control eye. Small but significant changes in SFCT (5-8%) were caused by retinal defocus. SFCT increased within 10 min of exposure to 2.00 D of monocular myopic defocus, but decreased more slowly in response to 2.00 D of monocular hyperopic defocus. In our relatively small sample we could detect no difference in the magnitude of changes to SFCT caused by defocus in myopic eyes compared to emmetropic eyes. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

  9. Magnification variations due to illumination curvature and object defocus in transmission electron microscopy (United States)

    van Duinen, Gijs; van Heel, Marin; Patwardhan, Ardan


    It has previously been shown that - in theory - magnification variations can occur in an imaging system as a function of defocus, depending on the field curvature of the illuminating system. We here present the results of practical experiments to verify this effect in the transmission electron microscope. We find that with illumination settings typically used in the electron microscopy of biological macromolecules, systematic variations in magnification of ~ 0.5% per μm defocus can easily occur. This work highlights the need for a magnification-invariant imaging mode to eliminate or to compensate for this effect.

  10. Adaptive optics ophthalmologic systems using dual deformable mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S; Olivier, S; Chen, D; Sadda, S; Joeres, S; Zawadzki, R; Werner, J S; Miller, D


    Adaptive Optics (AO) have been increasingly combined with a variety of ophthalmic instruments over the last decade to provide cellular-level, in-vivo images of the eye. The use of MEMS deformable mirrors in these instruments has recently been demonstrated to reduce system size and cost while improving performance. However, currently available MEMS mirrors lack the required range of motion for correcting large ocular aberrations, such as defocus and astigmatism. In order to address this problem, we have developed an AO system architecture that uses two deformable mirrors, in a woofer/tweeter arrangement, with a bimorph mirror as the woofer and a MEMS mirror as the tweeter. This setup provides several advantages, including extended aberration correction range, due to the large stroke of the bimorph mirror, high order aberration correction using the MEMS mirror, and additionally, the ability to ''focus'' through the retina. This AO system architecture is currently being used in four instruments, including an Optical Coherence Tomography (OCT) system and a retinal flood-illuminated imaging system at the UC Davis Medical Center, a Scanning Laser Ophthalmoscope (SLO) at the Doheny Eye Institute, and an OCT system at Indiana University. The design, operation and evaluation of this type of AO system architecture will be presented.

  11. Optical system defect propagation in ABCD systems

    DEFF Research Database (Denmark)

    McKinley, W.G.; Yura, H.T.; Hanson, Steen Grüner


    We describe how optical system defects (tilt/jitter, decenter, and despace) propagate through an arbitrary paraxial optical system that can be described by an ABCD ray transfer matrix. A pedagogical example is given that demonstrates the effect of alignment errors on a typical optical system....... © 1988 Optical Society of America...

  12. Optical designs of the LGS WFS system for GMT-LTAO (United States)

    Wang, Min; Uhlendorf, Kristina; Jones, Damien; Côté, Patrice; Châteauneuf, François; Gauvin, Jonny; Conan, Rodolphe; Espeland, Brady


    The Laser Tomographic Adaptive Optics system for Giant Magellan Telescope (GMT) uses a single conjugated deformable mirror, the segmented Adaptive Secondary Mirror (ASM), to correct atmospheric wavefront aberrations with the help of a constellation of six laser beacons equally spaced on the sky. We will present different approaches for the design of the Laser Guide Star (LGS) Wave Front Sensor (WFS) system for GMT to cover all sodium emission altitudes and telescope elevations, from 80 km to 200 km range and how the preliminary design was derived from these approaches. The designed LGS WFS system includes a defocus-compensation mechanism working with a simple zooming optics to achieve the pupil image with constant pupil size, nearly constant wavefront correction, as well as pupil distortion correction. Either a trombone-mirror structure or a direct LGS-WFS translation is used for the defocus compensation, when conjugating the LGS altitudes in the sky. In the designs, a zooming collimator images the ASM in the GMT at the exit pupil of the LGS WFS system, where the designed lenslet-array is tailored for the selected CCD format for the required plate scale on the sky. Additionally, we have proposed a novel and simple solution for pupilimage segmentation when working with smaller CCD arrays. This novel solution consists of a single multi-aperture blaze grating for pupil segmentation in the system.

  13. Comment on "Defocusing complex short-pulse equation and its multi-dark-soliton solution" (United States)

    Youssoufa, Saliou; Kuetche, Victor K.; Kofane, Timoleon C.


    In their recent paper, Feng et al. [Phys. Rev. E 93, 052227 (2016), 10.1103/PhysRevE.93.052227] proposed a complex short-pulse equation of both focusing and defocusing types. They studied in detail the defocusing case and derived its multi-dark-soliton solutions. Nonetheless, from a physical viewpoint in order to better and deeply understand their genuine implications, we find it useful to provide a real and proper background for the derivation of the previous evolution system while showing that the expression of the nonlinear electric polarization the above authors used in their scheme is not suitable for getting the defocusing complex short-pulse equation.

  14. Formation of Hot Images in Laser Beams through a Self-defocusing Kerr Medium Slab

    Institute of Scientific and Technical Information of China (English)

    WANG You-Wen; DENG Jian-Qin; CHEN Lie-Zun; WEN Shuang-Chun; YOU Kai-Ming


    A nonlinear hot image is usually thought as of a special case of self-focusing, and thus occurs when a laser beam propagates through a slab of self-focusing medium. Here we show theoretically that a hot image may also be formed by a thin slab of self-defocusing medium. The physical origin for this hot image formation is akin to the in-line volume-phase holographic imaging due to the intensity-dependent refractive-index modulation of the self-defocusing medium. Numerical simulations confirm the theoretical prediction and further identify the dependence of the hot image on the beam power, the modulation depth of obseuration and the thickness of self-defocusing medium. The analysis presented here brings new insight into the physics of hot image formation in the high power laser system.

  15. Difference Image Analysis of Defocused Observations with CSTAR

    CERN Document Server

    Oelkers, Ryan J; Wang, Lifan; Ashley, Michael C B; Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Lawrence, Jon S; Qiang, Liu; Luong-Van, Daniel; Pennypacker, Carl R; Yang, Huigen; Yuan, Xiangyan; York, Donald G; Zhou, Xu; Zhu, Zhenxi


    The Chinese Small Telescope ARray (CSTAR) carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 2008, 2009 and 2010. Aperture photometry of the 2008 and 2010 i-band images resulted in the discovery of over 200 variable stars. Yearly servicing left the array defocused for the 2009 winter season, during which the system also suffered from intermittent frosting and power failures. Despite these technical issues, nearly 800,000 useful images were obtained using g, r & clear filters. We developed a combination of difference imaging and aperture photometry to compensate for the highly crowded, blended and defocused frames. We present details of this approach, which may be useful for the analysis of time-series data from other small-aperture telescopes regardless of their image quality. Using this approach, we were able to recover 68 previously-known variables and detected variability in 37 additional objects. We also ha...

  16. Difference image analysis of defocused observations with CSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Oelkers, Ryan J.; Macri, Lucas M.; Wang, Lifan [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy Texas A and M University, College Station, TX 77843 (United States); Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel [School of Physics, University of New South Wales, NSW (Australia); Cui, Xiangqun; Gong, Xuefei; Qiang, Liu; Yang, Huigen; Yuan, Xiangyan; Zhou, Xu [Chinese Center for Antarctic Astronomy, Nanjing (China); Feng, Long-Long; Zhu, Zhenxi [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing (China); Pennypacker, Carl R. [Institute of Nuclear and Particle Astrophysics, Lawrence Berkeley National Laboratory, Berkely, CA (United States); York, Donald G., E-mail: [Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL (United States)


    The Chinese Small Telescope ARray carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 2008–2010. Aperture photometry of the 2008 and 2010 i-band images resulted in the discovery of over 200 variable stars. Yearly servicing left the array defocused for the 2009 winter season, during which the system also suffered from intermittent frosting and power failures. Despite these technical issues, nearly 800,000 useful images were obtained using g, r, and clear filters. We developed a combination of difference imaging and aperture photometry to compensate for the highly crowded, blended, and defocused frames. We present details of this approach, which may be useful for the analysis of time-series data from other small-aperture telescopes regardless of their image quality. Using this approach, we were able to recover 68 previously known variables and detected variability in 37 additional objects. We also have determined the observing statistics for Dome A during the 2009 winter season; we find the extinction due to clouds to be less than 0.1 and 0.4 mag for 40% and 63% of the dark time, respectively.

  17. Optically controlled welding system (United States)

    Gordon, Stephen S. (Inventor)


    An optically controlled welding system (10) wherein a welding torch (12) having through-the-torch viewing capabilities is provided with an optical beam splitter (56) to create a transmitted view and a reflective view of a welding operation. These views are converted to digital signals which are then processed and utilized by a computerized robotic welder (15) to make the welding torch responsive thereto. Other features includes an actively cooled electrode holder (26) which minimizes a blocked portion of the view by virtue of being constructed of a single spoke or arm (28) and a weld pool contour detector (14) comprising a laser beam directed onto the weld pool with the position of specular radiation reflected therefrom being characteristic of a penetrated or unpenetrated condition of the weld pool.

  18. Optical systems for synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R.


    Various fundamental topics which underlie the design and use of optical systems for synchrotron radiation are considered from the viewpoint of linear system theory. These topics include the damped harmonic oscillator, free space propagation of an optical field, electromagnetic theory of optical properties of materials, theory of dispersion, and the Kramers-Kronig relations. 32 refs., 5 figs. (LEW)

  19. Scanning and Defocusing Properties of Microstrip Reflectarray Antennas (United States)

    Rengarajan, Sembiam


    A symmetric reflectarray, consisting of variable-size square patch elements with a commonly used mathematical model for the horn in the form of a cosine function, has been designed using the transmit mode technique for different f/D ratios with 10 dB edge taper. Subsequently, the antennas were analyzed for the radiation pattern and gain. The infinite array model was used to determine the reflection phase of each patch element in the design and analysis codes. By displacing the feed laterally, the scan characteristics were obtained, such as the beam deviation factor, gain loss, and pattern degradation. The properties of reflect arrays were compared to those of the conventional paraboloidal reflectors. The same procedure was used to study the scan properties of offset reflectarrays. There is no cross-polarized radiation in the principal planes for a symmetric system. Cross-polarized radiation exists in non-principal planes off broadside in symmetric systems, with greater levels for larger values of subtended angles. Such cross-polarized radiation level increases with subtended angle just as cross-polarization level increases with decreasing values of f/D ratios for symmetric paraboloids in non-principal planes. Pattern distortions and gain loss were found to be more severe in the case of a microstrip reflectarray compared to the conventional parabolic reflector. The scan performance of the reflect arrays was found to improve with f/D ratios as is true for paraboloids. In general, scanning by means of displaced feed is limited to a few beam - widths in reflectarrays. Feed displacement in the axial direction of a symmetric reflectarray was investigated and compared to that of paraboloids. The gain loss due to the defocused feed of a reflectarray was found to be nearly the same as that of a paraboloid of the same subtended angle for larger values of f/D, and for displacements away from the antenna. The gain loss of an axially defocused reflectarray was found to be

  20. Coherent, non-planar illumination of a defocused specimen: consequences for transmission electron microscopy (United States)

    Patwardhan, Ardan

    The objective of this study has been to examine the imaging properties of transmission electron microscopes when coherent non-planar illumination is used in conjunction with defocused specimens. This situation is reminiscent of what is commonly the case in electron microscopic phase-contrast studies of biologically relevant macromolecules, using a field emission gun as a coherent electron source. For the sake of simplicity, the imaging system has been idealized as a thin lens with properties that can be described by the Fresnel approximation of the Huygens-Fresnel principle. The resulting expressions show that the system magnification has a defocus dependent factor, as do the contrast transfer functions. These factors are normally not taken into account in conventional derivations. The defocus dependent factor can be minimized by using planar illumination. The factor approaches infinity as the crossover moves closer to the specimen, and it is in the region close to the specimen that this factor is most significant. These results can have serious implications for high-resolution single-particle cryo electron microscopy as this technique often relies on combining data taken at a range of defocus values.

  1. Interactions of localized wave structures and dynamics in the defocusing coupled nonlinear Schrödinger equations (United States)

    Zhang, Guoqiang; Yan, Zhenya; Wen, Xiao-Yong; Chen, Yong


    We investigate the defocusing coupled nonlinear Schrödinger equations from a 3 ×3 Lax pair. The Darboux transformations with the nonzero plane-wave solutions are presented to derive the newly localized wave solutions including dark-dark and bright-dark solitons, breather-breather solutions, and different types of new vector rogue wave solutions, as well as interactions between distinct types of localized wave solutions. Moreover, we analyze these solutions by means of parameters modulation. Finally, the perturbed wave propagations of some obtained solutions are explored by means of systematic simulations, which demonstrates that nearly stable and strongly unstable solutions. Our research results could constitute a significant contribution to explore the distinct nonlinear waves (e.g., dark solitons, breather solutions, and rogue wave solutions) dynamics of the coupled system in related fields such as nonlinear optics, plasma physics, oceanography, and Bose-Einstein condensates.

  2. Influence of sample pool on interference pattern in defocused interferometric particle imaging (United States)

    Zhang, Hongxia; Zhou, Ye; Liu, Jing; Jia, Dagong; Liu, Tiegen


    Particles widely exist in various fields. In practical experiments, sometimes it is necessary to dissolve particles in water in a sample pool. This article proposes two typical layouts of the sample pool in defocused interferometric particle imaging (IPI). Layout I is the sample pool surface perpendicular to the incident light and layout II is the sample pool surface perpendicular to the scattered light. For layout I, the scattered light of the particles does not keep symmetric at the meridional and sagittal planes after being refracted by the sample pool surface, and elliptical interference patterns are formed at the defocused IPI image plane. But for layout II, the scattered light keeps symmetric after being refracted, and circular interference patterns are formed. Aimed at the two sample pool layouts, the ray-tracing software ZEMAX was used to simulate the spot shape of particles at different defocus distances. Furthermore, its effect on the ellipticity of the interference pattern with the tilt angle of the sample pool is analyzed. The relative error of the axis ratio for layout I does not exceed 9.2% at different defocus distances. The experimental results have good agreement with the theoretical analyses, and it indicates that layout II is more reasonable for the IPI system.

  3. Optical analysis of scanning microstereolithography systems (United States)

    Deshmukh, Suhas P.; Dubey, Shashikant; Gandhi, P. S.


    Microstereolithography (MSL) is rapidly developing technique for micro-fabrication. Vector-by-vector scanning MSL has a potential to create true 3D micro-devices as compared to mostly planar (2D-2 1/2 D) devices fabricated by conventional MEMS techniques. Previous literature shows two different scanning methods:(1) Galvanomirror scanning, (2) Photoreactor tank scanning. Galvanomirror scanning technique has higher fabrication speed but poor resolution because of defocusing of laser spot on the resin surface. Photo-reactor tank scanning has higher resolution but produces a wavy structures and limited speed of fabrication. This paper proposes and develops an offaxis lens scanning technique for MSL and carries out optical analysis to compare its performance with the existing techniques mentioned above. The comparison clearly demonstrates improved performance with the proposed offaxis lens scanning technique.

  4. Ocean Optics Instrumentation Systems (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation suites for a wide variety of measurements to characterize the ocean’s optical environment. These packages have been developed to...

  5. Tuneable planar integrated optical systems. (United States)

    Amberg, M; Oeder, A; Sinzinger, S; Hands, P J W; Love, G D


    Planar integrated free-space optical systems are well suited for a variety of applications, such as optical interconnects and security devices. Here, we demonstrate for the first time dynamic functionality of such microoptical systems by the integration of adaptive liquid-crystal-devices.

  6. Photometric defocus observations of transiting extrasolar planets

    CERN Document Server

    Hinse, Tobias C; Yoon, Jo-Na; Lee, Chung-Uk; Kim, Yong-Gi; Kim, Chun-Hwey


    We have carried out photometric follow-up observations of bright transiting extrasolar planets using the CbNUOJ 0.6m telescope. We have tested the possibility of obtaining high photometric precision by applying the telescope defocus technique allowing the use of several hundred seconds in exposure time for a single measurement. We demonstrate that this technique is capable of obtaining a root-mean-square scatter of order sub-millimagnitude over several hours for a V $\\sim$ 10 host star typical for transiting planets detected from ground-based survey facilities. We compare our results with transit observations with the telescope operated in in-focus mode. High photometric precision is obtained due to the collection of a larger amount of photons resulting in a higher signal compared to other random and systematic noise sources. Accurate telescope tracking is likely to further contribute to lowering systematic noise by probing the same pixels on the CCD. Furthermore, a longer exposure time helps reducing the eff...

  7. Optical prefiltering in subcarrier systems (United States)

    Greenhalgh, Philip A.; Abel, Robin D.; Davies, Phillip A.


    Subcarrier multiplexing (SCM) is a convenient method of implementing multi-access in a lightwave system. Conventionally SCM receivers detect all channels using high speed optoelectronic components, each channel then being selected using heterodyne techniques in the electrical domain. Optical prefiltering is a novel technique where channel selection is accomplished optically. This method has the primary advantage that only a low bandwidth optical detector and receiver is needed to recover the baseband information.

  8. Structure in defocused beams of x-ray mirrors: causes and possible solutions (United States)

    Sutter, John P.; Alcock, Simon G.; Rust, Fiona; Wang, Hongchang; Sawhney, Kawal


    Grazing incidence mirrors are now a standard optic for focusing X-ray beams. Both bimorph and mechanically bendable mirrors are widely used at Diamond Light Source because they permit a wide choice of focal lengths. They can also be deliberately set out of focus to enlarge the X-ray beam, and indeed many beamline teams now wish to generate uniform beam spots of variable size. However, progress has been slowed by the appearance of fine structure in these defocused beams. Measurements showing the relationship between the medium-frequency polishing error and this structure over a variety of beam sizes will be presented. A theoretical model for the simulations of defocused beams from general mirrors will then be developed. Not only the figure error and its first derivative the slope error, but also the second derivative, the curvature error, must be considered. In conclusion, possible ways to reduce the defocused beam structure by varying the actuators' configuration and settings will be discussed.

  9. Scattering of Light in Defocusing Media upon Linear Substrate Analysis of Formal Solutions

    CERN Document Server

    Ochirbat, G


    An analysis of formal solutions to the system of Maxwell equations has been performed for a scattering problem of stationary TM light waves in defocusing matter on a linear substrate. Bruster waves have been observed. A nontrivial plane wave has been found for which relation between a refraction constant and an intensity-dependent dielectric constant has been found. An asymptotic plane TM wave has been obtained, and a procedure of its finding has been elaborated.

  10. Simple Demonstration of the Impact of Spherical Aberration on Optical Imaging (United States)

    Escobar, Isabel; Saavedra, Genaro; Pons, Amparo; Martinez-Corral, Manuel


    We present an experiment, well adapted for students of introductory optics courses, for the visualization of the impact of spherical aberration in the point spread function of imaging systems. The demonstrations are based on the analogy between the point-spread function of spherically aberrated systems, and the defocused patterns of 1D slit-like…

  11. PSF Rotation with Changing Defocus and Applications to 3D Imaging for Space Situational Awareness (United States)

    Prasad, S.; Kumar, R.


    For a clear, well corrected imaging aperture in space, the point-spread function (PSF) in its Gaussian image plane has the conventional, diffraction-limited, tightly focused Airy form. Away from that plane, the PSF broadens rapidly, however, resulting in a loss of sensitivity and transverse resolution that makes such a traditional best-optics approach untenable for rapid 3D image acquisition. One must scan in focus to maintain high sensitivity and resolution as one acquires image data, slice by slice, from a 3D volume with reduced efficiency. In this paper we describe a computational-imaging approach to overcome this limitation, one that uses pupil-phase engineering to fashion a PSF that, although not as tight as the Airy spot, maintains its shape and size while rotating uniformly with changing defocus over many waves of defocus phase at the pupil edge. As one of us has shown recently [1], the subdivision of a circular pupil aperture into M Fresnel zones, with the mth zone having an outer radius proportional to m and impressing a spiral phase profile of form m? on the light wave, where ? is the azimuthal angle coordinate measured from a fixed x axis (the dislocation line), yields a PSF that rotates with defocus while keeping its shape and size. Physically speaking, a nonzero defocus of a point source means a quadratic optical phase in the pupil that, because of the square-root dependence of the zone radius on the zone number, increases on average by the same amount from one zone to the next. This uniformly incrementing phase yields, in effect, a rotation of the dislocation line, and thus a rotated PSF. Since the zone-to-zone phase increment depends linearly on defocus to first order, the PSF rotates uniformly with changing defocus. For an M-zone pupil, a complete rotation of the PSF occurs when the defocus-induced phase at the pupil edge changes by M waves. Our recent simulations of reconstructions from image data for 3D image scenes comprised of point sources at

  12. Optical detection in microfluidic systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter


    Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent...... to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest....

  13. Optical Digital Image Storage System (United States)


    This could be accomplished even if the files were artificially determined. " Super files," composed of a number of files, could be artificially order to expedite transfer through the scanning process. These " super files" could later be broken down into their actual component files. Another...hesitant about implementing an optical disk system. While Sandra Napier believed it "looks promising," she felt an optical disk replacement of microfilm

  14. Precision optical navigation guidance system (United States)

    Starodubov, D.; McCormick, K.; Nolan, P.; Johnson, D.; Dellosa, M.; Volfson, L.; Fallahpour, A.; Willner, A.


    We present the new precision optical navigation guidance system approach that provides continuous, high quality range and bearing data to fixed wing aircraft during landing approach to an aircraft carrier. The system uses infrared optical communications to measure range between ship and aircraft with accuracy and precision better than 1 meter at ranges more than 7.5 km. The innovative receiver design measures bearing from aircraft to ship with accuracy and precision better than 0.5 mRad. The system provides real-time range and bearing updates to multiple aircraft at rates up to several kHz, and duplex data transmission between ship and aircraft.

  15. Fiber-optic communication systems

    CERN Document Server

    Agrawal, Govind P


    This book provides a comprehensive account of fiber-optic communication systems. The 3rd edition of this book is used worldwide as a textbook in many universities. This 4th edition incorporates recent advances that have occurred, in particular two new chapters. One deals with the advanced modulation formats (such as DPSK, QPSK, and QAM) that are increasingly being used for improving spectral efficiency of WDM lightwave systems. The second chapter focuses on new techniques such as all-optical regeneration that are under development and likely to be used in future communication systems. All othe

  16. 非局域自散焦克尔介质中空间光暗孤子成丝的理论与实验研究%Theoretical and experimental investigations of spatial optical dark soliton filamentization in nonlocal self-defocusing Kerr medium

    Institute of Scientific and Technical Information of China (English)

    王靖; 郑一周; 周罗红; 杨振军; 陆大全; 郭旗; 胡巍


    对非局域自散焦克尔介质中的空间光暗孤子成丝进行了研究.理论上从非局域非线性理论模型出发,数值模拟研究了非局域程度和吸收系数对暗孤子成丝的影响.当入射背景光强一定时,非局域程度越大成丝起始点越远、成丝数量越少;而当入射背景光强与临界光强之比一定时,非局域程度基本不影响成丝起始点以及成丝数量,且非局域下的成丝数量与局域下一样.此外,当入射背景光强一定时,吸收系数越大成丝数量越少.实验上通过改变染料溶液的浓度以及背景光斑的椭圆率,分别研究了样品浓度和背景光斑椭圆率对暗孤子成丝的影响.当入射背景平均光强一定时,样品浓度越小成丝数量越少,背景光斑椭圆率越小成丝数量越少;而当入射背景平均光强与临界光强之比一定时,样品浓度基本不影响成丝数量.在实验中还观察到了光学冲击波现象.%In this paper, the spatial optical dark soliton filamentization in a nonlocal self-defocusing Kerr medium is investigated. Theoret- ically, starting from nonlocal nonlinear theoretical model, we examine the influences of the degree of nonlocality and the attenuation constant on the formation of dark soliton filaments by numerical simulation method. We find that when the input background optical intensity is determined, the greater the degree of nonlocality, the farther the initial poirit of the formation of dark filaments is and the less the number of dark filaments decreases with the increase of the degree of nonlocality; when the ratio of the background optical intensity to the critical optical intensity is fixed, the degree of nonlocality can hardly influence the number of dark filaments and the number of dark filaments under nonlocality is equal to that under locality. Besides, when the input background optical intensity is determined, the number of dark filaments decreases

  17. Direct exit-wave reconstruction from a single defocused image. (United States)

    Morgan, A J; Martin, A V; D'Alfonso, A J; Putkunz, C T; Allen, L J


    We propose a direct, non-iterative method for the exact recovery of the complex wave in the exit-surface plane of a coherently illuminated object from a single defocused image. The method is applicable for a wide range of illumination conditions. The defocus range is subject to certain conditions, which if satisfied allow the complex exit-surface wave to be directly recovered by solving a set of linear equations. These linear equations, whose coefficients depend on the incident illumination, are obtained by analyzing the autocorrelation function of an auxiliary wave which is related to the exit-surface wave in a simple way. This autocorrelation is constructed by taking the inverse Fourier transform of the defocused image. We present an experimental proof of concept by recovering the exit-surface wave of a microfiber illuminated by a plane wave formed using a HeNe laser.

  18. Super-resolution Localization and Defocused Fluorescence Microscopy on Resonantly Coupled Single-Molecule, Single-Nanorod Hybrids. (United States)

    Su, Liang; Yuan, Haifeng; Lu, Gang; Rocha, Susana; Orrit, Michel; Hofkens, Johan; Uji-i, Hiroshi


    Optical antennas made of metallic nanostructures dramatically enhance single-molecule fluorescence to boost the detection sensitivity. Moreover, emission properties detected at the optical far field are dictated by the antenna. Here we study the emission from molecule-antenna hybrids by means of super-resolution localization and defocused imaging. Whereas gold nanorods make single-crystal violet molecules in the tip's vicinity visible in fluorescence, super-resolution localization on the enhanced molecular fluorescence reveals geometrical centers of the nanorod antenna instead. Furthermore, emission angular distributions of dyes linked to the nanorod surface resemble that of nanorods in defocused imaging. The experimental observations are consistent with numerical calculations using the finite-difference time-domain method.

  19. Electro-optical techniques for signal conditioning (United States)

    Helfrich, R. W.


    Electro-optical (EO) processing is discussed as a potential alternative to the all-digital approach to signal processing. Nonuniformity compensation can be done by normalizing all the single element detectors outputs in a staring array for both gain and level. Distortion correction can be accomplished with blackbodies, scene statistics or defocused optics. An algorithm used in digital signal conditioning that can be closely approximated by EO techniques is Local Area Brightness Control (LABC). In a digital processor, LABC is performed on a pixel-by-pixel basis, resulting in an enormous amount of calculation. A partially defocused optical system can be used in an EO analog to the digital system. For both nonuniformity compensation and LABC, the EO technique can result in great simplification.

  20. In situ calibrated defocusing PTV for wall-bounded measurement volumes (United States)

    Fuchs, T.; Hain, R.; Kähler, C. J.


    In many situations, 3D velocity measurements in thin (∼1 mm) but wide (∼100  ×  100 mm2) flow channels is an important task. To resolve the in-plane and out-of-plane velocity gradients properly, a precise calibration is required, since 3D measurement approaches rely strongly on the accuracy of the calibration procedure. It is likely that calibration targets do not fit domains with small depths, due to their size. Furthermore, in fields where such measurements are of interest, the accessibility of the measurement volume is often limited or even impossible. To overcome these drawbacks, this paper introduces an in situ calibrated defocusing particle tracking velocimetry approach for wall-bounded measurement domains with depths in the low millimeter range. The calibration function for the particle depth location is directly derived from the particle image geometries and their displacements between two frames. Employing only a single camera, this defocusing approach is capable of measuring the air flow between two parallel glass plates at a distance of 1 mm with an average uncertainty of 2.43% for each track, relative to the maximum velocity. A tomographic particle tracking velocimetry measurement, serving as a benchmark for the single camera technique, reaches an average uncertainty of 1.59%. Altogether, with its straightforward set-up and without requiring a calibration target, this in situ calibrated defocusing approach opens new areas of application for optical flow velocimetry. In particular, for measurement domains with small optical windows and a lack of accessibility.

  1. Parameter recognition for defocus blur image using cepstrum analysis

    Institute of Scientific and Technical Information of China (English)

    Zhou Qu; Yan Guozheng; Wang Wenxing


    Successful restoration of blurred images depends primarily on the knowledge about the degradation parameter.Defocus blur model in the frequency domain is characterized by concentric rings and the blur radius of the point spread function (PSF) can be identified conveniently in the frequency field for people by manual means rather than for computer.This paper introduces a practical method for computer to estimate the defocus blur parameter in cepstrum area.Fourier transform plays an intermediate role in the path to cepstrum domain.We suggest a weighted adjustment operation in the frequency domain and then convert it to the cepstrum field to increase the accuracy of recognition.

  2. Optical Navigation System Project (United States)

    National Aeronautics and Space Administration — This proposal is for a flexible navigation system for deep space operations that does not require GPS measurements. The navigation solution is computed using an...

  3. Optical Navigation System Project (United States)

    National Aeronautics and Space Administration — This proposal is for a flexible navigation system for deep space operations that does not require GPS measurements. The navigation solution is computed using an...

  4. Tunable Optical Polymer Systems (United States)


    outperforms almost all other organic polymer systems reported thus far, the introduction of the first multiple color LBL electrochrome , and development...thin films outperform previously reported LBL assembled films and approach integration capability for a number of electrochromic , sensing and...Zacharia, N; Hammond, P. T. “ Electrochromism of LBL assembled thin polymer films containing metal oxide nanoparticles,” American Chemical Society

  5. Atmospheric Optical Communication Systems. (United States)


    Tnteral system noise due to dark current id is Oven by . 1d = 2qGrB"" (2-9) Dark current is due to detecor biasing in some instances, and in somue...8217 without extansive pro- gr-=:ing exer’ence. Although. the znodel is designed to be Lteracdve, slight mod-.- i~cadons winl ezw :&31 r~ing of the progrsm

  6. Chaotic systems in optical communications (United States)

    Siuzdak, J.


    Communications application of chaotic oscillations of lasers with optoelectronic feedback was discussed. The possibility of eavesdropping of the transmission was analyzed. It was proved that if the rogue party precisely knows parameters of the chaotic system it may recreate the entire signals solely by observation of the optical signal power causing security breach.

  7. Thermal lensing measurement from the coefficient of defocus aberration

    CSIR Research Space (South Africa)

    Bell, Teboho


    Full Text Available We measured the thermally induced lens from the coefficient of defocus aberration using a Shack-Hartmann wavefront sensor (SHWFS). As a calibration technique, we infer the focal length of standard lenses probed by a collimated Gaussian beam...

  8. Defocusing regimes of nonlinear waves in media with negative dispersion

    DEFF Research Database (Denmark)

    Bergé, L.; Kuznetsov, E.A.; Juul Rasmussen, J.


    Defocusing regimes of quasimonochromatic waves governed by a nonlinear Schrodinger equation with mixed-sign dispersion are investigated. For a power-law nonlinearity, we show that localized solutions to this equation defined at the so-called critical dimension cannot collapse in finite time...

  9. Optical Aberrations and Wavefront

    Directory of Open Access Journals (Sweden)

    Nihat Polat


    Full Text Available The deviation of light to create normal retinal image in the optical system is called aberration. Aberrations are divided two subgroup: low-order aberrations (defocus: spherical and cylindrical refractive errors and high-order aberrations (coma, spherical, trefoil, tetrafoil, quadrifoil, pentafoil, secondary astigmatism. Aberrations increase with aging. Spherical aberrations are compensated by positive corneal and negative lenticular spherical aberrations in youth. Total aberrations are elevated by positive corneal and positive lenticular spherical aberrations in elderly. In this study, we aimed to analyze the basic terms regarding optic aberrations which have gained significance recently. (Turk J Ophthalmol 2014; 44: 306-11

  10. The ANTARES Optical Beacon System

    CERN Document Server

    Ageron, M; Albert, A; Ameli, F; Anghinolfi, M; Anton, G; Anvar, S; Ardellier-Desages, F; Aslanides, E; Aubert, J J; Auer, R; Barbarito, E; Basa, S; Battaglieri, M; Becherini, Y; Beltramelli, J; Bertin, V; Bigi, A; Billault, M; Blaes, R; De Botton, N R; Bouwhuis, M C; Bradbury, S M; Bruijn, R; Brunner, J; Burgio, G F; Busto, J; Cafagna, F; Caillat, L; Calzas, A; Capone, A; Caponetto, L; Carmona, E; Carr, J; Cartwright, S L; Castel, D; Castorina, E; Cavasinni, V; Cecchini, S; Ceres, A; Charvis, P; Chauchot, P; Chiarusi, T; Circella, M; Colnard, C; Compere, C; Coniglione, R; Cottini, N; Coyle, P; Cuneo, S; Cussatlegras, A S; Damy, G; Van Dantzig, R; De Bonis, G; De Marzo, C; De Vita, R; Dekeyser, I; Delagnes, E; Denans, D; Deschamps, A; Destelle, J J; Dinkespieler, B; Distefano, C; Donzaud, C; Drogou, J F; Druillole, F; Durand, D; Ernenwein, J P; Escoffier, S; Falchini, E; Favard, S; Fehr, F; Feinstein, F; Ferry, S; Fiorello, C; Flaminio, V; Fratini, K; Fuda, J L; Galeotti, S; Gallone, J M; Giacomelli, G; Girard, N; Gojak, C; Goret, P; Graf, K; Hallewell, G; Harakeh, M N; Hartmann, B; Heijboer, A; Heine, E; Hello, Y; Hernández-Rey, J J; Hossl, J; Hoffman, C; Hogenbirk, J; Hubbard, John R; Jaquet, M; Jaspers, M; De Jong, M; Jouvenot, F; Kalantar-Nayestanaki, N; Kappes, A; Karg, T; Katz, U; Keller, P; Kok, E; Kok, H; Kooijman, P; Kopper, C; Korolkova, E V; Kouchner, A; Kretschmer, W; Kruijer, A; Kuch, S; Kudryavtsev, V A; Lagier, P; Lahmann, R; Lamanna, G; Lamare, P; Lambard, G; Languillat, J C; Laschinsky, H; Lavalle, J; Le Guen, Y; Le Provost, H; Le Van-Suu, A; Lefèvre, D; Legou, T; Lelaizant, G; Lim, G; Lo Presti, D; Löhner, H; Loucatos, Sotirios S; Louis, F; Lucarelli, F; Lyashuk, V; Marcelin, M; Margiotta, A; Masullo, R; Mazéas, F; Mazure, A; McMillan, J E; Megna, R; Melissas, M; Migneco, E; Milovanovic, A; Mongelli, M; Montaruli, T; Morganti, M; Moscoso, L; Musumeci, M; Naumann-Godo, M; Naumann, C; Niess, V; Noble, T; Olivetto, C; Ostasch, R; Palanque-Delabrouille, Nathalie; Payre, P; Peek, H; Pérez, A; Petta, C; Piattelli, P; Pillet, R; Pineau, J P; Poinsignon, J; Popa, V; Pradier, T; Racca, C; Randazzo, N; Van Randwijk, J; Real, D; Van Rens, B; Rethore, F; Rewiersma, P A M; Riccobene, G; Rigaud, V; Ripani, M; Roca, V; Roda, C; Rolin, J F; Rose, H J; Rostovtsev, A; Roux, J; Ruppi, M; Russo, G V; Rusydi, G; Salesa, F; Salomon, K; Sapienza, P; Schmitt, F; Schuller, J P; Shanidze, R; Sokalski, I A; Spona, T; Spurio, M; van der Steenhoven, G; Stolarczyk, T; Streeb, K; Sulak, L; Taiuti, M; Tamburini, C; Tao, C; Terreni, G; Thompson, L F; Urbano, F; Valdy, P; Valente, V; Vallage, B; Vaudaine, G; Venekamp, G; Verlaat, B; Vernin, P; De Vries-Uiterweerd, G; Van Wijk, R; Wijnker, G; De Witt-Huberts, P K A; Wobbe, G; De Wolf, E; Yao, A F; Zaborov, D; Zaccone, Henri; De Dios-Zornoza-Gomez, Juan; Zúñiga, J; al, et


    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of ...

  11. CP symmetry in optical systems

    CERN Document Server

    Dana, Brenda; Malomed, Boris A


    We introduce a model of a dual-core optical waveguide with opposite signs of the group-velocity-dispersion (GVD) in the two cores, and a phase-velocity mismatch between them. The coupler is embedded into an active host medium, which provides for the linear coupling of a gain-loss type between the two cores. The same system can be derived, without phenomenological assumptions, by considering the three-wave propagation in a medium with the quadratic nonlinearity, provided that the depletion of the second-harmonic pump is negligible. This linear system offers an optical realization of the charge-parity ($\\mathcal{CP}$) symmetry, while the addition of the intra-core cubic nonlinearity breaks the symmetry. By means of direct simulations and analytical approximations, it is demonstrated that the linear system generates expanding Gaussian states, while the nonlinear one gives rise to broad oscillating solitons, as well as a general family of stable stationary gap solitons.

  12. Active optics: variable curvature mirrors for ELT laser guide star refocusing systems (United States)

    Challita, Zalpha; Hugot, Emmanuel; Madec, Fabrice; Ferrari, Marc; Le Mignant, David; Vivès, Sébastien; Cuby, Jean-Gabriel


    The future generation of Extremely Large Telescopes will require a complex combination of technologies for adaptive optics (AO) systems assisted by laser guide stars (LGS). In this context, the distance from the LGS spot to the telescope pupil ranges from about 80 to 200 km, depending on the Sodium layer altitude and the elevation of the telescope. This variation leads to a defocusing effect on the LGS wave-front sensor which needs to be compensated. We propose an active mirror able to compensate for this variation, based on an original optical design including this active optics component. This LGS Variable Curvature Mirror (LGS-VCM) is a 120 mm spherical active mirror able to achieve 820 μm deflection sag with an optical quality better than 150 nm RMS, allowing the radius of curvature variation from F/12 to F/2. Based on elasticity theory, the deformation of the metallic mirror is provided by an air pressure applied on a thin meniscus with a variable thickness distribution. In this article, we detail the analytical development leading to the specific geometry of the active component, the results of finite element analysis and the expected performances in terms of surface error versus the range of refocalisation. Three prototypes have been manufactured to compare the real behavior of the mirror and the simulations data. Results obtained on the prototypes are detailed, showing that the deformation of the VCM is very close to the simulation, and leads to a realistic active concept.

  13. Optical systems for space and defence

    Energy Technology Data Exchange (ETDEWEB)

    Lettington, A.H. (Royal Signals and Radar Establishment, Malvern (United Kingdom))


    This book covered under the following topics relating to optical systems for space and defense. Environmental Testing and Quality Assurance; Surface Coatings and Surface Assessment; Optical Components and Design; Detectors; Optical Signal Processing; Radiometrically Calibrated Systems; Spaceborne Systems; Surveillance Systems; Intersatellite Links; and Lasers and Laser Applications.

  14. Nonlinear random optical waves: Integrable turbulence, rogue waves and intermittency (United States)

    Randoux, Stéphane; Walczak, Pierre; Onorato, Miguel; Suret, Pierre


    We examine the general question of statistical changes experienced by ensembles of nonlinear random waves propagating in systems ruled by integrable equations. In our study that enters within the framework of integrable turbulence, we specifically focus on optical fiber systems accurately described by the integrable one-dimensional nonlinear Schrödinger equation. We consider random complex fields having a Gaussian statistics and an infinite extension at initial stage. We use numerical simulations with periodic boundary conditions and optical fiber experiments to investigate spectral and statistical changes experienced by nonlinear waves in focusing and in defocusing propagation regimes. As a result of nonlinear propagation, the power spectrum of the random wave broadens and takes exponential wings both in focusing and in defocusing regimes. Heavy-tailed deviations from Gaussian statistics are observed in focusing regime while low-tailed deviations from Gaussian statistics are observed in defocusing regime. After some transient evolution, the wave system is found to exhibit a statistically stationary state in which neither the probability density function of the wave field nor the spectrum changes with the evolution variable. Separating fluctuations of small scale from fluctuations of large scale both in focusing and defocusing regimes, we reveal the phenomenon of intermittency; i.e., small scales are characterized by large heavy-tailed deviations from Gaussian statistics, while the large ones are almost Gaussian.

  15. Thermal/Optical analysis of optical system of star tracker (United States)

    Lu, Si-yu; Huang, Yi-fan


    Spacecraft would be expected to encounter diverse extreme environmental (EE) conditions throughout their mission phases. These EE conditions are often coupled. Star tracker is a high accurate 3-axis attitude measuring instrument used in various spacecrafts. In this paper, an effective scheme to the thermal/optical analysis in optical system of star sensor was described and the concept of thermal optical analysis of star tracker optical system was introduced in detail. Using finite element analysis (FEA) and ray tracing, we can study the relationship of optical properties of optical systems and optical system's temperature distribution . A lens system configuration having six uncemented elements was discussed. The lens system was a 56mm EFL, which was different from common lens used in imaging system that this lens system was required to have a high resolving power in design thoughts. It was designed to determine the attitude of space platform by detecting and mapping the geometric pattern of stars. Based on this system, the FEA models of the optical system were established for temperature distribution calculation and for thermal-elastic structural deformation analysis respectively. Using the models, the steady-state temperature distributions of the tracker were simulated. The rigid body displacements of the optical components under homogeneous temperature changes and certain temperature distributions were derived out. It is convenient to use Zernike polynomials as the data transmission between optical and structural analysis programs. Here, Zernike polynomials and their fitting method are used as an example to determine the thermal induced optical degradations of the optical system.

  16. Teaching Optics and Systems Engineering With Adaptive Optics Workbenches

    CERN Document Server

    Harrington, David; Hunter, Lisa; Max, Claire; Hoffmann, Mark; Pitts, Mark; Armstrong, J D


    Adaptive optics workbenches are fully functional optical systems that can be used to illustrate and teach a variety of concepts and cognitive processes. Four systems have been funded, designed and constructed by various institutions and people as part of education programs associated with the Center for Adaptive Optics, the Professional Development Program and the Institute for Science and Engineer Educators. Activities can range from first-year undergraduate explorations to professional level training. These workbenches have been used in many venues including the Center for Adaptive Optics AO Summer School, the Maui Community College hosted Akamai Maui Short Course, classrooms, training of new staff in laboratories and other venues. The activity content has focused on various elements of systems thinking, characterization, feedback and system control, basic optics and optical alignment as well as advanced topics such as phase conjugation, wave-front sensing and correction concepts and system design. The work...

  17. Quality parameters analysis of optical imaging systems with enhanced focal depth using the Wigner distribution function (United States)

    Zalvidea; Colautti; Sicre


    An analysis of the Strehl ratio and the optical transfer function as imaging quality parameters of optical elements with enhanced focal length is carried out by employing the Wigner distribution function. To this end, we use four different pupil functions: a full circular aperture, a hyper-Gaussian aperture, a quartic phase plate, and a logarithmic phase mask. A comparison is performed between the quality parameters and test images formed by these pupil functions at different defocus distances.

  18. Miniaturized optical system for atomic fountain clock

    Institute of Scientific and Technical Information of China (English)

    Lü De-Sheng; Qu Qiu-Zhi; Wang Bin; Zhao Jian-Bo; Li Tang; Liu Liang; Wang Yu-Zhu


    Using modularized components, we have built a miniaturized optical system for 87Rb atomic fountain clock that is fitted on an 80 cm × 60 cm optical breadboard. Compared with the conventional optical setup on the table, our system is more compact, more robust and miniaturized. Taking advantage of this system, laser beams are transmitted through eight optical fibre patch cords from the optical breadboard to an ultra high vacuum system. This optical setup has operated for five months in our fountain system and required no alignment.

  19. Phase-Modulated Optical Communication Systems

    CERN Document Server

    Ho, Keang-Po


    Fiber-optic communication systems have revolutionized our telecommunication infrastructures – currently, almost all telephone land-line, cellular, and internet communications must travel via some form of optical fibers. In these transmission systems, neither the phase nor frequency of the optical signal carries information – only the intensity of the signal is used. To transmit more information in a single optical carrier, the phase of the optical carrier must be explored. As a result, there is renewed interest in phase-modulated optical communications, mainly in direct-detection DPSK signals for long-haul optical communication systems. When optical amplifiers are used to maintain certain signal level among the fiber link, the system is limited by amplifier noises and fiber nonlinearities. Phase-Modulated Optical Communication Systems surveys this newly popular area, covering the following topics: The transmitter and receiver for phase-modulated coherent lightwave systems Method for performance analysis o...

  20. Electro-Optic System Development Lab (United States)

    Federal Laboratory Consortium — The Electro-Optic System Development Lab serves as a development facility for electro-optical systems ranging from visible through long wave infrared. Capabilities...

  1. Optical Energy Transfer and Conversion System (United States)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)


    An optical power transfer system comprising a fiber spooler, a fiber optic rotary joint mechanically connected to the fiber spooler, and an electrical power extraction subsystem connected to the fiber optic rotary joint with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, through the rotary joint, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy.

  2. Defocused Observations of Selected Exoplanet Transits with T100 in TUBITAK National Observatory of Turkey (TUG)

    CERN Document Server

    Basturk, Ozgur; Ozavci, Ibrahim; Yorukoglu, Onur; Selam, Selim O


    It is crucial to determine masses and radii of extrasolar planets with high precision to have constraints on their chemical composition, internal structure and thereby their formation and evolution. In order to achieve this goal, we apply the defocus technique in the observations of selected planetary systems with the 1 m Turkish telescope T100 in TUBITAK National Observatory (TUG). With this contribution, we aim to present preliminary analyses of transit light curves of the selected exoplanets KELT-3b, HAT-P-10b/WASP-11b, HAT-P-20b, and HAT-P-22b, observed with this technique using T100.

  3. Elliptic solutions of the defocusing NLS equation are stable

    Energy Technology Data Exchange (ETDEWEB)

    Bottman, Nathaniel; Deconinck, Bernard [Department of Applied Mathematics, University of Washington, Seattle, WA 98195-2420 (United States); Nivala, Michael, E-mail:, E-mail:, E-mail: [Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, CA 90095 (United States)


    The stability of the stationary periodic solutions of the integrable (one-dimensional, cubic) defocusing nonlinear Schroedinger (NLS) equation is reasonably well understood, especially for solutions of small amplitude. In this paper, we exploit the integrability of the NLS equation to establish the spectral stability of all such stationary solutions, this time by explicitly computing the spectrum and the corresponding eigenfunctions associated with their linear stability problem. An additional argument using an appropriate Krein signature allows us to conclude the (nonlinear) orbital stability of all stationary solutions of the defocusing NLS equation with respect to so-called subharmonic perturbations: perturbations that have period equal to an integer multiple of the period of the amplitude of the solution. All results presented here are independent of the size of the amplitude of the solutions and apply equally to solutions with trivial and nontrivial phase profiles.

  4. Model of anisotropic nonlinearity in self-defocusing photorefractive media. (United States)

    Barsi, C; Fleischer, J W


    We develop a phenomenological model of anisotropy in self-defocusing photorefractive crystals. In addition to an independent term due to nonlinear susceptibility, we introduce a nonlinear, non-separable correction to the spectral diffraction operator. The model successfully describes the crossover between photovoltaic and photorefractive responses and the spatially dispersive shock wave behavior of a nonlinearly spreading Gaussian input beam. It should prove useful for characterizing internal charge dynamics in complex materials and for accurate image reconstruction through nonlinear media.

  5. Effect of Defocused CO2 Laser on Equine Tissue Perfusion

    Directory of Open Access Journals (Sweden)

    Bergh A


    Full Text Available Treatment with defocused CO2 laser can have a therapeutic effect on equine injuries, but the mechanisms involved are unclear. A recent study has shown that laser causes an increase in equine superficial tissue temperature, which may result in an increase in blood perfusion and a stimulating effect on tissue regeneration. However, no studies have described the effects on equine tissue perfusion. The aim of the present study was to investigate the effect of defocused CO2 laser on blood perfusion and to correlate it with temperature in skin and underlying muscle in anaesthetized horses. Differences between clipped and unclipped haircoat were also assessed. Eight horses and two controls received CO2 laser treatment (91 J/cm2 in a randomised order, on a clipped and unclipped area of the hamstring muscles, respectively. The significant increase in clipped skin perfusion and temperature was on average 146.3 ± 33.4 perfusion units (334% and 5.5 ± 1.5°C, respectively. The significant increase in perfusion and temperature in unclipped skin were 80.6 ± 20.4 perfusion units (264% and 4.8 ± 1.4°C. No significant changes were seen in muscle perfusion or temperature. In conclusion, treatment with defocused CO2 laser causes a significant increase in skin perfusion, which is correlated to an increase in skin temperature.


    Directory of Open Access Journals (Sweden)

    I. R. Gulakov


    Full Text Available Impact of registered optical radiation intensity, overvoltage, dimensions of photosensitive surface, structure of p-n junction and avalanche photodetectors dead time operating in the photon counting mode on quantum optical system capacity has been carried out in this investigation. As a result, the quantum optical system maximum capacity of 81 kbit/s has been obtained.

  7. The ANTARES optical beacon system

    Energy Technology Data Exchange (ETDEWEB)

    Ageron, M. [CPPM - Centre de Physique des Particules de Marseille, CNRS/IN2P3 et Universite de la Mediterranee, 163 Avenue de Luminy, Case 902, 13288 Marseille Cedex 9 (France); Aguilar, J.A. [IFIC - Instituto de Fisica Corpuscular, Edificios de Investigacion de Paterna, CSIC - Universitat de Valencia, Apdo. de Correos 22085, 46071 Valencia (Spain)]. E-mail:; Albert, A. [GRPHE - Groupe de Recherche en Physique des Hautes Energies, Universite de Haute Alsace, 61 Rue Albert Camus, 68093 Mulhouse Cedex (France)) (and others)


    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular, when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.

  8. Packaging considerations for planar optical interconnection systems. (United States)

    Acklin, B; Jahns, J


    We discuss various aspects of building an integrated optoelectronic system that is based on the concept of planar optics. A particular optical interconnection system has been fabricated and demonstrated. It provides parallel interconnections with 1024 optical channels that could be useful as an optical backplane in an optoelectronic multichip module. We consider the design and the fabrication of the optical system, schemes for the hybrid integration with optoelectronic device arrays, and the thermal management of an integrated system. The proposed hybrid integration scheme is based on mature technologies such as thermal anodic bonding and flip-chip bonding. Possibilities for efficient heat sinking are described.

  9. Advanced optical manufacturing digital integrated system (United States)

    Tao, Yizheng; Li, Xinglan; Li, Wei; Tang, Dingyong


    It is necessarily to adapt development of advanced optical manufacturing technology with modern science technology development. To solved these problems which low of ration, ratio of finished product, repetition, consistent in big size and high precision in advanced optical component manufacturing. Applied business driven and method of Rational Unified Process, this paper has researched advanced optical manufacturing process flow, requirement of Advanced Optical Manufacturing integrated System, and put forward architecture and key technology of it. Designed Optical component core and Manufacturing process driven of Advanced Optical Manufacturing Digital Integrated System. the result displayed effective well, realized dynamic planning Manufacturing process, information integration improved ratio of production manufactory.

  10. High pressure fiber optic sensor system (United States)

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N


    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  11. Actuality and Future of Optical Systems

    Directory of Open Access Journals (Sweden)

    Natasa Zivic


    Full Text Available Today's high-capacity telecommunication systems are unimaginable without the use of optical fibres and accompanying optical components which are briefly presented in this paper with an accent on the receivers of optical signal. An overview of main characteristics of the key elements and the description of the most popular modulation formats in modern optical systems is shown. Some achievements and the directions of the further development in this area are also mentioned.

  12. Optical CDMA system using bacteriorhodopsin for optical data storage (United States)

    Bae; Yang; Jin; Lee; Park


    An optical CDMA (code division multiple access) system for the optical data storage using bacteriorhodopsin (BR) is reported as an application of the BR materials. The desired signal of multiple input can be recorded and reconstructed by use of orthogonal codes. An experimental setup is proposed and demonstrated.

  13. Optical multipolar spread functions of an aplanatic imaging system (United States)

    Rouxel, Jérémy R.; Toury, Timothée


    The electromagnetic field near the focus of a perfect imaging system is calculated for different multipolar sources that play an important role in the radiation of nanostructures. Those multipoles are the exact and extended multipoles occurring in electrodynamics. The theory of diffraction of vector waves is reviewed rigorously for a dipolar radiation and applied to the imaging of multipolar sources. Different geometries are considered in order to connect with experiments and the multipolar spread functions are given in a ready-to-use format up to the octupolar order, in the general case and in the paraxial approximation. Defocus imaging is finally considered to provide a first step toward multipolar imaging.

  14. An Optical Tri-valued Computing System

    Directory of Open Access Journals (Sweden)

    Junjie Peng


    Full Text Available A new optical computing experimental system is presented. Designed based on tri-valued logic, the system is built as a photoelectric hybrid computer system which is much advantageous over its electronic counterparts. Say, the tri-valued logic of the system guarantees that it is more powerful in information processing than that of systems with binary logic. And the optical characteristic of the system makes it be much capable in huge data processing than that of the electronic computers. The optical computing system includes two parts, electronic part and optical part. The electronic part consists of a PC and two embedded systems which are used for data input/output, monitor, synchronous control, user data combination and separation and so on. The optical part includes three components. They are optical encoder, logic calculator and decoder. It mainly answers for encoding the users' requests into tri-valued optical information, computing and processing the requests, decoding the tri-valued optical information to binary electronic information and so forth. Experiment results show that the system is quite right in optical information processing which demonstrates the feasibility and correctness of the optical computing system.

  15. Total 3D imaging of phase objects using defocusing microscopy: application to red blood cells

    CERN Document Server

    Roma, P M S; Amaral, F T; Agero, U; Mesquita, O N


    We present Defocusing Microscopy (DM), a bright-field optical microscopy technique able to perform total 3D imaging of transparent objects. By total 3D imaging we mean the determination of the actual shapes of the upper and lower surfaces of a phase object. We propose a new methodology using DM and apply it to red blood cells subject to different osmolality conditions: hypotonic, isotonic and hypertonic solutions. For each situation the shape of the upper and lower cell surface-membranes (lipid bilayer/cytoskeleton) are completely recovered, displaying the deformation of RBCs surfaces due to adhesion on the glass-substrate. The axial resolution of our technique allowed us to image surface-membranes separated by distances as small as 300 nm. Finally, we determine volume, superficial area, sphericity index and RBCs refractive index for each osmotic condition.

  16. ERIS adaptive optics system design (United States)

    Marchetti, Enrico; Le Louarn, Miska; Soenke, Christian; Fedrigo, Enrico; Madec, Pierre-Yves; Hubin, Norbert


    The Enhanced Resolution Imager and Spectrograph (ERIS) is the next-generation instrument planned for the Very Large Telescope (VLT) and the Adaptive Optics facility (AOF). It is an AO assisted instrument that will make use of the Deformable Secondary Mirror and the new Laser Guide Star Facility (4LGSF), and it is planned for the Cassegrain focus of the telescope UT4. The project is currently in its Phase A awaiting for approval to continue to the next phases. The Adaptive Optics system of ERIS will include two wavefront sensors (WFS) to maximize the coverage of the proposed sciences cases. The first is a high order 40x40 Pyramid WFS (PWFS) for on axis Natural Guide Star (NGS) observations. The second is a high order 40x40 Shack-Hartmann WFS for single Laser Guide Stars (LGS) observations. The PWFS, with appropriate sub-aperture binning, will serve also as low order NGS WFS in support to the LGS mode with a field of view patrolling capability of 2 arcmin diameter. Both WFSs will be equipped with the very low read-out noise CCD220 based camera developed for the AOF. The real-time reconstruction and control is provided by a SPARTA real-time platform adapted to support both WFS modes. In this paper we will present the ERIS AO system in all its main aspects: opto-mechanical design, real-time computer design, control and calibrations strategy. Particular emphasis will be given to the system performance obtained via dedicated numerical simulations.

  17. Quantum Entanglement in Optical Lattice Systems (United States)


    SECURITY CLASSIFICATION OF: Optical lattice systems provide an ideal platform for investigating entanglement because of their unprecedented level of...ABSTRACT Final report for ARO grant entitled "Quantum Entanglement in Optical Lattice Systems" Report Title Optical lattice systems provide an ideal ...2010): 0. doi: 10.1103/PhysRevA.82.063612 D. Blume, K. Daily. Breakdown of Universality for Unequal-Mass Fermi Gases with Infinite Scattering Length

  18. Fast and accurate auto-focusing algorithm based on the combination of depth from focus and improved depth from defocus. (United States)

    Zhang, Xuedian; Liu, Zhaoqing; Jiang, Minshan; Chang, Min


    An auto-focus method for digital imaging systems is proposed that combines depth from focus (DFF) and improved depth from defocus (DFD). The traditional DFD method is improved to become more rapid, which achieves a fast initial focus. The defocus distance is first calculated by the improved DFD method. The result is then used as a search step in the searching stage of the DFF method. A dynamic focusing scheme is designed for the control software, which is able to eliminate environmental disturbances and other noises so that a fast and accurate focus can be achieved. An experiment is designed to verify the proposed focusing method and the results show that the method's efficiency is at least 3-5 times higher than that of the traditional DFF method.

  19. Teaching Optics and Systems Engineering With Adaptive Optics Workbenches (United States)

    Harrington, D. M.; Ammons, M.; Hunter, L.; Max, C.; Hoffmann, M.; Pitts, M.; Armstrong, J. D.


    Adaptive optics workbenches are fully functional optical systems that can be used to illustrate and teach a variety of concepts and cognitive processes. Four systems have been funded, designed and constructed by various institutions and people as part of education programs associated with the Center for Adaptive Optics, the Professional Development Program and the Institute for Scientist & Engineer Educators. Activities can range from first-year undergraduate explorations to professional level training. These workbenches have been used in many venues including the Center for Adaptive Optics AO Summer School, the Maui Community College-hosted Akamai Maui Short Course, classrooms, training of new staff in laboratories and other venues. The activity content has focused on various elements of systems thinking, characterization, feedback and system control, basic optics and optical alignment as well as advanced topics such as phase conjugation, wave-front sensing and correction concepts, and system design. The workbenches have slightly different designs and performance capabilities. We describe here outlines for several activities utilizing these different designs and some examples of common student learner outcomes and experiences.

  20. Optical axis jitter rejection for double overlapped adaptive optics systems (United States)

    Luo, Qi; Luo, Xi; Li, Xinyang


    Optical axis jitters, or vibrations, which arise from wind shaking and structural oscillations of optical platforms, etc., cause a deleterious impact on the performance of adaptive optics systems. When conventional integrators are utilized to reject such high frequency and narrow-band disturbance, the benefits are quite small despite their acceptable capabilities to reject atmospheric turbulence. In our case, two suits of complete adaptive optics systems called double overlapped adaptive optics systems (DOAOS) are used to counteract both optical jitters and atmospheric turbulence. A novel algorithm aiming to remove vibrations is proposed by resorting to combine the Smith predictor and notch filer. With the help of loop shaping method, the algorithm will lead to an effective and stable controller, which makes the characteristics of error transfer function close to notch filters. On the basis of the spectral analysis of observed data, the peak frequency and bandwidth of vibrations can be identified in advance. Afterwards, the number of notch filters and their parameters will be determined using coordination descending method. The relationship between controller parameters and filtering features is discussed, and the robustness of the controller against varying parameters of the control object is investigated. Preliminary experiments are carried out to validate the proposed algorithms. The overall control performance of DOAOS is simulated. Results show that time delays are a limit of the performance, but the algorithm can be successfully implemented on our systems, which indicate that it has a great potential to reject jitters.

  1. Accuracy of optical navigation systems for automatic head surgery: optical tracking versus optical coherence tomography (United States)

    Díaz Díaz, Jesús; Riva, Mauro H.; Majdani, Omid; Ortmaier, Tobias


    The choice of a navigation system highly depends on the medical intervention and its accuracy demands. The most commonly used systems for image guided surgery (IGS) are based on optical and magnetic tracking systems. This paper compares two optical systems in terms of accuracy: state of the art triangulation-based optical tracking (OT) and optical coherence tomography (OCT). We use an experimental setup with a combined OCT and cutting laser, and an external OT. We simulate a robotic assisted surgical intervention, including planning, navigation, and processing, and compare the accuracies reached at a specific target with each navigation system.

  2. Capillary Electrophoresis - Optical Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sepaniak, M. J.


    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  3. Micro-optical-mechanical system photoacoustic spectrometer (United States)

    Kotovsky, Jack; Benett, William J.; Tooker, Angela C.; Alameda, Jennifer B.


    All-optical photoacoustic spectrometer sensing systems (PASS system) and methods include all the hardware needed to analyze the presence of a large variety of materials (solid, liquid and gas). Some of the all-optical PASS systems require only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the material environment. Methods for improving the signal-to-noise are provided and enable mirco-scale systems and methods for operating such systems.

  4. Prototype Optical Correlator For Robotic Vision System (United States)

    Scholl, Marija S.


    Known and unknown images fed in electronically at high speed. Optical correlator and associated electronic circuitry developed for vision system of robotic vehicle. System recognizes features of landscape by optical correlation between input image of scene viewed by video camera on robot and stored reference image. Optical configuration is Vander Lugt correlator, in which Fourier transform of scene formed in coherent light and spatially modulated by hologram of reference image to obtain correlation.

  5. Silicon retina for optical tracking systems (United States)

    Strohbehn, K.; Jenkins, R. E.; Sun, X.; Andreou, A. G.


    There are a host of position sensors, such as quadcells and CCD's, which are candidates for detecting optical position errors and providing error signals for a mirror positioning loop. We are developing a novel, very high bandwidth, biologically inspired position sensor for optical position tracking systems. We present recent test results and design issues for the use of biologically inspired silicon retinas for spaceborne optical position tracking systems.

  6. Analysis of optical amplifier noise in coherent optical communication systems with optical image rejection receivers

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Mikkelsen, Benny; Mahon, Cathal J.


    performance. Two types of optical image rejection receivers are investigated: a novel, all-optical configuration and the conventional, microwave-based configuration. The analysis shows that local oscillator-spontaneous emission beat noise (LO-SP), signal-spontaneous emission beat noise (S-SP), and spontaneous......A detailed theoretical analysis of optical amplifier noise in coherent optical communication systems with heterodyne receivers is presented. The analysis quantifies in particular how optical image rejection receiver configurations reduce the influence of optical amplifier noise on system......-spontaneous beat noise (SP-SP) can all be reduced by 3 dB, thereby doubling the dynamic range of the optical amplifier. A 2.5-dB improvement in dynamic range has been demonstrated experimentally with the all-optical image rejection configuration. The implications of the increased dynamic range thus obtained...

  7. Virtual focus and depth estimation from defocused video sequences. (United States)

    Yang, Junlan; Schonfeld, Dan


    In this paper, we present a novel method for virtual focus and object depth estimation from defocused video captured by a moving camera. We use the term virtual focus to refer to a new approach for producing in-focus image sequences by processing blurred videos captured by out-of-focus cameras. Our method relies on the concept of Depth-from-Defocus (DFD) for virtual focus estimation. However, the proposed approach overcomes limitations of DFD by reformulating the problem in a moving-camera scenario. We introduce the interframe image motion model, from which the relationship between the camera motion and blur characteristics can be formed. This relationship subsequently leads to a new method for blur estimation. We finally rely on the blur estimation to develop the proposed technique for object depth estimation and focused video reconstruction. The proposed approach can be utilized to correct out-of-focus video sequences and can potentially replace the expensive apparatus required for auto-focus adjustments currently employed in many camera devices. The performance of the proposed algorithm is demonstrated through error analysis and computer simulated experiments.

  8. System for optical sorting of microscopic objects

    DEFF Research Database (Denmark)


    The present invention relates to a system for optical sorting of microscopic objects and corresponding method. An optical detection system (52) is capable of determining the positions of said first and/or said second objects. One or more force transfer units (200, 205, 210, 215) are placed...

  9. Optics Toolbox: An Intelligent Relational Database System For Optical Designers (United States)

    Weller, Scott W.; Hopkins, Robert E.


    Optical designers were among the first to use the computer as an engineering tool. Powerful programs have been written to do ray-trace analysis, third-order layout, and optimization. However, newer computing techniques such as database management and expert systems have not been adopted by the optical design community. For the purpose of this discussion we will define a relational database system as a database which allows the user to specify his requirements using logical relations. For example, to search for all lenses in a lens database with a F/number less than two, and a half field of view near 28 degrees, you might enter the following: FNO English-like language, and which are easily modified by the user. An example rule is: IF require microscope objective in air and require NA > 0.9 THEN suggest the use of an oil immersion objective The heart of the expert system is the rule interpreter, sometimes called an inference engine, which reads the rules and forms conclusions based on them. The use of a relational database system containing lens prototypes seems to be a viable prospect. However, it is not clear that expert systems have a place in optical design. In domains such as medical diagnosis and petrology, expert systems are flourishing. These domains are quite different from optical design, however, because optical design is a creative process, and the rules are difficult to write down. We do think that an expert system is feasible in the area of first order layout, which is sufficiently diagnostic in nature to permit useful rules to be written. This first-order expert would emulate an expert designer as he interacted with a customer for the first time: asking the right questions, forming conclusions, and making suggestions. With these objectives in mind, we have developed the Optics Toolbox. Optics Toolbox is actually two programs in one: it is a powerful relational database system with twenty-one search parameters, four search modes, and multi

  10. Integrated Optical Interconnect Architectures for Embedded Systems

    CERN Document Server

    Nicolescu, Gabriela


    This book provides a broad overview of current research in optical interconnect technologies and architectures. Introductory chapters on high-performance computing and the associated issues in conventional interconnect architectures, and on the fundamental building blocks for integrated optical interconnect, provide the foundations for the bulk of the book which brings together leading experts in the field of optical interconnect architectures for data communication. Particular emphasis is given to the ways in which the photonic components are assembled into architectures to address the needs of data-intensive on-chip communication, and to the performance evaluation of such architectures for specific applications.   Provides state-of-the-art research on the use of optical interconnects in Embedded Systems; Begins with coverage of the basics for high-performance computing and optical interconnect; Includes a variety of on-chip optical communication topologies; Features coverage of system integration and opti...

  11. Fibre Optic Protection System for Concrete Structures

    Institute of Scientific and Technical Information of China (English)

    J.S.Leng; A.Hameed; D.Winter; R.A.Barnes; G.C.Mays; G.F.Fernando


    The design concepts, modelling and implementation of various fibre optic sensor protection systems for development in concrete structures were investigated. Design concepts and on-site requirements for surface-mounted and embedded optical fibre sensor in concrete were addressed. Finite element (FE) modelling of selected sensor protection systems in strain-transfer efficiency from the structure to the sensing region was also studied. And experimental validation of specified sensor protection system was reported. Results obtained indicate that the protection system for the sensors performs adequately in concrete environment and there is very good correlation between results obtained by the protected fibre optic sensors and conventional electrical resistance strain gauges.

  12. Optical system components for navigation grade fiber optic gyroscopes (United States)

    Heimann, Marcus; Liesegang, Maximilian; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, Klaus-Dieter


    Interferometric fiber optic gyroscopes belong to the class of inertial sensors. Due to their high accuracy they are used for absolute position and rotation measurement in manned/unmanned vehicles, e.g. submarines, ground vehicles, aircraft or satellites. The important system components are the light source, the electro optical phase modulator, the optical fiber coil and the photodetector. This paper is focused on approaches to realize a stable light source and fiber coil. Superluminescent diode and erbium doped fiber laser were studied to realize an accurate and stable light source. Therefor the influence of the polarization grade of the source and the effects due to back reflections to the source were studied. During operation thermal working conditions severely affect accuracy and stability of the optical fiber coil, which is the sensor element. Thermal gradients that are applied to the fiber coil have large negative effects on the achievable system accuracy of the optic gyroscope. Therefore a way of calculating and compensating the rotation rate error of a fiber coil due to thermal change is introduced. A simplified 3 dimensional FEM of a quadrupole wound fiber coil is used to determine the build-up of thermal fields in the polarization maintaining fiber due to outside heating sources. The rotation rate error due to these sources is then calculated and compared to measurement data. A simple regression model is used to compensate the rotation rate error with temperature measurement at the outside of the fiber coil. To realize a compact and robust optical package for some of the relevant optical system components an approach based on ion exchanged waveguides in thin glass was developed. This waveguides are used to realize 1x2 and 1x4 splitter with fiber coupling interface or direct photodiode coupling.

  13. Optical antenna for photofunctional molecular systems. (United States)

    Ikeda, Katsuyoshi; Uosaki, Kohei


    Optical antennas can enhance the efficiency of photon-molecule interactions. To design efficient antenna structures, it is essential to consider physicochemical aspects in addition to electromagnetic considerations. Specifically, chemical interactions between optical antennas and molecules have to be controlled to enhance the overall efficiency. For this purpose, sphere-plane nanostructures are suitable optical antennas for molecular-modified functional electrode systems when a well-defined electrode is utilized as a platform.

  14. Digitalization optical open loop test system for fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Deng-wei; SHU Xiao-wu; MU Xu-dong; LIU Cheng


    In order to receive and process the open loop signal from fiber optic gyroscopes speedily,stably and expediently,and to realize the amity interface between human and machine,a digital system that can convert GPIB (general purpose interface bus ) parallel bus into Universal Serial Bus is developed.All the interface functions of GP1B and the hardware system are realized through FPGA.With a digital sampling and processing system designed with VC++ in Windows platform,the real-time controlling procedure,high-speed receiving and sending data can be carried out,and the results can be displayed too.So the design of the system is flexible,the reliability and the stability are improved,error rate is no more than 10-11,the highest bit rate is 8 MB/s and the open loop detection system for optic fiber gyros achieves standardization and complete digitalization simultaneously.

  15. Micro electro mechanical system optical switching (United States)

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J


    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  16. Micro electro mechanical system optical switching

    Energy Technology Data Exchange (ETDEWEB)

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J


    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  17. Management Concerns for Optical Based Filing Systems (United States)


    terminals, WORM Palo Alto, CA 94303 drives, optical jukeboxes, printers, scanners. Candi Technology Inc. Systems integrators providing 2354 Calle Del Mundo ...n.3, p. 68, 6 February 1989. Dortch, M., "A Storage Media Primer ", LAN Times, v.6, n.1, pp. 38-39, January 1989. Dukeman, John, "Optical Disk - A

  18. Integrated optical devices for photonics instrumentation systems

    Energy Technology Data Exchange (ETDEWEB)

    McWright, G.M.; Lafaw, D.A.; Lowry, M.; Tindall, W.


    We discuss the design, fabrication, and evaluation of high speed integrated optical devices for application to photonics instrumentation systems. Specifically, we have demonstrated integrated optical devices with bandwidths in excess of 25 GHz and implemented these devices in single-shot, streak camera based recording schemes. 5 refs., 6 figs.

  19. On Another Edge of Defocusing: Hyperbolicity of Asymmetric Lemon Billiards (United States)

    Bunimovich, Leonid; Zhang, Hong-Kun; Zhang, Pengfei


    Defocusing mechanism provides a way to construct chaotic (hyperbolic) billiards with focusing components by separating all regular components of the boundary of a billiard table sufficiently far away from each focusing component. If all focusing components of the boundary of the billiard table are circular arcs, then the above separation requirement reduces to that all circles obtained by completion of focusing components are contained in the billiard table. In the present paper we demonstrate that a class of convex tables— asymmetric lemons, whose boundary consists of two circular arcs, generate hyperbolic billiards. This result is quite surprising because the focusing components of the asymmetric lemon table are extremely close to each other, and because these tables are perturbations of the first convex ergodic billiard constructed more than 40 years ago.

  20. Defocusing of null rays in infinite derivative gravity (United States)

    Conroy, Aindriú; Koshelev, Alexey S.; Mazumdar, Anupam


    Einstein's General theory of relativity permits spacetime singularities, where null geodesic congruences focus in the presence of matter, which satisfies an appropriate energy condition. In this paper, we provide a minimal defocusing condition for null congruences without assuming any ansatz-dependent background solution. The two important criteria are: (1) an additional scalar degree of freedom, besides the massless graviton must be introduced into the spacetime; and (2) an infinite derivative theory of gravity is required in order to avoid tachyons or ghosts in the graviton propagator. In this regard, our analysis strengthens earlier arguments for constructing non-singular bouncing cosmologies within an infinite derivative theory of gravity, without assuming any ansatz to solve the full equations of motion.

  1. Integrated optical biosensor system (IOBS) (United States)

    Grace, Karen M.; Sweet, Martin R.; Goeller, Roy M.; Morrison, Leland Jean; Grace, Wynne Kevin; Kolar, Jerome D.


    An optical biosensor has a first enclosure with a pathogen recognition surface, including a planar optical waveguide and grating located in the first enclosure. An aperture is in the first enclosure for insertion of sample to be investigated to a position in close proximity to the pathogen recognition surface. A laser in the first enclosure includes means for aligning and means for modulating the laser, the laser having its light output directed toward said grating. Detection means are located in the first enclosure and in optical communication with the pathogen recognition surface for detecting pathogens after interrogation by the laser light and outputting the detection. Electronic means is located in the first enclosure and receives the detection for processing the detection and outputting information on the detection, and an electrical power supply is located in the first enclosure for supplying power to the laser, the detection means and the electronic means.

  2. Mobile based optical form evaluation system

    Directory of Open Access Journals (Sweden)

    Asım Sinan YÜKSEL


    Full Text Available Optical forms that contain multiple-choice answers are widely used both for electing students and evaluating student achievements in education systems in our country and worldwide. Optical forms are evaluated by employing optical mark recognition techniques through optical readers. High cost of these machines, limited access to them, long waiting time for evaluation results make the process hard for educationists working in cities or countries. In this study, a mobile application was developed for the educationists who own mobile phones or tablets for the purpose of evaluating students' answer sheets quickly and independent of location and optical readers. Optical form recognition, reading and evaluation processes are done on the image of student's answer sheet that is taken with the mobile phone or tablet of educationist. The Android based mobile application that we developed has a user-friendly interface, high success rate and is the first of our knowledge application that operates on mobile platforms in this field.

  3. Finite thickness lens model for self-focusing (defocusing) in Kerr medium

    Institute of Scientific and Technical Information of China (English)

    Shi-fang GUO; Qiang TIAN


    A "finite thickness lens" model for self-focusing (defocusing) in Kerr medium is presented. An onaxis normalization transmittance formula is presented for arbitrary nonlinear phase shift for the finite thickness Kerr medium by introducing a nonlinear ABCD-matrix for the transition of a Gaussian beam from linear to nonlinear medium, without complex calculation for the beam radius at the far field aperture. The variation of the peak and valley transmittance difference is found to enhance linearly as the phase shift at the focus increases by increasing the thickness of the medium. If the ratio of the Rayleigh distance divided by the thickness of the medium (d/zo) is constant and small enough, the peak and valley transmittance difference stays constant. Finally, a qualitative formula is presented to express the relationship between the system parameters and the on-axis phase shift at the focus.

  4. MX optical fiber communication system (United States)

    Keiser, G.

    The fiber optic (FO) network for the proposed MX mobile basing scheme is described. C3 operations would be implemented through 15,000 km of FO links between 4800 sites. Burying the cables would ensure continued C3 operations in a hostile environment, although protection would be needed from burrowing rodents. Technology development criteria, such as optical sources and photodetectors for the 1300-1600 nm long wavelength region, are noted, together with construction of a test site at an Air Force base in California.

  5. Predicting the optical gap of conjugated systems (United States)

    Botelho, Andre Leitao

    The adapted Su-Schrieffer-Heeger model is developed in this work as a tool for in silico prediction of the optical gap of pi-conjugated systems for photovoltaic applications. Full transferability of the model ensures reliable predictive power - excellent agreement with 180 independent experimental data points covering virtually all existing conjugated system types with an accuracy exceeding the time-dependent density functional theory, one of the most accurate first-principles methods. Insights on the structure-property relation of conjugated systems obtained from the model lead to guiding rules for optical gap design: 1) fusing aromatic rings parallel to the conjugated path does not significantly lower the optical gap, 2) fusing rings perpendicularly lowers the optical gap of the monomer, but has a reduced benefit from polymerization, and 3) copolymers take advantage of the lower optical gap of perpendicular fused rings and benefit from further optical gap reduction through added parallel fused rings as electronic communicators. A copolymer of parallel and perpendicular benzodithiophenes, differing only in sulfur atom locations, is proposed as a candidate to achieve the optimal 1.2 eV donor optical gap for organic photovoltaics. For small-molecule organic photovoltaics, substituting the end pairs of carbon atoms on pentacene with sulfur atoms is predicted to lower the optical gap from 1.8 eV to 1.1 eV. Furthermore, the model offers an improvement of orders of magnitude in the computational efficiency over commonly used first-principles tools.

  6. A defocus-information-free autostereoscopic three-dimensional (3D) digital reconstruction method using direct extraction of disparity information (DEDI) (United States)

    Li, Da; Cheung, Chifai; Zhao, Xing; Ren, Mingjun; Zhang, Juan; Zhou, Liqiu


    Autostereoscopy based three-dimensional (3D) digital reconstruction has been widely applied in the field of medical science, entertainment, design, industrial manufacture, precision measurement and many other areas. The 3D digital model of the target can be reconstructed based on the series of two-dimensional (2D) information acquired by the autostereoscopic system, which consists multiple lens and can provide information of the target from multiple angles. This paper presents a generalized and precise autostereoscopic three-dimensional (3D) digital reconstruction method based on Direct Extraction of Disparity Information (DEDI) which can be used to any transform autostereoscopic systems and provides accurate 3D reconstruction results through error elimination process based on statistical analysis. The feasibility of DEDI method has been successfully verified through a series of optical 3D digital reconstruction experiments on different autostereoscopic systems which is highly efficient to perform the direct full 3D digital model construction based on tomography-like operation upon every depth plane with the exclusion of the defocused information. With the absolute focused information processed by DEDI method, the 3D digital model of the target can be directly and precisely formed along the axial direction with the depth information.

  7. Optical spring effect in nanoelectromechanical systems (United States)

    Tian, Feng; Zhou, Guangya; Du, Yu; Chau, Fook Siong; Deng, Jie


    In this Letter, we report a hybrid system consisting of nano-optical and nano-mechanical springs, in which the optical spring effect works to adjust the mechanical frequency of a nanoelectromechanical systems resonator. Nano-scale folded beams are fabricated as the mechanical springs and double-coupled one-dimensional photonic crystal cavities are used to pump the "optical spring." The dynamic characteristics of this hybrid system are measured and analyzed at both low and high input optical powers. This study leads the physical phenomenon of optomechanics in complex nano-opto-electro-mechanical systems (NOEMS) and could benefit the future applications of NOEMS in chip-level communication and sensing.

  8. Nonlinear Mixing in Optical Multicarrier Systems (United States)

    Hameed, Mahmood Abdul

    Although optical fiber has a vast spectral bandwidth, efficient use of this bandwidth is still important in order to meet the ever increased capacity demand of optical networks. In addition to wavelength division multiplexing, it is possible to partition multiple low-rate subcarriers into each high speed wavelength channel. Multicarrier systems not only ensure efficient use of optical and electrical components, but also tolerate transmission impairments. The purpose of this research is to understand the impact of mixing among subcarriers in Radio-Over-Fiber (RoF) and high speed optical transmission systems, and experimentally demonstrate techniques to minimize this impact. We also analyze impact of clipping and quantization on multicarrier signals and compare bandwidth efficiency of two popular multiplexing techniques, namely, orthogonal frequency division multiplexing (OFDM) and Nyquist modulation. For an OFDM-RoF system, we present a novel technique that minimizes the RF domain signal-signal beat interference (SSBI), relaxes the phase noise limit on the RF carrier, realizes the full potential of optical heterodyne-based RF carrier generation, and increases the performance-to-cost ratio of RoF systems. We demonstrate a RoF network that shares the same RF carrier for both downlink and uplink, avoiding the need of an additional RF oscillator in the customer unit. For multi-carrier optical transmission, we first experimentally compare performance degradations of coherent optical OFDM and single-carrier Nyquist pulse modulated systems in a nonlinear environment. We then experimentally evaluate SSBI compensation techniques in the presence of semiconductor optical amplifier (SOA) induced nonlinearities for a multicarrier optical system with direct detection. We show that SSBI contamination can be significantly reduced from the data signal when the carrier-to-signal power ratio is sufficiently low.

  9. Optics and multilayer coatings for EUVL systems

    Energy Technology Data Exchange (ETDEWEB)

    Soufli, R; Bajt, S; Hudyma, R M; Taylor, J S


    EUV lithography (EUVL) employs illumination wavelengths around 13.5 nm, and in many aspects it is considered an extension of optical lithography, which is used for the high-volume manufacturing (HVM) of today's microprocessors. The EUV wavelength of illumination dictates the use of reflective optical elements (mirrors) as opposed to the refractive lenses used in conventional lithographic systems. Thus, EUVL tools are based on all-reflective concepts: they use multilayer (ML) coated optics for their illumination and projection systems, and they have a ML-coated reflective mask.

  10. Fiber optical parametric amplifiers in optical communication systems

    DEFF Research Database (Denmark)

    Marhic, Michel E.; Andrekson, Peter A.; Petropoulos, Periklis


    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-...... in excess of 14,000 Tb/s x km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed.......The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time......-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512Gb/s have been transmitted over 6,000km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products...

  11. Optical Design for Extremely Large Telescope Adaptive Optics Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, B J


    Designing an adaptive optics (AO) system for extremely large telescopes (ELT's) will present new optical engineering challenges. Several of these challenges are addressed in this work, including first-order design of multi-conjugate adaptive optics (MCAO) systems, pyramid wavefront sensors (PWFS's), and laser guide star (LGS) spot elongation. MCAO systems need to be designed in consideration of various constraints, including deformable mirror size and correction height. The y,{bar y} method of first-order optical design is a graphical technique that uses a plot with marginal and chief ray heights as coordinates; the optical system is represented as a segmented line. This method is shown to be a powerful tool in designing MCAO systems. From these analyses, important conclusions about configurations are derived. PWFS's, which offer an alternative to Shack-Hartmann (SH) wavefront sensors (WFS's), are envisioned as the workhorse of layer-oriented adaptive optics. Current approaches use a 4-faceted glass pyramid to create a WFS analogous to a quad-cell SH WFS. PWFS's and SH WFS's are compared and some newly-considered similarities and PWFS advantages are presented. Techniques to extend PWFS's are offered: First, PWFS's can be extended to more pixels in the image by tiling pyramids contiguously. Second, pyramids, which are difficult to manufacture, can be replaced by less expensive lenslet arrays. An approach is outlined to convert existing SH WFS's to PWFS's for easy evaluation of PWFS's. Also, a demonstration of PWFS's in sensing varying amounts of an aberration is presented. For ELT's, the finite altitude and finite thickness of LGS's means that the LGS will appear elongated from the viewpoint of subapertures not directly under the telescope. Two techniques for dealing with LGS spot elongation in SH WFS's are presented. One method assumes that the laser will be pulsed and uses a segmented micro

  12. Optical seismic sensor systems and methods (United States)

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun


    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  13. Soliton, rational, and periodic solutions for the infinite hierarchy of defocusing nonlinear Schrödinger equations (United States)

    Ankiewicz, Adrian


    Analysis of short-pulse propagation in positive dispersion media, e.g., in optical fibers and in shallow water, requires assorted high-order derivative terms. We present an infinite-order "dark" hierarchy of equations, starting from the basic defocusing nonlinear Schrödinger equation. We present generalized soliton solutions, plane-wave solutions, and periodic solutions of all orders. We find that "even"-order equations in the set affect phase and "stretching factors" in the solutions, while "odd"-order equations affect the velocities. Hence odd-order equation solutions can be real functions, while even-order equation solutions are complex. There are various applications in optics and water waves.

  14. Economics Of Optical Fibre Transmission Systems (United States)

    Murray, W. J.


    Optical fibre as a telecommunication transmission medium has become one of the most significant developments so far of the digital era. A major contributory factor to the availability of optical fibre transmission systems has been the outstanding progress in the technology of manufacturing high quality glass fibre having relatively low attenuation and broad bandwidths. This and other achievements has enabled manufacturers in the United Kingdom to develop a range of optical fibre cables and transmission equipment for operation over short and long distances at the CCITT recommended digital hierarchical rates of 2, 8, 34 and 140Mbit/s which have been adopted by British Telecom (BT) for modernisation to an all digital transmission network. These optical fibre systems are now becoming increasingly price and performance competitive with conventional technology in many parts of telecommunications networks. In the British Telecom (BT) network the 140Mbit/s optical fibre systems are now economically competitive with equivalent systems on coaxial cable and microwave radio. The economics of 8 and 34Mbit/s systems are not yet sufficiently attractive, compared with 2Mbit/s digital line systems on pair type copper cables, for large scale use in rural and local distribution networks and are presently only justified on cost in and around large cities. As system costs decrease large applications are predicted particularly in support of future high speed data, cable television and visual information services.

  15. LDEF active optical system components experiment (United States)

    Blue, M. D.


    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  16. Airborne Optical Systems Test Bed (AOSTB) (United States)


    modified as needed. • Leverage existing software data processing chain with minor modifications for variations in data formatting . • Collect...the task of improving the nation’s air defense system. The Air Force, in turn, reached out to MIT for assistance, which led to the formation of MIT...desiccant, in order to control the dew point inside the enclosures. The optical design can be seen below in Figure 9. Figure 9 - Optical Layout

  17. Fiber optic gyroscopes for vehicle navigation systems (United States)

    Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao


    Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

  18. Adaptive optics and phase diversity imaging for responsive space applications.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark William; Wick, David Victor


    The combination of phase diversity and adaptive optics offers great flexibility. Phase diverse images can be used to diagnose aberrations and then provide feedback control to the optics to correct the aberrations. Alternatively, phase diversity can be used to partially compensate for aberrations during post-detection image processing. The adaptive optic can produce simple defocus or more complex types of phase diversity. This report presents an analysis, based on numerical simulations, of the efficiency of different modes of phase diversity with respect to compensating for specific aberrations during post-processing. It also comments on the efficiency of post-processing versus direct aberration correction. The construction of a bench top optical system that uses a membrane mirror as an active optic is described. The results of characterization tests performed on the bench top optical system are presented. The work described in this report was conducted to explore the use of adaptive optics and phase diversity imaging for responsive space applications.

  19. Optical countermeasures against CLOS weapon systems

    NARCIS (Netherlands)

    Toet, A.; Benoist, K.W.; Lingen, J.N.J. van; Schleijpen, H.M.A.


    There are many weapon systems in which a human operator acquires a target, tracks it and designates it. Optical countermeasures against this type of systems deny the operator the possibility to fulfill this visual task. We describe the different effects that result from stimulation of the human

  20. Bright solitons in defocusing media with spatial modulation of the quintic nonlinearity

    CERN Document Server

    Zeng, Jianhua


    It has been recently demonstrated that self-defocusing (SDF) media with the cubic nonlinearity, whose local coefficient grows from the center to periphery fast enough, support stable bright solitons, without the use of any linear potential. Our objective is to test the genericity of this mechanism for other nonlinearities, by applying it to one- and two-dimensional (1D and 2D) quintic SDF media. The models may be implemented in optics (in particular, in colloidal suspensions of nanoparticles), and the 1D model may be applied to the description of the Tonks-Girardeau gas of ultracold bosons. In 1D, the nonlinearity-modulation function is taken as $% g_{0}+\\sinh ^{2}(\\beta x) $. This model admits a subfamily of exact solutions for fundamental solitons. Generic \\ soliton solutions are constructed in a numerical form, and also by means of the Thomas-Fermi and variational approximations (TFA and VA). In particular, a new ansatz for the VA is proposed, in the form of "raised $\\mathrm{sech}$", which provides for an ...

  1. Multiband optics for imaging systems (Conference Presentation) (United States)

    Sanghera, Jasbinder S.; Gibson, Daniel J.; Bayya, Shyam S.; Nguyen, Vinh Q.; Kotov, Mikhail; McClain, Collin


    There is a strong desire to reduce size and weight of single and multiband IR imaging systems in Intelligence, Surveillance and Reconnaissance (ISR) operations on hand-held, helmet mounted or airborne platforms. NRL is developing new IR glasses that expand the glass map and provide compact solutions to multispectral imaging systems. These glasses were specifically designed to have comparable glass molding temperatures and thermal properties to enable lamination and co-molding of the optics which leads to a reduction in the number of air-glass interfaces (lower Fresnel reflection losses). Our multispectral optics designs using these new materials demonstrate reduced size, complexity and improved performance. This presentation will cover discussions on the new optical materials, multispectral designs, as well fabrication and characterization of new optics. Additionally, graded index (GRIN) optics offer further potential for both weight savings and increased performance but have so far been limited to visible and NIR bands (wavelengths shorter than about 0.9 µm). NRL is developing a capability to extend GRIN optics to longer wavelengths in the infrared by exploiting diffused IR transmitting chalcogenide glasses. These IR-GRIN lenses are compatible with all IR wavebands (SWIR, MWIR and LWIR) and can be used alongside conventional materials. The IR-GRIN lens technology, design space and anti-reflection considerations will be presented in this talk.

  2. Argus phase II optical data collection system (United States)

    Wasson, Wayne E.


    The Argus aircraft is a highly modified NC-135E fitted with an infrared and ultraviolet-visible sensor suite for radiometric and spectral data collection. Each suite is operated independently with its own separate gimbal for precision pointing, telescope, and relay optics. The system includes a silica window for the ultraviolet-visible, and a zinc selenide window for the infrared. The entire system was developed and fabricated in-house at the Phillips Laboratory. All sensors are calibrated as a system onboard the aircraft through a unique facility called the aircraft optical calibration facility. The data is all recorded digitally, and can be transferred to secure data reduction facilities via optical fiber. The system is modular, in that the ultraviolet-visible and infrared benches can be separated, or the entire system can be quickly removed to allow for the introduction of other sensor suites or systems. The gimbals and telescopes can be used independently of the rest of the system. The aircraft is also fitted with an anemometry system, which can be operated independently of the sensor systems. This aircraft is capable of many types of missions, and will soon be fitted with a LIDAR system for remote sensing. The philosophy in building the system is to make it capable of quick changes during mission.

  3. Experimental and theoretical analysis of defocused CO2 laser microchanneling on PMMA for enhanced surface finish (United States)

    Prakash, Shashi; Kumar, Subrata


    The poor surface finish of CO2 laser-micromachined microchannel walls is a major limitation of its utilization despite several key advantages, like low fabrication cost and low time consumption. Defocused CO2 laser beam machining is an effective solution for fabricating smooth microchannel walls on polymer and glass substrates. In this research work, the CO2 laser microchanneling process on PMMA has been analyzed at different beam defocus positions. Defocused processing has been investigated both theoretically and experimentally, and the depth of focus and beam diameter have been determined experimentally. The effect of beam defocusing on the microchannel width, depth, surface roughness, heat affected zone and microchannel profile were examined. A previously developed analytical model for microchannel depth prediction has been improved by incorporating the threshold energy density factor. A semi-analytical model for predicting the microchannel width at different defocus positions has been developed. A semi-empirical model has also been developed for predicting microchannel widths at different defocusing conditions for lower depth values. The developed models were compared and verified by performing actual experiments. Multi-objective optimization was performed to select the best optimum set of input parameters for achieving the desired surface roughness.

  4. Optical Soliton Simulation in Optical Fibers by OptiSystem (United States)

    Gaik Tay, Kim; Huong Kah Ching, Audrey; Loi, Wei Sen; Tiong Ong, Chee


    Fiber optic communication is often known to offer higher frequency transmission of signals with greater bit rate and larger data carrying capacity over a long distance with lower loss and interference as compared to copper wire electrical communication. However, several factors that would affect the performance of an optical fiber transmission are such as group velocity dispersion (GVD), fiber loss and also self-phase modulation (SPM). In this paper, the effects of GVD, SPM, optical soliton formation and fiber loss are simulated using OptiSystem 14. It is found that GVD broaden pulse in temporal domain without modifying its spectrum. Meanwhile, SPM creates chirp in spectrum with its temporal profile maintained. This work concluded that a balance between the GVD and SPM is essential to form solitonthat is able to travel for a long distance without being distorted. It is also found that the decrease in the amplitude of the soliton is dependent on the fiber loss and this decay in the signal increases with the propagation distance.

  5. Fiber optical parametric amplifiers in optical communication systems. (United States)

    Marhic, Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud


    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. [Formula: see text].

  6. Optical fiber telecommunications systems and networks

    CERN Document Server

    Kaminow, Ivan; Willner, Alan E


    Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

  7. Volumetric optical coherence microscopy enabled by aberrated optics (Conference Presentation) (United States)

    Mulligan, Jeffrey A.; Liu, Siyang; Adie, Steven G.


    Optical coherence microscopy (OCM) is an interferometric imaging technique that enables high resolution, non-invasive imaging of 3D cell cultures and biological tissues. Volumetric imaging with OCM suffers a trade-off between high transverse resolution and poor depth-of-field resulting from defocus, optical aberrations, and reduced signal collection away from the focal plane. While defocus and aberrations can be compensated with computational methods such as interferometric synthetic aperture microscopy (ISAM) or computational adaptive optics (CAO), reduced signal collection must be physically addressed through optical hardware. Axial scanning of the focus is one approach, but comes at the cost of longer acquisition times, larger datasets, and greater image reconstruction times. Given the capabilities of CAO to compensate for general phase aberrations, we present an alternative method to address the signal collection problem without axial scanning by using intentionally aberrated optical hardware. We demonstrate the use of an astigmatic spectral domain (SD-)OCM imaging system to enable single-acquisition volumetric OCM in 3D cell culture over an extended depth range, compared to a non-aberrated SD-OCM system. The transverse resolution of the non-aberrated and astigmatic imaging systems after application of CAO were 2 um and 2.2 um, respectively. The depth-range of effective signal collection about the nominal focal plane was increased from 100 um in the non-aberrated system to over 300 um in the astigmatic system, extending the range over which useful data may be acquired in a single OCM dataset. We anticipate that this method will enable high-throughput cellular-resolution imaging of dynamic biological systems over extended volumes.

  8. The ERIS adaptive optics system (United States)

    Riccardi, A.; Esposito, S.; Agapito, G.; Antichi, J.; Biliotti, V.; Blain, C.; Briguglio, R.; Busoni, L.; Carbonaro, L.; Di Rico, G.; Giordano, C.; Pinna, E.; Puglisi, A.; Spanò, P.; Xompero, M.; Baruffolo, A.; Kasper, M.; Egner, S.; Suàrez Valles, M.; Soenke, C.; Downing, M.; Reyes, J.


    ERIS is the new AO instrument for VLT-UT4 led by a Consortium of Max-Planck Institut fuer Extraterrestrische Physik, UK-ATC, ETH-Zurich, ESO and INAF. The ERIS AO system provides NGS mode to deliver high contrast correction and LGS mode to extend high Strehl performance to large sky coverage. The AO module includes NGS and LGS wavefront sensors and, with VLT-AOF Deformable Secondary Mirror and Laser Facility, will provide AO correction to the high resolution imager NIX (1-5um) and the IFU spectrograph SPIFFIER (1-2.5um). In this paper we present the preliminary design of the ERIS AO system and the estimated correction performance.

  9. The ERIS Adaptive Optics System

    CERN Document Server

    Riccardi, A; Agapito, G; Antichi, J; Biliotti, V; Blain, C; Briguglio, R; Busoni, L; Carbonaro, L; Di Rico, G; Giordano, C; Pinna, E; Puglisi, A; Spanò, P; Xompero, M; Baruffolo, A; Kasper, M; Egner, S; Valles, M Suàrez; Soenke, C; Downing, M; Reyes, J


    ERIS is the new AO instrument for VLT-UT4 led by a Consortium of Max-Planck Institut fuer Extraterrestrische Physik, UK-ATC, ETH-Zurich, ESO and INAF. The ERIS AO system provides NGS mode to deliver high contrast correction and LGS mode to extend high Strehl performance to large sky coverage. The AO module includes NGS and LGS wavefront sensors and, with VLT-AOF Deformable Secondary Mirror and Laser Facility, will provide AO correction to the high resolution imager NIX (1-5um) and the IFU spectrograph SPIFFIER (1-2.5um). In this paper we present the preliminary design of the ERIS AO system and the estimated correction performance.

  10. COANP-fullerenes system for optical modulation (United States)

    Likhomanova, S. V.; Kamanina, N. V.


    The advanced investigations of ϕ-conjugated organic molecule COANP sensitized with fullerenes have been revealed to consider this system as an affective medium for optical limiting and phase modulation. The special accent has been given to influence of the nanostructured relief at the interface on the spectral and photoconductive features.

  11. Real-time study of shape and thermal fluctuations in the echinocyte transformation of human erythrocytes using defocusing microscopy. (United States)

    Etcheverry, Sebastián; Gallardo, María José; Solano, Pablo; Suwalsky, Mario; Mesquita, Oscar N; Saavedra, Carlos


    We present a real-time method to measure the amplitude of thermal fluctuations in biological membranes by means of a new treatment of the defocusing microscopy (DM) optical technique. This approach was also applied to study the deformation of human erythrocytes to its echinocyte structure. This was carried out by making three-dimensional shape reconstructions of the cell and measuring the thermal fluctuations of its membrane, as the cell is exposed to the anti-inflammatory drug naproxen and as it recovers its original shape, when it is subsequently cleansed of the drug. The results showed biomechanical changes in the membrane even at low naproxen concentration (0.2 mM). Also, we found that when the cell recovered its original shape, the membrane properties were different compared to the nondrugged initial erythrocyte, indicating that the drug administration-recovery process is not completely reversible.

  12. Accurate testing of aspheric surfaces using the transport of intensity equation by properly selecting the defocusing distance. (United States)

    Soltani, Peyman; Darudi, Ahmad; Nehmetallah, George; Moradi, Ali Reza; Amiri, Javad


    In the last decade, the transport of intensity has been increasingly used in microscopy, wavefront sensing, and metrology. In this study, we verify by simulation and experiment the use of the transport of intensity equation (TIE) in the accurate testing of optical aspheric surfaces. Guided by simulation results and assuming that the experimental setup parameters and the conic constants are known, one can estimate an appropriate defocusing distance Δz that leads to an accurate solution of the TIE. In this paper, this method is verified through the construction of a non-nulled experiment for testing the 2D profile of an aspheric surface. The theoretical method and experimental results are compared to validate the results. Finally, to validate the TIE methodology, the phase distribution obtained by TIE is compared with the phase distribution obtained by a Shack-Hartmann sensor.

  13. Optical Filters, Modulators and Interconnects for Optical Communication Systems (United States)

    Han, Sang-Kook

    This dissertation describes the theoretical and experimental studies on the guided wave optical devices in the InGaAlAs/InP material system and the integration of the optical devices which utilize single quantum well (SQW) as well as multi-quantum well (MQW) structures. This study encompasses the fabrication and characterization of passive ridge waveguides, efficient phase modulators using the quadratic electro-optic effect, as well as efficient, narrow bandwidth wavelength filters. For the purpose of the monolithic integration of an SQW laser diode with an MQW modulator in GaAs/AlGaAs without a complex regrowth process, an impurity-induced layer disordering (IILD) technique is used to facilitate a novel tapered waveguide interconnect structure. The narrow bandwidth and widely tunable wavelength filters are essential for the implementation of highly dense wavelength-division-multiplexers/demultiplexers (WDM) in multi-wavelength optical networks and systems. The vertically stacked directional coupler structure wavelength filter device operating at 1.55 μm which permits the maximum asymmetry possible in directional coupler devices to achieve a narrow bandwidth is presented. The quaternary InGaAlAs layers grown on InP substrate are used and it facilitates larger tunability due to material dispersion. The spectral index method and coupled mode theory are used for theoretical calculations of the filter response. The characteristics of the filter are measured and the tunability of the device is discussed. An array of many filters with different center wavelength in a single chip is studied and a relatively broad range of center wavelength is easily obtained by a small variation in the design of the structure. To achieve an integration of a high gain SQW laser diode and an MQW electroabsorption intensity modulator with a high on/off ratio, we utilize a tapered waveguide interconnect using an IILD technique which permits transfer of the energy generated in an SQW laser

  14. Strategies for Dense Optical CDMA Communication Systems

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-bao; LIN Jin-tong


    In this paper,we have formulated a strategy that the limited available code sequences in pure Direct-Sequence(DS)or Frequency-Hopping(FH)system can be reused to realize dense optical CDMA:the strategy of novel hybrid DS/FH system.In which,the case that there are n users employing the same FH pattern but different DS code patterns is considered.On the condition that the impact of channel noises is neglected,the upper bound probability of error is evaluated based on the stationary random process theory.The results show that the hybrid system is suitable for Dense Optical CDMA(DOCDMA)communication.Moreover,the problems such as the link-impairment,dispersion of group velocity, the pure(DS or FH)system can be solved effectively.

  15. Progress with the lick adaptive optics system

    Energy Technology Data Exchange (ETDEWEB)

    Gavel, D T; Olivier, S S; Bauman, B; Max, C E; Macintosh, B


    Progress and results of observations with the Lick Observatory Laser Guide Star Adaptive Optics System are presented. This system is optimized for diffraction-limited imaging in the near infrared, 1-2 micron wavelength bands. We describe our development efforts in a number of component areas including, a redesign of the optical bench layout, the commissioning of a new infrared science camera, and improvements to the software and user interface. There is also an ongoing effort to characterize the system performance with both natural and laser guide stars and to fold this data into a refined system model. Such a model can be used to help plan future observations, for example, predicting the point-spread function as a function of seeing and guide star magnitude.

  16. The LIGO Suspended Optic Digital Control System

    CERN Document Server

    Heefner, J W


    The original LIGO suspension control system [1] used analog circuitry to implement the closed loop damping required for local control of each the suspended optics. Recent developments in analog to digital converters (ADC), digital to analog converters (DAC), increased processor speed and performance, and the use of reflective memory have made a digital alternative possible. Such a control system would provide additional performance and flexibility that will be required for operation of the interferometers. This paper will describe the real-time digital servo control systems that have been designed, developed and implemented for the LIGO suspended optics. In addition, the paper will describe how the suspension controls have been integrated into the overall LIGO control and data acquisition systems [2].

  17. Turbidity Measurement Using An Optical Tomography System


    Sallehuddin Bin Ibrahim


    Turbidity is used to describe water quality and it can be caused by the presence of suspended particles and organic matter such as algae, clay and silt. The measurement of turbidity level of water is vital to domestic water supplies since it is related to public health and water treatment process. This paper presents an investigation on an optical tomography system to estimate the turbidity level in a sample of water. The optical sensors consist of infrared light-emitting diodes (LED) as tran...

  18. Stokes analysis of an optical system (United States)

    Georgiev, Georgi; Slavkovsky, Thomas


    As a transfer from research to teaching we are using stokes analysis to represent changes in the vectors for polarization of light as acted upon by the matrices of optical elements in undergraduate physics lab. The goal is to integrate students' knowledge for matrix analysis with an experimental determination of the changes in the polarization of light. This method allows students to learn how to design an optical system by using mathematical analysis, a skill necessary for future scientists or engineers in the fields of optics. We have tested and implemented the lab. The results are that it is well accepted by the students, but is very involved computationally, and needs to be shortened. The Stokes analysis needs to be introduces earlier in the curriculum in order to make the students comfortable with the formalism.

  19. Ultra Small Integrated Optical Fiber Sensing System

    Directory of Open Access Journals (Sweden)

    Peter Van Daele


    Full Text Available This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL, fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

  20. Fiber laser coupled optical spark delivery system (United States)

    Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO


    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  1. SAFARI optical system architecture and design concept (United States)

    Pastor, Carmen; Jellema, Willem; Zuluaga-Ramírez, Pablo; Arrazola, David; Fernández-Rodriguez, M.; Belenguer, Tomás.; González Fernández, Luis M.; Audley, Michael D.; Evers, Jaap; Eggens, Martin; Torres Redondo, Josefina; Najarro, Francisco; Roelfsema, Peter


    SpicA FAR infrared Instrument, SAFARI, is one of the instruments planned for the SPICA mission. The SPICA mission is the next great leap forward in space-based far-infrared astronomy and will study the evolution of galaxies, stars and planetary systems. SPICA will utilize a deeply cooled 2.5m-class telescope, provided by European industry, to realize zodiacal background limited performance, and high spatial resolution. The instrument SAFARI is a cryogenic grating-based point source spectrometer working in the wavelength domain 34 to 230 μm, providing spectral resolving power from 300 to at least 2000. The instrument shall provide low and high resolution spectroscopy in four spectral bands. Low Resolution mode is the native instrument mode, while the high Resolution mode is achieved by means of a Martin-Pupplet interferometer. The optical system is all-reflective and consists of three main modules; an input optics module, followed by the Band and Mode Distributing Optics and the grating Modules. The instrument utilizes Nyquist sampled filled linear arrays of very sensitive TES detectors. The work presented in this paper describes the optical design architecture and design concept compatible with the current instrument performance and volume design drivers.

  2. Optical signal monitoring in phase modulated optical fiber transmission systems (United States)

    Zhao, Jian

    Optical performance monitoring (OPM) is one of the essential functions for future high speed optical networks. Among the parameters to be monitored, chromatic dispersion (CD) is especially important since it has a significant impact on overall system performance. In this thesis effective CD monitoring approaches for phase-shift keying (PSK) based optical transmission systems are investigated. A number of monitoring schemes based on radio frequency (RF) spectrum analysis and delay-tap sampling are proposed and their performance evaluated. A method for dispersion monitoring of differential phase-shift keying (DPSK) signals based on RF power detection is studied. The RF power spectrum is found to increase with the increase of CD and decrease with polarization mode dispersion (PMD). The spectral power density dependence on CD is studied theoretically and then verified through simulations and experiments. The monitoring sensitivity for nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero differential phase-shift keying (RZ-DPSK) based systems can reach 80ps/nm/dB and 34ps/nm/dB respectively. The scheme enables the monitoring of differential group delay (DGD) and CD simultaneously. The monitoring sensitivity of CD and DGD can reach 56.7ps/nm/dB and 3.1ps/dB using a bandpass filter. The effects of optical signal-to-noise ratio (OSNR), DGD, fiber nonlinearity and chirp on the monitoring results are investigated. Two RF pilot tones are employed for CD monitoring of DPSK signals. Specially selected pilot tone frequencies enable good monitoring sensitivity with minimum influence on the received signals. The dynamic range exceeding 35dB and monitoring sensitivity up to 9.5ps/nm/dB are achieved. Asynchronous sampling technique is employed for CD monitoring. A signed CD monitoring method for 10Gb/s NRZ-DPSK and RZ-DPSK systems using asynchronous delay-tap sampling technique is studied. The demodulated signals suffer asymmetric waveform distortion if

  3. Proton Beam Defocusing as a Result of Self-Modulation in Plasma

    CERN Document Server

    Turner, Marlene; Gschwendtner, Edda; Lotov, Konstantin; Sosedkin, Alexander


    The AWAKE experiment will use a \\SI{400}{GeV/c} proton beam with a longitudinal bunch length of $\\sigma_z = 12\\,\\rm{cm}$ to create and sustain GV/m plasma wakefields over 10 meters . A 12 cm long bunch can only drive strong wakefields in a plasma with $n_{pe} = 7 \\times 10^{14}\\,\\rm{electrons/cm}^3$ after the self-modulation instability (SMI) developed and microbunches formed, spaced at the plasma wavelength. The fields present during SMI focus and defocus the protons in the transverse plane \\cite{SMI}. We show that by inserting two imaging screens downstream the plasma, we can measure the maximum defocusing angle of the defocused protons for plasma densities above $n_{pe} = 5 \\times 10^{14}\\,\\rm{electrons/cm}^{-3}$. Measuring maximum defocusing angles around 1 mrad indirectly proves that SMI developed successfully and that GV/m plasma wakefields were created. In this paper we present numerical studies on how and when the wakefields defocus protons in plasma, the expected measurement results of the two screen...

  4. Optical passive athermalization for infrared zoom system (United States)

    Li, Shenghui; Yang, Changcheng; Zheng, Jia; Lan, Ning; Xiong, Tao; Li, Yong


    In an infrared zoom system, it is difficult to obtain the best thermal compensation for all effective focal length (EFL) simultaneously by moving a single lens group. According to the principle of optical passive athermalization, the equations of focal length, achromatization and athermalization of both long and short EFL are established respectively. By analyzing the thermal aberration value relations between long EFL and short EFL, the thermal aberration values of the switching groups for short EFL athermalization are calculated. Firstly, the athermalization of long EFL is designed. Then through reasonable optical materials matching of the switching groups, the short EFL achieves athermalization as well. In this paper, a re-imaging switching zoom system is designed. It has a relative aperture of f/4.0, 100% cold shield efficiency, the EFL of 180mm/30mm at 3.7-4.8μm. The long EFL includes four refractive elements and one hybrid refractive/diffractive element. The switching groups of short EFL have two types, one is composed of four refractive elements, and the other is composed of two refractive elements and one hybrid refractive/diffractive element. Both of the short EFL achieve athermalization. With the aluminum materials of system structures, the zoom system achieves optical passive athermalization. It has the diffraction limited image quality and stable image plane from -30°C to 70°C.

  5. Green photonics realized by optical complex systems (United States)

    Nanri, Hiroto; Sasaki, Wakao


    We have experimentally demonstrated a new smart grid model which can control DC electric power flow autonomously among individual homes, by using an optical self-organized node with optical non-linear characteristics, and these homes are assumed to be installed by distributed power supplies, and electric power storage devices, and also supposed to be supplied partly by the commercial electric power grid utilities. An electric power network is composed of nodes and devises called Power Gate Unit (PGU). The nodes have optical nonlinearity for self-organizing informations about surplus or shortage of electric power as to individual homes. The PGU is a distributing unit of actual electric power based on above informations of power surplus or shortage at each home. The PGU at each home is electrically connected to both the onsite power supplies and household load such as a solar panel, a DC motor, and a storage battery as well as the commercial electric power grid utilities. In this work, we composed our experimental self-organized DC power grid with above components and supposed the supplied maximum power from the commercial electric power grid utilities to be limited to 5V-0.5A. In this network, information about surplus or shortage of electric power will propagate through the nodes. In the experiments, surplus electric current 0.4A at a particular node was distributed toward a PGU of another node suffering from shortage of electric current. We also confirmed in the experiments and simulations that even when signal propagation path was disconnected accidentally the network could recover an optimized path. The present smart grid system we have attained may be applied by optical fiber link in the near future because our essential components controlling PGU, i.e. the nodes are electro-optical hybrid which are easily applicable to fiber optical link so as to control electric power transmission line.

  6. Novel optical system for neonatal brain imaging (United States)

    Chen, Yu; Zhou, Shuoming; Nioka, Shoko; Chance, Britton; Anday, Endla; Ravishankar, Sudha; Delivoria-Papadopoulos, Maria


    A highly portable, fast, safe and affordable imaging system that provides interpretable images of brain function in full- and pre-term neonates within a few seconds has been applied to neonates with normal and pathological states. We have used a uniquely sensitive optical tomography system, termed phased array, which has revealed significant functional responses, particularly to parietal stimulation in neonate brain. This system can indicate the blood concentration and oxygenation change during the parietal brain activation in full- and pre-term neonates. The preliminary clinical results, especially a longitudinal study of a cardiac arrest neonate, suggest a variety of future applications.

  7. Optical Design Using an Expert System

    Energy Technology Data Exchange (ETDEWEB)

    Lerner, S A


    We present, as a different perspective on optimization, an expert system for optimization of optical systems that can be used in conjunction with damped least squared methods to find minima for specific design forms. Expert system optimization differs from global optimization in that it preserves the basic structure of the optical system and limits its search for a minima to a relatively small portion of the design space. In general, the high density of local minima obscures the general trend of the merit function in the region of interest for systems with a large number of variables and constraints. Surprisingly, there may be a potential decrease of an order a magnitude in the merit function for a region of solution space. While global optimization is well-suited to identifying design forms of interest, expert system optimization can be used for in-depth optimization of such forms. An expert system based upon such techniques was used to obtain the winning entry for the 2002 IODC lens design problem. The expert system used is discussed along with other design examples.

  8. Turbidity Measurement Using An Optical Tomography System

    Directory of Open Access Journals (Sweden)

    Sallehuddin Bin Ibrahim


    Full Text Available Turbidity is used to describe water quality and it can be caused by the presence of suspended particles and organic matter such as algae, clay and silt. The measurement of turbidity level of water is vital to domestic water supplies since it is related to public health and water treatment process. This paper presents an investigation on an optical tomography system to estimate the turbidity level in a sample of water. The optical sensors consist of infrared light-emitting diodes (LED as transmitters and photodiodes as the receivers where the projections of the sensors are designed in fan beam mode. The system was tested using a vertical flow pipe. The Independent Component Analysis (ICA method was used to display the concentration profile. Results obtained proved that the technique can provide the concentration profile representing the turbidity level of water.

  9. Quantum optical properties in plasmonic systems (United States)

    Ooi, C. H. Raymond


    Plasmonic metallic particle (MP) can affect the optical properties of a quantum system (QS) in a remarkable way. We develop a general quantum nonlinear formalism with exact vectorial description for the scattered photons by the QS. The formalism enables us to study the variations of the dielectric function and photon spectrum of the QS with the particle distance between QS and MP, exciting laser direction, polarization and phase in the presence of surface plasmon resonance (SPR) in the MP. The quantum formalism also serves as a powerful tool for studying the effects of these parameters on the nonclassical properties of the scattered photons. The plasmonic effect of nanoparticles has promising possibilities as it provides a new way for manipulating quantum optical properties of light in nanophotonic systems.

  10. Myopic defocus in the evening is more effective at inhibiting eye growth than defocus in the morning: Effects on rhythms in axial length and choroid thickness in chicks. (United States)

    Nickla, Debora L; Thai, Pearl; Zanzerkia Trahan, Rinita; Totonelly, Kristen


    Animal models have shown that myopic defocus is a potent inhibitor of ocular growth: brief (1-2 h) daily periods of defocus are sufficient to counter the effects of much longer periods of hyperopic defocus, or emmetropic vision. While the variables of duration and frequency have been well-documented with regard to effect, we ask whether the efficacy of the exposures might also depend on the time of day that they are given. We also ask whether there are differential effects on the rhythms in axial length or choroidal thickness. 2-week-old chickens were divided into 2 groups: (1) "2-hr lens-wear". Chicks wore monocular +10D lenses for 2 h per day for 5 days at one of 3 times of day: 5:30 a.m. (n = 11), 12 p.m. (n = 8) or 7:30 p.m. (n = 11). (2) "2-hr minus lens-removal". Chicks wore monocular -10D lenses continually for 7 days, except for a 2-hr period when lenses were removed; the removal occurred at one of 2 times: 5:30 a.m. (n = 8) or 7:30 p.m. (n = 8). Both paradigms exposed eyes to brief myopic defocus that differed in its magnitude, and in the visual experience for the rest of the day. High frequency A-scan ultrasonography was done at the start of the experiment; on the last day, it was done at 6-hr intervals, starting at noon, over 24-hr, to assess rhythm parameters. Refractive errors were measured using a Hartinger's refractometer at the end. In both paradigms, myopic defocus in the evening was significantly more effective at inhibiting eye growth than in the morning ("2-hr lens-wear": X-C: -149 vs -83 μm/5d; "2-hr lens-removal": X-C: 91 vs 245 μm/7d; post-hoc Bonferroni test, p choroidal rhythm, there was no effect on phase, however, the amplitude was larger in most, but not all, experimental groups. These findings have potential translational applications to myopia prevention in schoolchildren, who are exposed to extended periods of hyperopic defocus during reading sessions, due to the nearness of the page. We propose that bouts of such

  11. Fiber Optic Temperature Sensors for Thermal Protection Systems Project (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes an innovative fiber optic-based, multiplexable, highly ruggedized, integrated sensor system for real-time...

  12. Optical tomography system for laboratory turbulence measurements (United States)

    McMackin, Lenore J.; Pierson, Robert E.; Hugo, Ronald J.; Truman, C. Randall


    We describe the design and operation of a high speed optical tomography system for measuring 2D images of a dynamic phase object at a rate of 5 kHz. Data from a set of eight Hartmann wavefront sensors is back-projected to produce phase images showing the details of the inner structure of a heated air flow. Series of reconstructions at different downstream locations illustrate the development of flow structure and the effect of acoustic flow forcing.

  13. LSST active optics system software architecture (United States)

    Thomas, Sandrine J.; Chandrasekharan, Srinivasan; Lotz, Paul; Xin, Bo; Claver, Charles; Angeli, George; Sebag, Jacques; Dubois-Felsmann, Gregory P.


    The Large Synoptic Survey Telescope (LSST) is an 8-meter class wide-field telescope now under construction on Cerro Pachon, near La Serena, Chile. This ground-based telescope is designed to conduct a decade-long time domain survey of the optical sky. In order to achieve the LSST scientific goals, the telescope requires delivering seeing limited image quality over the 3.5 degree field-of-view. Like many telescopes, LSST will use an Active Optics System (AOS) to correct in near real-time the system aberrations primarily introduced by gravity and temperature gradients. The LSST AOS uses a combination of 4 curvature wavefront sensors (CWS) located on the outside of the LSST field-of-view. The information coming from the 4 CWS is combined to calculate the appropriate corrections to be sent to the 3 different mirrors composing LSST. The AOS software incorporates a wavefront sensor estimation pipeline (WEP) and an active optics control system (AOCS). The WEP estimates the wavefront residual error from the CWS images. The AOCS determines the correction to be sent to the different degrees of freedom every 30 seconds. In this paper, we describe the design and implementation of the AOS. More particularly, we will focus on the software architecture as well as the AOS interactions with the various subsystems within LSST.

  14. Contributions to the defocusing effect on pole figure measurements by X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Palacios G, J.; Salat F, R. S.; Jimenez J, A.; Kryshtab, T., E-mail: [Instituto Politecnico Nacional, Escuela Superior de Fisica y Matematicas, Av. IPN s/n, 07738 Mexico D. F. (Mexico)


    A simple method, considering a parallel beam approximation has been made to reproduce the main features of the defocusing effect, observed when pole figures are measured with the Schulz reflection technique using X-ray diffraction. A Lorentzian curve was used to approximate the primary beam profile. This method applied to low index reflections of copper and silver shows qualitatively and partially quantitatively, the extent the elongation of the ellipse resulting from the intersection of the beam with the tilted sample causes the defocusing effect. Differences observed experimentally are attributed mainly to the divergence of the beam, but also partially to the particular primary beam profile. Additionally, measurements with two different vertical heights of the receiving slit, i. e. the measured arch length of the Debye-Scherrer ring, indicate that this parameter plays no role in defocusing. (Author)

  15. Controllable Optical Solitons in Optical Fiber System with Distributed Coefficients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Fei; HE Wan-Quan; ZHANG Pei; ZHANG Peng


    We present how to control the dynamics of optical solitons in optical fibers under nonlinearity and dispersion management, together with the fiber loss or gain. We obtain a family of exact solutions for the nonlinear Schr(o)dinger equation, which describes the propagation of optical pulses in optical fibers, and investigate the dynamical features of solitons by analyzing the exact analytical solutions in different physical situations. The results show that under the appropriate condition, not only the group velocity dispersion and the nonlinearity, but also the loss/gain can be used to manipulate the light pulse.

  16. Clinical trial analyzing the impact of continuous defocused CO2 laser vaporisation on the malignant transformation of erosive oral lichen planus. (United States)

    Mücke, Thomas; Gentz, Irina; Kanatas, Anastasios; Ritschl, Lucas M; Mitchell, David A; Wolff, Klaus-Dietrich; Deppe, Herbert


    The erosive oral lichen planus (OLP) represents a management challenge to the clinician and can have debilitating consequences to patients' quality of life. The aims of this work were to determine the incidence of malignant transformation to squamous cell carcinoma (SCC) in patients undergoing traditional symptomatic treatments (oral salve containing lidocaine hydrochloride or systemic diclofenac) compared to patients that were managed with a defocused continuous CO2 laser beam. A total of 171 patients with histologically confirmed erosive OLP were included into this study. After treatment, patients were assessed until completion of wound healing, at least every 3-6 months for the first 2 years, and every 6-12 months thereafter. The study included 87 women (50.9%) and 84 men (49.1%). A total of 103 patients (60.2%) underwent symptomatic conservative treatment, and 68 patients (39.8%) underwent continuous defocused CO2 laser treatments. SCC developed in 16 patients (9.4%), 2 patients (2.9%) after continuous defocused CO2 laser treatment and 14 patients (13.6%) with symptomatic treatment only. This study provides insight into the potential impact of the CO2 laser in the management of patients with erosive OLP and the influence on the recurrence rate of erosive OLP, as well as malignant transformation to oral SCC.

  17. Document Indexing for Image-Based Optical Information Systems. (United States)

    Thiel, Thomas J.; And Others


    Discussion of image-based information retrieval systems focuses on indexing. Highlights include computerized information retrieval; multimedia optical systems; optical mass storage and personal computers; and a case study that describes an optical disk system which was developed to preserve, access, and disseminate military documents. (19…

  18. Retinal Defocus and Eye Dominance Effect on Eye-Hand Reaction Time


    Naveen K. Yadav, MS; Benjamin Arthur, BS; Jennifer A. Gould, BS


    Purpose: To study the effect of retinal defocus and sighting eye dominance on simple eye-hand reaction time in young visually-normal adults.Methods: Sixteen visually-normal individuals participated in a simple eye-hand reaction time test with different amounts of spherical and astigmatic retinal defocus introduced binocularly in the spectacle plane (plano to +10.00D sphere and +0.50 to +2.00D cyl). Reaction time was assessed under binocular-viewing conditions using the RT-2S Simple Reaction T...

  19. Recent development of plasma optical systems (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, A. A., E-mail: [Institute of Physics, National Academy of Science, Kiev 03028 (Ukraine)


    The article devotes a brief description of the recent development and current status of an ongoing research of plasma optical systems based on the fundamental plasma optical idea magnetic electron isolation, equipotentialization magnetic field lines, and the axi-symmetric cylindrical electrostatic plasma lens (PL) configuration. The experimental, theoretical, and simulation investigations have been carried out over recent years collaboratively between IP NASU (Kiev), LBNL (Berkeley, USA), and HCEI RAS (Tomsk). The crossed electric and magnetic fields inherent the PL configuration that provides the attractive method for establishing a stable plasma discharge at low pressure. Using PL configuration, several high reliability plasma devices were developed. These devices are attractive for many high-tech applications.

  20. Experimental study on "cat-eye" effect with defocusing condition%离焦状态下“猫眼”效应的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘秉琦; 周斌; 张瑜; 武东生


    Retro-reflected wave power of "cat-eye" target is an important index for active laser detection system,which can evaluate high or low "cat-eye" effect of photoelectrical device and provide reference for detector's optimal design.A mathematical model of positive and negative defocusing distance on retro-reflected wave power of"cat-eye" target is built.Effect of defocusing distance on retro-reflected wave power of"cat-eye"target is simulated.Experimental research on typical "cat-eye" target is realized by using the active laser detection system and an inverted telescope.Theoretical simulation result and experimental result show that retro-reflected wave power will be rapidly decline with defocusing distance's increase in finite defocusing condition and this phenomenon is more notable in negative defocusing condition,which can provide experimental basis for research on applicable conditions of active laser detection system and stealth technology of"cat-eye" targets.%“猫眼”目标回波功率是激光主动探测系统的重要指标,可用米评估光电装备“猫眼”效应的强弱,并为探测器的优化设计提供参考。分别建立了正负离焦状态下“猫眼”目标回波功率数学模型,仿真分析了离焦量对“猫眼”目标回波功率的影响,利用搭建的激光主动探测系统及倒置的望远系统,实现了离焦状态下典型“猫眼”效应的实验。理论仿真结果与实验结果表明,激光在有限离焦下,“猫眼”目标回波功率将随离焦量的增大而显著下降,特别是负离焦状态的影响更加明显。这为进~步研究基于“猫眼”效应的激光主动探测适用条件及探讨“猫眼”目标隐身技术提供必要的实验依据。

  1. Generalized pupil aberrations of optical imaging systems (United States)

    Elazhary, Tamer T.

    In this dissertation fully general conditions are presented to correct linear and quadratic field dependent aberrations that do not use any symmetry. They accurately predict the change in imaging aberrations in the presence of lower order field dependent aberrations. The definitions of the image, object, and coordinate system are completely arbitrary. These conditions are derived using a differential operator on the scalar wavefront function. The relationships are verified using ray trace simulations of a number of systems with varying degrees of complexity. The math is shown to be extendable to provide full expansion of the scalar aberration function about field. These conditions are used to guide the design of imaging systems starting with only paraxial surface patches, then growing freeform surfaces that maintain the analytic conditions satisfied for each point in the pupil. Two methods are proposed for the design of axisymmetric and plane symmetric optical imaging systems. Design examples are presented as a proof of the concept.

  2. Three-dimensional optical logic devices using spatial multiwaveguide system

    Institute of Scientific and Technical Information of China (English)

    Jianxia Pan; Yiling Sun


    Based on the weakly coupled-mode theory, the coupled-mode equations of the spatial multiwaveguide system are presented in general. The intensity distribution in each waveguide is determined by numerical method. Optical logic devices based on spatial multiwaveguide system are proposed. The analysis results show that the spatial multiwaveguide system permits different Boolean logic states obtained by phase modulation.. Applications of the logic devices include optical calculation, optical interconnection, and spatial optical signal processing.

  3. Advanced Components For Fiber-Optical Systems (United States)

    Depaula, Ramon; Stowe, David W.


    Paper reviews statuses of some advanced passive and active optical components for use with optical fibers. Emphasis on highly birefringent components controling polarization, because control of polarization critical in applications as fiber-optical gyroscopes, interferometric sensors, and coherent communications.

  4. A Study of Synchronization Techniques for Optical Communication Systems (United States)

    Gagliardi, R. M.


    The study of synchronization techniques and related topics in the design of high data rate, deep space, optical communication systems was reported. Data cover: (1) effects of timing errors in narrow pulsed digital optical systems, (2) accuracy of microwave timing systems operating in low powered optical systems, (3) development of improved tracking systems for the optical channel and determination of their tracking performance, (4) development of usable photodetector mathematical models for application to analysis and performance design in communication receivers, and (5) study application of multi-level block encoding to optical transmission of digital data.


    Directory of Open Access Journals (Sweden)

    N. D. Zoric


    Full Text Available The paper deals with the influence of diffractive optical elements on the optical aberrations. The correction of optical aberrations was investigated in the simple optical systems with one and two lenses (singlet and doublet. The advantages of diffractive optical elements are their ability to generate arbitrary complex wave fronts from a piece of optical material that is essentially flat. The optical systems consisting of the standard surfaces were designed and optimized by using the same starting points. Further, the diffractive and aspheric surfaces were introduced into the developed systems. The resulting hybrid systems were optimized. To compare the complicity of the development of narrow field systems and wide field optical systems, the optimization has been done separately for these two types of the instruments. The optical systems were designed by using special Optical Design Software. Тhe characteristics of designed diffractive surfaces were controlled in Software DIFSYS 2.30. Due to the application of diffractive optical elements the longitudinal chromatic aberration was 5 times reduced for the narrow field systems. The absolute value of Seidel coefficient related to the spherical aberration was reduced in the range of 0.03. Considering that diffractive optical elements have the known disadvantages, like possible parasitic diffraction orders and probable decrease of the transmission, we also developed and analyzed the optical systems with combined aspheric and diffractive surfaces. A combination of the aspheric and diffractive surfaces in the optical disk system of the disk reading lens, gave cutting down of the longitudinal color aberrations almost 15 times on-axis, comparing to the lens consisting of the aspherical and standard surfaces. All of the designed diffractive optical elements possess the parameters within the fabrication limits.

  6. A Space-Based Optical Communication System Utilizing Fiber Optics (United States)


    single mode elliptic core fibers," Opt. Commun., 49, 3, 178-183 (1984). 35 15. B.J. Klein and J.J. Degnan, " Optical antenna gain. 1: Transmitting...antennas," Appl. Opt., 13,9,2134- 2141 (1974). 16. B.J. Klein and J.J. Degnan, " Optical antenna gain. 2: Receiving antennas," Appl. Opt., 13, 10,2397- 2401...1974). 17. B.J. Klein and J.J. Degnan, " Optical antenna gain. 3: The effect of secondary element support struts on transmitter gain," Appl. Opt., 15

  7. Optics

    CERN Document Server

    Fincham, W H A


    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  8. Optical monitoring system for a turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, Dennis H; Smed, Jan P; Williams, James P; Jonnalagadda, Vinay


    The monitoring system for a gas turbine engine including a viewing tube assembly having an inner end and an outer end. The inner end is located adjacent to a hot gas flow path within the gas turbine engine and the outer end is located adjacent to an outer casing of the gas turbine engine. An aperture wall is located at the inner end of the viewing tube assembly and an optical element is located within the viewing tube assembly adjacent to the inner end and is spaced from the aperture wall to define a cooling and purge chamber therebetween. An aperture is defined in the aperture wall for passage of light from the hot gas flow path to the optical element. Swirl passages are defined in the viewing tube assembly between the aperture wall and the optical element for passage of cooling air from a location outside the viewing tube assembly into the chamber, wherein swirl passages effect a swirling movement of air in a circumferential direction within the chamber.

  9. Research on the optical system for space optical clock at NTSC (United States)

    Tian, X.; Han, J. X.; Zhang, S.; Zou, H. X.; Chang, H.


    Optical clocks surpass the primary Cs microwave clocks with excellent performances. This allows new studies both in fundamental physics and engineering. The paper presents the optical system for our space optical clock at NTSC. Different from it in the laboratory, novel approaches and techniques were used to meet the space requirement of compactness and reliability. The modular consisting of three robust subunits was developed, which was one laser sources breadboard and two optical paths systems breadboards. The compact dimension of the optical system is 540mm×440mm×130mm and the total mass was approximate 28 kilogram. The deformation of two optical paths systems was calculated under an overload test by a mechanical analysis and it could meet the requirement. It is a advancement from lab to engineering application based on the work, which provides effective foundation for improving the optical system.

  10. Systems and methods for free space optical communication (United States)

    Harper, Warren W [Benton City, WA; Aker, Pamela M [Richland, WA; Pratt, Richard M [Richland, WA


    Free space optical communication methods and systems, according to various aspects are described. The methods and systems are characterized by transmission of data through free space with a digitized optical signal acquired using wavelength modulation, and by discrimination between bit states in the digitized optical signal using a spectroscopic absorption feature of a chemical substance.

  11. Precision-analog fiber-optic transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Stover, G.


    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters.

  12. Physical-layer network coding in coherent optical OFDM systems. (United States)

    Guan, Xun; Chan, Chun-Kit


    We present the first experimental demonstration and characterization of the application of optical physical-layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share the same link so as to enhance system throughput, while individual OFDM frames can be recovered with digital signal processing at the destined node.

  13. Theoretical optical spectroscopy of complex systems

    Energy Technology Data Exchange (ETDEWEB)

    Conte, A. Mosca, E-mail: [MIFP, NAST, ETSF,CNR INFM-SMC, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy); Violante, C., E-mail: [MIFP, NAST, ETSF,CNR INFM-SMC, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy); Missori, M., E-mail: [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Salaria Km 29.300, 00016 Monterotondo Scalo (Rome) (Italy); Bechstedt, F., E-mail: [Institut fur Festkorpertheorie und -optik, Friedrich-Schiller-Universitat, Max-Wien-Platz 1, 07743 Jena (Germany); Teodonio, L. [MIFP, NAST, ETSF,CNR INFM-SMC, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy); Istituto centrale per il restauro e la conservazione del patrimonio archivistico e librario (IC-RCPAL), Italian Minister for Cultural Heritage, Via Milano 76, 00184 Rome (Italy); Ippoliti, E.; Carloni, P. [German Research School for Simulation Sciences, Julich (Germany); Guidoni, L., E-mail: [Università degli Studi di L’Aquila, Dipartimento di Chimica e Materiali, Via Campo di Pile, 67100 L’Aquila (Italy); Pulci, O., E-mail: [MIFP, NAST, ETSF,CNR INFM-SMC, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy)


    Highlights: ► We review some theoretical condensed matter ab initio spectroscopic computational techniques. ► We show several applications ranging from 0 to 3 dimensional systems. ► For each system studied, we show which kind of information it is possible to obtain by performing these calculations. -- Abstract: We review here some of the most reliable and efficient computational theoretical ab initio techniques for the prediction of optical and electronic spectroscopic properties and show some important applications to molecules, surfaces, and solids. We investigate the role of the solvent in the optical absorption spectrum of indole molecule. We study the excited-state properties of a photo-active minimal model molecule for the retinal of rhodopsin, responsible for vision mechanism in animals. We then show a study about spectroscopic properties of Si(1 1 1) surface. Finally we simulate a bulk system: paper, that is mainly made of cellulose, a pseudo-crystalline material representing 40% of annual biomass production in the Earth.

  14. Systems engineering and analysis of electro-optical and infrared systems

    CERN Document Server

    Arrasmith, William Wolfgang


    Introduction to Electro-optic and Infrared (EO/IR) Systems Engineering?Radiation in the Visible and Infrared Parts of the Electromagnetic SpectrumRadiation SourcesThe Effect of the Atmosphere on Optical PropagationBasic OpticsOptical ModulationThe Detection of Optical RadiationNoise in the Optical Detection ProcessTechnical Performance Measures and Metrics of Optical DetectorsModern Detectors and their Measures of PerformanceThe Effects of Cooling on Optical Detector NoiseSignal and Image ProcessingElectro-Optic and Infrared Systems AnalysisLaser Imaging Systems?Spectral Imaging?LIDAR and LADA

  15. High-energy pulse compressor using self-defocusing spectral broadening in anomalously dispersive media

    DEFF Research Database (Denmark)

    Bache, Morten; Zhou, Binbin


    A new high-energy pulse compressor uses self-defocusing spectral broadening in anomalously dispersive quadratic nonlinear crystals, followed by positive group-delay-dispersion compensation. Compression to sub-50 fs is possible from Joule-class 1.03 µm femtosecond amplifiers in large-aperture KDP....

  16. Removing defocused objects from single focal plane scans of cytological slides

    Directory of Open Access Journals (Sweden)

    David Friedrich


    Full Text Available Background: Virtual microscopy and automated processing of cytological slides are more challenging compared to histological slides. Since cytological slides exhibit a three-dimensional surface and the required microscope objectives with high resolution have a low depth of field, these cannot capture all objects of a single field of view in focus. One solution would be to scan multiple focal planes; however, the increase in processing time and storage requirements are often prohibitive for clinical routine. Materials and Methods: In this paper, we show that it is a reasonable trade-off to scan a single focal plane and automatically reject defocused objects from the analysis. To this end, we have developed machine learning solutions for the automated identification of defocused objects. Our approach includes creating novel features, systematically optimizing their parameters, selecting adequate classifier algorithms, and identifying the correct decision boundary between focused and defocused objects. We validated our approach for computer-assisted DNA image cytometry. Results and Conclusions: We reach an overall sensitivity of 96.08% and a specificity of 99.63% for identifying defocused objects. Applied on ninety cytological slides, the developed classifiers automatically removed 2.50% of the objects acquired during scanning, which otherwise would have interfered the examination. Even if not all objects are acquired in focus, computer-assisted DNA image cytometry still identified more diagnostically or prognostically relevant objects compared to manual DNA image cytometry. At the same time, the workload for the expert is reduced dramatically.

  17. FASTDEF: fast defocus and astigmatism estimation for high-throughput transmission electron microscopy. (United States)

    Vargas, J; Otón, J; Marabini, R; Jonic, S; de la Rosa-Trevín, J M; Carazo, J M; Sorzano, C O S


    In this work we present a fast and automated algorithm for estimating the contrast transfer function (CTF) of a transmission electron microscope. The approach is very suitable for High Throughput work because: (a) it does not require any initial defocus estimation, (b) it is almost an order of magnitude faster than existing approaches, (c) it opens the way to well-defined extensions to the estimation of higher order aberrations, at the same time that provides defocus and astigmatism estimations comparable in accuracy to well established methods, such as Xmipp and CTFFIND3 approaches. The new algorithm is based on obtaining the wrapped modulating phase of the power spectra density pattern by the use of a quadrature filter. This phase is further unwrapped in order to obtain the continuous and smooth absolute phase map; then a Zernike polynomial fitting is performed and the defocus and astigmatism parameters are determined. While the method does not require an initial estimation of the defocus parameters or any non-linear optimization procedure, these approaches can be used if further refinement is desired. Results of the CTF estimation method are presented for standard negative stained images, cryo-electron microscopy images in the absence of carbon support, as well as micrographs with only ice. Additionally, we have also tested the proposed method with micrographs acquired from tilted and untilted samples, obtaining good results. The algorithm is freely available as a part of the Xmipp package [].

  18. Long-time asymptotics for the defocusing integrable discrete nonlinear Schr\\"odinger equation




    We investigate the long-time asymptotics for the defocusing integrable discrete nonlinear Schr\\"odinger equation by means of the Deift-Zhou nonlinear steepest descent method. The leading term is a sum of two terms that oscillate with decay of order $t^{-1/2}$.

  19. Long-time asymptotics for the defocusing integrable discrete nonlinear Schrödinger equation




    We investigate the long-time asymptotics for the defocusing integrable discrete nonlinear Schrödinger equation of Ablowitz-Ladik by means of the inverse scattering transform and the Deift-Zhou nonlinear steepest descent method. The leading part is a sum of two terms that oscillate with decay of order $t^{-1/2}$.

  20. Fully three-dimensional defocus-gradient corrected backprojection in cryoelectron microscopy

    DEFF Research Database (Denmark)

    Kazantsev, Ivan G; Klukowska, J.; Herman, Gabor T.;


    Recognizing that the microscope depth of field is a significant resolution-limiting factor in 3D cryoelectron microscopy, Jensen and Kornberg proposed a concept they called defocus-gradient corrected backprojection (DGCBP) and illustrated by computer simulations that DGCBP can effectively eliminate...

  1. Potential for integrated optical circuits in advanced aircraft with fiber optic control and monitoring systems (United States)

    Baumbick, Robert


    The current Fiber Optic Control System Integration (FOCSI) program is reviewed and the potential role of IOCs in FOCSI applications is described. The program is intended for building, environmentally testing, and demonstrating operation in piggyback flight tests (no active control with optical sensors) of a representative sensor system for propulsion and flight control. The optical sensor systems are to be designed to fit alongside the bill-of-materials sensors for comparison. The sensors are to be connected to electrooptic architecture cards which will contain the optical sources and detectors to recover and process the modulated optical signals. The FOCSI program is to collect data on the behavior of passive optical sensor systems in a flight environment and provide valuable information on installation amd maintenance problems for this technology, as well as component survivability (light sources, connectors, optical fibers, etc.).

  2. Optical alignment of Centaur's inertial guidance system (United States)

    Gordan, Andrew L.


    During Centaur launch operations the launch azimuth of the inertial platform's U-accelerometer input axis must be accurately established and maintained. This is accomplished by using an optically closed loop system with a long-range autotheodolite whose line of sight was established by a first-order survey. A collimated light beam from the autotheodolite intercepts a reflecting Porro prism mounted on the platform azimuth gimbal. Thus, any deviation of the Porro prism from its predetermined heading is optically detected by the autotheodolite. The error signal produced is used to torque the azimuth gimbal back to its required launch azimuth. The heading of the U-accelerometer input axis is therefore maintained automatically. Previously, the autotheodolite system could not distinguish between vehicle sway and rotational motion of the inertial platform unless at least three prisms were used. One prism was mounted on the inertial platform to maintain azimuth alignment, and two prisms were mounted externally on the vehicle to track sway. For example, the automatic azimuth-laying theodolite (AALT-SV-M2) on the Saturn vehilce used three prisms. The results of testing and modifying the AALT-SV-M2 autotheodolite to simultaneously monitor and maintain alignment of the inertial platform and track the sway of the vehicle from a single Porro prism.

  3. Capacities of linear quantum optical systems (United States)

    Lupo, Cosmo; Giovannetti, Vittorio; Pirandola, Stefano; Mancini, Stefano; Lloyd, Seth


    A wide variety of communication channels employ the quantized electromagnetic field to convey information. Their communication capacity crucially depends on losses associated to spatial characteristics of the channel such as diffraction and antenna design. Here we focus on the communication via a finite pupil, showing that diffraction is formally described as a memory channel. By exploiting this equivalence we then compute the communication capacity of an optical refocusing system, modeled as a converging lens. Even though loss of information originates from the finite pupil of the lens, we show that the presence of the refocusing system can substantially enhance the communication capacity. We mainly concentrate on communication of classical information, the extension to quantum information being straightforward.

  4. Capacities of linear quantum optical systems

    CERN Document Server

    Lupo, Cosmo; Pirandola, Stefano; Mancini, Stefano; Lloyd, Seth


    A wide variety of communication channels employ the quantized electromagnetic field to convey information. Their communication capacity crucially depends on losses associated to spatial characteristics of the channel such as diffraction and antenna design. Here we focus on the communication via a finite pupil, showing that diffraction is formally described as a memory channel. By exploiting this equivalence we then compute the communication capacity of an optical refocusing system, modeled as a converging lens. Even though loss of information originates from the finite pupil of the lens, we show that the presence of the refocusing system can substantially enhance the communication capacity. We mainly concentrate on communication of classical information, the extension to quantum information being straightforward.

  5. Indexing system for optical beam steering (United States)

    Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.


    This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

  6. Noncontacting Optical Measurement And Inspection Systems (United States)

    Asher, Jeffrey A.; Jackson, Robert L.


    Product inspection continues to play a growing role in the improvement of quality and reduction of scrap. Recent emphasis on precision measurements and in-process inspection have been a driving force for the development of noncontacting sensors. Noncontacting sensors can provide long term, unattended use due to the lack of sensor wear. Further, in applications where, sensor contact can damage or geometrically change the part to be measured or inspected, noncontacting sensors are the only technical approach available. MTI is involved in the development and sale of noncontacting sensors and custom inspection systems. This paper will review the recent advances in noncontacting sensor development. Machine vision and fiber optics sensor systems are finding a wide variety of industrial inspection applications. This paper will provide detailed examples of several state-of-the-art applications for these noncontacting sensors.

  7. Bioinspired optical sensors for unmanned aerial systems (United States)

    Chahl, Javaan; Rosser, Kent; Mizutani, Akiko


    Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

  8. Natural production of biological optical systems (United States)

    Choi, Seung Ho; Kim, Young L.


    Synthesis and production in nature often provide ideas to design and fabricate advanced biomimetic photonic materials and structures, leading to excellent physical properties and enhanced performance. In addition, the recognition and utilization of natural or biological substances have been typical routes to develop biocompatible and biodegradable materials for medical applications. In this respect, biological lasers utilizing such biomaterials and biostructures have been received considerable attention, given a variety of implications and potentials for bioimaging, biosensing, implantation, and therapy. However, without relying on industrial facilities, eco-friendly massive production of such optical components or systems has not yet been investigated. We show examples of bioproduction of biological lasers using agriculture and fisheries. We anticipate that such approaches will open new possibilities for scalable eco-friendly `green' production of biological photonics components and systems.

  9. Optical PPM-CDMA Communication System with Optical Hard-Limiter

    Institute of Scientific and Technical Information of China (English)


    An optical PPM-CDMA communication system with an opticalhard-limiter in front of the correlator of a receiver is proposed in order to reduce multi-user interference. The performance of the system is evaluated when the effects of both multi-user interference and photo detector shot noise are considered. An upper bound on the bit error rate is derived. The comparison of the performance of the above receiver with that of the optical PPM-CDMA system without an optical hard-limiter is made. Simulation results show that the performance of the system with an optical hard-limiter is superior to that of the conventional one.

  10. All-optical virtual private network and ONUs communication in optical OFDM-based PON system. (United States)

    Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun


    We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible.

  11. A novel power-efficient scheme asymmetrically and symmetrically clipping optical (ASCO)-OFDM for IM/DD optical systems

    National Research Council Canada - National Science Library

    Wu, Nan; Bar-Ness, Yeheskel


    ...) for intensity modulation direct detection (IM/DD) optical systems. By using this novel scheme of an OFDM optical system, not only odd subcarriers but also even subcarriers can be modulated to transmit a clipping optical signal...

  12. Optics

    CERN Document Server

    Fincham, W H A


    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  13. Calculation Of Extraction Optics For Ion System With Plazma Emitter

    CERN Document Server

    Frolov, B A


    The 2-D code for simulating of ion optics system of positive ion extraction from a plasma source is described. Example calculation of 100 kV optics for the extraction ion IHEP gun is presented. The trajectories of particles and emittance plots are resulted. The aberrations influ-ence strongly on ion optics for considered geometry.

  14. A Reference Optical System of Laser Doppler Longitudinal Displacement Measurement

    Institute of Scientific and Technical Information of China (English)

    张存满; 赵洋; 李达成


    In this paper, a new reference optical system is put forward to achieve longitudinal displacement measurement. An optical grating is used for frequency mixing and getting high SNR signals in the measurement. Conditions and methods for getting Doppler beat signals are presented.The experiments indicate that this optical syetem can be used to measure the longitudinal displacement with high accuracy.

  15. Multiparameter fiber optic sensing system for monitoring enhanced geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Challener, William A


    The goal of this project was to design, fabricate and test an optical fiber cable which supports multiple sensing modalities for measurements in the harsh environment of enhanced geothermal systems. To accomplish this task, optical fiber was tested at both high temperatures and strains for mechanical integrity, and in the presence of hydrogen for resistance to darkening. Both single mode (SM) and multimode (MM) commercially available optical fiber were identified and selected for the cable based on the results of these tests. The cable was designed and fabricated using a tube-within-tube construction containing two MM fibers and one SM fiber, and without supporting gel that is not suitable for high temperature environments. Commercial fiber optic sensing instruments using Raman DTS (distributed temperature sensing), Brillouin DTSS (distributed temperature and strain sensing), and Raleigh COTDR (coherent optical time domain reflectometry) were selected for field testing. A microelectromechanical systems (MEMS) pressure sensor was designed, fabricated, packaged, and calibrated for high pressure measurements at high temperatures and spliced to the cable. A fiber Bragg grating (FBG) temperature sensor was also spliced to the cable. A geothermal well was selected and its temperature and pressure were logged. The cable was then deployed in the well in two separate field tests and measurements were made on these different sensing modalities. Raman DTS measurements were found to be accurate to ±5°C, even with some residual hydrogen darkening. Brillouin DTSS measurements were in good agreement with the Raman results. The Rayleigh COTDR instrument was able to detect some acoustic signatures, but was generally disappointing. The FBG sensor was used to determine the effects of hydrogen darkening, but drift over time made it unreliable as a temperature or pressure sensor. The MEMS sensor was found to be highly stable and accurate to better than its 0.1% calibration.

  16. Optical Imaging and Microscopy Techniques and Advanced Systems

    CERN Document Server

    Török, Peter


    This text on contemporary optical systems is intended for optical researchers and engineers, graduate students and optical microscopists in the biological and biomedical sciences. This second edition contains two completely new chapters. In addition most of the chapters from the first edition have been revised and updated. The book consists of three parts: The first discusses high-aperture optical systems, which form the backbone of optical microscopes. An example is a chapter new in the second edition on the emerging field of high numerical aperture diffractive lenses which seems to have particular promise in improving the correction of lenses. In this part particular attention is paid to optical data storage. The second part is on the use of non-linear optical techniques, including nonlinear optical excitation (total internal reflection fluorescence, second and third harmonic generation and two photon microscopy) and non-linear spectroscopy (CARS). The final part of the book presents miscellaneous technique...

  17. Performance of laser based optical imaging system (United States)

    Shah, Dhrupesh S.; Banerjee, Arup; Vora, Anup; Biswas, Amiya; Patel, Naimesh; Kurulkar, Amit; Dutt, Ashutosh


    Day night imaging application requires high dynamic range optical imaging system to detect targets of interest covering mid-day (>32000 Lux)[1], and moonless night ( 1mLux)[1] under clear sky- (visibility of >10km, atmospheric loss of 500m, atmospheric loss of >15dB/Km) conditions. Major governing factors for development of such camera systems are (i) covert imaging with ability to identify the target, (ii) imaging irrespective to the scene background, (iii) reliable operation , (iv) imaging capabilities in inclement weather conditions, (v) resource requirement vs availability power & mass, (vi) real-time data processing, (vii) self-calibration, and (viii) cost. Identification of optimum spectral band of interest is most important to meet these requirements. Conventional detection systems sensing in MWIR and LWIR band has certain draw backs in terms of target detection capabilities, susceptibility to background and huge thermo-mechanical resource requirement. Alternatively, range gated imaging camera system sensing in NIR/SWIR spectrum has shown significant potential to detect wide dynamic range targets. ToF Camera configured in NIR band has certain advantages in terms of Focal Plane Assembly (FPA) development with large format detectors and thermo-mechanical resource requirement compared to SWIR band camera configuration. In past, ToF camera systems were successfully configured in NIR spectrum using silicon based Electron Multiplying CCD (EMCCD), Intensifier CCD (ICCD) along with Gating device and pulsed laser source having emission in between 800nm to 900nm. However, these systems have a very low dynamic range and not suitable for clear sky mid-day conditions. Recently silicon based scientific grade CMOS image sensors have shown significant improvement in terms of high NIR responsivity and available in bigger formats (5MP or more), adequate Full well capacity for day time imaging (>30Ke), very low readout noise (<2e) required for night imaging and higher frame

  18. Systems, Devices, and Materials for Digital Optical Processing. (United States)

    Title, Mark Alan

    The massive parallelism and flexibility of three -dimensional optical communication may allow the development of new parallel computers free from the constraints of planar electronic technology. To bring the optical computer from possibility to reality, however, requires technological and scientific development in new optical systems, devices, and materials. We present here research results in each of these areas. First described is a prototype optical information processing system using CdS/liquid crystal spatial light modulators for optical logic and memory. This system has been developed as the first step in the implementation of a fine-grained, globally-interconnected optical processing element array. Notable system features include the implementation of programmable electronic control and the analysis of the optical power distribution within the processor, both directly applicable to the design of new and more advanced optical information processing systems. Next presented is the design and initial performance data for a new spatial light modulator combining an array of silicon phototransistors with the electro-optic material (Pb,La)(Zr,Ti)O _3, opening new possibilities for "intelligent" optical logic, memory, and switching devices. Important to the optimal performance of this Si/PLZT device is the fabrication of embedded electrodes in the electro-optic material, reducing the device operating voltage and switching energy while improving the uniformity of the optical modulation. An extensive computer model of embedded electrode performance and details of the electrode fabrication by reactive ion beam etching and electroless Ni deposition are presented. Finally, in the area of optical materials development we present initial results in the RF magnetron deposition of electro -optic PLZT on r-plane sapphire. This work is important to the fabrication of a monolithic, Si/PLZT-on-sapphire spatial light modulator, promising superior performance to devices using

  19. Simulating Astronomical Adaptive Optics Systems Using Yao (United States)

    Rigaut, François; Van Dam, Marcos


    Adaptive Optics systems are at the heart of the coming Extremely Large Telescopes generation. Given the importance, complexity and required advances of these systems, being able to simulate them faithfully is key to their success, and thus to the success of the ELTs. The type of systems envisioned to be built for the ELTs cover most of the AO breeds, from NGS AO to multiple guide star Ground Layer, Laser Tomography and Multi-Conjugate AO systems, with typically a few thousand actuators. This represents a large step up from the current generation of AO systems, and accordingly a challenge for existing AO simulation packages. This is especially true as, in the past years, computer power has not been following Moore's law in its most common understanding; CPU clocks are hovering at about 3GHz. Although the use of super computers is a possible solution to run these simulations, being able to use smaller machines has obvious advantages: cost, access, environmental issues. By using optimised code in an already proven AO simulation platform, we were able to run complex ELT AO simulations on very modest machines, including laptops. The platform is YAO. In this paper, we describe YAO, its architecture, its capabilities, the ELT-specific challenges and optimisations, and finally its performance. As an example, execution speed ranges from 5 iterations per second for a 6 LGS 60x60 subapertures Shack-Hartmann Wavefront sensor Laser Tomography AO system (including full physical image formation and detector characteristics) up to over 30 iterations/s for a single NGS AO system.

  20. Effect of defocusing amount on thickness measurement based on laser ultrasound%离焦量对激光超声测厚的影响

    Institute of Scientific and Technical Information of China (English)

    马健; 赵扬; 周凤艳; 孙继华


    In order to study the influence of defocusing amount on laser ultrasonic signal amplitude , thickness measurement experiment was carried out .Aluminum test blocks in different thickness were irradiated by the same pulse laser while using plano-convex spherical lens whose focal length was 100mm.The lens was fixed at a 5-D optical stage and the horizontal axis knob was adjusted to change the defocusing amount .The ultrasound signals were received by piezoelectric probe with 5MHz center frequency and the ultrasonic signal data of all test blocks under each defocusing amount were recorded.The thickness of each aluminum test block was obtained according to the time interval between the signals .The results indicate that relative errors between the measurement value and the actual value are in the range of 3% and the maximum signal amplitude can be obtained when the defocusing amount is -10mm under the same laser irradiation .%为了研究离焦量对激光超声信号幅值的影响,采用相同能量的脉冲激光辐照不同厚度的铝质试块进行了工件测厚的实验。光路会聚采用焦距100 mm的平凸球面聚焦透镜,将该透镜固定于5维光学调整架上,调节水平轴旋钮以改变离焦量;利用中心频率5MHz的压电探头接收激光超声波信号,并记录所有试块在每个离焦量下的超声信号数据;依据信号之间的时间间隔,求出每个铝质试块的厚度。结果表明,测厚结果与工件实际厚度之间的相对误差均在3%范围内;在等量激光脉冲激励下,当工件表面处于离焦量-10mm时,获得信号的幅值最大。

  1. Optical design of the adaptive optics laser guide star system

    Energy Technology Data Exchange (ETDEWEB)

    Bissinger, H. [Lawrence Livermore National Lab., CA (United States)


    The design of an adaptive optics package for the 3 meter Lick telescope is presented. This instrument package includes a 69 actuator deformable mirror and a Hartmann type wavefront sensor operating in the visible wavelength; a quadrant detector for the tip-tile sensor and a tip-tilt mirror to stabilize atmospheric first order tip-tile errors. A high speed computer drives the deformable mirror to achieve near diffraction limited imagery. The different optical components and their individual design constraints are described. motorized stages and diagnostics tools are used to operate and maintain alignment throughout observation time from a remote control room. The expected performance are summarized and actual results of astronomical sources are presented.

  2. Smart Optical Material Characterization System and Method (United States)

    Choi, Sang Hyouk (Inventor); Park, Yeonjoon (Inventor)


    Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

  3. Advanced modelling of optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Thrane, L.; Yura, H.T.;


    Analytical and numerical models for describing and understanding the light propagation in samples imaged by optical coherence tomography (OCT) systems are presented. An analytical model for calculating the OCT signal based on the extended Huygens–Fresnel principle valid both for the single...... and multiple scattering regimes is reviewed. An advanced Monte Carlo model for calculating the OCT signal is also reviewed, and the validity of this model is shown through a mathematical proof based on the extended Huygens–Fresnel principle. Moreover, for the first time the model is verified experimentally....... From the analytical model, an algorithm for enhancing OCT images is developed; the so-called true-reflection algorithm in which the OCT signal may be corrected for the attenuation caused by scattering. For the first time, the algorithm is demonstrated by using the Monte Carlo model as a numerical...

  4. Raman amplification in optical communication systems

    DEFF Research Database (Denmark)

    Kjær, Rasmus


    Fiber Raman amplifiers are investigated with the purpose of identifying new applications and limitations for their use in optical communication systems. Three main topics are investigated, namely: New applications of dispersion compensating Raman amplifiers, the use Raman amplification to increase...... fiberbaserede Raman-forstærkere med henblik på at identificere både deres begrænsninger og nye anvendelsesmuligheder i optiske kommunikationssystemer. En numerisk forstærkermodel er blevet udviklet for bedre at forstå forstærkerens dynamik, dens gain- og støjbegrænsninger. Modellen bruges til at forudsige...... forstærkerens statiske og dynamiske egenskaber, og det eftervises at dens resultater er i god overensstemmelse med eksperimentelle forstærkermålinger. Dispersions-kompenserende fiber er på grund af sin store udbredelse og fiberens høje Raman gain effektivitet et meget velegnet Raman gain-medium. Tre nye...

  5. Physical Optics Based Computational Imaging Systems (United States)

    Olivas, Stephen Joseph

    There is an ongoing demand on behalf of the consumer, medical and military industries to make lighter weight, higher resolution, wider field-of-view and extended depth-of-focus cameras. This leads to design trade-offs between performance and cost, be it size, weight, power, or expense. This has brought attention to finding new ways to extend the design space while adhering to cost constraints. Extending the functionality of an imager in order to achieve extraordinary performance is a common theme of computational imaging, a field of study which uses additional hardware along with tailored algorithms to formulate and solve inverse problems in imaging. This dissertation details four specific systems within this emerging field: a Fiber Bundle Relayed Imaging System, an Extended Depth-of-Focus Imaging System, a Platform Motion Blur Image Restoration System, and a Compressive Imaging System. The Fiber Bundle Relayed Imaging System is part of a larger project, where the work presented in this thesis was to use image processing techniques to mitigate problems inherent to fiber bundle image relay and then, form high-resolution wide field-of-view panoramas captured from multiple sensors within a custom state-of-the-art imager. The Extended Depth-of-Focus System goals were to characterize the angular and depth dependence of the PSF of a focal swept imager in order to increase the acceptably focused imaged scene depth. The goal of the Platform Motion Blur Image Restoration System was to build a system that can capture a high signal-to-noise ratio (SNR), long-exposure image which is inherently blurred while at the same time capturing motion data using additional optical sensors in order to deblur the degraded images. Lastly, the objective of the Compressive Imager was to design and build a system functionally similar to the Single Pixel Camera and use it to test new sampling methods for image generation and to characterize it against a traditional camera. These computational

  6. A distributed fiber optic sensor system for dike monitoring using Brillouin optical frequency domain analysis (United States)

    Nöther, Nils; Wosniok, Aleksander; Krebber, Katerina; Thiele, Elke


    We report on the development of a complete system for spatially resolved detection of critical soil displacement in river embankments. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain in silica optical fibers. Our development consists of the measurement unit, an adequate coating for the optical fibers and a technique to integrate the coated optical fibers into geotextiles as they are commonly used in dike construction. We present several laboratory and field tests that prove the capability of the system to detect areas of soil displacement as small as 2 meters. These are the first tests of truly distributed strain measurements on optical fibers embedded into geosynthetics.

  7. All-optically integrated multimodality imaging system: combined photoacoustic microscopy, optical coherence tomography, and fluorescence imaging (United States)

    Chen, Zhongjiang; Yang, Sihua; Xing, Da


    We have developed a multimodality imaging system by optically integrating all-optical photoacoustic microscopy (AOPAM), optical coherence tomography (OCT) and fluorescence microscopy (FLM) to provide complementary information including optical absorption, optical back-scattering and fluorescence contrast of biological tissue. By sharing the same low-coherence Michelson interferometer, AOPAM and OCT could be organically optically combined to obtain the absorption and scattering information of the biological tissues. Also, owing to using the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence signals are obtained to present the radiative and nonradiative transition process of absorption. Simultaneously photoacoustic angiography, tissue structure and fluorescence molecular in vivo images of mouse ear were acquired to demonstrate the capabilities of the optically integrated trimodality imaging system, which can present more information to study tumor angiogenesis, vasculature, anatomical structure and microenvironments in vivo.

  8. Optical manipulation with two beam traps in microfluidic polymer systems

    DEFF Research Database (Denmark)

    Khoury Arvelo, Maria; Matteucci, Marco; Sørensen, Kristian Tølbøl


    An optical trapping system with two opposing laser beams, also known as the optical stretcher, are naturally constructed inside a microfluidic lab-on-chip system. We present and compare two approaches to combine a simple microfluidic system with either waveguides directly written in the microflui...

  9. Electro-Optical Data Acquisition and Tracking System (United States)

    Federal Laboratory Consortium — The Electro-Optical Data Acquisition and Tracking System (EDATS) dynamically tracks and measures target signatures. It consists of an instrumentation van integrated...

  10. Fiber Optic Temperature Sensors for Thermal Protection Systems Project (United States)

    National Aeronautics and Space Administration — In Phase 1, Intelligent Fiber Optic Systems Corporation (IFOS), in collaboration with North Carolina State University, successfully demonstrated a Fiber Bragg...


    Directory of Open Access Journals (Sweden)

    R. V. Anitropov


    Full Text Available Subject of Research. The research results, structural composition analysis and the parametric synthesis of the projected imaging and non-imaging optical systems were presented. We made an attempt to use the gained experience about imaging systems while designing non-imaging systems, by adapting the composition theory for the calculations of non-imaging systems. Several patterns were revealed, which provide a deeper understanding of the design process of non-imaging optical systems; measures of its optimization were proposed. Method. We investigated the applicability of the theory of composition and synthesis of non-imaging optical systems. The main provisions of the theory of composition are based on the division of all available optical elements in four types depending on their functionality, which corresponds to a modular design. Similar items were identified in non-imaging optical systems and adaptation of composition theory to their design became possible. Main Results. General design patterns of imaging and non-imaging optical systems were studied. Classification of systems, components, as well as technical and generic characteristics of imaging and non-imaging optical systems was determined. Search mechanism of the initial optical system by means of structural and parametric synthesis of non-imaging optical system was formalized. The basic elements were determined included in non-imaging systems and their classification by functionality was done. They were subdivided into basic, corrective, wide angle and high aperture ones. The rules for formation of these elements and their composition were determined: surface reflecting, refracting, spherical and nonspherical elements with total internal reflection. The foundations of composition theory for non-imaging optical systems were laid. The approbation of this method was carried out on the example of the illumination system calculation for surgical room. A 3D model of an illumination optical

  12. Effectiveness of adaptive optics system in satellite-to-ground coherent optical communication. (United States)

    Jian, Huang; Ke, Deng; Chao, Liu; Peng, Zhang; Dagang, Jiang; Zhoushi, Yao


    Adaptive optics (AO) systems can suppress the signal fade induced by atmospheric turbulence in satellite-to-ground coherent optical communication. The lower bound of the signal fade under AO compensation was investigated by analyzing the pattern of aberration modes for a one-stage imaging AO system. The distribution of the root mean square of the residual aberration is discussed on the basis of the spatial and temporal characteristics of the residual aberration of the AO system. The effectiveness of the AO system for improving the performance of coherent optical communication is presented in terms of the bit error rate and system availability.

  13. Cascaded optical transparency in multimode-cavity optomechanical systems. (United States)

    Fan, Linran; Fong, King Y; Poot, Menno; Tang, Hong X


    Electromagnetically induced transparency has great theoretical and experimental importance in many areas of physics, such as atomic physics, quantum optics and, more recent, cavity optomechanics. Optical delay is the most prominent feature of electromagnetically induced transparency, and in cavity optomechanics, the optical delay is limited by the mechanical dissipation rate of sideband-resolved mechanical modes. Here we demonstrate a cascaded optical transparency scheme by leveraging the parametric phonon-phonon coupling in a multimode optomechanical system, where a low damping mechanical mode in the unresolved-sideband regime is made to couple to an intermediate, high-frequency mechanical mode in the resolved-sideband regime of an optical cavity. Extended optical delay and higher transmission as well as optical advancing are demonstrated. These results provide a route to realize ultra-long optical delay, indicating a significant step towards integrated classical and quantum information storage devices.

  14. Rapid Polarization Activity in Optical Communication Systems (United States)

    Yevick, David; Reimer, Michael; Soliman, George


    We have recently analyzed the high-speed polarization and polarization-mode-dispersion (PMD) transients associated with mechanical impacts on a dispersion compensation module consisting of several km of optical fiber. These generate in our experiments rotational frequencies of up to several hundred radians/sec on the Poincare sphere that can severely degrade the performance of both standard and non-conventional communications systems. Accordingly, we implemented several procedures for performing high-speed polarization measurements, employed these to analyze small and large amplitude excitations and compared the results with a heuristic fiber model. Theoretically, we extended our previous work on applying the Magnus expansion to the analysis of the dependence of the PMD and polarization-dependent-loss (PDL) on frequency. From these, we obtained simple procedures for modeling polarization behavior over a wide frequency range from a small number of experimental measurements. Finally, we analyzed the applicability of various models of stochastic time-dependent refractive index variations to system outage prediction.

  15. Optical two-beam traps in microfluidic systems (United States)

    Berg-Sørensen, Kirstine


    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast in a rapid prototyping manner, to hard polymers that could even be produced by injection moulding, or to silica in which waveguides may either be written directly, or with grooves for optical fibers. Here, we review different solutions to the system and also show results obtained in a polymer chip with DUV written waveguides and in an injection molded polymer chip with grooves for optical fibers.

  16. Passive thermo-optic feedback for robust athermal photonic systems (United States)

    Rakich, Peter T.; Watts, Michael R.; Nielson, Gregory N.


    Thermal control devices, photonic systems and methods of stabilizing a temperature of a photonic system are provided. A thermal control device thermally coupled to a substrate includes a waveguide for receiving light, an absorption element optically coupled to the waveguide for converting the received light to heat and an optical filter. The optical filter is optically coupled to the waveguide and thermally coupled to the absorption element. An operating point of the optical filter is tuned responsive to the heat from the absorption element. When the operating point is less than a predetermined temperature, the received light is passed to the absorption element via the optical filter. When the operating point is greater than or equal to the predetermined temperature, the received light is transmitted out of the thermal control device via the optical filter, without being passed to the absorption element.

  17. Organo-erbium systems for optical amplification at telecommunications wavelengths. (United States)

    Ye, H Q; Li, Z; Peng, Y; Wang, C C; Li, T Y; Zheng, Y X; Sapelkin, A; Adamopoulos, G; Hernández, I; Wyatt, P B; Gillin, W P


    Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology.

  18. Passive depth estimation using chromatic aberration and a depth from defocus approach. (United States)

    Trouvé, Pauline; Champagnat, Frédéric; Le Besnerais, Guy; Sabater, Jacques; Avignon, Thierry; Idier, Jérôme


    In this paper, we propose a new method for passive depth estimation based on the combination of a camera with longitudinal chromatic aberration and an original depth from defocus (DFD) algorithm. Indeed a chromatic lens, combined with an RGB sensor, produces three images with spectrally variable in-focus planes, which eases the task of depth extraction with DFD. We first propose an original DFD algorithm dedicated to color images having spectrally varying defocus blurs. Then we describe the design of a prototype chromatic camera so as to evaluate experimentally the effectiveness of the proposed approach for depth estimation. We provide comparisons with results of an active ranging sensor and real indoor/outdoor scene reconstructions.

  19. Self-Focusing/Defocusing of Chirped Gaussian Laser Beam in Collisional Plasma with Linear Absorption (United States)

    Wani, Manzoor Ahmad; Kant, Niti


    This paper presents an investigation on the self-focusing/defocusing of chirped Gaussian laser beam in collisional plasma with linear absorption. We have derived the differential equation for the beam width parameter by using WKB and paraxial approximations and solved it numerically. The effect of chirp and other laser plasma parameters is seen on the behavior of beam width parameter with dimensionless distance of propagation. The results are discussed and presented graphically. Our simulation results show that the amplitude of oscillations decreases with the distance of propagation. Due to collisional frequency, the laser beam shows fast divergence which can be minimized by the introduction of chirp parameter. The chirp decreases the effect of defocusing and increases the ability of self-focusing of laser beam in collisional plasma. Supported by a financial grant from CSIR, New Delhi, India, under Project No. 03(1277)/13/EMR-II

  20. Optical two-beam traps in microfluidic systems

    DEFF Research Database (Denmark)

    Berg-Sørensen, Kirstine


    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast...... written waveguides and in an injection molded polymer chip with grooves for optical fibers. (C) 2016 The Japan Society of Applied Physics....

  1. Defocusing Techniques for Multi-pass Laser Welding of Austenitic Stainless Steel (United States)

    Karhu, Miikka; Kujanpää, Veli

    This study introduces an experimental work carried out in multi-pass laser welding with cold filler wire and laser-arc hybrid welding of thick section austenitic stainless steel. As it has been demonstrated earlier, hybrid and cold wire welding with a keyhole-mode can offer very efficient way to produce multi-pass welds in narrow gap thick section joints. However, when multi-pass welding is applied to one pass per layer method without e.g. scanning or defocusing, the used groove width needs to be very narrow in order to ensure the proper melting of groove side walls and thus to avoid lack of fusion/cold-run defects. As a consequence of the narrow groove, particularly in thick section joints, the accessibility of an arc torch or a wire nozzle into the very bottom of a groove in root pass welding can be considerably restricted. In an alternative approach described in this paper, a power density of a laser beam spot was purposely dispersed by using a defocusing technique. In groove filling experiments, a power density of defocused laser beam was kept in the range, which led the welding process towards to conduction limited regime and thus enabled to achieve broader weld cross-sections. The object was to study the feasibility of defocusing as a way to fill and bridge wider groove geometries than what can be welded with focused keyhole-mode welding with filler addition. The paper covers the results of multi-pass welding of up to 60 mm thick joints with single side preparations.

  2. Stable helical solitons in optical media

    Indian Academy of Sciences (India)

    Boris Malomed; G D Peng; P L Chu; Isaac Towers; Alexander V Buryak; Rowland A Sammut


    We present a review of new results which suggest the existence of fully stable spinning solitons (self-supporting localised objects with an internal vorticity) in optical fibres with self-focusing Kerr (cubic) nonlinearity, and in bulk media featuring a combination of the cubic self-defocusing and quadratic nonlinearities. Their distinctive difference from other optical solitons with an internal vorticity, which were recently studied in various optical media, theoretically and also experimentally, is that all the spinning solitons considered thus far have been found to be unstable against azimuthal perturbations. In the first part of the paper, we consider solitons in a nonlinear optical fibre in a region of parameters where the fibre carries exactly two distinct modes, viz., the fundamental one and the first-order helical mode. From the viewpoint of application to communication systems, this opens the way to doubling the number of channels carried by a fibre. Besides that, these solitons are objects of fundamental interest. To fully examine their stability, it is crucially important to consider collisions between them, and their collisions with fundamental solitons, in (ordinary or hollow) optical fibres. We introduce a system of coupled nonlinear Schrödinger equations for the fundamental and helical modes with nonstandard values of the cross-phase-modulation coupling constants, and show, in analytical and numerical forms, results of collisions between solitons carried by the two modes. In the second part of the paper, we demonstrate that the interaction of the fundamental beam with its second harmonic in bulk media, in the presence of self-defocusing Kerr nonlinearity, gives rise to the first ever example of completely stable spatial ring-shaped solitons with intrinsic vorticity. The stability is demonstrated both by direct simulations and by analysis of linearized equations.

  3. Building electro-optical systems making it all work

    CERN Document Server

    Hobbs, Philip C D


    Praise for the First Edition ""Now a new laboratory bible for optics researchers has joined the list: it is Phil Hobbs's Building Electro-Optical Systems: Making It All Work.""-Tony Siegman, Optics & Photonics News Building a modern electro-optical instrument may be the most interdisciplinary job in all of engineering. Be it a DVD player or a laboratory one-off, it involves physics, electrical engineering, optical engineering, and computer science interacting in complex ways. This book will help all kinds of technical people sort through the complexit

  4. High-precision photometry by telescope defocusing - IV

    DEFF Research Database (Denmark)

    Southworth, John; Hinse, T. C.; Dominik, M.


    the published detections of orbital eccentricity in this system. We model the light curves using the JKTEBOP code and calculate the physical properties of the system by recourse to five sets of theoretical stellar model predictions. The resulting planetary radius, Rb = 1.932 ± 0.052 ± 0.010 RJup (statistical...

  5. Nonlinear optical signal processing for high-speed, spectrally efficient fiber optic systems and networks (United States)

    Zhang, Bo

    The past decade has witnessed astounding boom in telecommunication network traffic. With the emergence of multimedia over Internet, the high-capacity optical transport systems have started to shift focus from the core network towards the end users. This trend leads to diverse optical networks with transparency and reconfigurability requirement. As single channel data rate continues to increase and channel spacing continues to shrink for high capacity, high spectral efficiency, the workload on conventional electronic signal processing elements in the router nodes continues to build up. Performing signal processing functions in the optical domain can potentially alleviate the speed bottleneck if the unique optical properties are efficiently leveraged to assist electronic processing methodologies. Ultra-high bandwidth capability along with the promise for multi-channel and format-transparent operation make optical signal processing an attractive technology which is expected to have great impact on future optical networks. For optical signal processing applications in fiber-optic network and systems, a laudable goal would be to explore the unique nonlinear optical processes in novel photonic devices. This dissertation investigates novel optical signal processing techniques through simulations and experimental demonstrations, analyzes limitations of these nonlinear processing elements and proposes techniques to enhance the system performance or designs for functional photonic modules. Two key signal-processing building blocks for future optical networks, namely slow-light-based tunable optical delay lines and SOA-based high-speed wavelength converters, are presented in the first part of the dissertation. Phase preserving and spectrally efficient slow light are experimentally demonstrated using advanced modulation formats. Functional and novel photonic modules, such as multi-channel synchronizer and variable-bit-rate optical time division multiplexer are designed and

  6. Subpixel based defocused points removal in photon-limited volumetric dataset (United States)

    Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Maraka, Harsha Vardhan R.; Ryle, James P.; Sheridan, John T.


    The asymptotic property of the maximum likelihood estimator (MLE) has been utilized to reconstruct three-dimensional (3D) sectional images in the photon counting imaging (PCI) regime. At first, multiple 2D intensity images, known as Elemental images (EI), are captured. Then the geometric ray-tracing method is employed to reconstruct the 3D sectional images at various depth cues. We note that a 3D sectional image consists of both focused and defocused regions, depending on the reconstructed depth position. The defocused portion is redundant and should be removed in order to facilitate image analysis e.g., 3D object tracking, recognition, classification and navigation. In this paper, we present a subpixel level three-step based technique (i.e. involving adaptive thresholding, boundary detection and entropy based segmentation) to discard the defocused sparse-samples from the reconstructed photon-limited 3D sectional images. Simulation results are presented demonstrating the feasibility and efficiency of the proposed method.

  7. Digital optical computers at the optoelectronic computing systems center (United States)

    Jordan, Harry F.


    The Digital Optical Computing Program within the National Science Foundation Engineering Research Center for Opto-electronic Computing Systems has as its specific goal research on optical computing architectures suitable for use at the highest possible speeds. The program can be targeted toward exploiting the time domain because other programs in the Center are pursuing research on parallel optical systems, exploiting optical interconnection and optical devices and materials. Using a general purpose computing architecture as the focus, we are developing design techniques, tools and architecture for operation at the speed of light limit. Experimental work is being done with the somewhat low speed components currently available but with architectures which will scale up in speed as faster devices are developed. The design algorithms and tools developed for a general purpose, stored program computer are being applied to other systems such as optimally controlled optical communication networks.

  8. BeamOptics : a Symbolic Platform for Modeling and the Solution of Beam Optics System

    Energy Technology Data Exchange (ETDEWEB)

    Yu-Chiu Chao


    BeamOptics [1] is a Mathematica-based computing platform devoted to the following objectives: (1) Structured representation and manipulation of particle beam optics systems with symbolic capabilities, (2) Analytical and numerical modeling of beam optics system behaviors, (3) Solution to specific beam optical or general accelerator system problems, in algebraic form in certain cases, through customized algorithms. Taking advantage of and conforming to the highly formal and self-contained structure of Mathematica, BeamOptics provides a unique platform for developing accelerator design and analysis programs. The feature of symbolic computation and the ability to manipulate the beam optics system at the programming language level enable the user to solve or optimize his system with considerably more efficiency, rigour and insight than can be easily achieved with passive modeling or numerical simulation methods. BeamOptics is developed with continuous evolution in mind. New features and algorithms from diverse sources can be incorporated without major modification, due to its formal and generic structure. In this report, a survey is given of the basic structure and methodology of BeamOptics, as well as a demonstration of some of its more specialized applications, and possible direction of evolution.

  9. A novel optical scattering collection system for particulate monitoring applications

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, B.E.; Miller, A.C. Jr. [Oak Ridge National Lab., TN (United States); Nuspliger, R.J. [Environmental Systems Corp., Knoxville, TN (United States)


    Light collecting systems often require radically different optical surfaces than those commonly found in optical imaging systems. An optical particulate monitor must probe a volume in emission stacks to obtain a good statistical distribution of suspended particles. However, ideal imaging systems map object planes into conjugate image planes and can probe only small volumes. The authors describe the design, fabrication and performance of a novel optical scattering collection system that exploits precision-engineered reflective conical surfaces (axicons) in a telescopic arrangement that maps a line in object space onto the detector plane in image space. Such non-spherical surfaces are nearly impossible to fabricate using traditional methods, but can readily be made using the deterministic method of single-point diamond turning. In addition to complex optical surfaces, single-point diamond turning also makes possible the precision engineering of reference surfaces useful for built-in alignment of multiple surfaces and rapid assembly of the finished system.

  10. Optical Systems of Biopsy: The Invisible Eye

    Directory of Open Access Journals (Sweden)

    Kriti Bagri-Manjrekar


    Full Text Available The exploration of new methods and techniques for the diagnosis of malignant tumours has always attracted the attention of scientists. The development of adjunct tools to facilitate the non invasive screening of high risk lesions in real time has the potential to significantly improve our ability to reduce the dismal morbidity and mortality of oral cancer. Despite easy accessibility of the oral cavity to examination, there is no satisfactory method to adequately screen and detect precancers non-invasively. The current method of oral cancer diagnosis clinically relies heavily on visual examination of the oral cavity. However, discerning potentially malignant and early malignant lesions from common benign inflammatory conditions can be difficult at times. There is a need for an objective method that could provide real- time results and be routinely applied to a large population. Though science is yet to present such a perfect technique, Optical Biopsy Systems developed using knowledge of light and tissue interaction, can provide a plausible option.

  11. Graphically Selecting Optical Material for Color Correction and Passive Athermalization

    Directory of Open Access Journals (Sweden)

    Raghad Ismail Ibrahim


    Full Text Available This paper presents pair optical glass by using a graphical method for selecting achromatize and athermalize an imaging lens. An athermal glass map that plots thermal glass constant versus inverse Abbe number is derived through analysis of optical glasses in visible light. By introducing the equivalent Abbe number and equivalent thermal glass constant, although it is a multi-lens system, we have a simple way to visually identify possible optical materials. ZEMAX will be used to determine the change in focus through the expected temperature changes in Earth orbit. The thermal defocuses over -20°C to +60°C are reduced to be much less than the depth of focus of the system

  12. Residential solar-heating system uses pyramidal optics (United States)


    Report describes reflective panels which optimize annual solar energy collection in attic installation. Subunits include collection, storage, distribution, and 4-mode control systems. Pyramid optical system heats single-family and multi-family dwellings.

  13. Optical systems fabricated by printing-based assembly

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung


    Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

  14. Modulation transfer function in optical and electro-optical systems

    CERN Document Server

    Boreman, Glenn D


    This tutorial introduces the theory and applications of MTF, used to specify the image quality achieved by an imaging system. It covers basic linear systems theory and the relationship between impulse response, resolution, MTF, OTF, PTF, and CTF. Practical measurement and testing issues are discussed.

  15. Optical systems for synchrotron radiation. Lecture 1. Introductory topics. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R.


    Various fundamental topics are considered which underlie the design and use of optical systems for synchrotron radiation. The point of view of linear system theory is chosen which acts as a unifying concept throughout the series. In this context the important optical quantities usually appear as either impulse response functions (Green's functions) or frequency transfer functions (Fourier Transforms of the Green's functions). Topics include the damped harmonic oscillator, free-space optical field propagation, optical properties of materials, dispersion, and the Kramers-Kronig relations.

  16. Optical fiber gas sensing system based on FBG filtering (United States)

    Wang, Shutao


    An optical fiber gas sensing system based on the law of Beer-Lambert is designed to determine the concentration of gas. This technique relies on the fact that the target gas has a unique, well-defined absorption characteristic within the infrared region of electromagnetic spectrum. The narrow-band filtering characteristic of optical fiber Bragg grating is used to produce the narrow spectrum light signal. An aspheric objective optical fiber collimator is used in the system as an optical fiber gas sensing detector to improve the sensitivity and stability. Experimental results show there is a high measuring sensitivity at 0.01%, and the measuring range goes beyond 5%.

  17. Optical-digital hybrid image search system in cloud environment (United States)

    Ikeda, Kanami; Kodate, Kashiko; Watanabe, Eriko


    To improve the versatility and usability of optical correlators, we developed an optical-digital hybrid image search system consisting of digital servers and an optical correlator that can be used to perform image searches in the cloud environment via a web browser. This hybrid system employs a simple method to obtain correlation signals and has a distributed network design. The correlation signals are acquired by using an encoder timing signal generated by a rotating disk, and the distributed network design facilitates the replacement and combination of the digital correlation server and the optical correlator.

  18. A proposed fibre optic time domain optical coherence tomography system using a micro-photonic stationary optical delay line (United States)

    Jansz, Paul Vernon; Wild, Graham; Hinckley, Steven


    Conventional time domain Optical Coherence Tomography (OCT) relies on a reference Optical Delay Line (ODL). These reference ODLs require the physical movement of a mirror to scan a given depth range. This movement results in instrument degradation. We propose a new optical fibre based time domain OCT system that makes use of a micro-photonic structure as a stationary ODL. The proposed system uses an in-fibre interferometer, either a Michelson or a Mach-Zhender. The reference ODL makes use of a collimator to expand the light from the optical fibre. This is them expanded in one dimension via planar optics, that is, a cylindrical lens based telescope, using a concave and convex lens. The expanded beam is them passed through a transmissive Spatial Light Modulator (SLM), specifically a liquid crystal light valve used as an optical switch. Light is then reflected back through the system off the micro-photonic structure. The micro-photonic structure is a one dimensional array of stagged mirror steps, called a Stepped Mirror Structure (SMS). The system enables the selection of discrete optical delay lengths. The proposed ODL is capable of depth hoping and multicasting. We discuss the fabrication of the SMS, which consists of eight steps, each approximately 150 μm high. A change in notch frequency using an in-fibre Mach Zhender interferometer was used to gauge the average step height. The results gave an average step height of 146 μm.

  19. Integrated optical measurement system for fluorescence spectroscopy in microfluidic channels

    DEFF Research Database (Denmark)

    Hübner, Jörg; Mogensen, Klaus Bo; Jørgensen, Anders Michael


    A transportable miniaturized fiber-pigtailed measurement system is presented which allows quantitative fluorescence detection in microliquid handling systems. The microliquid handling chips are made in silica on silicon technology and the optical functionality is monolithically integrated...... with the microfluidic channel system. This results in inherent stability and photolithographic alignment precision. Permanently attached optical fibers provide a rugged connection to the light source, detection, and data processing unit, which potentially allows field use of such systems. Fluorescence measurements...

  20. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    Yun-Jiang Rao; Jian Jiang; Zheng-Lin Ran


    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  1. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)


    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  2. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems. (United States)

    Downie, J D; Goodman, J W


    A ground-based adaptive optics imaging telescope system attempts to improve image quality by measuring and correcting for atmospherically induced wavefront aberrations. The necessary control computations during each cycle will take a finite amount of time, which adds to the residual error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper investigates this possibility by studying the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for adaptive optics use.

  3. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle. (United States)

    Miida, Yusuke; Matsuura, Yuji


    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  4. Different Types of Coding Input Data In Optical Transmission Systems

    Directory of Open Access Journals (Sweden)

    Ján Ružbarský


    Full Text Available Optical fiber transmission systems are currently the most widely used transmission media. Their development in time had improved their characteristics to such an extent that they gradually replaced very popular copper cable connections. Inspite of that optical fibers still have not reached perfection and constant improvement is needed. Apart from notable advantages such as large data transfer, few numbers of repeaters required on the transmission path or higher safety of transmitted data, optical fiber has also drawbacks that include not sufficient purity optical fibers, fiber fragility and also higher proclivity to nonlinear effects. Weaknesses of optical systems can be depressed by e.g. a selection of an appropriate laser, a proper combination of materials used for fiber production during the manufacture process, or even by using an encryption of transmitted data. This article is focused on the comparison of optical signal properties in various source encoding types of input data.

  5. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems (United States)

    Downie, John D.


    A ground-based adaptive optics imaging telescope system attempts to improve image quality by detecting and correcting for atmospherically induced wavefront aberrations. The required control computations during each cycle will take a finite amount of time. Longer time delays result in larger values of residual wavefront error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper presents a study of the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for the adaptive optics application. An optimization of the adaptive optics correction algorithm with respect to an optical processor's degree of accuracy is also briefly discussed.

  6. Geometric optics theory and design of astronomical optical systems using Mathematica

    CERN Document Server

    Romano, Antonio


    This text, now in its second edition, presents the mathematical background needed to design many optical combinations that are used in astronomical telescopes and cameras. It uses a novel approach to third-order aberration theory based on Fermat’s principle and the use of particular optical paths (called stigmatic paths) instead of rays, allowing for easier derivation of third-order formulae. Each optical combination analyzed is accompanied by a downloadable Mathematica® notebook that automates its third-order design, eliminating the need for lengthy calculations. The essential aspects of an optical system with an axis of rotational symmetry are introduced first, along with a development of Gaussian optics from Fermat’s principal. A simpler approach to third-order monochromatic aberrations based on both Fermat’s principle and stigmatic paths is then described, followed by a new chapter on fifth-order aberrations and their classification. Several specific optical devices are discussed and analyzed, incl...

  7. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems (United States)

    Downie, John D.


    A ground-based adaptive optics imaging telescope system attempts to improve image quality by detecting and correcting for atmospherically induced wavefront aberrations. The required control computations during each cycle will take a finite amount of time. Longer time delays result in larger values of residual wavefront error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper presents a study of the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for the adaptive optics application. An optimization of the adaptive optics correction algorithm with respect to an optical processor's degree of accuracy is also briefly discussed.

  8. Passive optical networks based on optical CDMA: Design and system analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG ChongFu; QIU Kun; XU Bo


    In this paper, a novel Passive Optical Network based on Optical Code Division Multiple Access (OCDMA-PON) is presented. The design of the Optical Line Terminator (OLT) and the Optical Network Unit (ONU) for the OCDMA-PON are studied in detail. The proposed OCDMA-PON combines the advantages of PON and OCDMA technology and it can be applied to an optical access network with full services on demand, such as internet protocol, video on demand, tele-presence and high quality audio. Compared to other multiple access technologies, the proposed OCDMA-PON provides more ONU and assembly flexibly for PON. We analyze in detail the scalability and system transmission performance of such a network. Simulation results indicate that the proposed scheme is feasible and that the novel design can improve the scalability and transmission performance of the optical access networks.

  9. Application of Optical Forces in Microphotonic Systems (United States)


    wavelength of a semiconductor laser by mechanically modifying the optical cavity is an intriguing application of optomechanical devices. Alegre et al. [48...nanocavities," Applied Physics Letters 83, 4294-4296 (2003). [19]. J. Chan, M. Eichenfield, R. Camacho , and O. Painter, "Optical and of a "zipper" photonic crystaloptomechanical cavity," Opt. Express 17, 3802-3817 (2009). [20]. M. Eichenfield, R. Camacho , J. Chan, K. J. Vahala

  10. Three-dimensional optical transfer functions in the aberration-corrected scanning transmission electron microscope. (United States)

    Jones, L; Nellist, P D


    In the scanning transmission electron microscope, hardware aberration correctors can now correct for the positive spherical aberration of round electron lenses. These correctors make use of nonround optics such as hexapoles or octupoles, leading to the limiting aberrations often being of a nonround type. Here we explore the effect of a number of potential limiting aberrations on the imaging performance of the scanning transmission electron microscope through their resulting optical transfer functions. In particular, the response of the optical transfer function to changes in defocus are examined, given that this is the final aberration to be tuned just before image acquisition. The resulting three-dimensional optical transfer functions also allow an assessment of the performance of a system for focal-series experiments or optical sectioning applications. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  11. Fiber Optic Experience with the Smart Actuation System on the F-18 Systems Research Aircraft (United States)

    Zavala, Eddie


    High bandwidth, immunity to electromagnetic interference, and potential weight savings have led to the development of fiber optic technology for future aerospace vehicle systems. This technology has been incorporated in a new smart actuator as the primary communication interface. The use of fiber optics simplified system integration and significantly reduced wire count. Flight test results showed that fiber optics could be used in aircraft systems and identified critical areas of development of fly-by-light technology. This paper documents the fiber optic experience gained as a result of this program, and identifies general design considerations that could be used in a variety of specific applications of fiber optic technology. Environmental sensitivities of fiber optic system components that significantly contribute to optical power variation are discussed. Although a calibration procedure successfully minimized the effect of fiber optic sensitivities, more standardized calibration methods are needed to ensure system operation and reliability in future aerospace vehicle systems.

  12. An Optical Receiver Post-Processing System for the Integrated Radio and Optical Communications Software Defined Radio Test Bed (United States)

    Nappier, Jennifer M.; Tokars, Roger P.; Wroblewski, Adam C.


    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration's (NASA) Glenn Research Center is investigating the feasibility of a hybrid radio frequency (RF) and optical communication system for future deep space missions. As a part of this investigation, a test bed for a radio frequency (RF) and optical software defined radio (SDR) has been built. Receivers and modems for the NASA deep space optical waveform are not commercially available so a custom ground optical receiver system has been built. This paper documents the ground optical receiver, which is used in order to test the RF and optical SDR in a free space optical communications link.

  13. The analysis of optical wave beams propagation in lens systems (United States)

    Kazakov, I.; Mosentsov, S.; Moskaletz, O.


    In this paper some aspects of the formation and propagation of optical wave beams in lens systems were considered. As an example, the two-lens optical information processing system was considered. Analysis of the two-lens optical circuit has been made with a systems approach perspective. As part of the radio-optical analogies had been applied certain provisions of the theory of dynamical systems to the spatial optical system. The lens system is represented as a simple series-connected optical elements with known spatial impulse response. General impulse response of such a system has been received, as well as consider some special cases of the impulse response. The question of the relationship between the parameters and the size of the input aperture lenses for undistorted transmission of the optical signal has been considered. Analysis of the energy loss resulting from the finite aperture of the lens. It's based on an assessment of the fraction of radiation that propagates beyond the lens. Analysis showed that the energy losses depend explicitly on the following parameters: radiation wavelength, distance between input aperture and lens, and ratio of the input aperture and lens aperture. With the computer help simulation the dependence of losses was shown on the above parameters

  14. Information Optics and Photonics Algorithms, Systems, and Applications

    CERN Document Server

    Javidi, Bahram


    This book addresses applications, recent advances, and emerging areas in fields with applications in information optics and photonics systems. The objective of this book is to illustrate and discuss novel approaches, analytical techniques, models, and technologies that enhance sensing, measurement, processing, interpretation, and visualization of information using free space optics and photonics. The material in this book concentrates on integration of diverse fields for cross-disciplinary applications including bio-photonics, digitally enhanced sensing and imaging systems, multi-dimensional optical imaging and image processing, bio-inspired imaging, 3D visualization, 3D displays, imaging on the nano-scale, quantum optics, super resolution imaging, photonics for biological applications, and holographic information systems. As a result, this book is a useful resource for researchers, engineers, and graduate students who work in the diverse fields comprising information optics and photonics.

  15. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam


    This book provides an in-depth treatment of both linear fiber-optic systems and their key enabling devices. It presents a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers. To the second edition of this book important new aspects of linear fiber-optic transmission technologies are added, such as high level system architectural issues, algorithms for deriving the optimal frequency assignment, directly modulated or externally modulated laser t...

  16. Digital Signal Processing for Optical Coherent Communication Systems

    DEFF Research Database (Denmark)

    Zhang, Xu

    In this thesis, digital signal processing (DSP) algorithms are studied to compensate for physical layer impairments in optical fiber coherent communication systems. The physical layer impairments investigated in this thesis include optical fiber chromatic dispersion, polarization demultiplexing......, light sources frequency and phase offset and phase noise. The studied DSP algorithms are considered as key building blocks in digital coherent receivers for the next generation of optical communication systems such as 112-Gb/s dual polarization (DP) quadrature phase shift keying (QPSK) optical...... spectrum narrowing tolerance 112-Gb/s DP-QPSK optical coherent systems using digital adaptive equalizer. The demonstrated results show that off-line DSP algorithms are able to reduce the bit error rate (BER) penalty induced by signal spectrum narrowing. Third, we also investigate bi...

  17. Application of optical system simulation software in a fiber optic telecommunications program (United States)

    Koontz, Warren L. G.; Mandloi, Divya


    One of our objectives in the College of Applied Science and Technology at RIT is to offer our students some kind of "hands-on" experience along with theory. Providing a hands-on experience can be costly, however, especially in the field of optical communication. Although reasonably priced laboratory kits are available, the optical-electronic components in these kits are well below communication grade. Thus if we rely only on hardware, our students can only experiment with low power, low bit rate communication over a few kilometers of fiber. Computer simulation software offers an affordable alternative "hands-on" experience. With this software, a student can create a model of an optical system, execute the model and view measures of the system's performance. The system components can include DFB laser diodes, high-speed modulators, hundreds of kilometers of fiber, APD receivers and other optical and electrical components. The student can view the optical signals in the time or frequency domain, measure optical power and signal-to-noise ratio and much more. He or she can also view the effects of parameter variations or find the optimal value of a parameter. The software is easy to learn, especially if the student has previous experience with an electronic system simulator. This paper describes our application of an optical-electronic system simulator in the Telecommunications Engineering Technology program at RIT. We are developing a series of exercises to complement courses in fiber optic. These exercises will allow students to model and test systems that they have designed. We expect computer simulation to enhance our fiber optic courses significantly by adding a reasonably realistic and accessible test bed for student designs.

  18. Fiber-optic system for monitoring fast photoactivation dynamics of optical highlighter fluorescent proteins. (United States)

    Pei, Zhiguo; Qin, Lingsong; Zhang, Zhihong; Zeng, Shaoqun; Huang, Zhen-Li


    Characterizing the photoactivation performance of optical highlighter fluorescent proteins is crucial to the realization of photoactivation localization microscopy. In contrast to those fluorescence-based approaches that require complex data processing and calibration procedures, here we report a simple and quantitative alternative, which relies on the measurement of small absorption spectra changes over time with a fiber-optic system. Using Dronpa as a representative highlighter protein, we have investigated the capacity of this system in monitoring the fast photoactivation process.

  19. Optical two-beam traps in microfluidic systems

    DEFF Research Database (Denmark)

    Berg-Sørensen, Kirstine


    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast...... in a rapid prototyping manner, to hard polymers that could even be produced by injection moulding, or to silica in which waveguides may either be written directly, or with grooves for optical fibers. Here, we review different solutions to the system and also show results obtained in a polymer chip with DUV...

  20. An optical CDMA system based on chaotic sequences (United States)

    Liu, Xiao-lei; En, De; Wang, Li-guo


    In this paper, a coherent asynchronous optical code division multiple access (OCDMA) system is proposed, whose encoder/decoder is an all-optical generator. This all-optical generator can generate analog and bipolar chaotic sequences satisfying the logistic maps. The formula of bit error rate (BER) is derived, and the relationship of BER and the number of simultaneous transmissions is analyzed. Due to the good property of correlation, this coherent OCDMA system based on these bipolar chaotic sequences can support a large number of simultaneous users, which shows that these chaotic sequences are suitable for asynchronous OCDMA system.

  1. Transfer function characterization of grazing incidence optical systems. (United States)

    Harvey, J E; Moran, E C; Zmek, W P


    By using Fourier techniques and linear systems theory we have derived an analytic expression for a generalized transfer function for grazing incidence optical systems operating at ultraviolet and x-ray wavelengths that includes the effects of optical fabrication errors over the entire range of relevant spatial frequencies. The Fourier transform of this transfer function yields the image distribution (or point spread function) from which encircled energy characteristics or other image quality criteria can be obtained. This transfer function characterization of grazing incidence optical systems allows parametric trade studies and sensitivity analyses to be performed as well as the derivation of fabrication tolerances necessary to satisfy a given image quality requirement.

  2. Integrated Micro-Optical Fluorescence Detection System for Microfluidic Electrochromatography

    Energy Technology Data Exchange (ETDEWEB)



    The authors describe the design and microfabrication of an extremely compact optical system as a key element in an integrated capillary-channel electrochromatograph with laser induced fluorescence detection. The optical design uses substrate-mode propagation within the fused silica substrate. The optical system includes a vertical cavity surface-emitting laser (VCSEL) array, two high performance microlenses and a commercial photodetector. The microlenses are multilevel diffractive optics patterned by electron beam lithography and etched by reactive ion etching in fused silica. Two generations of optical subsystems are described. The first generation design is integrated directly onto the capillary channel-containing substrate with a 6 mm separation between the VCSEL and photodetector. The second generation design separates the optical system onto its own module and the source to detector length is further compressed to 3.5 mm. The systems are designed for indirect fluorescence detection using infrared dyes. The first generation design has been tested with a 750 nm VCSEL exciting a 10{sup -4} M solution of CY-7 dye. The observed signal-to-noise ratio of better than 100:1 demonstrates that the background signal from scattered pump light is low despite the compact size of the optical system and meets the system sensitivity requirements.

  3. Theoretical and experimental analysis of an optical driven servo system (United States)

    Lu, F.; Wang, X. J.; Huang, J. H.; Liu, Y. F.


    An optical driven servo system model based on single-type PLZT ceramic is proposed in this paper. The control equation of the proposed servo system is derived based on the mathematical model of PLZT with coupled multi-physics fields. The parameters of photodeformation of the PLZT actuator during both the illumination phase and light off phase are identified through the static experiment. Then displacement response of optical driven servo system is numerically simulated based on the control equation presented in this paper. After that, the closed-loop control experiment of optical driven servo system based on PLZT single-type ceramic with a simple on-off method is carried out. The experimental results show that the optical driven servo system with simple on-off method can achieve the target displacement by applying UV light to the PLZT actuator. Furthermore, an improved on-off control strategy is proposed to decrease the undesirable fluctuation around the target displacement.

  4. Current Trends of High capacity Optical Interconnection Data Link in High Performance Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed


    Full Text Available Optical technologies are ubiquitous in telecommunications networks and systems, providing multiple wavelength channels of transport at 2.5 Gbit/sec to 40 Gbit/sec data rates over single fiber optic cables. Market pressures continue to drive the number of wavelength channels per fiber and the data rate per channel. This trend will continue for many years to come as electronic commerce grows and enterprises demand higher and reliable bandwidth over long distances. Electronic commerce, in turn, is driving the growth curves for single processor and multiprocessor performance in data base transaction and Web based servers. Ironically, the insatiable taste for enterprise network bandwidth, which has driven up the volume and pushed down the price of optical components for telecommunications, is simultaneously stressing computer system bandwidth increasing the need for new interconnection schemes and providing for the first time commercial opportunities for optical components in computer systems. The evolution of integrated circuit technology is causing system designs to move towards communication based architectures. We have presented the current tends of high performance system capacity of optical interconnection data transmission link in high performance optical communication and computing systems over wide range of the affecting parameters.

  5. Achievable Precision for Optical Ranging Systems (United States)

    Moision, Bruce; Erkmen, Baris I.


    Achievable RMS errors in estimating the phase, frequency, and intensity of a direct-detected intensity-modulated optical pulse train are presented. For each parameter, the Cramer-Rao-Bound (CRB) is derived and the performance of the Maximum Likelihood estimator is illustrated. Approximations to the CRBs are provided, enabling an intuitive understanding of estimator behavior as a function of the signaling parameters. The results are compared to achievable RMS errors in estimating the same parameters from a sinusoidal waveform in additive white Gaussian noise. This establishes a framework for a performance comparison of radio frequency (RF) and optical science. Comparisons are made using parameters for state-of-the-art deep-space RF and optical links. Degradations to the achievable errors due to clock phase noise and detector jitter are illustrated.

  6. Mechanisms of stochastic focusing and defocusing in biological reaction networks: insight from accurate chemical master equation (ACME) solutions. (United States)

    Giirsoy, Gamze; Terebus, Anna; Cao, Youfang; Liang, Jie; Gursoy, Gamze; Terebus, Anna; Youfang Cao; Jie Liang; Gursoy, Gamze; Cao, Youfang; Terebus, Anna; Liang, Jie


    Stochasticity plays important roles in regulation of biochemical reaction networks when the copy numbers of molecular species are small. Studies based on Stochastic Simulation Algorithm (SSA) has shown that a basic reaction system can display stochastic focusing (SF) by increasing the sensitivity of the network as a result of the signal noise. Although SSA has been widely used to study stochastic networks, it is ineffective in examining rare events and this becomes a significant issue when the tails of probability distributions are relevant as is the case of SF. Here we use the ACME method to solve the exact solution of the discrete Chemical Master Equations and to study a network where SF was reported. We showed that the level of SF depends on the degree of the fluctuations of signal molecule. We discovered that signaling noise under certain conditions in the same reaction network can lead to a decrease in the system sensitivities, thus the network can experience stochastic defocusing. These results highlight the fundamental role of stochasticity in biological reaction networks and the need for exact computation of probability landscape of the molecules in the system.

  7. Optical fiber sensors measurement system and special fibers improvement (United States)

    Jelinek, Michal; Hrabina, Jan; Hola, Miroslava; Hucl, Vaclav; Cizek, Martin; Rerucha, Simon; Lazar, Josef; Mikel, Bretislav


    We present method for the improvement of the measurement accuracy in the optical frequency spectra measurements based on tunable optical filters. The optical filter was used during the design and realization of the measurement system for the inspection of the fiber Bragg gratings. The system incorporates a reference block for the compensation of environmental influences, an interferometric verification subsystem and a PC - based control software implemented in LabView. The preliminary experimental verification of the measurement principle and the measurement system functionality were carried out on a testing rig with a specially prepared concrete console in the UJV Řež. The presented system is the laboratory version of the special nuclear power plant containment shape deformation measurement system which was installed in the power plant Temelin during last year. On the base of this research we started with preparation other optical fiber sensors to nuclear power plants measurement. These sensors will be based on the microstructured and polarization maintaining optical fibers. We started with development of new methods and techniques of the splicing and shaping optical fibers. We are able to made optical tapers from ultra-short called adiabatic with length around 400 um up to long tapers with length up to 6 millimeters. We developed new techniques of splicing standard Single Mode (SM) and Multimode (MM) optical fibers and splicing of optical fibers with different diameters in the wavelength range from 532 to 1550 nm. Together with development these techniques we prepared other techniques to splicing and shaping special optical fibers like as Polarization-Maintaining (PM) or hollow core Photonic Crystal Fiber (PCF) and theirs cross splicing methods with focus to minimalize backreflection and attenuation. The splicing special optical fibers especially PCF fibers with standard telecommunication and other SM fibers can be done by our developed techniques. Adjustment

  8. Laboratory testing & measurement on optical imaging systems

    CSIR Research Space (South Africa)

    Theron, B


    Full Text Available  “Rectification” of Greek literature Reproduction of a page of Ibn Sahl's manuscript showing his discovery of the law of refraction”, now known as Snell's law. [5] Some History of Arabic Optics 2 See [4]  Arabic military interest in optics (Caliphs... science. Vol 2. Mathematics and the physical sciences, Routledge, 1996 [5] image used: “Reproduction of a page of Ibn Sahl's manuscript showing his discovery of the law of refraction”, now known as Snell's law.”, image from http...

  9. Optical response of correlated electron systems (United States)

    Maslov, Dmitrii L.; Chubukov, Andrey V.


    Recent progress in experimental techniques has made it possible to extract detailed information on dynamics of carriers in a correlated electron material from its optical conductivity, σ (Ω,T) . This review consists of three parts, addressing the following three aspects of optical response: (1) the role of momentum relaxation; (2) Ω /T scaling of the optical conductivity of a Fermi-liquid metal, and (3) the optical conductivity of non-Fermi-liquid metals. In the first part (section 2), we analyze the interplay between the contributions to the conductivity from normal and umklapp electron–electron scattering. As a concrete example, we consider a two-band metal and show that although its optical conductivity is finite it does not obey the Drude formula. In the second part (sections 3 and 4), we re-visit the Gurzhi formula for the optical scattering rate, 1/τ (Ω,T)\\propto {{ Ω }2}+4{π2}{{T}2} , and show that a factor of 4{π2} is the manifestation of the ‘first-Matsubara-frequency rule’ for boson response, which states that 1/τ (Ω,T) must vanish upon analytic continuation to the first boson Matsubara frequency. However, recent experiments show that the coefficient b in the Gurzhi-like form, 1/τ (Ω,T)\\propto {{ Ω }2}+b{π2}{{T}2} , differs significantly from b  =  4 in most of the cases. We suggest that the deviations from Gurzhi scaling may be due to the presence of elastic but energy-dependent scattering, which decreases the value of b below 4, with b  =  1 corresponding to purely elastic scattering. In the third part (section 5), we consider the optical conductivity of metals near quantum phase transitions to nematic and spin-density-wave states. In the last case, we focus on ‘composite’ scattering processes, which give rise to a non-Fermi-liquid behavior of the optical conductivity at T  =  0: {σ\\prime}(Ω )\\propto {{ Ω }-1/3} at low frequencies and {σ\\prime}(Ω )\\propto {{ Ω }-1} at higher frequencies. We

  10. All-optical sampling OFDM system performance analysis

    Institute of Scientific and Technical Information of China (English)

    Hang Ye; Hongwei Chen; Chao Tang; Minghua Chen; Shizhong Xie


    The performance of a novel all-optical sampling orthogonal frequency division multiplexing (OFDM) system is proposed and analyzed. Time delays and phase shifters are used to realize all optical forward/inverse discrete Fourier transform (DFT/IDFT). Different system configurations are tested and analyzed to optimize the performance, including the system capacity, modulation formats, DFT/IDFT constructions,and the width of the sample pulse. The 50- and 100-Gb/s real-time all-optical sampling (AOS) OFDM systems are investigated. All results are analyzed, and useful suggestions are offered for future high-speed applications.%@@ The performance of a novel all-optical sampling orthogonal frequency division multiplexing (OFDM) system is proposed and analyzed. Time delays and phase shifters are used to realize all optical forward/inverse discrete Fourier transform (DFT/IDFT). Different system configurations are tested and analyzed to optimize the performance, including the system capacity, modulation formats, DFT/IDFT constructions,and the width of the sample pulse. The 50-and 100-Gb/s real-time all-optical sampling (AOS) OFDM systems are investigated. All results are analyzed, and useful suggestions are offered for future high-speed applications.

  11. Wavelength Division Multiplexing Passive Optical Network modeling Using Optical System Simulator

    Directory of Open Access Journals (Sweden)

    Nahla Abdulrahman Hussain


    Full Text Available Due to the continuing demand for larger bandwidth, the optical transport becoming general in the access network. Using optical fiber technologies, the communications infrastructure becomes powerful, providing very high speeds to transfer a high capacity of data. Existing telecommunications infrastructures is currently widely used Passive Optical Network that apply Wavelength Division Multiplexing (WDM and is awaited to play an important role in the future Internet supporting a large diversity of services and next generation networks. This paper presents a design of WDM-PON network, the simulation and analysis of transmission parameters in the Optisystem 7.0 environment for bidirectional traffic. The simulation shows the behavior of optical fiber links when the signal passes through all the components such as optical fiber, splitters, multiplexers then find a good quality of signal in all receivers. The system performance is presented through various parameters such as BER analyzer and the Eye Diagram.

  12. Optical Imaging Sensors and Systems for Homeland Security Applications

    CERN Document Server

    Javidi, Bahram


    Optical and photonic systems and devices have significant potential for homeland security. Optical Imaging Sensors and Systems for Homeland Security Applications presents original and significant technical contributions from leaders of industry, government, and academia in the field of optical and photonic sensors, systems and devices for detection, identification, prevention, sensing, security, verification and anti-counterfeiting. The chapters have recent and technically significant results, ample illustrations, figures, and key references. This book is intended for engineers and scientists in the relevant fields, graduate students, industry managers, university professors, government managers, and policy makers. Advanced Sciences and Technologies for Security Applications focuses on research monographs in the areas of -Recognition and identification (including optical imaging, biometrics, authentication, verification, and smart surveillance systems) -Biological and chemical threat detection (including bios...

  13. Optimization of a particle optical system in a mutilprocessor environment

    CERN Document Server

    Wei Lei; Wang Bao Ping; Yin Han Chu


    In the design of a charged particle optical system, many geometrical and electric parameters have to be optimized to improve the performance characteristics. In every optimization cycle, the electromagnetic field and particle trajectories have to be calculated. Therefore, the optimization of a charged particle optical system is limited by the computer resources seriously. Apart from this, numerical errors of calculation may also influence the convergence of merit function. This article studies how to improve the optimization of charged particle optical systems. A new method is used to determine the gradient matrix. With this method, the accuracy of the Jacobian matrix can be improved. In this paper, the charged particle optical system is optimized with a Message Passing Interface (MPI). The electromagnetic field, particle trajectories and gradients of optimization variables are calculated on networks of workstations. Therefore, the speed of optimization has been increased largely. It is possible to design a c...

  14. Automated Mulitple Object Optical Tracking and Recognition System Project (United States)

    National Aeronautics and Space Administration — OPTRA proposes to develop an optical tracking system that is capable of recognizing and tracking up to 50 different objects within an approximately 2 degree x 3...

  15. FTTA System Demo Using Optical Fiber-Coupled Active Antennas

    Directory of Open Access Journals (Sweden)

    Niels Neumann


    Full Text Available The convergence of optical and wireless systems such as Radio-over-Fiber (RoF networks is the key to coping with the increasing bandwidth demands due to the increasing popularity of video and other high data rate applications. A high level of integration of optical technologies enables simple base stations with a fiber-to-the-antenna (FTTA approach. In this paper, we present a complete full-duplex RoF–FTTA system consisting of integrated active fiber-coupled optical receiving and transmitting antennas that are directly connected to a standard single mode fiber optical link. Data rates up to 1 Gbit/s could be shown without advanced modulation formats on a 1.5 GHz carrier frequency. The antennas as well as the whole system are explained and the results of the system experiments are discussed.

  16. Measurement of Supersonic Jet Noise with Optical Wave Microphone System

    Institute of Scientific and Technical Information of China (English)

    Masataka KOSAKA; Kunisato SETO; MD. Tawhidul Islam KHAN; Yoichi NAKAZONO


    An optical wave microphone system is a new technique of sound measurement. This technique has been developed as a new plasma diagnostic technique to measure electron density fluctuations in the nuclear fusion research. Because the sound wave is a pressure or a density fluctuation, it is possible for this technique to measure the sound wave, too. The acoustical characteristics of the optical wave microphone system were examined by using a speaker as a first step. Next, feasibility of this device to measure jet noise was examined. It was found that the optical wave microphone system could measure the jet noise as well as a sound from speaker.Hence the optical wave microphone system can be considered one of the devices equivalent to condenser microphone. Because of these reason, this device is very convenient to scan the acoustic filed through jet flow from the inside to the out side and more preferable for not disturbing the observation field.

  17. Optical Power Transfer System for Powering a Remote Mobility System for Multiple Missions (United States)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)


    An optical power transfer system for powering a remote mobility system for multiple missions comprising a high power source and a chilling station connected to a laser source. The laser source transmits a high optical energy to a beam switch assembly via an optical fiber. The beam switch assembly is optically connected to actively cooled fiber spoolers. Docking stations are adapted for securing the fiber spoolers until alternatively ready for use by a remote mobility system. The remote mobility system is optically connected to the fiber spoolers and has a receiving port adapted for securing the fiber spoolers thereon. The fiber spooler transmits the optical energy to a power conversion system which converts the optical energy received to another usable form of energy. More than one power source may be used where the remote mobility system transfers from one source to another while maintaining an operational radius to each source.

  18. Application of the geometrical theory of diffraction to Cassegrain subreflectors with laterally defocused feeds

    DEFF Research Database (Denmark)

    Sørensen, O.; Rusch, W.


    The geometrical theory of diffraction (GTD) as formulated by R. G. Kouyoumjian has been applied to predict the radiation characteristics of hyperboloidal subreflectors with laterally defocused feeds. In caustic or multicaustic directions the scattered fields are determined using an equivalent ring...... current placed along the edge of the subreflector. The theoretical results are compared to measured amplitude and phase data. In order to improve the agreement, the blocking effects of the feed horn have been accounted for using the geometrical theory of diffraction. The calculated subreflector fields...

  19. Mode-Locked Semiconductor Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Oxenløwe, Leif Katsuo


    We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized.......We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized....

  20. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice


    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  1. Measuring System of Magnetostriction Under AC Excitation Using Optical Methods


    Nakase, Tomoya; Nakano, Masanori; Fujiwara, F.; TAKAHASHI, N


    A measuring system for magnetostriction of silicon steel sheet using optical methods and a single sheet tester has been developed to establish a standard test method for IEC and JIS. Various factors affecting measurement accuracy and reproducibility of the developed system are examined. Two optical instruments, such as a laser Doppler vibrometer and a heterodyne displacement meter, are compared. 3-D characteristics of magnetostriction under ac excitation in the rolling direction are measured ...

  2. Intruder localization and identification in fiber optic systems (United States)

    Zyczkowski, M.


    The ultimate goal in all fiber optic systems is to extract information about the mechanical perturbations. For example, this information may be the frequency dependent index of perturbation. For security systems we desire to detect and differentiate between different intruders based on the mechanical response. This article shows experimental investigation of ideal intruder classifier. We considered demodulation, denoising, deconvolution and normalisation. We present additionally possible configuration of fiber optic sensor to localizing perturbation place.

  3. Adaptive optics at Lick Observatory: system architecture and operations (United States)

    Brase, James M.; An, Jong; Avicola, Kenneth; Bissinger, Horst D.; Friedman, Herbert W.; Gavel, Donald T.; Johnston, Brooks; Max, Claire E.; Olivier, Scot S.; Presta, Robert W.; Rapp, David A.; Salmon, J. Thaddeus; Waltjen, Kenneth E.; Fisher, William A.


    We will describe an adaptive optics system developed for the 1 meter Nickel and 3 meter Shane telescopes at Lick Observatory. Observing wavelengths will be in the visible for the 1 meter telescope and in the near IR on the 3 meter. The adaptive optics system design is based on a 69 actuator continuous surface deformable mirror and a Hartmann wavefront sensor equipped with an intensified CCD framing camera. The system has been tested at the Cassegrain focus of the 1 meter telescope where the subaperture size is 12.5 cm. The wavefront control calculations are performed on a four processor single board computer controlled by a Unix-based system. We will describe the optical system and give details of the wavefront control system design. We will present predictions of the system performance and initial test results.

  4. Optical free-space wavelength-division-multiplexing transport system. (United States)

    Lin, Chun-Yu; Lin, Ying-Pyng; Lu, Hai-Han; Chen, Chia-Yi; Jhang, Tai-Wei; Chen, Min-Chou


    An optical free-space wavelength-division-multiplexing (WDM) transport system employing vertical cavity surface emitting lasers and spatial light modulators with 16-quadrature amplitude modulation orthogonal frequency-division multiplexing modulating signals over a 17.5 m free-space link is proposed and demonstrated. With the help of a low-noise amplifier and data comparator, good bit error rate performance is obtained for each optical channel. Such an optical free-space WDM transport system would be attractive for providing services including data and telecommunication services.

  5. An optical transmission spectrum of the transiting hot Jupiter in the metal-poor WASP-98 planetary system (United States)

    Mancini, L.; Giordano, M.; Mollière, P.; Southworth, J.; Brahm, R.; Ciceri, S.; Henning, Th.


    The WASP-98 planetary system represents a rare case of a hot Jupiter hosted by a metal-poor main-sequence star. We present a follow-up study of this system based on multiband photometry and high-resolution spectroscopy. Two new transit events of WASP-98 b were simultaneously observed in four passbands (g', r', i', z'), using the telescope-defocusing technique, yielding eight high-precision light curves with point-to-point scatters of less than 1 mmag. We also collected three spectra of the parent star with a high-resolution spectrograph, which we used to remeasure its spectral characteristics, in particular its metallicity. We found this to be very low, [Fe/H] = -0.49 ± 0.10, but larger than was previously reported, [Fe/H] = -0.60 ± 0.19. We used these new photometric and spectroscopic data to refine the orbital and physical properties of this planetary system, finding that the stellar and planetary mass measurements are significantly larger than those in the discovery paper. In addition, the multiband light curves were used to construct an optical transmission spectrum of WASP-98 b and probe the characteristics of its atmosphere at the terminator. We measured a lower radius at z' compared with the other three passbands. The maximum variation is between the r' and z' bands, has a confidence level of roughly 6σ and equates to 5.5 pressure scale heights. We compared this spectrum to theoretical models, investigating several possible types of atmospheres, including hazy, cloudy, cloud-free, and clear atmospheres with titanium and vanadium oxide opacities. We could not find a good fit to the observations, except in the extreme case of a clear atmosphere with TiO and VO opacities, in which the condensation of Ti and V was suppressed. As this case is unrealistic, our results suggest the presence of an additional optical-absorbing species in the atmosphere of WASP-98 b, of unknown chemical nature.

  6. A new approach for the verification of optical systems (United States)

    Siddique, Umair; Aravantinos, Vincent; Tahar, Sofiène


    Optical systems are increasingly used in microsystems, telecommunication, aerospace and laser industry. Due to the complexity and sensitivity of optical systems, their verification poses many challenges to engineers. Tra­ditionally, the analysis of such systems has been carried out by paper-and-pencil based proofs and numerical computations. However, these techniques cannot provide perfectly accurate results due to the risk of human error and inherent approximations of numerical algorithms. In order to overcome these limitations, we propose to use theorem proving (i.e., a computer-based technique that allows to express mathematical expressions and reason about them by taking into account all the details of mathematical reasoning) as an alternative to computational and numerical approaches to improve optical system analysis in a comprehensive framework. In particular, this paper provides a higher-order logic (a language used to express mathematical theories) formalization of ray optics in the HOL Light theorem prover. Based on the multivariate analysis library of HOL Light, we formalize the notion of light ray and optical system (by defining medium interfaces, mirrors, lenses, etc.), i.e., we express these notions mathematically in the software. This allows us to derive general theorems about the behavior of light in such optical systems. In order to demonstrate the practical effectiveness, we present the stability analysis of a Fabry-Perot resonator.

  7. A Concept for Zero-Alignment Micro Optical Systems

    Energy Technology Data Exchange (ETDEWEB)



    We are developing a method of constructing compact, three-dimensional photonics systems consisting of optical elements, e.g., lenses and mirrors, photo-detectors, and light sources, e.g., VCSELS or circular-grating lasers. These optical components, both active and passive, are mounted on a lithographically prepared silicon substrate. We refer to the substrate as a micro-optical table (MOT) in analogy with the macroscopic version routinely used in optics laboratories. The MOT is a zero-alignment, microscopic optical-system concept. The position of each optical element relative to other optical elements on the MOT is determined in the layout of the MOT photomask. Each optical element fits into a slot etched in the silicon MOT. The slots are etched using a high-aspect-ratio silicon etching (HARSE) process. Additional positioning features in each slot's cross-section and complementary features on each optical element permit accurate placement of that element's aperture relative to the MOT substrate. In this paper we present the results of the first fabrication and micro-assembly experiments of a silicon-wafer based MOT. Based on these experiments, estimates of position accuracy are reported. We also report on progress in fabrication of lens elements in a hybrid sol-gel material (HSGM). Diffractive optical elements have been patterned in a 13-micron thick HSGM layer on a 150-micron thick soda-lime glass substrate. The measured ms surface roughness was 20 nm. Finally, we describe modeling of MOT systems using non-sequential ray tracing (NSRT).


    Institute of Scientific and Technical Information of China (English)


    Objective Focusing on the problem such as slow scanning speed, complex system design and low light efficiency, a new parallel confocal 3D profile detecting method based on optical fiber technology, which realizes whole-field confocal detecting, is proposed. Methods The optical fiber plate generates an 2D point light source array, which splits one light beam into N2 subbeams and act the role of pinholes as point source and point detecting to filter the stray light and reflect light. By introducing the construction and working principle of the multi-beam 3D detecting system, the feasibility is investigated. Results Experiment result indicates that the optical fiber technology is applicable in rotation. The measuring parameters that influence the detecting can easily be adapted to satisfy different requirments of measurement. Compared with the conventional confocal method, the parallel confocal detecting system using optical fiber plate is simple in the mechanism, the measuring field is larger and the speed is faster.

  9. A 10-Gbps optical WiMAX transport system. (United States)

    Lin, Ying-Pyng; Lu, Hai-Han; Wu, Po-Yi; Chen, Chia-Yi; Jhang, Tai-Wei; Ruan, Sheng-Siang; Wu, Kuan-Hung


    A 10-Gbps optical worldwide interoperability for microwave access (WiMAX) transport system employing vertical cavity surface emitting laser (VCSEL) and spatial light modulator (SLM) with 16-quadrature amplitude modulation (QAM)-orthogonal frequency-division multiplexing (OFDM) modulating signal is proposed. With the assistance of equalizer and low noise amplifier (LNA) at the receiving site, good bit error rate (BER) performance, clear constellation map, and clear eye diagram are achieved in the proposed systems. An optical WiMAX transport system, transmitting 16-QAM-OFDM signal over a 6-m free-space link, with a data rate of 10 Gbps is successfully demonstrated. Such a 10-Gbps optical WiMAX transport system would be attractive for providing services including Internet and telecommunication services. Our proposed system is suitable for the free-space lightwave transport system in visible light communication (VLC) application.

  10. A fiber-optical cable television system using a reflective semiconductor optical amplifier (United States)

    Peng, P. C.; Shiu, K. C.; Liu, W. C.; Chen, K. J.; Lu, H. H.


    This investigation demonstrates a fiber-optical cable television system using a reflective semiconductor optical amplifier (RSOA) for uplink transmission. The downstream signal is cable television and the upstream signal is generated by remodulating the downstream signal via an RSOA with a radio-frequency signal. Favorable carrier-to-noise ratio, composite second-order, and composite triple beat are obtained for the downstream and the upstream signal is successfully transmitted over 60 km of single-mode fiber.

  11. Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa


    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

  12. TV-acquired optical diagnostics systems on ATA

    Energy Technology Data Exchange (ETDEWEB)

    Kalibjian, R.; Chong, Y.P.; Cornish, J.P.; Jackson, C.H.; Fessenden, T.J.


    The purpose of this paper is to report on optical system developments on the ATA and their applications to ATA beam characterization. Television (TV)-acquired optical diagnostics data provide spatial and temporal properties of the ATA beam that complements recorded information from other types of sensors, such as, beam-wall current monitors, x-ray probes, and rf probes. The ATA beam operates: (1) in the normal mode at 50-MeV, 10-kA at a 1-Hz rate; and (2) in the 1-KHz burst mode (for 10-pulses) at a 0.5 Hz rate. The beam has a 70-ns pulse width in vacuum propagation; however, beam-head erosion will occur in atmospheric propagation, thus limiting the pulse width to less than 50-ns. Various optical systems are used for ATA diagnostics. Optical-imaging provides a convenient measurement in a single pulse of the 2-dimensional profile of the beam intensity. It can also provide multiple 2-D framing in a single pulse. In some studies it may be desirable to study optical events with temporal resolution less than 100-ps with 1-dimensional streak cameras. Spatially integrated data from phototube cameras can also be used for background measurement applications as well as for single pixel monitoring. The optical line-of-sight (LOS) configurations have been made versatile to accommodate a large number of options for the various optical systems.

  13. The control of an optical hyper-chaotic system

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Shumin [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Tian Lixin [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)]. E-mail:; Wang Xuedi [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)


    This paper discusses the problem of hyper-chaos control of an optical system. Based on Lyapunov stability theory, a non-autonomous feedback controller is designed. The proposed controller ensures that the hyper-chaotic system will be asymptotically stable. Numerical simulation of the original and the controlled system is provided to show the effectiveness of our method.

  14. Film-thickness Error Analysis of Optical Disk Systems

    Institute of Scientific and Technical Information of China (English)

    WANG Yang; GU Donghong; GAN Fuxi


    It is difficult to exactly control the film thickness of optical disk multilayer in the actual coating process. The thickness error becomes a main factor affecting the optical characters of the film system. The thickness error′s sensitivity factor of dielectric optical multilayer is derived from the optical matrix in this paper. The effect of the thickness error on the reflectivity or reflectivity contrast of the optical disk multilayer is analyzed with a numerical calculation. The sensitivities to thickness error for different layers or in different film-thickness ranges are compared and discussed. A sketchy method defining allowable thickness error is given. Some experimental results verify the applicability of our theoretical analysis.

  15. Research on the Design of an Optical Information Storage Sensing System Using a Diffractive Optical Element

    Directory of Open Access Journals (Sweden)

    Min Gu


    Full Text Available This paper introduces a compact optical information storage sensing system. Applications of this system include longitudinal surface plasmon resonance detection of gold nanorods with a single femtosecond laser in three-dimensional space as well as data storage. A diffractive optical element (DOE is applied in the system to separate the recording-reading beam from the servo beam. This allows us to apply a single laser and one objective lens in a single optical path for the servo beam and the recording-reading beam. The optical system has a linear region of 8 λ, which is compatible with current DVD servo modules. The wavefront error of the optical system is below 0.03 λrms. The minimum grating period of the DOE is 13.4 µm, and the depth of the DOE is 1.2 µm, which makes fabrication of it possible. The DOE is also designed to conveniently control the layer-selection process, as there is a linear correlation between the displacement of the DOE and the layer-selection distance. The displacement of DOE is in the range of 0–6.045 mm when the thickness of the layer-selection is 0.3 mm. Experiments were performed and the results have been verified.

  16. Research of optical rotation measurement system based on centroid algorithm (United States)

    Cao, Junjie; Jia, Hongzhi; Shen, Xinrong; Jiang, Shixin


    An optical rotation measurement system based on digital signal processor, modulated laser, and step motor rotating stage is established. Centroid algorithm featured fast and simple calculation is introduced to process light signals with or without sample to obtain the optical rotating angle through the step difference between two centroids. The system performance is proved experimentally with standard quartz tubes and glucose solutions. After various measurements, the relative error and precision of the system are determined to 0.4% and 0.004°, which demonstrates the reliable repeatability and high accuracy of whole measurement system.

  17. Online damage inspection of optics for ATP system (United States)

    Chen, Jing; Jiang, Yu; Mao, Yao; Gan, Xun; Liu, Qiong


    In the Electro-Optical acquisition-tracking-pointing system (ATP), the optical components will be damaged with the several influencing factors. In this situation, the rate will increase sharply when the arrival of damage to some extent. As the complex processing techniques and long processing cycle of optical components, the damage will cause the great increase of the system development cost and cycle. Therefore, it is significant to detect the laser-induced damage in the ATP system. At present, the major research on the on-line damage detection technology of optical components is for the large optical system in the international. The relevant detection systems have complicated structures and many of components, and require enough installation space reserved, which do not apply for ATP system. To solve the problem mentioned before, This paper use a method based on machine vision to detect the damage on-line for the present ATP system. To start with, CCD and PC are used for image acquisition. Secondly, smoothing filters are used to restrain false damage points produced by noise. Then, with the shape feature included in the damage image, the OTSU Method which can define the best segmentation threshold automatically is used to achieve the goal to locate the damage regions. At last, we can supply some opinions for the lifetime of the optical components by analyzing the damage data, such as damage area, damage position. The method has the characteristics of few-detectors and simple-structures which can be installed without any changes of the original light path. With the method, experimental results show that it is stable and effective to achieve the goal of detecting the damage of optical components on-line in the ATP system.

  18. Defocusing beam line design for an irradiation facility at the TAEA SANAEM Proton Accelerator Facility

    CERN Document Server

    Gencer, A.; Efthymiopoulos, I.; Yiğitoğlu, M.


    Electronic components must be tested to ensure reliable performance in high radiation environments such as Hi-Limu LHC and space. We propose a defocusing beam line to perform proton irradiation tests in Turkey. The Turkish Atomic Energy Authority SANAEM Proton Accelerator Facility was inaugurated in May 2012 for radioisotope production. The facility has also an R&D room for research purposes. The accelerator produces protons with 30 MeV kinetic energy and the beam current is variable between View the MathML source10μA and View the MathML source1.2mA. The beam kinetic energy is suitable for irradiation tests, however the beam current is high and therefore the flux must be lowered. We plan to build a defocusing beam line (DBL) in order to enlarge the beam size, reduce the flux to match the required specifications for the irradiation tests. Current design includes the beam transport and the final focusing magnets to blow up the beam. Scattering foils and a collimator is placed for the reduction of the beam ...

  19. Two-component vector solitons in defocusing Kerr-type media with spatially modulated nonlinearity

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Wei-Ping, E-mail: [Department of Electronic and Information Engineering, Shunde Polytechnic, Guangdong Province, Shunde 528300 (China); Texas A and M University at Qatar, P.O. Box 23874 Doha (Qatar); Belić, Milivoj [Texas A and M University at Qatar, P.O. Box 23874 Doha (Qatar); Institute of Physics, University of Belgrade, P.O. Box 57, 11001 Belgrade (Serbia)


    We present a class of exact solutions to the coupled (2+1)-dimensional nonlinear Schrödinger equation with spatially modulated nonlinearity and a special external potential, which describe the evolution of two-component vector solitons in defocusing Kerr-type media. We find a robust soliton solution, constructed with the help of Whittaker functions. For specific choices of the topological charge, the radial mode number and the modulation depth, the solitons may exist in various forms, such as the half-moon, necklace-ring, and sawtooth vortex-ring patterns. Our results show that the profile of such solitons can be effectively controlled by the topological charge, the radial mode number, and the modulation depth. - Highlights: • Two-component vector soliton clusters in defocusing Kerr-type media are reported. • These soliton clusters are constructed with the help of Whittaker functions. • The half-moon, necklace-ring and vortex-ring patterns are found. • The profile of these solitons can be effectively controlled by three soliton parameters.

  20. Defocused Shock Wave Therapy for Chronic Soft Tissue Wounds in the Lower Limbs: A Pilot Study. (United States)

    Porso, Manuela; Loreti, Simona; Nusca, Sveva Maria; Luziatelli, Sara; Caccia, Donatella; Taborri, Giulia; Trischitta, Donatella; Taurino, Maurizio; Padua, Luca; Saraceni, Vincenzo Maria; Vulpiani, Maria Chiara; Vetrano, Mario


    Chronic soft tissue wounds of the lower limbs are debilitating, painful and often unresponsive to advanced dressing treatments. Extracorporeal shock wave therapy (ESWT) could represent an alternative treatment. Ten patients with chronic soft tissue wounds of the legs, unresponsive to advanced dressing treatments for more than 3 mo, underwent three defocused ESWT sessions at 72-h intervals. In every session, the sum of 300 standard pulses + 100 pulses per square centimeter was applied at 0.15 mJ/mm(2) and 4 Hz over the edge of the wound. The wound size in square centimeters, Bates-Jensen Wound Assessment Tool and visual analogue scale were used as outcome measures. A significant reduction in wound size and Bates-Jensen Wound Assessment Tool and visual analogue scale values from pre-treatment to 90 d was observed. Seven of ten ulcers healed completely and nine of ten patients reported complete pain relief. Defocused ESWT represents a non-invasive, feasible strategy for difficult-to-treat soft tissue wounds of the lower limbs. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  1. Fiber-Optic Monitoring System of Particle Counters

    Directory of Open Access Journals (Sweden)

    A. A. Titov


    Full Text Available The article considers development of a fiber-optic system to monitor the counters of particles. Presently, optical counters of particles, which are often arranged at considerable distance from each other, are used to study the saltation phenomenon. For monitoring the counters, can be used electric communication lines.However, it complicates and raises the price of system Therefore, we offered a fiber-optic system and the counter of particles, free from these shortcomings. The difference between the offered counter of particles and the known one is that the input of radiation to the counter and the output of radiation scattering on particles are made by the optical fibers, and direct radiation is entered the optical fiber rather than is delayed by a light trap and can be used for lighting the other counters thereby allowing to use their connection in series.The work involved a choice of the quartz multimode optical fiber for communication, defining the optical fiber and lenses parameters of the counter of particles, and a selection of the radiation source and the photo-detector.Using the theory of light diffraction on a particle, a measuring range of the particle sizes has been determined. The system speed has been estimated, and it has been shown that a range of communication can reach 200km.It should be noted that modulation noise of counters of particles connected in series have the impact on the useful signal. To assess the extent of this influence we have developed a calculation procedure to illustrate that with ten counters connected in series this influence on the signal-to-noise ratio will be insignificant.Thus, it has been shown that the offered fiber-optic system can be used for monitoring the counters of particles across the desertified territories. 

  2. Testing methodologies and systems for semiconductor optical amplifiers (United States)

    Wieckowski, Michael

    Semiconductor optical amplifiers (SOA's) are gaining increased prominence in both optical communication systems and high-speed optical processing systems, due primarily to their unique nonlinear characteristics. This in turn, has raised questions regarding their lifetime performance reliability and has generated a demand for effective testing techniques. This is especially critical for industries utilizing SOA's as components for system-in-package products. It is important to note that very little research to date has been conducted in this area, even though production volume and market demand has continued to increase. In this thesis, the reliability of dilute-mode InP semiconductor optical amplifiers is studied experimentally and theoretically. The aging characteristics of the production level devices are demonstrated and the necessary techniques to accurately characterize them are presented. In addition, this work proposes a new methodology for characterizing the optical performance of these devices using measurements in the electrical domain. It is shown that optical performance degradation, specifically with respect to gain, can be directly qualified through measurements of electrical subthreshold differential resistance. This metric exhibits a linear proportionality to the defect concentration in the active region, and as such, can be used for prescreening devices before employing traditional optical testing methods. A complete theoretical analysis is developed in this work to explain this relationship based upon the device's current-voltage curve and its associated leakage and recombination currents. These results are then extended to realize new techniques for testing semiconductor optical amplifiers and other similarly structured devices. These techniques can be employed after fabrication and during packaged operation through the use of a proposed stand-alone testing system, or using a proposed integrated CMOS self-testing circuit. Both methods are capable

  3. Temporal changes of novel transcripts in the chicken retina following imposed defocus. (United States)

    Ohngemach, Sibylle; Buck, Christine; Simon, Perikles; Schaeffel, Frank; Feldkaemper, Marita


    Changes in retinal gene expression are one of the first steps in the signaling pathway underlying the visual control of eye growth. We tried to identify novel, yet unknown, genes, that alter their expression pattern following imposed defocus, wearing of diffusers, or during recovery from myopia. Sequences found earlier by differential display studies were applied to 5'-RACE and identified as 15 kDa selenoprotein P and prolidase. Moreover, we obtained more sequence information for a yet unidentified gene. We have studied the time course of expressions of these genes following lens or diffuser treatment. Ten to 14 day old white leghorn chickens (4-7) were treated with a monocular +7 D or -7 D lenses for 2, 4, 6, or 24 h, or treated with monocular or binocular diffusers for 2, 4, or 6 h. Chickens of another group were allowed to recover from 4 days of diffuser wear for 4 h. Untreated chicks served as a control for contralateral eye effects. Following the extraction of retinal RNA, the relative expression of the three genes was determined by semi-quantitative real time PCR. We found a significant up regulation of selenoprotein P expression after 24 h of treatment with positive (+380%) or negative lenses (+387%) which was even more prominent in the contralateral untreated eyes (positive: +542%; negative: +786%). A rapid change in selenoprotein mRNA levels was induced by binocular diffuser wear for 2 h (+425%), whereas defocus blur in one eye led to an increase only after 6 h (+261%). There was a significant upregulation of prolidase mRNA after 24 h of treatment with positive (+75%) but not with negative lenses. Moreover, blur induced by diffusers resulted in a highly significant rise of prolidase mRNA levels after 4 h, both with monocular (142%) and binocular (106%) treatment. This is similar to what was found in the previous differential display (DD) screening of monocularly treated eyes. In contrast to the findings of the DD screening, the mRNA expression of the

  4. Introduction to Optical Tweezers: Background, System Designs, and Commercial Solutions. (United States)

    van Mameren, Joost; Wuite, Gijs J L; Heller, Iddo


    Optical tweezers are a means to manipulate objects with light. With the technique, microscopically small objects can be held and steered, while forces on the trapped objects can be accurately measured and exerted. Optical tweezers can typically obtain a nanometer spatial resolution, a picoNewton force resolution, and a millisecond time resolution, which makes them excellently suited to study biological processes from the single-cell down to the single-molecule level. In this chapter, we will provide an introduction on the use of optical tweezers in single-molecule approaches. We will introduce the basic principles and methodology involved in optical trapping, force calibration, and force measurements. Next we describe the components of an optical tweezers setup and their experimental relevance in single-molecule approaches. Finally, we provide a concise overview of commercial optical tweezers systems. Commercial systems are becoming increasingly available and provide access to single-molecule optical tweezers experiments without the need for a thorough background in physics.

  5. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam Y


    Designed for a one-semester course on fiber-optics systems and communication links, this book provides a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers.

  6. A dual-modal retinal imaging system with adaptive optics. (United States)

    Meadway, Alexander; Girkin, Christopher A; Zhang, Yuhua


    An adaptive optics scanning laser ophthalmoscope (AO-SLO) is adapted to provide optical coherence tomography (OCT) imaging. The AO-SLO function is unchanged. The system uses the same light source, scanning optics, and adaptive optics in both imaging modes. The result is a dual-modal system that can acquire retinal images in both en face and cross-section planes at the single cell level. A new spectral shaping method is developed to reduce the large sidelobes in the coherence profile of the OCT imaging when a non-ideal source is used with a minimal introduction of noise. The technique uses a combination of two existing digital techniques. The thickness and position of the traditionally named inner segment/outer segment junction are measured from individual photoreceptors. In-vivo images of healthy and diseased human retinas are demonstrated.

  7. Nodal aberration theory for wild-filed asymmetric optical systems (United States)

    Chen, Yang; Cheng, Xuemin; Hao, Qun


    Nodal Aberration Theory (NAT) was used to calculate the zero field position in Full Field Display (FFD) for the given aberration term. Aiming at wide-filed non-rotational symmetric decentered optical systems, we have presented the nodal geography behavior of the family of third-order and fifth-order aberrations. Meanwhile, we have calculated the wavefront aberration expressions when one optical element in the system is tilted, which was not at the entrance pupil. By using a three-piece-cellphone lens example in optical design software CodeV, the nodal geography is testified under several situations; and the wavefront aberrations are calculated when the optical element is tilted. The properties of the nodal aberrations are analyzed by using Fringe Zernike coefficients, which are directly related with the wavefront aberration terms and usually obtained by real ray trace and wavefront surface fitting.

  8. An Optically Controlled 3D Cell Culturing System

    Directory of Open Access Journals (Sweden)

    Kelly S. Ishii


    Full Text Available A novel 3D cell culture system was developed and tested. The cell culture device consists of a microfluidic chamber on an optically absorbing substrate. Cells are suspended in a thermoresponsive hydrogel solution, and optical patterns are utilized to heat the solution, producing localized hydrogel formation around cells of interest. The hydrogel traps only the desired cells in place while also serving as a biocompatible scaffold for supporting the cultivation of cells in 3D. This is demonstrated with the trapping of MDCK II and HeLa cells. The light intensity from the optically induced hydrogel formation does not significantly affect cell viability.

  9. Magneto-optic detection system with noise cancellation (United States)

    Lewicki, G. W.; Guisinger, J. E. (Inventor)


    In a magneto-optic readout system, a polarized beam of light from a laser is subjected to the magneto-optical effect of a magnetic record medium, and then passed through an analyzer which resolves the beam into two orthogonal vector components so oriented that the two components are of equal amplitude when the angle of rotation due to the magneto-optic effect is zero. Separate photodetectors produce two output signals which are proportional to the amplitudes of the vector components. The two output signals are combined in a differential amplifier through separate logarithmic transfer circuits to produce an output signal proportional to the ratio of the two original detector signals.

  10. Magneto-optical system for high speed real time imaging (United States)

    Baziljevich, M.; Barness, D.; Sinvani, M.; Perel, E.; Shaulov, A.; Yeshurun, Y.


    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  11. GPU-based computational adaptive optics for volumetric optical coherence microscopy (United States)

    Tang, Han; Mulligan, Jeffrey A.; Untracht, Gavrielle R.; Zhang, Xihao; Adie, Steven G.


    Optical coherence tomography (OCT) is a non-invasive imaging technique that measures reflectance from within biological tissues. Current higher-NA optical coherence microscopy (OCM) technologies with near cellular resolution have limitations on volumetric imaging capabilities due to the trade-offs between resolution vs. depth-of-field and sensitivity to aberrations. Such trade-offs can be addressed using computational adaptive optics (CAO), which corrects aberration computationally for all depths based on the complex optical field measured by OCT. However, due to the large size of datasets plus the computational complexity of CAO and OCT algorithms, it is a challenge to achieve high-resolution 3D-OCM reconstructions at speeds suitable for clinical and research OCM imaging. In recent years, real-time OCT reconstruction incorporating both dispersion and defocus correction has been achieved through parallel computing on graphics processing units (GPUs). We add to these methods by implementing depth-dependent aberration correction for volumetric OCM using plane-by-plane phase deconvolution. Following both defocus and aberration correction, our reconstruction algorithm achieved depth-independent transverse resolution of 2.8 um, equal to the diffraction-limited focal plane resolution. We have translated the CAO algorithm to a CUDA code implementation and tested the speed of the software in real-time using two GPUs - NVIDIA Quadro K600 and Geforce TITAN Z. For a data volume containing 4096×256×256 voxels, our system's processing speed can keep up with the 60 kHz acquisition rate of the line-scan camera, and takes 1.09 seconds to simultaneously update the CAO correction for 3 en face planes at user-selectable depths.

  12. Optical response in a laser-driven quantum pseudodot system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, D. Gul [Physics Department, Graduate School of Natural and Applied Sciences, Dokuz Eylül University, 35390 Izmir (Turkey); Sakiroglu, S., E-mail: [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey); Ungan, F.; Yesilgul, U. [Department of Optical Engineering, Faculty of Technology, Cumhuriyet University, 58140 Sivas (Turkey); Kasapoglu, E. [Physics Department, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Sari, H. [Department of Primary Education, Faculty of Education, Cumhuriyet University, 58140 Sivas (Turkey); Sokmen, I. [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey)


    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  13. Automatic quadrature control and measuring system. [using optical coupling circuitry (United States)

    Hamlet, J. F. (Inventor)


    A quadrature component cancellation and measuring system comprising a detection system for detecting the quadrature component from a primary signal, including reference circuitry to define the phase of the quadrature component for detection is described. A Raysistor optical coupling control device connects an output from the detection system to a circuit driven by a signal based upon the primary signal. Combining circuitry connects the primary signal and the circuit controlled by the Raysistor device to subtract quadrature components. A known current through the optically sensitive element produces a signal defining the magnitude of the quadrature component.

  14. System for recording bivariate intensity distribution of optical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Vil' danov, R.R.; Deryugin, I.A.; Gladyshev, D.A.; Mirzaeu, A.T.


    This paper describes a system for recording the space-energy characteristics of optical radiation based on an MF-6 photodetector matrix and an AI-4096-3M multivariate pulse analyzer. The system can record optical images with from 2 to 64 quantization levels with visual monitoring of input data in the form of a space distribution in axonometric projection. The recording time for a complete image is from 11 to 700 msec. The system has been used to determine and monitor the crosssectional intensity distribution of laser beams as a function of radiation mode.

  15. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources. (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José


    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window.

  16. All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

    DEFF Research Database (Denmark)

    Prince, Kamau; Chiuchiarelli, A; Presi, M


    We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency.......We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency....

  17. Seamless Transmission between Single-Mode Optical Fibers Using Free Space Optics System (United States)

    Yoshida, Koichi; Tsujimura, Takeshi

    This paper presents a free space optics system installed between two single-mode optical fibers (SMFs). The result looks as if the two SMFs were seamlessly connected without the need for any photoelectric devices. Misalignments between the two SMFs caused by disturbances are actively compensated for by introducing a laser beam controller that incorporates an opto-mechatronic mechanism with four degrees of freedom. Experiments using a prototype are conducted to verify the effectiveness of the proposed FSO system for initial beam acquisition and beam tracking when there is a vibration disturbance.

  18. Space camera optical axis pointing precision measurement system (United States)

    Chen, Gang; Meng, Fanbo; Yang, Zijun; Guo, Yubo; Ye, Dong


    In order to realize the space camera which on satellite optical axis pointing precision measurement, a monocular vision measurement system based on object-image conjugate is established. In this system the algorithms such as object-image conjugate vision models and point by point calibration method are applied and have been verified. First, the space camera axis controller projects a laser beam to the standard screen for simulating the space camera's optical axis. The laser beam form a target point and has been captured by monocular vision camera. Then the two-dimensional coordinates of the target points on the screen are calculated by a new vision measurement model which based on a looking-up and matching table, the table has been generated by object-image conjugate algorithm through point by point calibration. Finally, compare the calculation of coordinates offered by measurement system with the theory of coordinate offered by optical axis controller, the optical axis pointing precision can be evaluated. Experimental results indicate that the absolute precision of measurement system up to 0.15mm in 2m×2m FOV. This measurement system overcome the nonlinear distortion near the edge of the FOV and can meet the requirement of space camera's optical axis high precision measurement and evaluation.

  19. Chick eyes compensate for chromatic simulations of hyperopic and myopic defocus: Evidence that the eye uses longitudinal chromatic aberration to guide eye-growth


    Rucker, Frances J.; Wallman, Josh


    Longitudinal chromatic aberration (LCA) causes short wavelengths to be focused in front of long wavelengths. This chromatic signal is evidently used to guide ocular accommodation. We asked whether chick eyes exposed to static gratings simulating the chromatic effects of myopic or hyperopic defocus would “compensate” for the simulated defocus.

  20. Visible-Light Tomography Using an Optical Imaging-System

    NARCIS (Netherlands)

    Ingesson, L. C.; Koning, J. J.; Donne, A. J. H.; D.C. Schram,


    A system for tomography in the wavelength range 200-1 100 nm has been designed for the Rijnhuizen Tokamak Project (RTP). The plasma is viewed from five directions in one poloidal plane with a total of 80 detectors. An optical imaging system consisting of two spherical mirrors for each viewing direct

  1. Kansas Communication and Instruction System through Fiber-Optic Transmission. (United States)

    Kansas State Dept. of Education, Topeka.

    Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

  2. Evaluations on aero-optic effects of subsonic airborne electro-optical system

    Institute of Scientific and Technical Information of China (English)

    Kexin Yin; Huilin Jiang


    @@ A simple method based on CFD code and Matlab for aero-optic effects is presented. Density fluctuation from CFD code due to the changes of such factors as altitude, speed, equipment location, and wavelength is introduced as an input to Matlab. The overall calculations are in Matlab. The results show that the performance of electro-optical (EO) system can be improved when the altitude increasing, the speed is as slowly as possible, and the equipment location moves to the leading edge of the airborne platform as far as possible, for the wavelength there is an optimum one when the indexes of contrast and resolution of the system are both considered. All of these methods can minimize the optical aberrations. Several numerical simulations demonstrate the method.

  3. Patterns in passive optical systems with boundary effects

    Institute of Scientific and Technical Information of China (English)

    李春萍; 沈柯


    Pattern formation is closely related to system boundary conditions in nonlinear dynamic systems, apart from the system control parameters. To avoid complexity, system boundary conditions are usually considered to be infinite or periodic, and the initial conditions spatially homogeneous. But it is not always the case in real situations, or sometimes periodic boundary conditions are not exact. To show the important and interesting boundary effects in real pattern formation, we suggest a simple universal boundary condition in a typical optical pattern formation system. Numerical simulations of the passive optical system show that pattern characteristics such as distribution symmetry, peak number,structure strength, evolution course and stability are all greatly influenced by the system boundary conditions.

  4. An optically remote powered subsea video monitoring system (United States)

    Lau, Fat Kit; Stewart, Brian; McStay, Danny


    The drive for Ocean pollution prevention requires a significant increase in the extent and type of monitoring of subsea hydrocarbon production equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such monitoring systems will all require to be powered. Conventionally electrical powering is supplied by standard subsea electrical cabling. The ability to visualise the assets being monitored and any changes or faults in the equipment is advantageous to an overall monitoring system. However the effective use of video cameras, particularly if the transmission of real time high resolution video is desired, requires a high data rate and low loss communication capability. This can be challenging for heavy and costly electrical cables over extended distances. For this reason optical fibre is often adopted as the communication channel. Using optical fibre cables for both communications and power delivery can also reduce the cost of cabling. In this paper we report a prototype optically remote powered subsea video monitoring system that provides an alternative approach to powering subsea video cameras. The source power is transmitted to the subsea module through optical fibre with an optical-to-electrical converter located in the module. To facilitate intelligent power management in the subsea module, a supercapacitor based intermediate energy storage is installed. Feasibility of the system will be demonstrated. This will include energy charging and camera operation times.

  5. Distributed optically integrated manufacture system based on CORBA (United States)

    Cen, Ming; Jiang, Jian-chun; Liu, Xing-fa; Hu, Rui-fei


    Focused on the shortcoming and insufficiency of reconfigurable manufacture system (RMS) for optical manufacturing in control layer and interface of manufacturing execution systems (MES) and control layer, the difference of MES-plan layer interface and that of MES-control layer is discussed, and an architecture of distributed optically integrated manufacture executing system based on fieldbus/Ethernet network and common object request broker architecture (CORBA) is presented. In this solution, the optical manufacture equipments are connected by fieldbus network, a gateway is used for the communication of fieldbus manufacture equipment and MES in the workshop, and CORBA services which provide a general interface for communication of heterogeneous fieldbus manufacture equipment of workshop are realized on the gateway. Then all specifics of heterogeneous fieldbus manufacture equipments are concealed, which show as virtual equipment and can be accessed in a simple and unified way. So the control layer is composed of virtual equipment and easy to be reconfigured. Similarly workshop management function components are modeled and encapsulated by CORBA interface, and MES could be integrated to RMS expediently. The optical integrated manufacture system presented is proved with good ability of flexible, reconfigurable, opening and high feasibility, and met the reconfigurable requirement of distributed optical manufacturing workshop preferably.

  6. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.


    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  7. Micro-opto-electro-mechanical (MOEM) adaptive optic system (United States)

    Clark, Rodney L.; Karpinisky, John R.; Hammer, Jay A.; Anderson, Roland B.; Lindsey, Randall L.; Brown, Daniel M.; Merritt, Paul H.


    This paper discusses the application of MOEM technology to adaptive optics. An experiment is described in which a micromachined mirror array is used in a closed loop adaptive optic demonstration. An interferometer wavefront sensor is used for wavefront sensing. Parallel analog electronics are used for the wavefront reconstruction. Parallel operational amplifiers are used to drive the micromirrors. The actuators utilize a novel silicon design developed by SY Technology, Inc. The actuators have a measured frequency response of 15kHz, and a maximum usable stroke of 4 microns. The entire adaptive optic demonstration has a bandwidth exceeding 10kHz. Measured performance is described. The experiments conducted are designed to explore the feasibility of creating a single chip adaptive optic system, also described in this paper. This chip would combine all on a single VLSI chip aspects of a complete adaptive optics system, wavefront sensing, wavefront reconstruction, and wavefront correction. The wavefront sensing would be accomplished with a novel compact shearing interferometer design. The analog refractive and diffractive micro optics will be fabricated using a new single step analog mask technology. The reconstruction circuit would use an analog resistive grid solver. The resistive grid would be fabricated in polysilicon. The drive circuits and micromirror actuators would use standard CMOS silicon fabrication methods.

  8. Electro-optical imaging system performance measurement

    NARCIS (Netherlands)

    Bijl, P.; Toet, A.; Valeton, J.M.


    The minimum resolvable temperature difference (MRTD), the minimum resolvable contrast (MRC), and the triangle orientation discrimination (TOD) are end-to-end EO system performance measures; that is, laboratory measures that characterize EO system performance with a human observer in the loop. Such s

  9. Computers and the design of ion beam optical systems (United States)

    White, Nicholas R.

    Advances in microcomputers have made it possible to maintain a library of advanced ion optical programs which can be used on inexpensive computer hardware, which are suitable for the design of a variety of ion beam systems including ion implanters, giving excellent results. This paper describes in outline the steps typically involved in designing a complete ion beam system for materials modification applications. Two computer programs are described which, although based largely on algorithms which have been in use for many years, make possible detailed beam optical calculations using microcomputers, specifically the IBM PC. OPTICIAN is an interactive first-order program for tracing beam envelopes through complex optical systems. SORCERY is a versatile program for solving Laplace's and Poisson's equations by finite difference methods using successive over-relaxation. Ion and electron trajectories can be traced through these potential fields, and plots of beam emittance obtained.

  10. Ground-based optical observation system for LEO objects (United States)

    Yanagisawa, T.; Kurosaki, H.; Oda, H.; Tagawa, M.


    We propose a ground-based optical observation system for monitoring LEO objects, which uses numerous optical sensors to cover a vast region of the sky. Its potential in terms of detection and orbital determination were examined. About 30 cm LEO objects at 1000 km altitude are detectable using an 18 cm telescope, a CCD camera and the analysis software developed. Simulations and a test observation showed that two longitudinally separate observation sites with arrays of optical sensors can identify the same objects from numerous data sets and determine their orbits precisely. The proposed system may complement or replace the current radar observation system for monitoring LEO objects, like space-situation awareness, in the near future.

  11. Note: Optical receiver system for 152-channel magnetoencephalography (United States)

    Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong


    An optical receiver system composing 13 serial data restore/synchronizer modules and a single module combiner converted optical 32-bit serial data into 32-bit synchronous parallel data for a computer to acquire 152-channel magnetoencephalography (MEG) signals. A serial data restore/synchronizer module identified 32-bit channel-voltage bits from 48-bit streaming serial data, and then consecutively reproduced 13 times of 32-bit serial data, acting in a synchronous clock. After selecting a single among 13 reproduced data in each module, a module combiner converted it into 32-bit parallel data, which were carried to 32-port digital input board in a computer. When the receiver system together with optical transmitters were applied to 152-channel superconducting quantum interference device sensors, this MEG system maintained a field noise level of 3 fT/√Hz @ 100 Hz at a sample rate of 1 kSample/s per channel.

  12. Note: Optical receiver system for 152-channel magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong [Center for Biosignals, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)


    An optical receiver system composing 13 serial data restore/synchronizer modules and a single module combiner converted optical 32-bit serial data into 32-bit synchronous parallel data for a computer to acquire 152-channel magnetoencephalography (MEG) signals. A serial data restore/synchronizer module identified 32-bit channel-voltage bits from 48-bit streaming serial data, and then consecutively reproduced 13 times of 32-bit serial data, acting in a synchronous clock. After selecting a single among 13 reproduced data in each module, a module combiner converted it into 32-bit parallel data, which were carried to 32-port digital input board in a computer. When the receiver system together with optical transmitters were applied to 152-channel superconducting quantum interference device sensors, this MEG system maintained a field noise level of 3 fT/√Hz @ 100 Hz at a sample rate of 1 kSample/s per channel.

  13. System and Method for Multi-Wavelength Optical Signal Detection (United States)

    McGlone, Thomas D. (Inventor)


    The system and method for multi-wavelength optical signal detection enables the detection of optical signal levels significantly below those processed at the discrete circuit level by the use of mixed-signal processing methods implemented with integrated circuit technologies. The present invention is configured to detect and process small signals, which enables the reduction of the optical power required to stimulate detection networks, and lowers the required laser power to make specific measurements. The present invention provides an adaptation of active pixel networks combined with mixed-signal processing methods to provide an integer representation of the received signal as an output. The present invention also provides multi-wavelength laser detection circuits for use in various systems, such as a differential absorption light detection and ranging system.

  14. Design of optical systems for large space telescopes (United States)

    Malamed, Evgeny R.; Sokolsky, M. N.


    On the basis of long-term experience of LOMO PLC in creating large optical systems for ground and space telescopes, with diameter of primary mirror from 1 to 6 meters, the following issues should be considered: principles of constructing optical systems for space telescopes and selecting their optimum design in respect of dimensions/mass and performance criteria; ensuring the fulfillment of image quality requirements in the process of manufacturing optical systems for controlling ground telescope elements in operating conditions; providing automatic adjustment of telescope secondary mirror, automatic focusing, interferometric control of image quality by means of stellar interferometer with radial shift and internal control with Gartman's test. Description of space telescope equipped with primary mirror of diameter 1.5 m, manufactured in LOMO PLC, is given.

  15. Optical mapping system for visualizing arrhythmias in isolated mouse atria. (United States)

    Schmidt, Robyn; Nygren, Anders


    Optical mapping has become an important technique in the study of cardiac electrophysiology, especially in terms of investigating the mechanisms of cardiac arrhythmias. The increasing availability of transgenic mice as models for cardiovascular disease is driving the need for instrumentation suitable for the study of electrical activity in the mouse heart. In this paper we evaluate our optical mapping system's ability to clearly record induced arrhythmic activity in an isolated mouse atrial preparation. Preliminary results indicate that the signal quality is high enough that individual optically recorded action potentials can be discerned in many pixels, even without post-processing for noise removal. The optical mapping video is clear enough for general observations regarding the patterns of electrical propagation during arrhythmic behaviour. The induced arrhythmias appear to have a regular pattern of activity, and are likely best classified as atrial tachycardias.

  16. Optical diagnostics based on elastic scattering: An update of clinical demonstrations with the Optical Biopsy System

    Energy Technology Data Exchange (ETDEWEB)

    Bigio, I.J.; Boyer, J.; Johnson, T.M.; Lacey, J.; Mourant, J.R. [Los Alamos National Lab., NM (United States); Conn, R. [Lovelace Medical Center, Albuquerque, NM (United States); Bohorfoush, A. [Wisconsin Medical School, Milwaukee, WI (United States)


    The Los Alamos National Laboratory has continued the development of the Optical Biopsy System (OBS) for noninvasive, real-time in situ diagnosis of tissue pathologies. Our clinical studies have expanded since the last Biomedical Optics Europe conference (Budapest, September 1993), and we report here on the latest results of clinical tests in gastrointestinal tract. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the tissue. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, manifest significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes in an optical signature that is derived from the wavelength-dependence of elastic scattering. The OBS employs a small fiberoptic probe that is amenable to use with any endoscope or catheter, or to direct surface examination. The probe is designed to be used in optical contact with the tissue under examination and has separate illuminating and collecting fibers. Thus, the light that is collected and transmitted to the analyzing spectrometer must first scatter through a small volume of the tissue before entering the collection fiber(s). Consequently, the system is also sensitive to the optical absorption spectrum of the tissue, over an effective operating range of <300 to 950 nm, and such absorption adds valuable complexity to the scattering spectral signature.

  17. Optical design of digital control systems

    CERN Document Server

    Tou, Julius T


    In this book, we study theoretical and practical aspects of computing methods for mathematical modelling of nonlinear systems. A number of computing techniques are considered, such as methods of operator approximation with any given accuracy; operator interpolation techniques including a non-Lagrange interpolation; methods of system representation subject to constraints associated with concepts of causality, memory and stationarity; methods of system representation with an accuracy that is the best within a given class of models; methods of covariance matrix estimation;methods for low-rank mat

  18. Rapid Process to Generate Beam Envelopes for Optical System Analysis (United States)

    Howard, Joseph; Seals, Lenward


    The task of evaluating obstructions in the optical throughput of an optical system requires the use of two disciplines, and hence, two models: optical models for the details of optical propagation, and mechanical models for determining the actual structure that exists in the optical system. Previous analysis methods for creating beam envelopes (or cones of light) for use in this obstruction analysis were found to be cumbersome to calculate and take significant time and resources to complete. A new process was developed that takes less time to complete beam envelope analysis, is more accurate and less dependent upon manual node tracking to create the beam envelopes, and eases the burden on the mechanical CAD (computer-aided design) designers to form the beam solids. This algorithm allows rapid generation of beam envelopes for optical system obstruction analysis. Ray trace information is taken from optical design software and used to generate CAD objects that represent the boundary of the beam envelopes for detailed analysis in mechanical CAD software. Matlab is used to call ray trace data from the optical model for all fields and entrance pupil points of interest. These are chosen to be the edge of each space, so that these rays produce the bounding volume for the beam. The x and y global coordinate data is collected on the surface planes of interest, typically an image of the field and entrance pupil internal of the optical system. This x and y coordinate data is then evaluated using a convex hull algorithm, which removes any internal points, which are unnecessary to produce the bounding volume of interest. At this point, tolerances can be applied to expand the size of either the field or aperture, depending on the allocations. Once this minimum set of coordinates on the pupil and field is obtained, a new set of rays is generated between the field plane and aperture plane (or vice-versa). These rays are then evaluated at planes between the aperture and field, at a

  19. Submarine Optical Fiber Cable Systems for High Speed Growth Developments in Optical Communication Networks

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed


    Full Text Available Optical Submarine Cable systems play a principal role in international telecommunications, thanks to their superiority over satellite systems in terms of stability, latency and upgradability. The business of constructing and then maintaining and selling capacity over submarine fiber optic cables is fascinating, and is absolutely fundamental to modern day communications. The sector has its own unique challenges due to the extraordinarily rapid pace of development in transmission technologies as well as the timescales and levels of investment required to build new systems. In the present paper, ultimate optical transmission of ultra multi channels huge submarine cables under different depth conditions has been investigated over wide range of the affecting parameters. The double impact of both temperature and pressure is also analyzed. We have employed multiplexing technique namely UW-WDM to be merged number of 10000 transmitted channels on the same submarine optical transmission links respectively. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. The product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. As well as we have taken into account the estimation of the total cost planning and transmission data rate capacity of the submarine fiber cable system for this multiplexing technique under study.

  20. Camera, handlens, and microscope optical system for imaging and coupled optical spectroscopy (United States)

    Mungas, Greg S. (Inventor); Boynton, John (Inventor); Sepulveda, Cesar A. (Inventor); Nunes de Sepulveda, legal representative, Alicia (Inventor); Gursel, Yekta (Inventor)


    An optical system comprising two lens cells, each lens cell comprising multiple lens elements, to provide imaging over a very wide image distance and within a wide range of magnification by changing the distance between the two lens cells. An embodiment also provides scannable laser spectroscopic measurements within the field-of-view of the instrument.

  1. The optical system for the Big European Bubble Chamber

    CERN Document Server

    Harigel, G G


    The optical system for the new giant bubble chamber, built for the European Organization for Nuclear Research (CERN), consists of four sets of fisheye windows, each equipped with a wide-angle lens which has an aperture angle of 108 degrees , while the fifth set has a periscope for visual observation of the chamber interior. Each of the fisheye sets is assembled from three hemispherical windows. The largest hemisphere is made from Schott BK7 glass and is exposed to the temperature of liquid hydrogen. The entire optical system has been operated successfully for the past 4 years. (13 refs).

  2. Weakly Nonlinear Geometric Optics for Hyperbolic Systems of Conservation Laws

    CERN Document Server

    Chen, Gui-Qiang; Zhang, Yongqian


    We establish an $L^1$-estimate to validate the weakly nonlinear geometric optics for entropy solutions of nonlinear hyperbolic systems of conservation laws with arbitrary initial data of small bounded variation. This implies that the simpler geometric optics expansion function can be employed to study the properties of general entropy solutions to hyperbolic systems of conservation laws. Our analysis involves new techniques which rely on the structure of the approximate equations, besides the properties of the wave-front tracking algorithm and the standard semigroup estimates.

  3. Design of high-capacity fiber-optic transport systems (United States)

    Liao, Zhi Ming


    We study the design of fiber-optic transport systems and the behavior of fiber amplifiers/lasers with the aim of achieving higher capacities with larger amplifier spacing. Solitons are natural candidates for transmitting short pulses for high-capacity fiber-optic networks because of its innate ability to use two of fiber's main defects, fiber dispersion and fiber nonlinearity to balance each other. In order for solitons to retain its dynamic nature, amplifiers must be placed periodically to restore powers to compensate for fiber loss. Variational analysis is used to study the long-term stability of a periodical- amplifier system. A new regime of operation is identified which allows the use of a much longer amplifier spacing. If optical fibers are the blood vessels of an optical communication system, then the optical amplifier based on erbium-doped fiber is the heart. Optical communication systems can avoid the use of costly electrical regenerators to maintain system performance by being able to optically amplify the weakened signals. The length of amplifier spacing is largely determined by the gain excursion experienced by the solitons. We propose, model, and demonstrate a distributed erbium-doped fiber amplifier which can drastically reduce the amount of gain excursion experienced by the solitons, therefore allowing a much longer amplifier spacing and superior stability. Dispersion management techniques have become extremely valuable tools in the design of fiber-optic communication systems. We have studied in depth the advantage of different arnplification schemes (lumped and distributed) for various dispersion compensation techniques. We measure the system performance through the Q factor to evaluate the added advantage of effective noise figure and smaller gain excursion. An erbium-doped fiber laser has been constructed and characterized in an effort to develop a test bed to study transmission systems. The presence of mode-partition noise in an erbium

  4. Spatial and temporal pulse propagation for dispersive paraxial optical systems. (United States)

    Marcus, G


    The formalism for pulse propagation through dispersive paraxial optical systems first presented by Kostenbauder (IEEE J. Quant. Elec.261148-1157 (1990)) using 4 × 4 ray-pulse matrices is extended to 6 × 6 matrices and includes non-separable spatial-temporal couplings in both transverse dimensions as well as temporal dispersive effects up to a quadratic phase. The eikonal in a modified Huygens integral in the Fresnell approximation is derived and can be used to propagate pulses through complicated dispersive optical systems within the paraxial approximation. In addition, a simple formula for the propagation of ultrashort pulses having a Gaussian profile both spatially and temporally is presented.

  5. Fibre Optical Radiation Sensing System for TESLA

    CERN Document Server

    Körfer, M


    High energy accelerators generate ionising radiation along the beam-line and at target places. This radiation is related to beam losses or dark currents. The in-situ measurement of this ionising dose that is distributed over long distances or large areas requires a new monitor system. This paper presents first results and the concept of such a monitor system at the Tesla Test Facility.

  6. Electronic system for optical shutter control (United States)

    Viljoen, H. C.; Gaylord, T. K.


    The paper describes a precise and versatile electronic system for shutter control in light beam experiments. Digital and analog circuitry is used to provide automatic timing, exposure control, manual operation, and remote programmability. A block diagram of the system is presented and the individual circuits - the timer control circuit, the clock control circuit, the comparator circuit, the exposure (integrator) circuit, and the shutter drive circuit are discussed in detail and diagrams are provided.

  7. Digital reconstruction of optically-induced potentials. (United States)

    Barsi, Christopher; Fleischer, Jason W


    The holographic reconstruction of optically-induced objects typically assumes that the object is axially thin. Here, we demonstrate a simple approach that works for axially thick objects which evolve dynamically. Results are verified by reconstructing linear scattering experiments in a self-defocusing photorefractive crystal.

  8. ATHENA: system studies and optics accommodation (United States)

    Ayre, M.; Bavdaz, M.; Ferreira, I.; Wille, E.; Fransen, S.; Stefanescu, A.; Linder, M.


    ATHENA is currently in Phase A, with a view to adoption upon a successful Mission Adoption Review in 2019/2020. After a brief presentation of the reference spacecraft (SC) design, this paper will focus on the functional and environmental requirements, the thermo-mechanical design and the Assembly, Integration, Verification & Test (AIVT) considerations related to housing the Silicon Pore Optics (SPO) Mirror Modules (MM) in the very large Mirror Assembly Module (MAM). Initially functional requirements on the MM accommodation are presented, with the Effective Area and Half Energy Width (HEW) requirements leading to a MAM comprising (depending on final mirror size selected) between 700-1000 MMs, co-aligned with exquisite accuracy to provide a common focus. A preliminary HEW budget allocated across the main error-contributors is presented, and this is then used as a reference to derive subsequent requirements and engineering considerations, including: The procedures and technologies for MM-integration into the Mirror Structure (MS) to achieve the required alignment accuracies in a timely manner; stiffness requirements and handling scheme required to constrain deformation under gravity during x-ray testing; temperature control to constrain thermo-elastic deformation during flight; and the role of the Instrument Switching Mechanism (ISM) in constraining HEW and Effective Area errors. Next, we present the key environmental requirements of the MMs, and the need to minimise shock-loading of the MMs is stressed. Methods to achieve this Ø are presented, including: Selection of a large clamp-band launch vehicle interface (LV I/F); lengthening of the shock-path from the LV I/F to the MAM I/F; modal-tuning of the MAM to act as a low-pass filter during launch shock events; use of low-shock HDRMs for the MAM; and the possibility to deploy a passive vibration solution at the LV I/F to reduce loads.

  9. Simplifying numerical ray tracing for characterization of optical systems. (United States)

    Gagnon, Yakir Luc; Speiser, Daniel I; Johnsen, Sönke


    Ray tracing, a computational method for tracing the trajectories of rays of light through matter, is often used to characterize mechanical or biological visual systems with aberrations that are larger than the effect of diffraction inherent in the system. For example, ray tracing may be used to calculate geometric point spread functions (PSFs), which describe the image of a point source after it passes through an optical system. Calculating a geometric PSF is useful because it gives an estimate of the detail and quality of the image formed by a given optical system. However, when using ray tracing to calculate a PSF, the accuracy of the estimated PSF directly depends on the number of discrete rays used in the calculation; higher accuracies may require more computational power. Furthermore, adding optical components to a modeled system will increase its complexity and require critical modifications so that the model will describe the system correctly, sometimes necessitating a completely new model. Here, we address these challenges by developing a method that represents rays of light as a continuous function that depends on the light's initial direction. By utilizing Chebyshev approximations (via the chebfun toolbox in MATLAB) for the implementation of this method, we greatly simplified the calculations for the location and direction of the rays. This method provides high precision and fast calculation speeds that allow the characterization of any symmetrical optical system (with a centered point source) in an analytical-like manner. Next, we demonstrate our methods by showing how they can easily calculate PSFs for complicated optical systems that contain multiple refractive and/or reflective interfaces.

  10. Shape reconstruction and height fluctuations of red blood cells using defocusing microscopy

    CERN Document Server

    Siman, L; Amaral, F T; Agero, U; Mesquita, O N


    In this paper the bright-field defocusing microscopy (DM) technique is presented. DM is able to obtain quantitative information of each plane/surface of pure phase objects, as live unlabeled cells, and its application to red blood cells (RBCs) is demonstrated. Based on contrast, simple methods to obtain thickness profile and three dimensional (3D) total reconstruction of RBCs are proposed and the actual height profiles of upper and lower surface-membranes (lipid bilayer$/$cytoskeleton) of discocyte and stomatocyte red cells are presented as examples. In addition, using the mean square contrast fluctuation and modeling the RBC membranes fluctuations spectra as dependent of a bending modulus $(\\kappa_c)$, a surface tension $(\\sigma)$ and a confining potential $(\\gamma)$ term, slowly varying quantities along the cell radius, a genetic algorithm (GA) is used and the radial height fluctuations of each surface-membrane are accessed, separately. The radial behaviors of $\\kappa_c$, $\\sigma$ and $\\gamma$ are also obta...

  11. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal

    DEFF Research Database (Denmark)

    Zhou, Binbin; Bache, Morten


    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited...... in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phasematching wavelengths due to degenerate four-wave mixing to the soliton. We also...... observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations....

  12. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal. (United States)

    Zhou, Binbin; Bache, Morten


    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phase-matching wavelengths due to degenerate four-wave mixing to the soliton. We also observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations.

  13. White-Light Nonlinear Photonic Lattices in Self-Defocusing Media

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan-Mei; LIU Si-Min


    Using fully incoherent white light emitted from an incandescent lamp and amplitude mask, we experimentally investigate the influence of several factors on the fabrication of the lattice in photovoltaic self-defocusing LiNbO3:Fe crystal, the factors include the orientation of the crystalline c axis relative to the principal axis of the photonic lattice and the filament, the diameter of input dark spot and the separation of the adjacent input dark spots. Experimental results reveal that the best fabricating condition of photonic lattices is that the principal axis of lattice is tilted for 45° relative to the crystalline c axis which is parallel to the filament of the lamp. In addition, it is necessary that the diameter of the input dark spot is larger than the half of their separation.

  14. Analog signal processing for optical coherence imaging systems (United States)

    Xu, Wei

    Optical coherence tomography (OCT) and optical coherence microscopy (OCM) are non-invasive optical coherence imaging techniques, which enable micron-scale resolution, depth resolved imaging capability. Both OCT and OCM are based on Michelson interferometer theory. They are widely used in ophthalmology, gastroenterology and dermatology, because of their high resolution, safety and low cost. OCT creates cross sectional images whereas OCM obtains en face images. In this dissertation, the design and development of three increasingly complicated analog signal processing (ASP) solutions for optical coherence imaging are presented. The first ASP solution was implemented for a time domain OCT system with a Rapid Scanning Optical Delay line (RSOD)-based optical signal modulation and logarithmic amplifier (Log amp) based demodulation. This OCT system can acquire up to 1600 A-scans per second. The measured dynamic range is 106dB at 200A-scan per second. This OCT signal processing electronics includes an off-the-shelf filter box with a Log amp circuit implemented on a PCB board. The second ASP solution was developed for an OCM system with synchronized modulation and demodulation and compensation for interferometer phase drift. This OCM acquired micron-scale resolution, high dynamic range images at acquisition speeds up to 45,000 pixels/second. This OCM ASP solution is fully custom designed on a perforated circuit board. The third ASP solution was implemented on a single 2.2 mm x 2.2 mm complementary metal oxide semiconductor (CMOS) chip. This design is expandable to a multiple channel OCT system. A single on-chip CMOS photodetector and ASP channel was used for coherent demodulation in a time domain OCT system. Cross-sectional images were acquired with a dynamic range of 76dB (limited by photodetector responsivity). When incorporated with a bump-bonded InGaAs photodiode with higher responsivity, the expected dynamic range is close to 100dB.

  15. Self-characterization of linear and nonlinear adaptive optics systems (United States)

    Hampton, Peter J.; Conan, Rodolphe; Keskin, Onur; Bradley, Colin; Agathoklis, Pan


    We present methods used to determine the linear or nonlinear static response and the linear dynamic response of an adaptive optics (AO) system. This AO system consists of a nonlinear microelectromechanical systems deformable mirror (DM), a linear tip-tilt mirror (TTM), a control computer, and a Shack-Hartmann wavefront sensor. The system is modeled using a single-input-single-output structure to determine the one-dimensional transfer function of the dynamic response of the chain of system hardware. An AO system has been shown to be able to characterize its own response without additional instrumentation. Experimentally determined models are given for a TTM and a DM.

  16. Alignment method of off-axis RC reflective optical system (United States)

    Xue-min, Zhang; Xing, Song; Zhi-jun, Zhang; Hou, Xiao-hua


    Off-axis optical system has a wide application in space optics and remote detective area. The high surface shape accuracy can be ensured with the development of advanced manufacture technique. So the only condition which limits the wide application of off-axis optical system is how to realize the precise alignment of it. Based on a RC reflective optical system whose diameter is 400mm, the alignment method which combines the high resolution initial placement and computer-aided alignment is introduced. By designing a system which can measure the off-axis fabrication and off-axis angle precisely, the high resolution initial placement of off-axis mirror can be ensured with a measurement accuracy of +/-0.05mm and +/-10". The good initial placement can give a good initial state, so the computer-aided model can be converged well. The experiment shows that a system which has a good initial placement could have a good wave aberration of 0.04λ after three times iteration adjustment.

  17. Transparent thin film polarizing and optical control systems

    Directory of Open Access Journals (Sweden)

    Nelson V. Tabiryan


    Full Text Available We show that a diffractive waveplate can be combined with a phase retardation film for fully converting light of arbitrary polarization state into a polarized light. Incorporating a photonic bandgap layer into a system of such polarizers that unify different polarization states in the input light into a single polarization state at its output, rather than absorbing or reflecting half of it, we developed and demonstrated a polarization-independent optical controller capable of switching between transmittive and reflective states. The transition between those states is smoothly controlled with low-voltage and low-power sources. Using versatile fabrication methods, this “universally polarizing optical controller” can be integrated into a thin package compatible with a variety of display, spatial light modulation, optical communication, imaging and other photonics systems.

  18. Anisoplanatism in adaptive optics systems due to pupil aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, B


    Adaptive optics systems typically include an optical relay that simultaneously images the science field to be corrected and also a set of pupil planes conjugate to the deformable mirror of the system. Often, in the optical spaces where DM's are placed, the pupils are aberrated, leading to a displacement and/or distortion of the pupil that varies according to field position--producing a type of anisoplanatism, i.e., a degradation of the AO correction with field angle. The pupil aberration phenomenon is described and expressed in terms of Seidel aberrations. An expression for anisoplanatism as a function of pupil distortion is derived, an example of an off-axis parabola is given, and a convenient method for controlling pupil-aberration-generated anisoplanatism is proposed.

  19. Optical character recognition systems for different languages with soft computing

    CERN Document Server

    Chaudhuri, Arindam; Badelia, Pratixa; K Ghosh, Soumya


    The book offers a comprehensive survey of soft-computing models for optical character recognition systems. The various techniques, including fuzzy and rough sets, artificial neural networks and genetic algorithms, are tested using real texts written in different languages, such as English, French, German, Latin, Hindi and Gujrati, which have been extracted by publicly available datasets. The simulation studies, which are reported in details here, show that soft-computing based modeling of OCR systems performs consistently better than traditional models. Mainly intended as state-of-the-art survey for postgraduates and researchers in pattern recognition, optical character recognition and soft computing, this book will be useful for professionals in computer vision and image processing alike, dealing with different issues related to optical character recognition.

  20. Characterization of optical systems for the ALPS II experiment (United States)

    Spector, Aaron D.; Põld, Jan H.; Bähre, Robin; Lindner, Axel; Willke, Benno


    ALPS II is a light shining through a wall style experiment that will use the principle of resonant enhancement to boost the conversion and reconversion probabilities of photons to relativistic WISPs. This will require the use of long baseline low-loss optical cavities. Very high power build up factors in the cavities must be achieved in order to reach the design sensitivity of ALPS II. This necessitates a number of different sophisticated optical and control systems to maintain the resonance and ensure maximal coupling between the laser and the cavity. In this paper we report on the results of the characterization of these optical systems with a 20 m cavity and discuss the results in the context of ALPS II.

  1. Complex geometric optics for symmetric hyperbolic systems I: linear theory

    CERN Document Server

    Maj, Omar


    We obtain an asymptotic solution for $\\ep \\to 0$ of the Cauchy problem for linear first-order symmetric hyperbolic systems with oscillatory initial values written in the eikonal form of geometric optics with frequency $1/\\ep$, but with complex phases. For the most common linear wave propagation models, this kind on Cauchy problems are well-known in the applied literature and their asymptotic theory, referred to as complex geometric optics, is attracting interest for applications. In this work, which is the first of a series of papers dedicated to complex geometric optics for nonlinear symmetric hyperbolic systems, we develop a rigorous linear theory and set the basis for the subsequent nonlinear analysis.

  2. Characterization of optical systems for the ALPS II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Spector, Aaron D. [Hamburg Univ. (Germany). Inst. fuer Experimentalphsik; Pold, Jan H.; Lindner, Axel [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Baehre, Robin; Willke, Benno [Max-Planck-Institute for Gravitational Physics, Hannover (Germany); Hannover Univ. (Germany). Inst. fuer Gravitationsphysik


    ALPS II is a light shining through a wall style experiment that will use the principle of resonant enhancement to boost the conversion and reconversion probabilities of photons to relativistic WISPs. This will require the use of long baseline low-loss optical cavities. Very high power build up factors in the cavities must be achieved in order to reach the design sensitivity of ALPS II. This necessitates a number of different sophisticated optical and control systems to maintain the resonance and ensure maximal coupling between the laser and the cavity. In this paper we report on the results of the characterization of these optical systems with a 20m cavity and discuss the results in the context of ALPS II.

  3. Characterization of optical systems for the ALPS II experiment

    CERN Document Server

    Spector, Aaron D; Bähre, Robin; Lindner, Axel; Willke, Benno


    ALPS II is a light shining through a wall style experiment that will use the principle of resonant enhancement to boost the conversion and reconversion probabilities of photons to relativistic WISPs. This will require the use of long baseline low-loss optical cavities. Very high power build up factors in the cavities must be achieved in order to reach the design sensitivity of ALPS II. This necessitates a number of different sophisticated optical and control systems to maintain the resonance and ensure maximal coupling between the laser and the cavity. In this paper we report on the results of the characterization of these optical systems with a 20 m cavity and discuss the results in the context of ALPS II.

  4. Meso-/micro-optical system interface coupling solutions.

    Energy Technology Data Exchange (ETDEWEB)

    Armendariz, Marcelino G.; Kemme, Shanalyn A.; Boye, Robert R. (01713 Photonic Microsystems Technology)


    Optoelectronic microsystems are more and more prevalent as researchers seek to increase transmission bandwidths, implement electrical isolation, enhance security, or take advantage of sensitive optical sensing methods. Board level photonic integration techniques continue to improve, but photonic microsystems and fiber interfaces remain problematic, especially upon size reduction. Optical fiber is unmatched as a transmission medium for distances ranging from tens of centimeters to kilometers. The difficulty with using optical fiber is the small size of the core (approximately 9 {micro}m for the core of single mode telecommunications fiber) and the tight requirement on spot size and input numerical aperture (NA). Coupling to devices such as vertical cavity emitting lasers (VCSELs) and photodetectors presents further difficulties since these elements work in a plane orthogonal to the electronics board and typically require additional optics. This leads to the need for a packaging solution that can incorporate dissimilar materials while maintaining the tight alignment tolerances required by the optics. Over the course of this LDRD project, we have examined the capabilities of components such as VCSELs and photodetectors for high-speed operation and investigated the alignment tolerances required by the optical system. A solder reflow process has been developed to help fulfill these packaging requirements and the results of that work are presented here.

  5. Simple fiber optic sensor for applications in security systems (United States)

    Zyczkowski, M.; Karol, M.; Markowski, P.; Napierala, M. S.


    In this paper we demonstrate measurement results of the modalmetric fiber optic sensor used for the monitoring of the fiber optic link integrity to protect it against unauthorized access to classified information. The presented construction is based on the detection of changes of the modes distribution in a multimode fiber. Any mechanical stress on the multimode fiber causes changes of polarization and distribution of propagating modes, hence it changes the distribution of modes at the end of the multimode fiber. Observation of these changes using a narrow core single-mode fiber allows to use the structure as an optical fiber sensor. We used several kilometers long optical links to conduct field tests of laboratory sensor. On this basis the prototype module of modalmetric fiber optic sensor wasbuilt. The modification of optoelectronic part, the variation of sensor length and the change of the method of light reflection at the end of the fiber enable the use of the modalmetric fiber optic sensor in many applications. The sensor finds wide range of applications in security systems. It can be applied to protect the museum's collection, transmission lines and to protect objects of critical infrastructure.

  6. Study of a middle-wavelength infrared athermalized optical system

    Institute of Scientific and Technical Information of China (English)

    GAO Hong-yun; XIONG Tao; LI Sheng-hui


    For cooled 320×240 detector with stating focal plane array, a novel middle infi'arod athermal optical system is presented. The system is composed of 5 spherical lenses. The materials of lenses are silicon and germanium. The optical parameters and modulation transfer function (MTF) are investigated. The system has the diffraction limited image quality and stable image plane from -30℃ to 70 ℃. The characteristic parameters of the system are as follows:flnumber of 4, cold shield efficiency of 100%, spectrum region of 3.7-4.8 μm and transmissivity of 80%. The system has the merits of simple structure, low price, and it is easy to machining.

  7. Optical Biosensors to Explore Biological Systems

    DEFF Research Database (Denmark)

    Palanco, Marta Espina; Mogensen, Klaus Bo; Andersen, Nils H. Skovgaard


    the capability of different light based techniques for biosensing. As the first example, surface enhanced Raman spectroscopy (SERS) is performed in onion using silver plasmonic nanostructures. Our studies detect different molecular compounds present in the plant based on their SERS signals. SERS imaging allows......The study of live biological systems requires the use of advanced techniques that provide high structural and chemical information and at the same time, avoid damage in the system and modification of the structural/chemical features. Techniques based on interaction with light have shown...... protein may be used as an efficient sensor in an organic environment via a biomimetic membrane model. The combination of both biomimetic membranes and protein membranes as a signal transduction medium has interesting applications in biology and medicine. It is crucial that the matrix where a protein...

  8. Establishing Information Security Systems via Optical Imaging (United States)


    Laser Object Computer Fig. 5. A schematic setup for the proposed method using holography: BSC, Beam splitter cube; CCD, Charge-coupled device. The...SLM Object~~~, ........ . . . . . . . . . . . . . . . . . Laser CCD DJ Fig. 9. A schematic for computational ghost imaging: BD, bucket detector...polarization. (c) Since the sophisticated optoelectronic devices and systems should be analyzed before the retrieval, any hostile hacker will need to

  9. The Airborne Optical Systems Testbed (AOSTB) (United States)


    implemented unique scanning modalities, resulting in a relatively low-cost airborne ladar system. The hardware components have a flexible roll-on/roll...can be adjusted by varying a micrometer stage which in turn changes the achromatic lens-pair spacing. This allows us the flexibility to image targets...representing the viewing screen . In a point cloud, each pixel is assigned a point with x and y coordinates corresponding to the pixel position in the

  10. Automated system for laser damage testing of coated optics (United States)

    Ness, Dale C.; Streater, Alan D.


    Research Electro-Optics Inc. (REO) has recently developed a new laser damage testing facility for the purpose of optimizing process parameters for fabrication and coating of high-damage optics. It also enables full or sample qualification of optics with laser damage specifications. The fully automated laser damage testing system uses microscope photography for detection of damage and a 3 ns pulse length 1064 nm laser for irradiation of the sample. It can test and statistically analyze damage events from a large number of shots, enabling large area testing for low probability events. The system measures and maps sizes and locations of damage sites down to a few microns in diameter. The results are not subject to variations due to the human operator. For coatings deposited by ion beam sputtering, small defects (less than 20 microns) are found to be most prevalent at the fluences specified for small optics for the National Ignition Facility. The ability to measure and characterize small defects has improved REO's ability to optimize their processes for making coated optics with high damage thresholds. In addition to qualifying particular parts, the periodic testing also assures that equipment and processes remain optimized.

  11. DWDM Fiber-Wireless Access System with Centralized Optical Frequency Comb-based RF Carrier Generation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltrán, Marta; Sánchez, José;


    We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported.......We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported....

  12. New compact and efficient local oscillator optic system for the KSTAR electron cyclotron emission imaging system (United States)

    Nam, Y. B.; Lee, D. J.; Lee, J.; Kim, C.; Yun, G. S.; Lee, W.; Park, H. K.


    Electron cyclotron emission imaging (ECEI) diagnostic on Korean Superconducting Tokamak Advanced Research utilizes quasi-optical heterodyne-detection method to measure 2D (vertical and radial) Te fluctuations from two toroidally separated poloidal cross section of the plasma. A cylindrical lens local oscillator (LO) optics with optical path length (OPL) 2-2.5 m has been used in the current ECEI system to couple the LO source to the 24 vertically aligned array of ECE detectors. For efficient and compact LO optics employing the Powell lens is proposed so that the OPL of the LO source is significantly reduced from ˜2.0 m to 0.4 m with new optics. The coupling efficiency of the LO source is expected to be improved especially at the edge channels. Results from the optical simulation together with the laboratory test of the prototype optics will be discussed in this paper.

  13. HYPATIA and STOIC: an active optics system for a large space telescope (United States)

    Devaney, Nicholas; Reinlein, Claudia; Lange, Nicolas; Goy, Matthias; Goncharov, Alexander; Hallibert, Pascal


    The next generation of UVOIR space telescopes will be required to provide excellent wavefront control despite perturbations due to thermal changes, gravity release and vibrations. The STOIC project is a response to an ESA Invitation to Tender to develop an active optics correction chain for future space telescopes. The baseline space telescope being considered is a two-mirror, 4m telescope with a monolithic primary mirror - we refer to this concept as Hypatia. The primary mirror diameter could be extended, but is limited in the near future by launch vehicle dimensions. A deformable mirror (pupil diameter 110mm) will be an integral part of the telescope design; it is being designed for high precision and the ability to maintain a stable form over long periods of time. The secondary mirror of the telescope will be activated to control tip-tilt, defocus and alignment with the primary. Wavefront sensing will be based on phase diversity and a dedicated Shack-Hartmann wavefront sensor. The project will develop a laboratory prototype to demonstrate key aspects of the active correction chain. We present the current state of the preliminary design for both the Hypatia space telescope and the laboratory breadboard.

  14. Optical waveguide focusing system with short free-working distance

    NARCIS (Netherlands)

    Wang, H.; Groen, F.H.; Pereira, S.F.; Braat, J.J.M.


    In photonics, light usually diffracts in all directions when it emerges from a planar optical waveguide. Besides this fact, in this letter we show that a waveguide with a rectangular cross section can be turned to a focusing system by using three-dimensional self-imaging technique. We obtained a con

  15. Comprehensive research on self phase modulation based optical delay systems

    Institute of Scientific and Technical Information of China (English)

    Yang Ai-Ying; Sun Yu-Nan


    This paper comprehensively investigates the properties of self phase modulation based optical delay systems consisting of dispersion compensation fibre and highly nonlinear fibres.It researches into the impacts of power level launched into highly nonlinear fibres,conversion wavelength,dispersion slope,modulation format and optical filter bandwidth on the overall performance of optical delay systems.The results reveal that,if the power launched into highly nonlinear fibres is fixed,the time delay generally varies linearly with the conversion wavelength,but jumps intermittently at some conversion wavelengths.However,the time delay varies semi-periodically with the power launched into highly nonlinear fibres.The dispersion slope of highly nonlinear fibres has significant influence on the time delay,especially for the negative dispersion slope.The time delay differs with modulation formats due to the different combined interaction of nonlinearity and dispersion in fibres.The bandwidth of the optical filters also greatly affects the time delay because it determines the bandwidth of the passed signal in the self phase modulation based time delay systems.The output signal quality of the overall time delay systems depends on the conversion wavelength and input power level.The optimisation of the power level and conversion wavelength to provide the best output signal quality is made at the end of this paper.

  16. Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren


    Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated...

  17. Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren


    Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated...

  18. Optical system design with conformal decentered and tilted elements

    Institute of Scientific and Technical Information of China (English)

    Jun Chang; Wubin He; Ruirui Wang; Shulong Feng


    @@ We investigate the aberration properties of the conformal optical system with decentered and tilted elements by vector aberration theory.By decentering and tilting the window and corrector of the system,two elements are effectively used together in a particular manner by aberration compensation to achieve off-axis imaging.A conceptual design is performed with a half-field of 2°, the F# of 4, and the wavelength ranging of 3700-4800 nm.The imaging quality can reach the optical diffraction limit and satisfy corresponding requirements.%We investigate the aberration properties of the conformal optical system with decentered and tilted elements by vector aberration theory.By decentering and tilting the window and corrector of the system,two elements are effectively used together in a particular manner by aberration compensation to achieve off-axis imaging.A conceptual design is performed with a half-field of 2°, the F# of 4, and the wavelength ranging of 3700-4800 nm.The imaging quality can reach the optical diffraction limit and satisfy corresponding requirements.

  19. Large Binocular Telescope Adaptive Optics System: New achievements and perspectives in adaptive optics

    CERN Document Server

    Esposito, Simone; Pinna, Enrico; Puglisi, Alfio; Quirós-Pacheco, Fernando; Arcidiacono, Carmelo; Xompero, Marco; Briguglio, Runa; Agapito, Guido; Busoni, Lorenzo; Fini, Luca; Argomedo, Javier; Gherardi, Alessandro; Brusa, Guido; Miller, Douglas; Guerra, Juan Carlos; Stefanini, Paolo; Salinari, Piero; 10.1117/12.898641


    The Large Binocular Telescope (LBT) is a unique telescope featuring two co-mounted optical trains with 8.4m primary mirrors. The telescope Adaptive Optics (AO) system uses two innovative key components, namely an adaptive secondary mirror with 672 actuators and a high-order pyramid wave-front sensor. During the on-sky commissioning such a system reached performances never achieved before on large ground-based optical telescopes. Images with 40mas resolution and Strehl Ratios higher than 80% have been acquired in H band (1.6 micron). Such images showed a contrast as high as 10e-4. Based on these results, we compare the performances offered by a Natural Guide Star (NGS) system upgraded with the state-of-the-art technology and those delivered by existing Laser Guide Star (LGS) systems. The comparison, in terms of sky coverage and performances, suggests rethinking the current role ascribed to NGS and LGS in the next generation of AO systems for the 8-10 meter class telescopes and Extremely Large Telescopes (ELTs)...

  20. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography. (United States)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha


    We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.


    Roberts, F. E.


    The PYROLASER package is an operating system for the Pyrometer Instrument Company's Pyrolaser. There are 6 individual programs in the PYROLASER package: two main programs, two lower level subprograms, and two programs which, although independent, function predominantly as macros. The package provides a quick and easy way to setup, control, and program a standard Pyrolaser. Temperature and emissivity measurements may be either collected as if the Pyrolaser were in the manual operations mode, or displayed on real time strip charts and stored in standard spreadsheet format for post-test analysis. A shell is supplied to allow macros, which are test-specific, to be easily added to the system. The Pyrolaser Simple Operation program provides full on-screen remote operation capabilities, thus allowing the user to operate the Pyrolaser from the computer just as it would be operated manually. The Pyrolaser Simple Operation program also allows the use of "quick starts". Quick starts provide an easy way to permit routines to be used as setup macros for specific applications or tests. The specific procedures required for a test may be ordered in a sequence structure and then the sequence structure can be started with a simple button in the cluster structure provided. One quick start macro is provided for continuous Pyrolaser operation. A subprogram, Display Continuous Pyr Data, is used to display and store the resulting data output. Using this macro, the system is set up for continuous operation and the subprogram is called to display the data in real time on strip charts. The data is simultaneously stored in a spreadsheet format. The resulting spreadsheet file can be opened in any one of a number of commercially available spreadsheet programs. The Read Continuous Pyrometer program is provided as a continuously run subprogram for incorporation of the Pyrolaser software into a process control or feedback control scheme in a multi-component system. The program requires the


    Roberts, F. E.


    The PYROLASER package is an operating system for the Pyrometer Instrument Company's Pyrolaser. There are 6 individual programs in the PYROLASER package: two main programs, two lower level subprograms, and two programs which, although independent, function predominantly as macros. The package provides a quick and easy way to setup, control, and program a standard Pyrolaser. Temperature and emissivity measurements may be either collected as if the Pyrolaser were in the manual operations mode, or displayed on real time strip charts and stored in standard spreadsheet format for post-test analysis. A shell is supplied to allow macros, which are test-specific, to be easily added to the system. The Pyrolaser Simple Operation program provides full on-screen remote operation capabilities, thus allowing the user to operate the Pyrolaser from the computer just as it would be operated manually. The Pyrolaser Simple Operation program also allows the use of "quick starts". Quick starts provide an easy way to permit routines to be used as setup macros for specific applications or tests. The specific procedures required for a test may be ordered in a sequence structure and then the sequence structure can be started with a simple button in the cluster structure provided. One quick start macro is provided for continuous Pyrolaser operation. A subprogram, Display Continuous Pyr Data, is used to display and store the resulting data output. Using this macro, the system is set up for continuous operation and the subprogram is called to display the data in real time on strip charts. The data is simultaneously stored in a spreadsheet format. The resulting spreadsheet file can be opened in any one of a number of commercially available spreadsheet programs. The Read Continuous Pyrometer program is provided as a continuously run subprogram for incorporation of the Pyrolaser software into a process control or feedback control scheme in a multi-component system. The program requires the

  3. An adaptive optics imaging system designed for clinical use. (United States)

    Zhang, Jie; Yang, Qiang; Saito, Kenichi; Nozato, Koji; Williams, David R; Rossi, Ethan A


    Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2-3 arc minutes, (arcmin) 2) ~0.5-0.8 arcmin and, 3) ~0.05-0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3-5 arcmin, 2) ~0.7-1.1 arcmin and 3) ~0.07-0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.

  4. Vision System for Relative Motion Estimation from Optical Flow

    Directory of Open Access Journals (Sweden)

    Sergey M. Sokolov


    Full Text Available For the recent years there was an increasing interest in different methods of motion analysis based on visual data acquisition. Vision systems, intended to obtain quantitative data regarding motion in real time are especially in demand. This paper talks about the vision systems that allow the receipt of information on relative object motion in real time. It is shown, that the algorithms solving a wide range of practical problems by definition of relative movement can be generated on the basis of the known algorithms of an optical flow calculation. One of the system's goals is the creation of economically efficient intellectual sensor prototype in order to estimate relative objects motion based on optic flow. The results of the experiments with a prototype system model are shown.

  5. The Algol triple system spatially resolved at optical wavelengths

    CERN Document Server

    Zavala, R T; Boboltz, D A; Ojha, R; Shaffer, D B; Tycner, C; Richards, M T; Hutter, D J; 10.1088/2041-8205/715/1/L44


    Interacting binaries typically have separations in the milli-arcsecond regime and hence it has been challenging to resolve them at any wavelength. However, recent advances in optical interferometry have improved our ability to discern the components in these systems and have now enabled the direct determination of physical parameters. We used the Navy Prototype Optical Interferometer to produce for the first time images resolving all three components in the well-known Algol triple system. Specifically, we have separated the tertiary component from the binary and simultaneously resolved the eclipsing binary pair, which represents the nearest and brightest eclipsing binary in the sky. We present revised orbital elements for the triple system, and we have rectified the 180-degree ambiguity in the position angle of Algol C. Our directly determined magnitude differences and masses for this triple star system are consistent with earlier light curve modeling results.

  6. Remote optical sensor system for E-field measurements (United States)

    Heinzelmann, Robert; Stoehr, Andreas; Alder, Thomas; Kalinowski, D.; Schmidt, Manuel; Gross, Matthias; Jaeger, Dieter


    The concept of a remote optical sensor system for frequency selective electric field measurements will be presented. The system will be applicable to field measurement problems up to frequencies in the microwave regime. Additionally, it will provide minimum interference with the measured field, due to the optical fiber coupled sensor head. The electrooptic key components within the head of this sensor system are an array of photovoltaic cells and an electroabsorption waveguide modulator. Based on experimental results these components will be discussed and evaluated for the application within the sensor system. Furthermore, a novel fiber modulator coupling technique employing the monolithic integration of the device with InP V-grooves will be presented.

  7. Secure Communication System Basedon Chaosin Optical Fibre

    Institute of Scientific and Technical Information of China (English)

    Pak L Chu; Fan Zhang; William Mak; Robust Lai


    @@ 1 Introduction Recently, there have been intense research activities on the study of synchronized chaos generated by fibre lasers [1] and its application to secure communication systems . So far, all studies concentrate on two aspects:[2].So far,all studies concentrate on two aspects:(1) the effect of the transmission channel between the transmitter and the receiver has been neglected, and (2)the chaos and the signal are carried by one wavelength.Both theoretical and experimental investigations make these two assumptions. In the experiments, the transmission fibre is invariably short, in the order of tens of metres. Hence its dispersion and nonlinear effects are negligible. The fibre laser responsible for the generation of chaos is often designed to lase at one wavelength only.

  8. Optical design of the oblique Ece antenna system for JET

    Energy Technology Data Exchange (ETDEWEB)

    Sozzi, C. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy)]. E-mail:; Bruschi, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); Simonetto, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); DeLaLuna, E. [Asociacion EURATOM-CIEMAT, CIEMAT, Madrid (Spain); Fessey, J. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom); Riccardo, V. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom)


    Systematic disagreements between Ece and Thomson Scattering diagnostics observed in various fusion devices led to the proposal of the so called Oblique Ece diagnostics on JET. This system will allow the study of the electron distribution function at low energies to reveal deviations from the Maxwellian distribution. This paper is devoted to the design of the quasi optical antenna for this diagnostics. The physical bases of the diagnostics imply two lines of sight at about 10{sup o} and 20{sup o} respectively from the magnetic field gradient. Severe geometrical constraints are imposed by the location of the antenna. The design strategy and physical optics calculations used to validate it are presented.

  9. Optical calculation of correlation filters for a robotic vision system (United States)

    Knopp, Jerome


    A method is presented for designing optical correlation filters based on measuring three intensity patterns: the Fourier transform of a filter object, a reference wave and the interference pattern produced by the sum of the object transform and the reference. The method can produce a filter that is well matched to both the object, its transforming optical system and the spatial light modulator used in the correlator input plane. A computer simulation was presented to demonstrate the approach for the special case of a conventional binary phase-only filter. The simulation produced a workable filter with a sharp correlation peak.

  10. Optical fiber communication systems with Matlab and Simulink models

    CERN Document Server

    Binh, Le Nguyen


    ""This book adds an aspect of programming and simulation not so well developed in other books. It is complete in this sense and enables directly linking the physics of optical components and systems to realistic results.""-Martin Rochette, Associate Professor, McGill University, Quebec, Canada""…this will be an excellent textbook since it has all new development and information on optical communication systems…I think this book can easily replace many other textbooks in this field.""-Massoud Moussavi, California State Polytechnic University-Pomona""The book is well written. It describes the fu

  11. Hybrid quantum systems for enhanced nonlinear optical susceptibilities

    CERN Document Server

    Sullivan, Dennis; Kuzyk, Mark G


    Significant effort has been expended in the search for materials with ultra-fast nonlinear-optical susceptibilities, but most fall far below the fundamental limits. This work applies a theoretical materials development program that has identified a promising new hybrid made of a nanorod and a molecule. This system uses the electrostatic dipole moment of the molecule to break the symmetry of the metallic nanostructure that shifts the energy spectrum to make it optimal for a nonlinear-optical response near the fundamental limit. The structural parameters are varied to determine the ideal configuration, providing guidelines for making the best structures.

  12. Simulation of atmospheric turbulence for optical systems with extended sources. (United States)

    Safari, Majid; Hranilovic, Steve


    In this paper, the method of random wave vectors for simulation of atmospheric turbulence is extended to 2D×2D space to provide spatial degrees of freedom at both input and output planes. The modified technique can thus simultaneously simulate the turbulence-induced log-amplitude and phase distortions for optical systems with extended sources either implemented as a single large aperture or multiple apertures. The reliability of our simulation technique is validated in different conditions and its application is briefly investigated in a multibeam free-space optical communication scenario.

  13. Modeling light–tissue interaction in optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Jørgensen, Thomas Martini; Thrane, Lars


    Optical coherence tomography (OCT) performs high-resolution, cross-sectional tomographic imaging of the internal tissue microstructure by measuring backscattered or backreflected light. The scope of this chapter is to present analytical and numerical models that are able to describe light......-tissue interactions and its influence on the performance of OCT systems including multiple scattering effects in heterogeneous media. In general, these models, analytical as well as numerical, may serve as important tools for improving interpretation of OCT images and also serve as prerequisites for extraction...... of tissue optical scattering parameters....

  14. Ring resonator systems to perform optical communication enhancement using soliton

    CERN Document Server

    Amiri, Iraj Sadegh


    The title explain new technique of secured and high capacity optical communication signals generation by using the micro and nano ring resonators. The pulses are known as soliton pulses which are more secured due to having the properties of chaotic and dark soliton signals with ultra short bandwidth. They have high capacity due to the fact that ring resonators are able to generate pulses in the form of solitons in multiples and train form. These pulses generated by ring resonators are suitable in optical communication due to use the compact and integrated rings system, easy to control, flexibi

  15. An Analysis of the Magneto-Optic Imaging System (United States)

    Nath, Shridhar


    The Magneto-Optic Imaging system is being used for the detection of defects in airframes and other aircraft structures. The system has been successfully applied to detecting surface cracks, but has difficulty in the detection of sub-surface defects such as corrosion. The intent of the grant was to understand the physics of the MOI better, in order to use it effectively for detecting corrosion and for classifying surface defects. Finite element analysis, image classification, and image processing are addressed.

  16. Analytical applications of MD-FIA-optical detection systems

    Institute of Scientific and Technical Information of China (English)


    A brief introduction of recent research works in our laboratory concerning microdialysis(MD) based on optical detection combined with FIA is made in this mini-review. A biosensor system has been designed and realized the real time in vivo monitoring of some important clinic substances such as calcium, uric acid. The system has also been used to study the in vitro binding of drug-protein.

  17. Steady-state solution methods for open quantum optical systems


    Nation, P. D.


    We discuss the numerical solution methods available when solving for the steady-state density matrix of a time-independent open quantum optical system, where the system operators are expressed in a suitable basis representation as sparse matrices. In particular, we focus on the difficulties posed by the non-Hermitian structure of the Lindblad super operator, and the numerical techniques designed to mitigate these pitfalls. In addition, we introduce a doubly iterative inverse-power method that...

  18. Optical Alignment System for the PHENIX Muon Tracking Chambers

    CERN Document Server

    Murata, J; Armendariz, R L; Brooks, M L; Horaguchi, T; Kamihara, N; Kobayashi, H; Lee, D M; Shibata, T A; Sondheim, W E


    A micron-precision optical alignment system (OASys) for the PHENIX muon tracking chambers is developed. To ensure the required mass resolution of vector meson detection, the relative alignment between three tracking station chambers must be monitored with a precision of 25$\\mu$m. The OASys is a straightness monitoring system comprised of a light source, lens and CCD camera, used for determining the initial placement as well as for monitoring the time dependent movement of the chambers on a micron scale.

  19. Temperature control system for optical elements in astronomical instrumentation (United States)

    Verducci, Orlando; de Oliveira, Antonio C.; Ribeiro, Flávio F.; Vital de Arruda, Márcio; Gneiding, Clemens D.; Fraga, Luciano


    Extremely low temperatures may damage the optical components assembled inside of an astronomical instrument due to the crack in the resin or glue used to attach lenses and mirrors. The environment, very cold and dry, in most of the astronomical observatories contributes to this problem. This paper describes the solution implemented at SOAR for remotely monitoring and controlling temperatures inside of a spectrograph, in order to prevent a possible damage of the optical parts. The system automatically switches on and off some heat dissipation elements, located near the optics, as the measured temperature reaches a trigger value. This value is set to a temperature at which the instrument is not operational to prevent malfunction and only to protect the optics. The software was developed with LabVIEWTM and based on an object-oriented design that offers flexibility and ease of maintenance. As result, the system is able to keep the internal temperature of the instrument above a chosen limit, except perhaps during the response time, due to inertia of the temperature. This inertia can be controlled and even avoided by choosing the correct amount of heat dissipation and location of the thermal elements. A log file records the measured temperature values by the system for operation analysis.

  20. Capillarity-based preparation system for optical colorimetric sensor arrays (United States)

    Luo, Xiao-gang; Yi, Xin; Bu, Xiang-nan; Hou, Chang-jun; Huo, Dan-qun; Yang, Mei; Fa, Huan-bao; Lei, Jin-can


    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  1. Capillarity-based preparation system for optical colorimetric sensor arrays. (United States)

    Luo, Xiao-Gang; Yi, Xin; Bu, Xiang-Nan; Hou, Chang-Jun; Huo, Dan-Qun; Yang, Mei; Fa, Huan-Bao; Lei, Jin-Can


    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  2. Silicon carbide as a basis for spaceflight optical systems (United States)

    Curcio, Michael E.


    New advances in the areas of microelectronics and micro-mechanical devices have created a momentum in the development of lightweight, miniaturized, electro-optical space subsystems. The performance improvements achieved and new observational techniques developed as a result, have provided a basis for a new range of Small Explorer, Discovery-class and other low-cost mission concepts for space exploration. However, the ultimate objective of low-mass, inexpensive space science missions will only be achieved with a companion development in the areas of flight optical systems and sensor instrument benches. Silicon carbide (SiC) is currently emerging as an attractive technology to fill this need. As a material basis for reflective, flight telescopes and optical benches, SiC offers: the lightweight and stiffness characteristics of beryllium; glass-like inherent stability consistent with performance to levels of diffraction-limited visible resolution; superior thermal properties down to cryogenic temperatures; and an existing, commercially-based material and processing infrastructure like aluminum. This paper will describe the current status and results of on-going technology developments to utilize these material properties in the creation of lightweight, high- performing, thermally robust, flight optical assemblies. System concepts to be discussed range from an 18 cm aperture, 4-mirror, off-axis system weighing less than 2 kg to a 0.5 m, 15 kg reimager. In addition, results in the development of a thermally-stable, `GOES-like' scan mirror will be presented.

  3. Solar-blind ultraviolet optical system design for missile warning (United States)

    Chen, Yu; Huo, Furong; Zheng, Liqin


    Solar-blind region of Ultraviolet (UV) spectrum has very important application in military field. The spectrum range is from 240nm to 280nm, which can be applied to detect the tail flame from approaching missile. A solar-blind UV optical system is designed to detect the UV radiation, which is an energy system. iKon-L 936 from ANDOR company is selected as the UV detector, which has pixel size 13.5μm x 13.5 μm and active image area 27.6mm x 27.6 mm. CaF2 and F_silica are the chosen materials. The original structure is composed of 6 elements. To reduce the system structure and improve image quality, two aspheric surfaces and one diffractive optical element are adopted in this paper. After optimization and normalization, the designed system is composed of five elements with the maximum spot size 11.988μ m, which is less than the pixel size of the selected CCD detector. Application of aspheric surface and diffractive optical element makes each FOV have similar spot size, which shows the system almost meets the requirements of isoplanatic condition. If the focal length can be decreased, the FOV of the system can be enlarged further.

  4. Optical Disc Utilized As A Data Storage System For Reconnaissance (United States)

    Herzog, Donald G.


    Electra-optic and Radar sensing reconnaissance systems have many advantages including remote transmission and image data processing that conventional film camera systems do not have. However, data storage and retrieval that was naturally and easily accomplished with film must now be accommodated by other techniques. The optical disc data storage and retrieval systems offer significant advantage towards fulfilling this need. This paper will provide an overview description of the technology, some of the fundamental alternatives of configuration approach, and some examples of where it may be considered in the reconnaissance system. Silver halide film has been and still is the work horse of the image based reconnaissance field. It will not be replaced in the near future either, but rather a gradual transition to total electronic systems is expected. It is not the intent of this paper to debase film, because in fact it has its advantages. We have learned to optimize its advantages and minimize its disadvantages. However optical disc systems have a definite role to play in the reconnaissance field.

  5. Joint digital signal processing for superchannel coherent optical communication systems. (United States)

    Liu, Cheng; Pan, Jie; Detwiler, Thomas; Stark, Andrew; Hsueh, Yu-Ting; Chang, Gee-Kung; Ralph, Stephen E


    Ultra-high-speed optical communication systems which can support ≥ 1Tb/s per channel transmission will soon be required to meet the increasing capacity demand. However, 1Tb/s over a single carrier requires either or both a high-level modulation format (i.e. 1024QAM) and a high baud rate. Alternatively, grouping a number of tightly spaced "sub-carriers" to form a terabit superchannel increases channel capacity while minimizing the need for high-level modulation formats and high baud rate, which may allow existing formats, baud rate and components to be exploited. In ideal Nyquist-WDM superchannel systems, optical subcarriers with rectangular spectra are tightly packed at a channel spacing equal to the baud rate, thus achieving the Nyquist bandwidth limit. However, in practical Nyquist-WDM systems, precise electrical or optical control of channel spectra is required to avoid strong inter-channel interference (ICI). Here, we propose and demonstrate a new "super receiver" architecture for practical Nyquist-WDM systems, which jointly detects and demodulates multiple channels simultaneously and mitigates the penalties associated with the limitations of generating ideal Nyquist-WDM spectra. Our receiver-side solution relaxes the filter requirements imposed on the transmitter. Two joint DSP algorithms are developed for linear ICI cancellation and joint carrier-phase recovery. Improved system performance is observed with both experimental and simulation data. Performance analysis under different system configurations is conducted to demonstrate the feasibility and robustness of the proposed joint DSP algorithms.

  6. Optical inspection system for cylindrical objects (United States)

    Brenden, Byron B.; Peters, Timothy J.


    In the inspection of cylindrical objects, particularly O-rings, the object is translated through a field of view and a linear light trace is projected on its surface. An image of the light trace is projected on a mask, which has a size and shape corresponding to the size and shape which the image would have if the surface of the object were perfect. If there is a defect, light will pass the mask and be sensed by a detector positioned behind the mask. Preferably, two masks and associated detectors are used, one mask being convex to pass light when the light trace falls on a projection from the surface and the other concave, to pass light when the light trace falls on a depression in the surface. The light trace may be either dynamic, formed by a scanned laser beam, or static, formed by such a beam focussed by a cylindrical lens. Means are provided to automatically keep the illuminating receiving systems properly aligned.

  7. Wavefront sensors for adaptive optical systems (United States)

    Lukin, V. P.; Botygina, N. N.; Emaleev, O. N.; Konyaev, P. A.


    A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640x640 μm with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017λ at the reconstructed WF with wavelength λ . Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.

  8. A simple optical system for interpreting coherence theory

    CERN Document Server

    Kelly, Damien P


    A new theoretical technique for understanding, analyzing and developing optical systems is presented. The approach is statistical in nature, where information about an object under investigation is discovered, by examining deviations from a known reference statistical distribution. A Fourier optics framework and a scalar description of the propagation of monochromatic light is initially assumed. An object (belonging to a known class of objects) is illuminated with a speckle field and the intensity of the resulting scattered optical field is detected at a series of spatial locations by point square law detectors. A new speckle field is generated (with a new diffuser) and the object is again illuminated and the intensities are again measured and noted. By making a large number of these statistical measurements - an ensemble averaging process (which in general can be a temporal or a spatial averaging process) - it is possible to determine the statistical relationship between the intensities detected in different...

  9. Multiplexed optical operation of distributed nanoelectromechanical systems arrays. (United States)

    Sampathkumar, A; Ekinci, K L; Murray, T W


    We report a versatile all optical technique to excite and read-out a distributed nanoelectromechanical systems (NEMS) array. The NEMS array is driven by a distributed, intensity modulated optical pump through the photothermal effect. The ensuing vibrational response of the array is multiplexed onto a single probe beam in the form of a high frequency phase modulation. The phase modulation is optically down converted to a low frequency intensity modulation using an adaptive full-field interferometer, and subsequently detected using a CCD array. Rapid and single step mechanical characterization of ∼44 nominally identical high-frequency resonators is demonstrated. The technique may enable sensitivity improvements over single NEMS resonators by averaging signals coming from a multitude of devices in the array. In addition, the diffraction limited spatial resolution may allow for position-dependent read-out of NEMS sensor chips for sensing multiple analytes or spatially inhomogeneous forces.

  10. Optical design and characterization of an advanced computational imaging system (United States)

    Shepard, R. Hamilton; Fernandez-Cull, Christy; Raskar, Ramesh; Shi, Boxin; Barsi, Christopher; Zhao, Hang


    We describe an advanced computational imaging system with an optical architecture that enables simultaneous and dynamic pupil-plane and image-plane coding accommodating several task-specific applications. We assess the optical requirement trades associated with custom and commercial-off-the-shelf (COTS) optics and converge on the development of two low-cost and robust COTS testbeds. The first is a coded-aperture programmable pixel imager employing a digital micromirror device (DMD) for image plane per-pixel oversampling and spatial super-resolution experiments. The second is a simultaneous pupil-encoded and time-encoded imager employing a DMD for pupil apodization or a deformable mirror for wavefront coding experiments. These two testbeds are built to leverage two MIT Lincoln Laboratory focal plane arrays - an orthogonal transfer CCD with non-uniform pixel sampling and on-chip dithering and a digital readout integrated circuit (DROIC) with advanced on-chip per-pixel processing capabilities. This paper discusses the derivation of optical component requirements, optical design metrics, and performance analyses for the two testbeds built.

  11. High throughput optoelectronic smart pixel systems using diffractive optics (United States)

    Chen, Chih-Hao


    Recent developments in digital video, multimedia technology and data networks have greatly increased the demand for high bandwidth communication channels and high throughput data processing. Electronics is particularly suited for switching, amplification and logic functions, while optics is more suitable for interconnections and communications with lower energy and crosstalk. In this research, we present the design, testing, integration and demonstration of several optoelectronic smart pixel devices and system architectures. These systems integrate electronic switching/processing capability with parallel optical interconnections to provide high throughput network communication and pipeline data processing. The Smart Pixel Array Cellular Logic processor (SPARCL) is designed in 0.8 m m CMOS and hybrid integrated with Multiple-Quantum-Well (MQW) devices for pipeline image processing. The Smart Pixel Network Interface (SAPIENT) is designed in 0.6 m m GaAs and monolithically integrated with LEDs to implement a highly parallel optical interconnection network. The Translucent Smart Pixel Array (TRANSPAR) design is implemented in two different versions. The first version, TRANSPAR-MQW, is designed in 0.5 m m CMOS and flip-chip integrated with MQW devices to provide 2-D pipeline processing and translucent networking using the Carrier- Sense-MultipleAccess/Collision-Detection (CSMA/CD) protocol. The other version, TRANSPAR-VM, is designed in 1.2 m m CMOS and discretely integrated with VCSEL-MSM (Vertical-Cavity-Surface- Emitting-Laser and Metal-Semiconductor-Metal detectors) chips and driver/receiver chips on a printed circuit board. The TRANSPAR-VM provides an option of using the token ring network protocol in addition to the embedded functions of TRANSPAR-MQW. These optoelectronic smart pixel systems also require micro-optics devices to provide high resolution, high quality optical interconnections and external source arrays. In this research, we describe an innovative

  12. Design of Optical Systems with Extended Depth of Field: An Educational Approach to Wavefront Coding Techniques (United States)

    Ferran, C.; Bosch, S.; Carnicer, A.


    A practical activity designed to introduce wavefront coding techniques as a method to extend the depth of field in optical systems is presented. The activity is suitable for advanced undergraduate students since it combines different topics in optical engineering such as optical system design, aberration theory, Fourier optics, and digital image…

  13. Optical link design and validation testing of the Optical Payload for Lasercomm Science (OPALS) system (United States)

    Oaida, Bogdan V.; Wu, William; Erkmen, Baris I.; Biswas, Abhijit; Andrews, Kenneth S.; Kokorowski, Michael; Wilkerson, Marcus


    The Optical Payload for Lasercomm Science (OPALS) system developed by the Jet Propulsion Laboratory, California Institute of Technology, will be used for optical telecommunications link experiments from the International Space Station (ISS) to a ground telescope located at Table Mountain, CA. The launch of the flight terminal is scheduled for late February 2014 with an initially planned 90-day operations period following deployment on the exterior of the ISS. The simple, low-cost OPALS system will downlink a pre-encoded video file at 50 Mb/s on a 1550 nm laser carrier using on-off key (OOK) modulation and Reed-Solomon forward error correction. A continuous wave (cw) 976 nm multibeam laser beacon transmitted from the ground to the ISS will initiate link acquisition and tracking by the flight subsystem. Link analysis along with pre-flight results of the end-to-end free-space testing of the OPALS link are presented.

  14. Optical diagnostics integrated with laser spark delivery system (United States)

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam


    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  15. Steady-state solution methods for open quantum optical systems

    CERN Document Server

    Nation, P D


    We discuss the numerical solution methods available when solving for the steady-state density matrix of a time-independent open quantum optical system, where the system operators are expressed in a suitable basis representation as sparse matrices. In particular, we focus on the difficulties posed by the non-Hermitian structure of the Lindblad super operator, and the numerical techniques designed to mitigate these pitfalls. In addition, we introduce a doubly iterative inverse-power method that can give reduced memory and runtime requirements in situations where other iterative methods are limited due to poor bandwidth and profile reduction. The relevant methods are demonstrated on several prototypical quantum optical systems where it is found that iterative methods based on iLU factorization using reverse Cuthill-Mckee ordering tend to outperform other solution techniques in terms of both memory consumption and runtime as the size of the underlying Hilbert space increases. For eigenvalue solving, Krylov iterat...

  16. Design of VisSWIR continuous zoom optical system (United States)

    Yang, Mingyang; Yang, Hongtao; Qu, Rui; Mei, Chao; Zhou, Zuofeng


    For 640 pixel×512 pixel cooled staring focal plane array detector, a VisSWIR wideband continuous zoom optical system with 7X zoom range is presented based on the pattern of the negative zoom group and compensating lens group. The zoom system provides continuous changed in the field of view from narrow to the wide. The zoom optical system works in the range of 0.4μm 1.7μm, F number is 4, the pixel of the detector is 15μm. It realizes 20mm 140mm continuous zoom with a smooth zoom path and provided high image quality with the whole zoom range, the zoom ratio is 7:1. The modulation transfer function(MTF) for the system is above 0.5 within the whole focal length range at spatial frequency of 34lp/mm and it almost approaches the diffraction limit. RMS value of spot diameter was investigation, the maximum distortion value is less than 5% and the surface type of all lens applied is spherical. Moreover, the cam curve after optimization is given by the optical design software Code V macro. The design results provide that the zoom system has the small size, high resolution, excellent image quality and the smooth cam curve etc.

  17. Optical systems for synchrotron radiation. Lecture 2. Mirror systems

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R.


    The process of reflection of VUV and x-radiation is summarized. The functions of mirrors in synchrotron beamlines are described, which include deflection, filtration, power absorption, formation of a real image, focusing, and collimation. Fabrication of optical surfaces for synchrotron radiation beamlines are described, and include polishing of a near spherical surface as well as bending a cylindrical surface to toroidal shape. The imperfections present in mirrors, aberrations and surface figure inaccuracy, are discussed. Calculation of the thermal load of a mirror in a synchrotron radiation beam and the cooling of the mirror are covered briefly. 50 refs., 7 figs. (LEW)

  18. Progress in Nano-Electro-Optics VII Chemical, Biological, and Nanophotonic Technologies for Nano-Optical Devices and Systems

    CERN Document Server

    Ohtsu, Motoichi


    This book focuses on chemical and nanophotonic technology to be used to develop novel nano-optical devices and systems. It begins with temperature- and photo-induced phase transition of ferromagnetic materials. Further topics include: energy transfer in artificial photosynthesis, homoepitaxial multiple quantum wells in ZnO, near-field photochemical etching and nanophotonic devices based on a nonadiabatic process and optical near-field energy transfer, respectively and polarization control in the optical near-field for optical information security. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  19. Injection molding lens metrology using software configurable optical test system (United States)

    Zhan, Cheng; Cheng, Dewen; Wang, Shanshan; Wang, Yongtian


    Optical plastic lens produced by injection molding machine possesses numerous advantages of light quality, impact resistance, low cost, etc. The measuring methods in the optical shop are mainly interferometry, profile meter. However, these instruments are not only expensive, but also difficult to alignment. The software configurable optical test system (SCOTS) is based on the geometry of the fringe refection and phase measuring deflectometry method (PMD), which can be used to measure large diameter mirror, aspheric and freeform surface rapidly, robustly, and accurately. In addition to the conventional phase shifting method, we propose another data collection method called as dots matrix projection. We also use the Zernike polynomials to correct the camera distortion. This polynomials fitting mapping distortion method has not only simple operation, but also high conversion precision. We simulate this test system to measure the concave surface using CODE V and MATLAB. The simulation results show that the dots matrix projection method has high accuracy and SCOTS has important significance for on-line detection in optical shop.

  20. Miniature optical coherence tomography system based on silicon photonics (United States)

    Margallo-Balbás, Eduardo; Pandraud, Gregory; French, Patrick J.


    Optical Coherence Tomography (OCT) is a promising medical imaging technique. It has found applications in many fields of medicine and has a large potential for the optical biopsy of tumours. One of the technological challenges impairing faster adoption of OCT is the relative complexity of the optical instrumentation required, which translates into expensive and bulky setups. In this paper we report an implementation of Time Domain OCT (TD-OCT) based on a silicon photonic platform. The devices are fabricated using Silicon-On-Insulator (SOI) wafers, on which rib waveguides are defined. While most of the components needed are well-known in this technology, a fast delay line with sufficient scanning range is a specific requirement of TD-OCT. In the system reported, this was obtained making use of the thermo-optical effect of silicon. By modulating the thermal resistance of the waveguide to the substrate, it is possible to establish a trade-off between maximum working frequency and power dissipation. Within this trade-off, the systems obtained can be operated in the kHz range, and they achieve temperature shifts corresponding to scanning ranges of over 2mm. Though the current implementation still requires external sources and detectors to be coupled to the Planar Lightwave Circuit (PLC), future work will include three-dimensional integration of these components onto the substrate. With the potential to include the read-out and driving electronics on the same die, the reported approach can yield extremely compact and low-cost TD-OCT systems, enabling a wealth of new applications, including gastrointestinal pills with optical biopsy capabilities.

  1. Modern methods of production of large-sized multicomponent optical systems (United States)

    Galyavov, Igor R.; Belousov, Sergey P.; Ignatov, Aleksandr N.; Ponin, Oleg V.; Sharov, Aleksandr A.; Domnin, Aleksandr V.


    The article describes the technology of production of large-sized multicomponent optical systems of different function. All stages of a production cycle are considered: assembly of separate units of optical components, including aspherical and off-axis mirrors; preliminary assembly and adjustment of all system; final adjustment of optical system. Modern computer-controlled methods of testings and adjustment of multicomponent optical systems, using the examples of production of such systems at JSC LZOS, are described.

  2. Editorial: Special issue on smart optical instruments and systems for space applications

    Institute of Scientific and Technical Information of China (English)

    XING; Fei


    Optical systems are playing more and more important roles for space applications,such as high accurate attitude determination and remote sensing systems etc.Innovations in optical systems have brought great advantages,some even revolutionary for the space applications.Accordingly,in this special issue of Smart Optical systems and instruments

  3. Toward practical application of fiber optical parametric amplifiers in optical communication systems (United States)

    Wong, Kin-Yip

    One of the most powerful techniques in fiber optical communication systems is wave-length division multiplexing (WDM). By utilizing the large (˜300 nm), low-loss (0.2--0.4 dB/km) transmission bandwidth, a single fiber can transmit many wavelengths. One fiber can potentially support transmission of tens of terabits per second of information over thousands of kilometers, to meet the exponentially-growing capacity demand. One of the key components for WDM systems is the optical amplifier; currently the most widely used optical amplifier is the erbium-doped fiber amplifier (EDFA). However, its bandwidth and operating wavelength are limited. To mitigate the bandwidth limitation of EDFAs, alternative optical amplifiers have been investigated, and one of the most promising candidates is the fiber optical parametric amplifier (OPA). Fiber OPAs are based on the third-order nonlinear susceptibility chi (3) in fiber. They can exhibit large bandwidth, and may find applications as optical amplifiers for WDM transmission. They also generate another wavelength, called idler, which contains the same modulation information as the input signal, with an inverted spectrum. This phase-conjugated idler can be used not only for wavelength conversion in WDM networks, but also for mid-span spectral inversion (MSSI) which can combat fiber dispersion, and even some of the detrimental fiber nonlinearities. In this dissertation, a record high-performance fiber OPA with 60 dB signal gain, and a parametric wavelength converter with 40 dB of conversion gain and 3.8 dB of noise figure are experimentally demonstrated. An OPA with 92% pump depletion is analyzed theoretically and demonstrated experimentally. Polarization-independent OPA, both in one-pump and two-pump configurations are investigated. The differences between the two configurations are discussed and other solutions are also proposed to address some issues of linear orthogonal two-pump OPA. In addition, the applications of OPA: as a

  4. Integrated modeling of the GMT laser tomography adaptive optics system (United States)

    Piatrou, Piotr


    Laser Tomography Adaptive Optics (LTAO) is one of adaptive optics systems planned for the Giant Magellan Telescope (GMT). End-to-end simulation tools that are able to cope with the complexity and computational burden of the AO systems to be installed on the extremely large telescopes such as GMT prove to be an integral part of the GMT LTAO system development endeavors. SL95, the Fortran 95 Simulation Library, is one of the software tools successfully used for the LTAO system end-to-end simulations. The goal of SL95 project is to provide a complete set of generic, richly parameterized mathematical models for key elements of the segmented telescope wavefront control systems including both active and adaptive optics as well as the models for atmospheric turbulence, extended light sources like Laser Guide Stars (LGS), light propagation engines and closed-loop controllers. The library is implemented as a hierarchical collection of classes capable of mutual interaction, which allows one to assemble complex wavefront control system configurations with multiple interacting control channels. In this paper we demonstrate the SL95 capabilities by building an integrated end-to-end model of the GMT LTAO system with 7 control channels: LGS tomography with Adaptive Secondary and on-instrument deformable mirrors, tip-tilt and vibration control, LGS stabilization, LGS focus control, truth sensor-based dynamic noncommon path aberration rejection, pupil position control, SLODAR-like embedded turbulence profiler. The rich parameterization of the SL95 classes allows to build detailed error budgets propagating through the system multiple errors and perturbations such as turbulence-, telescope-, telescope misalignment-, segment phasing error-, non-common path-induced aberrations, sensor noises, deformable mirror-to-sensor mis-registration, vibration, temporal errors, etc. We will present a short description of the SL95 architecture, as well as the sample GMT LTAO system simulation

  5. Geometric Theory for the Design of Multielement Optical Systems

    Institute of Scientific and Technical Information of China (English)


    To establish a theoretical basis for providing a better design method of multielement optical systems, we have developed a third-order geometric theory of a plane-symmetric multielement optical system that consists of a planar light source, an arbitrary number of ellipsoidal gratings, and an image plane. Analytic formulas of spot diagrams are derived for the system by analytically following a ray-tracing formalism. With these formulas, coma, spherical aberration, and resultant aberration are discussed. To make the theory practical, we determine the aberration coefficients numerically, rather than analytically, with the aid of ray tracing that takes into account the angular distribution of rays originating from a given light source. A merit function is defined so as to represent closely the variance of the spots formed when an infinite number of rays are traced and to take into account the dimensions of the source and the last optical element. The theory is also applicable to mirror-grating or mirror systems.

  6. Wavefront Sensing for WFIRST with a Linear Optical Model (United States)

    Jurling, Alden S.; Content, David A.


    In this paper we develop methods to use a linear optical model to capture the field dependence of wavefront aberrations in a nonlinear optimization-based phase retrieval algorithm for image-based wavefront sensing. The linear optical model is generated from a ray trace model of the system and allows the system state to be described in terms of mechanical alignment parameters rather than wavefront coefficients. This approach allows joint optimization over images taken at different field points and does not require separate convergence of phase retrieval at individual field points. Because the algorithm exploits field diversity, multiple defocused images per field point are not required for robustness. Furthermore, because it is possible to simultaneously fit images of many stars over the field, it is not necessary to use a fixed defocus to achieve adequate signal-to-noise ratio despite having images with high dynamic range. This allows high performance wavefront sensing using in-focus science data. We applied this technique in a simulation model based on the Wide Field Infrared Survey Telescope (WFIRST) Intermediate Design Reference Mission (IDRM) imager using a linear optical model with 25 field points. We demonstrate sub-thousandth-wave wavefront sensing accuracy in the presence of noise and moderate undersampling for both monochromatic and polychromatic images using 25 high-SNR target stars. Using these high-quality wavefront sensing results, we are able to generate upsampled point-spread functions (PSFs) and use them to determine PSF ellipticity to high accuracy in order to reduce the systematic impact of aberrations on the accuracy of galactic ellipticity determination for weak-lensing science.

  7. Wavefront sensing for WFIRST with a linear optical model (United States)

    Jurling, Alden S.; Content, David A.


    In this paper we develop methods to use a linear optical model to capture the field dependence of wavefront aberrations in a nonlinear optimization-based phase retrieval algorithm for image-based wavefront sensing. The linear optical model is generated from a ray trace model of the system and allows the system state to be described in terms of mechanical alignment parameters rather than wavefront coefficients. This approach allows joint optimization over images taken at different field points and does not require separate convergence of phase retrieval at individual field points. Because the algorithm exploits field diversity, multiple defocused images per field point are not required for robustness. Furthermore, because it is possible to simultaneously fit images of many stars over the field, it is not necessary to use a fixed defocus to achieve adequate signal-to-noise ratio despite having images with high dynamic range. This allows high performance wavefront sensing using in-focus science data. We applied this technique in a simulation model based on the Wide Field Infrared Survey Telescope (WFIRST) Intermediate Design Reference Mission (IDRM) imager using a linear optical model with 25 field points. We demonstrate sub-thousandth-wave wavefront sensing accuracy in the presence of noise and moderate undersampling for both monochromatic and polychromatic images using 25 high-SNR target stars. Using these high-quality wavefront sensing results, we are able to generate upsampled point-spread functions (PSFs) and use them to determine PSF ellipticity to high accuracy in order to reduce the systematic impact of aberrations on the accuracy of galactic ellipticity determination for weak-lensing science.

  8. LFS-90 - A modular system design with fiber optic gyros (United States)

    Handrich, E.; Bueschelberger, H. J.; Kemmler, M.; Krings, M.

    The general design and the main components of the LFS-90, a fiber optic three-axis rate gyro package intended for flight control applications, are described. The LFS-90 fiber gyro system has a modular structure including a sensor module, an opto-module, a digital control module, and a data processor. With the addition of more modules, the system can be extended to a complete attitude and heading reference system for aerospace applications or a low-cost navigator for land vehicles. LFS-90 test data are presented, including the scale factor, bias, and random walk of the main parameters.

  9. Performance of PLL synchronized optical PPM communication systems (United States)

    Chen, C.-C.; Gardner, C. S.


    Receiver timing synchronization of an optical PPM communication system can be achieved using a phase-locked loop (PLL) if the photodetector output is properly processed. The synchronization performance is shown to improve with increasing signal power and decreasing loop bandwidth. The bit error rate performance of the PLL synchronized PPM system is analyzed and compared to that of the perfectly synchronized system. It is shown that the increase in signal power needed to compensate for the imperfect sychronization is small (less than 0.1 dB) for loop bandwidths less than 0.1 percent of the slot frequency.

  10. A displacement measurement system based on optical triangulation method

    Institute of Scientific and Technical Information of China (English)

    FU Xian-bin; LIU Bin; ZHANG Yu-cun


    A new displacement measurement system is described in this paper according to the basic principles of traditional laser triangulation method.The range of the traditional measuring method is enlarged by measuring in sections.Three independent CCDs,which are distributed uniformly along the optical axis,are used to achieve subsection measurement.The plane mirror is regarded as a virtual detector.When imaging beam is reflected by the plane mirror,the beam is imaged on the CCD.The designed system is equivalent to add a CCD.The feasibility of the displacement measurement system is verified by the experiment.

  11. Optical pulse generation system for the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Penko, F; Braucht,; Browning, D; Crane, J K; Dane, B; Deadrick, F; Dreifuerst, G; Henesian, M; Jones, B A; Kot, L; Laumann, C; Martinez, M; Moran, B; Rothenberg, J E; Skulina, K; Wilcox, R B


    We describe the Optical Pulse Generation (OPG) system for the National Ignition Facility ( NIF ). The OPG system begins with the Master Oscillator Room ( MOR ) where the initial, seed pulse for the entire laser system is produced and properly formatted to enhance ignition in the target. The formatting consists of temporally shaping the pulse and adding additional bandwidth to increase the coupling of the laser generated x-rays to the high density target plasma. The pulse produced in the MOR fans out to 48 identical preamplifier modules where it is amplified by a factor of ten billion and spatially shaped for injection into the 192 main amplifier chai

  12. Optical signal processing for enabling high-speed, highly spectrally efficient and high capacity optical systems (United States)

    Fazal, Muhammad Irfan

    The unabated demand for more capacity due to the ever-increasing internet traffic dictates that the boundaries of the state of the art maybe pushed to send more data through the network. Traditionally, this need has been satisfied by multiple wavelengths (wavelength division multiplexing), higher order modulation formats and coherent communication (either individually or combined together). WDM has the ability to reduce cost by using multiple channels within the same physical fiber, and with EDFA amplifiers, the need for O-E-O regenerators is eliminated. Moreover the availability of multiple colors allows for wavelength-based routing and network planning. Higher order modulation formats increases the capacity of the link by their ability to encode data in both the phase and amplitude of light, thereby increasing the bits/sec/Hz as compared to simple on-off keyed format. Coherent communications has also emerged as a primary means of transmitting and receiving optical data due to its support of formats that utilize both phase and amplitude to further increase the spectral efficiency of the optical channel, including quadrature amplitude modulation (QAM) and quadrature phase shift keying (QPSK). Polarization multiplexing of channels can double capacity by allowing two channels to share the same wavelength by propagating on orthogonal polarization axis and is easily supported in coherent systems where the polarization tracking can be performed in the digital domain. Furthermore, the forthcoming IEEE 100 Gbit/s Ethernet Standard, 802.3ba, provides greater bandwidth, higher data rates, and supports a mixture of modulation formats. In particular, Pol-MUX QPSK is increasingly becoming the industry's format of choice as the high spectral efficiency allows for 100 Gbit/s transmission while still occupying the current 50 GHz/channel allocation of current 10 Gbit/s OOK fiber systems. In this manner, 100 Gbit/s transfer speeds using current fiber links, amplifiers, and filters

  13. Limits of spherical blur determined with an adaptive optics mirror. (United States)

    Atchison, David A; Guo, Huanqing; Fisher, Scott W


    We extended an earlier study (Vision Research, 45, 1967-1974, 2005) in which we investigated limits at which induced blur of letter targets becomes noticeable, troublesome and objectionable. Here we used a deformable adaptive optics mirror to vary spherical defocus for conditions of a white background with correction of astigmatism; a white background with reduction of all aberrations other than defocus; and a monochromatic background with reduction of all aberrations other than defocus. We used seven cyclopleged subjects, lines of three high-contrast letters as targets, 3-6 mm artificial pupils, and 0.1-0.6 logMAR letter sizes. Subjects used a method of adjustment to control the defocus component of the mirror to set the 'just noticeable', 'just troublesome' and 'just objectionable' defocus levels. For the white-no adaptive optics condition combined with 0.1 logMAR letter size, mean 'noticeable' blur limits were +/-0.30, +/-0.24 and +/-0.23 D at 3, 4 and 6 mm pupils, respectively. White-adaptive optics and monochromatic-adaptive optics conditions reduced blur limits by 8% and 20%, respectively. Increasing pupil size from 3-6 mm decreased blur limits by 29%, and increasing letter size increased blur limits by 79%. Ratios of troublesome to noticeable, and of objectionable to noticeable, blur limits were 1.9 and 2.7 times, respectively. The study shows that the deformable mirror can be used to vary defocus in vision experiments. Overall, the results of noticeable, troublesome and objectionable blur agreed well with those of the previous study. Attempting to reduce higher-order aberrations or chromatic aberrations, reduced blur limits to only a small extent.

  14. Optical diagnostics based on elastic scattering: Recent clinical demonstrations with the Los Alamos Optical Biopsy System

    Energy Technology Data Exchange (ETDEWEB)

    Bigio, I.J.; Loree, T.R.; Mourant, J.; Shimada, T. [Los Alamos National Lab., NM (United States); Story-Held, K.; Glickman, R.D. [Texas Univ. Health Science Center, San Antonio, TX (United States). Dept. of Ophthalmology; Conn, R. [Lovelace Medical Center, Albuquerque, NM (United States). Dept. of Urology


    A non-invasive diagnostic tool that could identify malignancy in situ and in real time would have a major impact on the detection and treatment of cancer. We have developed and are testing early prototypes of an optical biopsy system (OBS) for detection of cancer and other tissue pathologies. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the microscopic structure of the tissue. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, manifest significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be strongly wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes in an optical signature that is derived from the wavelength dependence of elastic scattering. The data acquisition and storage/display time with the OBS instrument is {approximately}1 second. Thus, in addition to the reduced invasiveness of this technique compared with current state-of-the-art methods (surgical biopsy and pathology analysis), the OBS offers the possibility of impressively faster diagnostic assessment. The OBS employs a small fiber-optic probe that is amenable to use with any endoscope, catheter or hypodermic, or to direct surface examination (e.g. as in skin cancer or cervical cancer). It has been tested in vitro on animal and human tissue samples, and clinical testing in vivo is currently in progress.

  15. Quasi-optical ECRH beam system for MFTF-B

    Energy Technology Data Exchange (ETDEWEB)

    Yugo, J.J.; Shearer, J.W.; Ziolkowski, R.W.; Krause, K.H.; Berkey, J.H.; Fong, C.G.


    Multiple frequency electron cyclotron resonance heating (ECRH) is required in the anchor regions of MFTF-B. The requirement for a high transmission efficiency as well as some aspects of the operating environment make a quasi-optical transmission system attractive (neutron activation and damage of materials, x-rays, rf window coolant leaks, cryogenic temperatures, etc.). A quasi-optical transmission system increases the transmission efficiency and reduces the complexity of the hardware in the vacuum vessel. A beam transmission efficiency of 94 percent through the off-axis, fundamental electron cyclotron resonance position is achieved if the plasma density is limited to n/sub p/ less than 4 x 10/sup 8/ cm/sup -3/. For MFTF-B parameters and ECRH at 28 GHz the electron mean free path for an ionizing collision is 5 x 10/sup 6/ cm so that most electrons will reach the wall prior to producing additional ionization of the background gas.

  16. Digital optical tomography system for dynamic breast imaging. (United States)

    Flexman, Molly L; Khalil, Michael A; Al Abdi, Rabah; Kim, Hyun K; Fong, Christopher J; Desperito, Elise; Hershman, Dawn L; Barbour, Randall L; Hielscher, Andreas H


    Diffuse optical tomography has shown promising results as a tool for breast cancer screening and monitoring response to chemotherapy. Dynamic imaging of the transient response of the breast to an external stimulus, such as pressure or a respiratory maneuver, can provide additional information that can be used to detect tumors. We present a new digital continuous-wave optical tomography system designed to simultaneously image both breasts at fast frame rates and with a large number of sources and detectors. The system uses a master-slave digital signal processor-based detection architecture to achieve a dynamic range of 160 dB and a frame rate of 1.7 Hz with 32 sources, 64 detectors, and 4 wavelengths per breast. Included is a preliminary study of one healthy patient and two breast cancer patients showing the ability to identify an invasive carcinoma based on the hemodynamic response to a breath hold.

  17. Polarization Drift Channel Model for Coherent Fibre-Optic Systems

    CERN Document Server

    Czegledi, Cristian B; Agrell, Erik; Johannisson, Pontus


    A theoretical framework is introduced to model the dynamical changes of the state of polarization during transmission in coherent fibre-optic systems. The model generalizes the one-dimensional phase noise random walk to higher dimensions, accounting for random polarization drifts. The model is described in the Jones, Stokes and real 4-dimensional formalisms, and the mapping between them is derived. Such a model will be increasingly important in simulating and optimizing future optical systems, which to a higher and higher degree rely on transmission and detection on both polarizations jointly using sophisticated digital signal processing. Such analysis cannot be carried out using the more rudimentary polarization drift models in use today, which only account for deterministic effects. The proposed polarization drift model is the first of its kind and will likely be useful in a wide-range of photonics applications where stochastic polarization fluctuation is an issue.

  18. The optical system of the TUS space experiment (United States)

    Tkachev, L.; Biktemerova, S.; Garipov, G.; Grinyuk, A.; Grebenyuk, V.; Khrenov, B.; Klimov, P.; Naumov, D.; Porokhovoy, S.; Sabirov, B.; Saprykin, O.; Slunecka, M.; Tkachenko, A.; Yashin, I.


    The TUS space experiment has been proposed to address some of the most important astrophysical and particle physics problems. It is aimed to study the energy spectrum, composition and angular distribution of Ultra High Energy Cosmic Rays (UHECR) at E≈1020eV in the region of the GZK cutoff. The TUS mission is now planned for operation at the Small Space Apparatus (SSA) as an additional payload of the Foton-4 Russian-ESA satellite. The TUS optical system is an important part of the detector which will measure the fluorescence light radiated by EAS of the UHECR. It consists of a 7-segment Fresnel mirror-concentrator of 2 sq. m. The photo receiver at the mirror focal surface comprises 256 PMT pixels. In this paper the TUS optical system is described. Production of its technological prototype is in progress.

  19. Optical readout and control systems for the CMS tracker

    CERN Document Server

    Troska, Jan K; Faccio, F; Gill, K; Grabit, R; Jareno, R M; Sandvik, A M; Vasey, F


    The Compact Muon Solenoid (CMS) Experiment will be installed at the CERN Large Hadron Collider (LHC) in 2007. The readout system for the CMS Tracker consists of 10000000 individual detector channels that are time-multiplexed onto 40000 unidirectional analogue (40 MSample /s) optical links for transmission between the detector and the 65 m distant counting room. The corresponding control system consists of 2500 bi-directional digital (40 Mb/s) optical links based as far as possible upon the same components. The on-detector elements (lasers and photodiodes) of both readout and control links will be distributed throughout the detector volume in close proximity to the silicon detector elements. For this reason, strict requirements are placed on minimal package size, mass, power dissipation, immunity to magnetic field, and radiation hardness. It has been possible to meet the requirements with the extensive use of commercially available components with a minimum of customization. The project has now entered its vol...

  20. Acousto-optic laser projection systems for displaying TV information (United States)

    Gulyaev, Yu V.; Kazaryan, M. A.; Mokrushin, Yu M.; Shakin, O. V.


    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation.

  1. Parametric Analysis of Fiber Non-Linearity in Optical systems

    Directory of Open Access Journals (Sweden)

    Abhishek Anand


    Full Text Available With the advent of technology Wavelength Division Multiplexing (WDM is always an area of interest in the field of optical communication. When combined with Erbium Doped Fiber Amplifier (EDFA, it provides high data transmission rate and low attenuation. But due to fiber non-linearity such as Self Phase Modulation (SPM and Cross Phase Modulation (XPM the system performance has degraded. This non-linearity depends on different parameters of an optical system such as channel spacing, power of the channel and length of the fiber section. The degradation can be seen in terms of phase deviation and Bit Error Rate (BER performance. Even after dispersion compensation at the fiber end, residual pulse broadening still exists due to cross talk penalty.

  2. Optical Systems for the Fourth Generation Light Source, 4GLS

    CERN Document Server

    Quinn, Frances; MacDonald, Mike; Roper, Mark


    4GLS is a multi-user, multi-source facility proposed for construction at Daresbury Laboratory in the UK. By exploiting super-conducting linac technology with energy recovery, it will combine three free electron lasers and a range of conventional synchrotron radiation sources covering the THz to SXR region. The facility will provide femtosecond pulses at high repetition rate, with the FELs delivering GW power in the VUV and XUV region. This paper discusses the options and challenges for the optical systems associated with the suite of photon sources. The beamlines will need to operate both independently and in flexible, synchronised combinations. Together with the requirements for preserving the ultra-bright, fast pulse properties, this places unique demands on the design, layout and operational modes. The paper summarises current technical achievements and identifies the research and development necessary before detailed design of the 4GLS optical systems.

  3. Development of the readout system for waveguide multilayer optical card

    Institute of Scientific and Technical Information of China (English)

    GU Min-fen; LIANG Zhong-cheng; WANG Ren-zhou; DONG Xiang-mei; ZHANG Pei-ming; CHEN Jia-bi


    Waveguide multilayer optical card(WMOC)is a novel storage device of three-dimensional optical information.An ad-vancod readout system fitting for the WMOC is introduced in this paper.The hardware mainly consists of the light source for reading,WMOC,motorized stages addressing unit,microscope imaging unit,CCD detecting unit and PC controlling & processing unit.The movement of the precision motorized stage is controlled by the computer through Visual Basic(VB) language in software.A control panel is also designed to get the layer address and the page address through which the position of the motorized stages call be changed.The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.

  4. Resonant state expansion applied to planar open optical systems

    CERN Document Server

    Doost, M B; Muljarov, E A


    The resonant state expansion (RSE), a novel perturbation theory of Brillouin-Wigner type developed in electrodynamics [Muljarov, Langbein, and Zimmermann, Europhys. Lett., 92, 50010(2010)], is applied to planar, effectively one-dimensional optical systems, such as layered dielectric slabs and Bragg reflector microcavities. It is demonstrated that the RSE converges with a power law in the basis size. Algorithms for error estimation and their reduction by extrapolation are presented and evaluated. Complex eigenfrequencies, electro-magnetic fields, and the Green's function of a selection of optical systems are calculated, as well as the observable transmission spectra. In particular we find that for a Bragg-mirror microcavity, which has sharp resonances in the spectrum, the transmission calculated using the resonant state expansion reproduces the result of the transfer/scattering matrix method.

  5. Summary of the transfer of optical processing to systems: optical pattern recognition program (United States)

    Lindell, Scott D.


    Martin Marietta has successfully completed a TOPS optical pattern recognition program. The program culminated in August 1994 with an automatic target recognition flight demonstration inwhich an M60A2 tank was acquired, identified, and tracked with a visible seeker from a UH-1 helicopter flying a fiber optic guided missile (FOG-M) mission profile. The flight demonstration was conducted by the US Army Missile Command (MICOM) and supported by Martin Marietta. The pattern recognition system performance for acquiring and identifying the M60A2 tank, which was positioned among an array with five other vehicle types, was 90% probability of correct identification and a 4% false identification for over 40,000 frames of imagery processed. Imagery was processed at a 15 Hz input rate with a 1 ft3, 76 W, 4 GFLOP processor performing up to 800 correlations per second.

  6. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru Miyauchi; Yanjun Sun


    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirmlow optical loss and environmental stabilities.

  7. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru; Miyauchi; Yanjun; Sun


    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirm low optical loss and environmental stabilities.

  8. Closed-loop adaptive optical system with a liquid mirror. (United States)

    Vdovin, Gleb


    A deformable mirror based on internal reflection from an electrostatically deformable liquid-air interface is proposed and investigated. A differential equation describing the static behavior of such a mirror is analyzed and solved numerically. Stable closed-loop operation of an adaptive optical system with a liquid deformable mirror is demonstrated, including forming and the correction of low-order aberrations described by Zernike polynomials and the real-time correction of dynamically changing aberrations.

  9. Optical glass compatibility for the design of apochromatic systems


    Gruescu C.; Nicoara I.; Popov D.; Bodea R.; Hora H.


    The design of apochromatic systems is difficult because of two problems: the glass sorts compatibility and the c1/ca arbitrary input ratio. The optical glass manufacturers offer a wide range of sorts, so that the choice of triplet compatible glasses becomes itself an important separate problem. The paper provides a solution of mathematical modeling for the glass compatibility and, practically, analyses the sorts presented by Schott GmbH. The original software provided 22 compatible glass trip...

  10. Synchronization of a chaotic optical system using control (United States)

    Lai, Ying-Cheng; Grebogi, Celso


    It has been demonstrated that two identical chaotic systems can be made to synchronize by applying small, judiciously chosen, temporal parameter perturbations to one of them [Y. C. Lai and C. Grebogi, Phys. Rev. E 47, 2357(1993)]. This idea is applied to a nonlinear optical ring resonator modeled by the Ikeda-Hammel-Jones-Maloney map. The average time to achieve synchronization and the effect of noise are also discussed.

  11. Exploiting Repulsive and Attractive Optical Forces in Advanced Nanophotonic Systems (United States)


    photons from a filled cavity to an empty cavity in an amount that can be controlled with an achieved minimum of ~1000 photons per mechanical cycle. This...envision ultimately, in strongly coupled systems, coupling between single photon states can be modulated by a single phonon for quantum regime...platform for exploiting light-sound interaction with much improved strength and expanded parameter space . Novel optical phenomenon predicted

  12. EUV optical system for the reticle imaging microscope (RIM) (United States)

    Glatzel, H.; Daniel, J.; Khajehnouri, K.; Mueller, U.; Roff, T.; Rosenbohm, J.; Sporer, S.


    The EUV optical system of the Reticle Imaging Microscope (RIM) for EUV mask inspection consists of a pinched Xeplasma source, a pupil-relayed Koehler-type illumination system and an equal-radii Cassegrain-type microscope with a 10x magnification1. The 3D surface topologies were characterized over spatial wavelengths ranging from the clear apertures down to a few nanometers by using a portfolio of instruments including contacting profilometry, phase-shifting interferometry at 633 nm at various magnifications and Atomic Force Microscopy. Measured 3D topography maps were Fourier analyzed and Power Spectral Densities (PSDs) are computed over spatial periods ranging from the critical aperture down to a few nm. Integrated RMS surface errors over typically reported spatial period ranges were computed. For a different optical system we improved our polishing process to reduce surface errors for spatial periods below 10 mm. PSDs and integrated RMS surface errors will be shown in comparison with typical RIM surfaces. All surfaces of the RIM optical system were coated with high-reflectivity coatings to maximize optical throughput. A description of the coatings and their performance had been published recently by Michael Kriese et al.2 The transmitted wavefront error (TWF) of the imager module was measured in a double pass configuration using a Fizeau-type Interferometer at 633 nm wavelength and a convex retrosphere. The measured TWF will be shown over the entire Numerical Aperture (NA = 0.0625) of the microscope. The integrated RMS of the TWF measured 0.79 nm.

  13. DONUTS: A science frame autoguiding algorithm with sub-pixel precision, capable of guiding on defocused stars

    CERN Document Server

    McCormac, J; Skillen, I; Faedi, F; Todd, I; Watson, C A


    We present the DONUTS autoguiding algorithm, designed to fix stellar positions at the sub-pixel level for high-cadence time-series photometry, which is also capable of autoguiding on defocused stars. DONUTS was designed to calculate guide corrections from a series of science images and re-centre telescope pointing between each exposure. The algorithm has the unique ability of calculating guide corrections from under-sampled to heavily defocused point spread functions. We present the case for why such an algorithm is important for high precision photometry and give our results from off and on-sky testing. We discuss the limitations of DONUTS and the facilities where it soon will be deployed.

  14. Third Harmonic Generation of a Short Pulse Laser in a Tunnel Ionizing Plasma: Effect of Self-Defocusing

    Directory of Open Access Journals (Sweden)

    Niti Kant


    Full Text Available Third harmonic generation of a Gaussian short pulse laser in a tunnel ionizing plasma is investigated. A Gaussian short pulse laser propagating through a tunnel ionizing plasma generates third harmonic wave. Inhomogeneity of the electric field along the wavefront of the fundamental laser pulse causes more ionization along the axis of propagation while less ionization off axis, leading to strong density gradient with its maximum on the axis of propagation. The medium acts like a diverging lens and pulse defocuses strongly. The normalized third harmonic amplitude varies periodically with the distance with successive maxima acquiring lower value. The self-defocusing of the fundamental laser pulse decays the intensity of the third harmonic pulse.

  15. Quasi-integrability in the modified defocusing non-linear Schr\\"odinger model and dark solitons

    CERN Document Server

    Blas, H


    The concept of quasi-integrability has been examined in the context of deformations of the defocusing non-linear Schr\\"odinger model (NLS). Our results show that the quasi-integrability concept, recently discussed in the context of deformations of the sine-Gordon, Bullough-Dodd and focusing NLS models, holds for the modified defocusing NLS model with dark soliton solutions and it exhibits the new feature of an infinite sequence of alternating conserved and asymptotically conserved charges. For the special case of two dark soliton solutions, where the field components are eigenstates of a space-reflection symmetry, the first four and the sequence of even order charges are exactly conserved in the scattering process of the solitons. Such results are obtained through analytical and numerical methods, and employ adaptations of algebraic techniques used in integrable field theories. We perform extensive numerical simulations and consider the scattering of dark solitons for the cubic-quintic NLS model with potentia...

  16. Mechanical and optical characteristics of a new fiber optical system used for cardiac contraction measurement. (United States)

    Kloppe, A; Hoeland, K; Müller, S; Hexamer, M; Nowack, G; Mügge, A; Werner, J


    In order to obtain a better physiological performance and a closer restoration of the regular rhythm of failing hearts, a new fiber optical sensor system for the measurement of cardiac contraction has been developed. It consists of an opto-electrical unit and a sensing fiber which has to be positioned in the heart. The objective of this new fiber optic sensor system is to use the inotropic information to adjust a stimulation algorithm in single or multichamber pacing or to detect arrhythmia in insufficient heart function. In this study, the mechanical and optical characteristics of different fibers are investigated. The relationship between the attenuation (with an achieved numerical maximum of 0.3 dB), the bending diameter and the angle of bending is determined in a range of 20-160 mm. The most suitable fiber for the application in cardiological problems is determined (WT8 fiber), for which the sensitivity is analyzed. Additionally, power spectra are calculated from WT8 fiber signals obtained from pig hearts, working under physiological conditions. The maximal frequency response was 23 Hz. It is concluded that the fiber optical measurement of cardiac contraction is not only feasible and reproducible, but the WT8 fiber also shows optimal behavior in the range of parameters occurring in the heart chambers. Nevertheless, in order to restrict the measured signal reliably to bending processes within the chambers only, it is concluded that a special combined fiber has to be constructed with a high sensitivity only at its terminal section within the heart.

  17. The simulation study on optical target laser active detection performance (United States)

    Li, Ying-chun; Hou, Zhao-fei; Fan, Youchen


    According to the working principle of laser active detection system, the paper establishes the optical target laser active detection simulation system, carry out the simulation study on the detection process and detection performance of the system. For instance, the performance model such as the laser emitting, the laser propagation in the atmosphere, the reflection of optical target, the receiver detection system, the signal processing and recognition. We focus on the analysis and modeling the relationship between the laser emitting angle and defocus amount and "cat eye" effect echo laser in the reflection of optical target. Further, in the paper some performance index such as operating range, SNR and the probability of the system have been simulated. The parameters including laser emitting parameters, the reflection of the optical target and the laser propagation in the atmosphere which make a great influence on the performance of the optical target laser active detection system. Finally, using the object-oriented software design methods, the laser active detection system with the opening type, complete function and operating platform, realizes the process simulation that the detection system detect and recognize the optical target, complete the performance simulation of each subsystem, and generate the data report and the graph. It can make the laser active detection system performance models more intuitive because of the visible simulation process. The simulation data obtained from the system provide a reference to adjust the structure of the system parameters. And it provides theoretical and technical support for the top level design of the optical target laser active detection system and performance index optimization.

  18. Presentation of the first PLM integrated optical simulation software for the design and engineering of optical systems (United States)

    Delacour, Jacques F.; Cuinier, Jean-Luc


    The Computer Aided Design, Manufacturing and Engineering world has gradually welcomed simulation tools enabling the modeling of machining, thermal effects, mechanical, dynamic-motion, vibration and acoustic phenomena... but not optical simulation which has evolved independently from the CAD environment. The innovation presented here with SPEOS CAA V5 Based software integrated in CATIA and ENOVIA DMU V5 software from Dassault Systèmes, the premier global PLM solutions provider, is the first optical simulation solution connecting optics to the CAD/CAM/CAE world, and directly impacts and improve the optical design analysis and process. The optical properties are added directly within the software, sharing the same data for mechanical and optical analysis and thus avoiding all the transfer errors. This new approach improves the quality process and allows unlimited detailed mechanical parts used to be used for the simulation. All the geometric transformations and optical properties modifications are done interactively, helping the user to understand the way the photons are propagated in the whole system. New functions available in CATIA/ENOVIA V5 are light emission simulation, light/surface interaction and scattering, light/matter propagation producing optical performance, photometric measurements and stray light analysis. The early integration of optical performances means that a solution can be found faster that will globally fit to all the specifications. This new technology is opening new links with stress effects, thermal effects, mobile and motorized systems, ... during the design of an optical system, giving the ability to evaluate optical performance of any adaptive, opto-mechanical system, projection and display system under virtual environmental conditions (heat, stress,...) that will affect the optical performance.


    Directory of Open Access Journals (Sweden)

    T. V. Ivanova


    Full Text Available Subject of Research. The paper deals with the problems of higher order aspherical surfaces approximation using different equation types. The objects of research are two types of equations for higher order aspherical surfaces description used in different software for optical systems design (SАRО, OPAL, ZEMAX, CODE-V, etc. and dependent on z-coordinate or on a radial coordinate on the surface. Conversion from one type of equations to another is considered in view of application in different software for optical systems design. Methods. The subject matter of the method lies in usage of mean square method approximation for recalculation of high-order aspherical surface. Iterative algorithm for recalculation is presented giving the possibility to recalculate coefficients for different types of equations with required accuracy. Recommendations are given for choosing recalculation parameters such as the number of result equation coefficients, the number of points for recalculation and point allocation on a surface. Main Results. Example of recalculation for aspherical surface and accuracy estimation, including result aberration comparison between initial surface and recalculated surface are presented. The example has shown that required accuracy of surface representation was obtained. Practical Relevance. This technique is usable for recalculation of higher order aspherical surfaces in various types of software for optical systems design and also for research of optimal higher order aspherical surfaces description.

  20. An ATP System for Deep-Space Optical Communication (United States)

    Lee, Shinhak; Irtuzm Gerardi; Alexander, James


    An acquisition, tracking, and pointing (ATP) system is proposed for aiming an optical-communications downlink laser beam from deep space. In providing for a direction reference, the concept exploits the mature technology of star trackers to eliminate the need for a costly and potentially hazardous laser beacon. The system would include one optical and two inertial sensors, each contributing primarily to a different portion of the frequency spectrum of the pointing signal: a star tracker (50 Hz. The outputs of these sensors would be combined in an iterative averaging process to obtain high-bandwidth, high-accuracy pointing knowledge. The accuracy of pointing knowledge obtainable by use of the system was estimated on the basis of an 8-cm-diameter telescope and known parameters of commercially available star trackers and inertial sensors: The single-axis pointing-knowledge error was found to be characterized by a standard deviation of 150 nanoradians - below the maximum value (between 200 and 300 nanoradians) likely to be tolerable in deep-space optical communications.