Highly doped semiconductor plasmonic nanoantenna arrays for polarization selective broadband surface-enhanced infrared absorption spectroscopy of vanillin

Directory of Open Access Journals (Sweden)

Barho Franziska B.

2017-11-01

Full Text Available Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA spectroscopy using adapted nanoantenna substrates is an efficient technique for the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials for plasmonics, especially for more flexibility concerning the targeted spectral range. Here, we report on rectangular-shaped, highly Si-doped InAsSb nanoantennas sustaining polarization switchable longitudinal and transverse plasmonic resonances in the mid-infrared. For small array periodicities, the highest reflectance intensity is obtained. Large periodicities can be used to combine localized surface plasmon resonances (SPR with array resonances, as shown in electromagnetic calculations. The nanoantenna arrays can be efficiently used for broadband SEIRA spectroscopy, exploiting the spectral overlap between the large longitudinal or transverse plasmonic resonances and narrow infrared active absorption features of an analyte molecule. We demonstrate an increase of the vibrational line intensity up to a factor of 5.7 of infrared-active absorption features of vanillin in the fingerprint spectral region, yielding enhancement factors of three to four orders of magnitude. Moreover, an optimized readout for SPR sensing is proposed based on slightly overlapping longitudinal and transverse localized SPR.

Improving plasmonic waveguides coupling efficiency using nanoantennas

DEFF Research Database (Denmark)

Andryieuski, Andrei; Malureanu, Radu; Bouillard, Jean-Sebastien

2012-01-01

. The classical dipole antenna scheme can be improved by changing the nanoantenna geometry, adding constructive elements such as reflecting bars and mirrors and using arrays of antennas. The modelling designates that the coupling efficiency from a vertical fiber to a plasmonic waveguide can be improved more than......Plasmonic waveguides bear a lot of potential for photonic applications. However, one of the challenges for implementing them in devices is the low coupling efficiency to and from optical fibers. We report on our approach to facilitate the coupling efficiency with the use of metallic nanoantennas...... in 180 times in comparison with a direct fiber-waveguide coupling. Pros and cons of each configuration are discussed. Fabrication and characterisation results are reported....

Tunable optical switching in the near-infrared spectral regime by employing plasmonic nanoantennas containing phase change materials.

Science.gov (United States)

Savaliya, Priten B; Thomas, Arun; Dua, Rishi; Dhawan, Anuj

2017-10-02

We propose the design of switchable plasmonic nanoantennas (SPNs) that can be employed for optical switching in the near-infrared regime. The proposed SPNs consist of nanoantenna structures made up of a plasmonic metal (gold) such that these nanoantennas are filled with a switchable material (vanadium dioxide). We compare the results of these SPNs with inverted SPN structures that consist of gold nanoantenna structures surrounded by a layer of vanadium dioxide (VO 2 ) on their outer surface. These nanoantennas demonstrate switching of electric-field intensity enhancement (EFIE) between two states (On and Off states), which can be induced thermally, optically or electrically. The On and Off states of the nanoantennas correspond to the metallic and semiconductor states, respectively of the VO 2 film inside or around the nanoantennas, as the VO 2 film exhibits phase transition from its semiconductor state to the metallic state upon application of thermal, optical, or electrical energy. We employ finite-difference time-domain (FDTD) simulations to demonstrate switching in the EFIE for four different SPN geometries - nanorod-dipole, bowtie, planar trapezoidal toothed log-periodic, and rod-disk - and compare their near-field distributions for the On and Off states of the SPNs. We also demonstrate that the resonance wavelength of the EFIE spectra gets substantially modified when these SPNs switch between the two states.

Plasmonic nanoantenna arrays for surface-enhanced Raman spectroscopy of lipid molecules embedded in a bilayer membrane.

Science.gov (United States)

Kühler, Paul; Weber, Max; Lohmüller, Theobald

2014-06-25

We demonstrate a strategy for surface-enhanced Raman spectroscopy (SERS) of supported lipid membranes with arrays of plasmonic nanoantennas. Colloidal lithography refined with plasma etching is used to synthesize arrays of triangular shaped gold nanoparticles. Reducing the separation distance between the triangle tips leads to plasmonic coupling and to a strong enhancement of the electromagnetic field in the nanotriangle gap. As a result, the Raman scattering intensity of molecules that are located at this plasmonic "hot-spot" can be increased by several orders of magnitude. The nanoantenna array is then embedded with a supported phospholipid membrane which is fluid at room temperature and spans the antenna gap. This configuration offers the advantage that molecules that are mobile within the bilayer membrane can enter the "hot-spot" region via diffusion and can therefore be measured by SERS without static entrapment or adsorption of the molecules to the antenna itself.

Magneto-plasmonic nanoantennas: Basics and applications

Directory of Open Access Journals (Sweden)

Ivan S. Maksymov

2016-11-01

Full Text Available Plasmonic nanoantennas are a hot and rapidly expanding research field. Here we overview basic operating principles and applications of novel magneto-plasmonic nanoantennas, which are made of ferromagnetic metals and driven not only by light, but also by external magnetic fields. We demonstrate that magneto-plasmonic nanoantennas enhance the magneto-optical effects, which introduces additional degrees of freedom in the control of light at the nano-scale. This property is used in conceptually new devices such as magneto-plasmonic rulers, ultra-sensitive biosensors, one-way subwavelength waveguides and extraordinary optical transmission structures, as well as in novel biomedical imaging modalities. We also point out that in certain cases ‘non-optical’ ferromagnetic nanostructures may operate as magneto-plasmonic nanoantennas. This undesigned extra functionality capitalises on established optical characterisation techniques of magnetic nanomaterials and it may be useful for the integration of nanophotonics and nanomagnetism on a single chip.

Directional Emission from Dielectric Leaky-Wave Nanoantennas

Science.gov (United States)

Peter, Manuel; Hildebrandt, Andre; Schlickriede, Christian; Gharib, Kimia; Zentgraf, Thomas; Förstner, Jens; Linden, Stefan

2017-07-01

An important source of innovation in nanophotonics is the idea to scale down known radio wave technologies to the optical regime. One thoroughly investigated example of this approach are metallic nanoantennas which employ plasmonic resonances to couple localized emitters to selected far-field modes. While metals can be treated as perfect conductors in the microwave regime, their response becomes Drude-like at optical frequencies. Thus, plasmonic nanoantennas are inherently lossy. Moreover, their resonant nature requires precise control of the antenna geometry. A promising way to circumvent these problems is the use of broadband nanoantennas made from low-loss dielectric materials. Here, we report on highly directional emission from active dielectric leaky-wave nanoantennas made of Hafnium dioxide. Colloidal semiconductor quantum dots deposited in the nanoantenna feed gap serve as a local light source. The emission patterns of active nanoantennas with different sizes are measured by Fourier imaging. We find for all antenna sizes a highly directional emission, underlining the broadband operation of our design.

Optical antennas for far and near field metrology

NARCIS (Netherlands)

Silvestri, F.; Bernal Arango, F.; Vendel, K.J.A.; Gerini, G.; Bäumer, S.M.B.; Koenderink, A.F.

2016-01-01

This paper presents the use of optical antennas in metrology scenarios. Two design concepts are presented: dielectric nanoresonator arrays and plasmonic nanoantennas arrays. The first ones are able to focus an incident light beam at an arbitrary focal plane. The nanoantennas arrays can be employed

Novel Directional Nanoantennas for Single-Emitter Sources and Wireless Nano-Links

Directory of Open Access Journals (Sweden)

Maciej Klemm

2012-01-01

Full Text Available Optical nanoantennas are emerging as one of the key components in the future nanophotonic and plasmonic circuits. The first optical nanoantennas were in a form of simple spherical nanoparticles. Recently more complex Yagi-Uda nanoantenna structures were demonstrated. These nanoantennas enhance radiation of single emitters and provide well-defined directional radiation. In this contribution, we present the novel design of the directional nanoantenna, which is excited from the propagating mode of the plasmonic waveguide. The nanoantenna design is based on the travelling wave principle, well known at RF/microwave frequencies. By properly designing the propagating parts of the nanoantenna, a very efficient coupling to free space wave impedance can be achieved. Furthermore, the control over the radiation direction and beam width is relatively easy with this nanoantenna. Compared to the previously published Yagi-Uda designs, the new nanoantenna presented in this work has directivity three times higher.

Optical Nano-antennae as Compact and Efficient Couplers from Free-space to Waveguide Modes

DEFF Research Database (Denmark)

Zenin, Vladimir A.; Malureanu, Radu; Volkov, Valentyn

2015-01-01

Optical nano-antennae are one of the possible solutions for coupling free-space radiation into subwavelength waveguides. Our efforts were concentrated on coupling between an optical fibre and a plasmonic slot waveguide. Such coupling is still an issue to be solved in order to advance the use...... of plasmonic waveguides for optical interconnects. During the talk, we will present our modelling optimisation, fabrication and measurement of the nano-antennae functionality. For the modelling part, we used CST Microwave studio for optimising the antenna geometry. Various antennae were modelled and fabricated....... The fabrication was based on electron beam lithography and lift-off processes. The measurements were performed with scattering scanning near-field microscope and allowed the retrieval of both amplitude and phase of the propagating plasmon. The obtained values agree very well with the theoretically predicted ones...

Nanoantenna using mechanical resonance

KAUST Repository

Chang Hwa Lee,; Seok Woo Lee,; Lee, Seung S

2010-01-01

nanorod array. The modulated signals are received successfully with the transmission carrier wave frequency (248MHz) and the proposed nanoantenna is expected to be used in communication system for ultra small scale sensor. ©2010 IEEE.

Modulatable optical radiators and metasurfaces based on quantum nanoantennas

KAUST Repository

Chen, Pai-Yen

2015-01-20

We investigate the tunable and switchable optical radiators and metamaterials formed by metallic nanodipole antennas with submicroscopic gaps (1.2 nm), of which linear and third-order nonlinear quantum conductivities are observed due to the photon-assisted tunneling effect. The quantum conductivities induced at the nanogap are relevant to power dissipations, which can be enhanced by the strongly localized optical fields associated with the plasmonic resonance. We demonstrate that the scattering property of an individual quantum nanoantenna and the transparency of a metamasurface constituted of it can be tuned by electrostatically controlling the linear conductivity (electronic tuning) or by adjusting the irradiation intensity that varies the nonlinear quantum conductivity (all-optical tuning).

Modulatable optical radiators and metasurfaces based on quantum nanoantennas

KAUST Repository

Chen, Pai-Yen; Farhat, Mohamed

2015-01-01

We investigate the tunable and switchable optical radiators and metamaterials formed by metallic nanodipole antennas with submicroscopic gaps (1.2 nm), of which linear and third-order nonlinear quantum conductivities are observed due to the photon-assisted tunneling effect. The quantum conductivities induced at the nanogap are relevant to power dissipations, which can be enhanced by the strongly localized optical fields associated with the plasmonic resonance. We demonstrate that the scattering property of an individual quantum nanoantenna and the transparency of a metamasurface constituted of it can be tuned by electrostatically controlling the linear conductivity (electronic tuning) or by adjusting the irradiation intensity that varies the nonlinear quantum conductivity (all-optical tuning).

Optical nanoantennas for multiband surface-enhanced infrared and raman spectroscopy

KAUST Repository

D'Andrea, Cristiano

2013-04-23

In this article we show that linear nanoantennas can be used as shared substrates for surface-enhanced Raman and infrared spectroscopy (SERS and SEIRS, respectively). This is done by engineering the plasmonic properties of the nanoantennas, so to make them resonant in both the visible (transversal resonance) and the infrared (longitudinal resonance), and by rotating the excitation field polarization to selectively take advantage of each resonance and achieve SERS and SEIRS on the same nanoantennas. As a proof of concept, we have fabricated gold nanoantennas by electron beam lithography on calcium difluoride (1-2 μm long, 60 nm wide, 60 nm high) that exhibit a transverse plasmonic resonance in the visible (640 nm) and a particularly strong longitudinal dipolar resonance in the infrared (tunable in the 1280-3100 cm -1 energy range as a function of the length). SERS and SEIRS detection of methylene blue molecules adsorbed on the nanoantenna\\'s surface is accomplished, with signal enhancement factors of 5 × 102 for SERS (electromagnetic enhancement) and up to 105 for SEIRS. Notably, we find that the field enhancement provided by the transverse resonance is sufficient to achieve SERS from single nanoantennas. Furthermore, we show that by properly tuning the nanoantenna length the signals of a multitude of vibrational modes can be enhanced with SEIRS. This simple concept of plasmonic nanosensor is highly suitable for integration on lab-on-a-chip schemes for label-free chemical and biomolecular identification with optimized performances. © 2013 American Chemical Society.

Optical nanoantennas for multiband surface-enhanced infrared and raman spectroscopy

KAUST Repository

D'Andrea, Cristiano; Bochterle, Jö rg; Toma, Andrea; Huck, Christian W.; Neubrech, Frank; Messina, Elena; Fazio, Barbara; Maragó , Onofrio M.; Di Fabrizio, Enzo M.; Lamy De La Chapelle, Marc L.; Gucciardi, Pietro Giuseppe; Pucci, Annemarie

2013-01-01

In this article we show that linear nanoantennas can be used as shared substrates for surface-enhanced Raman and infrared spectroscopy (SERS and SEIRS, respectively). This is done by engineering the plasmonic properties of the nanoantennas, so to make them resonant in both the visible (transversal resonance) and the infrared (longitudinal resonance), and by rotating the excitation field polarization to selectively take advantage of each resonance and achieve SERS and SEIRS on the same nanoantennas. As a proof of concept, we have fabricated gold nanoantennas by electron beam lithography on calcium difluoride (1-2 μm long, 60 nm wide, 60 nm high) that exhibit a transverse plasmonic resonance in the visible (640 nm) and a particularly strong longitudinal dipolar resonance in the infrared (tunable in the 1280-3100 cm -1 energy range as a function of the length). SERS and SEIRS detection of methylene blue molecules adsorbed on the nanoantenna's surface is accomplished, with signal enhancement factors of 5 × 102 for SERS (electromagnetic enhancement) and up to 105 for SEIRS. Notably, we find that the field enhancement provided by the transverse resonance is sufficient to achieve SERS from single nanoantennas. Furthermore, we show that by properly tuning the nanoantenna length the signals of a multitude of vibrational modes can be enhanced with SEIRS. This simple concept of plasmonic nanosensor is highly suitable for integration on lab-on-a-chip schemes for label-free chemical and biomolecular identification with optimized performances. © 2013 American Chemical Society.

Investigation of a slot nanoantenna in optical frequency range

Science.gov (United States)

Dinesh kumar, V.; Asakawa, Kiyoshi

2009-11-01

Following the analogy of radio frequency slot antenna and its complementary dipole, we propose the implementation of a slot nanoantenna (SNA) in the optical frequency range. Using finite-difference time-domain (FDTD) method, we investigate the electromagnetic (EM) properties of a SNA formed in a thin gold film and compare the results with the properties of a gold dipole nanoantenna (DNA) of the same dimension as the slot. It is found that the response of the SNA is very similar to the DNA, like their counterparts in the radio frequency (RF) range. The SNA can enhance the near field intensity of incident field which strongly depends on its feedgap dimension. The resonance of the SNA is influenced by its slot length; for the increasing slot length, resonant frequency decreases whereas the sharpness of resonance increases. Besides, the resonance of the SNA is found sensitive to the thickness of metal film, when the latter is smaller than the skin depth. The effect of polarization of incident field on the EM response of the SNA was examined; the field enhancement is optimum when polarization is parallel to the feedgap. Finally, we calculate the radiation patterns of the DNA and SNA and compare them with those of the RF dipole antenna. The radiation pattern of the SNA is found to be independent of its slot length when excited at resonant frequency. To the best of our knowledge, this is the first study on a slot antenna in the optical frequency.

Controlling the shapes and sizes of metallic nanoantennas for detection of biological molecules using hybridization phase of plasmon resonances and photonic lattice modes

Science.gov (United States)

Gutha, Rithvik R.; Sharp, Christina; Wing, Waylin J.; Sadeghi, Seyed M.

2018-02-01

Chemical sensing based on Localized Surface Plasmonic Resonances (LSPR) and the ultra-sharp optical features of surface lattice resonances (SLR) of arrays of metallic nanoantennas have attracted much attention. Recently we studied biosensing based on the transition between LSPR and SLR (hybridization phase), demonstrating significantly higher refractive index sensitivity than each of these resonances individually. In this contribution we study the impact of size and shape of the metallic nanoantennas on the hybridization process and the way they influence application of this process for biosensing, wherein miniscule variation of the refractive index of the environment leads to dramatic changes in the spectral properties of the arrays.

Nanoantennas for visible and infrared radiation

International Nuclear Information System (INIS)

Biagioni, Paolo; Huang, Jer-Shing; Hecht, Bert

2012-01-01

Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

Nanoantennas for visible and infrared radiation

Energy Technology Data Exchange (ETDEWEB)

Biagioni, Paolo [CNISM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Huang, Jer-Shing [Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Hecht, Bert [Nano-Optics and Biophotonics Group, Department of Experimental Physics 5, Wilhelm Conrad Roentgen Research Center for Complex Material Systems (RCCM), Physics Institute, University of Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany)

2012-02-15

Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

Impedance of a nanoantenna

International Nuclear Information System (INIS)

Greffet, Jean-Jacques; Laroche, Marine; Marquier, Francois

2009-01-01

We introduce a generalized definition of the impedance of a nanoantenna that can be applied to any system. We also introduce a definition of the impedance of a two level system. Using this framework, we establish a link between the electrical engineering and the quantum optics picture of light emission.

Optical characterization of Jerusalem cross-shaped nanoaperture antenna arrays

Science.gov (United States)

Turkmen, Mustafa; Aslan, Ekin; Aslan, Erdem

2014-03-01

Recent advances in nanofabrication and computational electromagnetic design techniques have enabled the realization of metallic nanostructures in different shapes and sizes with adjustable resonance frequencies. To date, many metamaterial designs in various geometries with the used of different materials have been presented for the applications of surface plasmons, cloaking, biosensing, and frequency selective surfaces1-5. Surface plasmons which are collective electron oscillations on metal surfaces ensure that plasmonic nanoantennas can be used in many applications like biosensing at infrared (IR) and visible regions. The nanostructure that we introduce has a unit cell that consists of Jerusalem crossshaped nanoaperture on a gold layer, which is standing on suspended SiNx, Si or glass membranes. The proposed nanoaperture antenna array has a regular and stable spectral response. In this study, we present sensitivity of the resonance characteristics of Jerusalem cross-shaped nanoaperture antenna arrays to the changes in substrate parameters and metal thickness. We demonstrate that resonance frequency values can be adjusted by changing the thicknesses and types of the dielectric substrate and the metallic layer. Numerical calculations on spectral response of the nanoantenna array are performed by using Finite Difference Time Domain (FDTD) method6. The results of the simulations specify that resonance frequencies, the reflectance and transmittance values at resonances, and the band gap vary by the change of substrate parameters and metal thicknesses. These variations is a sign of that the proposed nanoantenna can be employed for sensing applications.

Integrated optical transceiver with electronically controlled optical beamsteering

Science.gov (United States)

Davids, Paul; DeRose, Christopher; Tauke-Pedretti, Anna

2017-08-22

A beam-steering optical transceiver is provided. The transceiver includes one or more modules, each comprising an antenna chip and a control chip bonded to the antenna chip. Each antenna chip has a feeder waveguide, a plurality of row waveguides that tap off from the feeder waveguide, and a plurality of metallic nanoantenna elements arranged in a two-dimensional array of rows and columns such that each row overlies one of the row waveguides. Each antenna chip also includes a plurality of independently addressable thermo-optical phase shifters, each configured to produce a thermo-optical phase shift in a respective row. Each antenna chip also has, for each row, a row-wise heating circuit configured to produce a respective thermo-optic phase shift at each nanoantenna element along its row. The control chip includes controllable current sources for the independently addressable thermo-optical phase shifters and the row-wise heating circuits.

Plasmonic Colloidal Nanoantennas for Tip-Enhanced Raman Spectrocopy

Science.gov (United States)

Dill, Tyler J.

Plasmonic nanoantennas that a support localized surface plasmon resonance (LSPR) are capable of confining visible light to subwavelength dimensions due to strong electromagnetic field enhancement at the probe tip. Nanoantenna enable optical methods such as tip-enhanced Raman spectroscopy (TERS), a technique that uses scanning probe microscopy tips to provide chemical information with nanoscale spatial resolution and single-molecule sensitivities. The LSPR supported by the probe tip is extremely sensitive to the nanoscale morphology of the nanoantenna. Control of nanoscale morphology is notoriously difficult to achieve, resulting in TERS probes with poor reproducibility. In my thesis, I demonstrate high-performance, predictable, and broadband nanospectroscopy probes that are fabricated by self-assembly. Shaped metal nanoparticles are organized into dense layers and deposited onto scanning probe tips. When coupled to a metal substrate, these probes support a strong optical resonance in the gap between the substrate and the probe, producing dramatic field enhancements. I show through experiment and electromagnetic modeling that close-packed but electrically isolated nanoparticles are electromagnetically coupled. Hybridized LSPRs supported by self-assembled nanoparticles with a broadband optical response, giving colloidal nanoantenna a high tolerance for geometric variation resulting from fabrication. I find that coupled nanoparticles act as a waveguide, transferring energy from many neighboring nanoparticles towards the active TERS apex. I also use surface-enhanced Raman spectroscopy (SERS) to characterize the effects of nanoparticle polydispersity and gap height on the Raman enhancement. These colloidal probes have consistently achieved dramatic Raman enhancements in the range of 108-109 with sub-50 nm spatial resolution. Furthermore, in contrast to other nanospectroscopy probes, these colloidal probes can be fabricated in a scalable fashion with a batch

Highly directive Fabry-Perot leaky-wave nanoantennas based on optical partially reflective surfaces

Energy Technology Data Exchange (ETDEWEB)

Lorente-Crespo, M.; Mateo-Segura, C., E-mail: C.Mateo-Segura@hw.ac.uk [Institute of Sensors, Signals and Systems, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom)

2015-05-04

Nanoantennas enhance the conversion between highly localized electromagnetic fields and far-field radiation. Here, we investigate the response of a nano-patch partially reflective surface backed with a silver mirror to an optical source embedded at the centre of the structure. Using full wave simulations, we demonstrate a two orders of magnitude increased directivity compared to the isotropic radiator, 50% power confinement to a 13.8° width beam and a ±16 nm bandwidth. Our antenna does not rely on plasmonic phenomena thus reducing non-radiative losses and conserving source coherence.

Unidirectional emission in an all-dielectric nanoantenna.

Science.gov (United States)

Feng, Tianhua; Zhang, Wei; Liang, Zixian; Xu, Yi

2018-03-28

All-dielectric nanoantennas are a promising alternative to plasmonic optical antennas for engineering light emission because of their low-loss nature in the optical spectrum. Nevertheless, it is still challenging to manipulate directional light emission with subwavelength all-dielectric nanoantennas. Here, we propose and numerically demonstrate that a hollow silicon nanodisk can serve as a versatile antenna for directing and enhancing the emission from either an electric or magnetic dipole emitter. When primarily coupled to both electric and magnetic dipole modes of a nanoantenna, broadband nearly-unidirectional emission can be realized by the interference of two modes, which can be spectrally tuned via the geometric parameters in an easy way. More importantly, the emission directions for the magnetic and electric dipole emitters are shown as opposite to each other through control of the phase difference between the induced magnetic and electric dipole modes of the antenna. Meanwhile, the Purcell factors can be enhanced by more than one order of magnitude and high quantum efficiencies can be maintained at the visible spectrum for both kinds of dipole emitters. We further show that these unidirectional emission phenomena can withstand small disorder effects of in-plane dipole orientation and location. Our study provides a simple yet versatile platform that can shape the emission of both magnetic and electric dipole emitters.

Role of the substrate in monolithic AlGaAs nonlinear nanoantennas

Directory of Open Access Journals (Sweden)

Gili Valerio Flavio

2017-06-01

Full Text Available We report the effect of the aluminum oxide substrate on the emission of monolithic AlGaAs-on-insulator nonlinear nanoantennas. By coupling nonlinear optical measurements with electron diffraction and microscopy observations, we find that the oxidation-induced stress causes negligible crystal deformation in the AlGaAs nanostructures and only plays a minor role in the polarization state of the harmonic field. This result highlights the reliability of the wet oxidation of thick AlGaAs optical substrates and further confirms the bulk χ(2 origin of second harmonic generation at 1.55 μm in these nanoantennas, paving the way for the development of AlGaAs-on-insulator monolithic metasurfaces.

Optical fiber meta-tips

Science.gov (United States)

Principe, Maria; Micco, Alberto; Crescitelli, Alessio; Castaldi, Giuseppe; Consales, Marco; Esposito, Emanuela; La Ferrara, Vera; Galdi, Vincenzo; Cusano, Andrea

2016-04-01

We report on the first example of a "meta-tip" configuration that integrates a metasurface on the tip of an optical fiber. Our proposed design is based on an inverted-Babinet plasmonic metasurface obtained by patterning (via focused ion beam) a thin gold film deposited on the tip of an optical fiber, so as to realize an array of rectangular aperture nanoantennas with spatially modulated sizes. By properly tuning the resonances of the aperture nanoantennas, abrupt variations can be impressed in the field wavefront and polarization. We fabricated and characterized several proof-of-principle prototypes operating an near-infrared wavelengths, and implementing the beam-steering (with various angles) of the cross-polarized component, as well as the excitation of surface waves. Our results pave the way to the integration of the exceptional field-manipulation capabilities enabled by metasurfaces with the versatility and ubiquity of fiber-optics technological platforms.

Ultrafast Non-thermal Response of Plasmonic Resonance in Gold Nanoantennas

Science.gov (United States)

Soavi, Giancarlo; Valle, Giuseppe Della; Biagioni, Paolo; Cattoni, Andrea; Longhi, Stefano; Cerullo, Giulio; Brida, Daniele

Ultrafast thermalization of electrons in metal nanostructures is studied by means of pump-probe spectroscopy. We track in real-time the plasmon resonance evolution, providing a tool for understanding and controlling gold nanoantennas non-linear optical response.

Quantum Effects in Nanoantennas and Their Applications in Tunability, Mixing, and Rectification

KAUST Repository

Chen, Pai-Yen

2015-08-04

It has been recently shown that optical nanoantennas made of single or paired metallic nanoparticles can efficiently couple the propagating light into and from deeply subwavelength volumes. The strong light-matter interaction mediated by surface plasmons in metallic nanostructures allows for localizing optical fields to a subdiffraction-limited region, thereby enhancing emission of nanoemitters and offering the flexible control of nanofocused radiation. Here we theoretically study the nanodipole antennas with submicroscopic gaps, i.e. a few nanometers, for which there exists linear and high-order nonlinear quantum conductivities due to the photon-assisted tunneling effect. Noticeably, these quantum conductivities induced at the nanogap are enhanced by several orders of magnitude, due to the strongly localized optical fields associated with the plasmonic resonance.In this talk, we will show that by tailoring the geometry of nanoantennas and the quantum well structure, a quantum nanodipole antenna with a gap size of few nanometers can induce linear, high-order quantum conductivities that are considerably enhanced by the surface plasmon resonance. We envisage here a number of intriguing nanophotonic applications of these quantum nanoantennas, including (i) modulatable and switchable radiators and metamaterials, with electronic and all-optical tuning (which is related to the two photon absorption), (ii) optical rectification for detection and energy harvesting of infrared and visible light, which are related to the relevant second-order quantum conductivity, (iii) harmonic sensing for the work function and the optical index of nanoparticle, e.g. DNA and molecules, loaded inside the nanogap, and (iv) high harmonic generation and wave mixing with nonlinear quantum conductivities.

Electron beam imaging and spectroscopy of plasmonic nanoantenna resonances

NARCIS (Netherlands)

Vesseur, P.C.

2011-01-01

Nanoantennas are metal structures that provide strong optical coupling between a nanoscale volume and the far field. This coupling is mediated by surface plasmons, oscillations of the free electrons in the metal. Increasing the control over the resonant plasmonic field distribution opens up a wide

Direct measurement of bull's-eye nanoantenna metal loss

Science.gov (United States)

Hassani Nia, Iman; Jang, Sung J.; Memis, Omer G.; Gelfand, Ryan; Mohseni, Hooman

2013-09-01

The loss in optical antennas can affect their performance for their practical use in many branches of science such as biological and solar cell applications. However the big question is that how much loss is due to the joule heating in the metals. This would affect the efficiency of solar cells and is very important for single photon detection and also for some applications where high heat generation in nanoantennas is desirable, for example, payload release for cancer treatment. There are few groups who have done temperature measurements by methods such as Raman spectroscopy or fluorescence polarization anisotropy. The latter method, which is more reliable than Raman spectroscopy, requires the deposition of fluorescent molecules on the antenna surface. The molecules and the polarization of radiation rotate depending upon the surface temperature. The reported temperature measurement accuracy in this method is about 0.1° C. Here we present a method based on thermo-reflectance that allows better temperature accuracy as well as spatial resolution of 500 nm. Moreover, this method does not require the addition of new materials to the nanoantenna. We present the measured heat dissipation from bull's-eye nanoantennas and compare them with 3D simulation results.

Gap Nanoantennas toward Molecular Plasmonic Devices

Directory of Open Access Journals (Sweden)

Aude L. Lereu

2012-01-01

Full Text Available Recently we have demonstrated that single fluorescent molecules can be used as non-perturbative vectorial probes of the local field. Here, we expand on such experiments exploiting fluorescence lifetime of single molecules to probe various types of gap nanoantennas. First, studies of the nanoantennas are carried out to evaluate the electric field. We then investigate hybrid systems composed by nanoantennas and randomly positioned fluorescent molecules. Finally, we present a fabrication scheme for the controlled placement of fluorescent molecules at welldefined positions with respect to the dimer nanoantenna, which is a more direct route to probe the local field in an a priori determined way.

Photothermal heating enabled by plasmonic nanoantennas for electrokinetic manipulation and sorting of submicron particles

DEFF Research Database (Denmark)

Ndukaife, Justus C.; Mishra, Avanish; Guler, Urcan

2014-01-01

The photo-induced collective heating enabled by a plasmonic nanoantenna array is for the first time harnessed for rapid concentration, manipulation and sorting of particles, with high throughput. This work could find application in biosensing, and surface enhanced spectroscopies © 2014 OSA....

Photon-phonon-enhanced infrared rectification in a two-dimensional nanoantenna-coupled tunnel diode

International Nuclear Information System (INIS)

Kadlec, Emil A.; Jarecki, Robert L.; Starbuck, Andrew; Peters, David W.; Davids, Paul S.

2016-01-01

The interplay of strong infrared photon-phonon coupling with electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast photon-assisted tunneling in metal-oxide-semiconductor (MOS) structures. Infrared active optical phonon modes in polar oxides lead to strong dispersion and enhanced electric fields at material interfaces. We find that the infrared dispersion of SiO_2 near a longitudinal optical phonon mode can effectively impedance match a photonic surface mode into a nanoscale tunnel gap that results in large transverse-field confinement. An integrated 2D nanoantenna structure on a distributed large-area MOS tunnel-diode rectifier is designed and built to resonantly excite infrared surface modes and is shown to efficiently channel infrared radiation into nanometer-scale gaps in these MOS devices. This enhanced-gap transverse-electric field is converted to a rectified tunneling displacement current resulting in a dc photocurrent. We examine the angular and polarization-dependent spectral photocurrent response of these 2D nanoantenna-coupled tunnel diodes in the photon-enhanced tunneling spectral region. Lastly, our 2D nanoantenna-coupled infrared tunnel-diode rectifier promises to impact large-area thermal energy harvesting and infrared direct detectors.

Nanoantenna couplers for metal-insulator-metal waveguide interconnects

Science.gov (United States)

Onbasli, M. Cengiz; Okyay, Ali K.

2010-08-01

State-of-the-art copper interconnects suffer from increasing spatial power dissipation due to chip downscaling and RC delays reducing operation bandwidth. Wide bandwidth, minimized Ohmic loss, deep sub-wavelength confinement and high integration density are key features that make metal-insulator-metal waveguides (MIM) utilizing plasmonic modes attractive for applications in on-chip optical signal processing. Size-mismatch between two fundamental components (micron-size fibers and a few hundred nanometers wide waveguides) demands compact coupling methods for implementation of large scale on-chip optoelectronic device integration. Existing solutions use waveguide tapering, which requires more than 4λ-long taper distances. We demonstrate that nanoantennas can be integrated with MIM for enhancing coupling into MIM plasmonic modes. Two-dimensional finite-difference time domain simulations of antennawaveguide structures for TE and TM incident plane waves ranging from λ = 1300 to 1600 nm were done. The same MIM (100-nm-wide Ag/100-nm-wide SiO2/100-nm-wide Ag) was used for each case, while antenna dimensions were systematically varied. For nanoantennas disconnected from the MIM; field is strongly confined inside MIM-antenna gap region due to Fabry-Perot resonances. Major fraction of incident energy was not transferred into plasmonic modes. When the nanoantennas are connected to the MIM, stronger coupling is observed and E-field intensity at outer end of core is enhanced more than 70 times.

Plexciton quenching by resonant electron transfer from quantum emitter to metallic nanoantenna.

Science.gov (United States)

Marinica, D C; Lourenço-Martins, H; Aizpurua, J; Borisov, A G

2013-01-01

Coupling molecular excitons and localized surface plasmons in hybrid nanostructures leads to appealing, tunable optical properties. In this respect, the knowledge about the excitation dynamics of a quantum emitter close to a plasmonic nanoantenna is of importance from fundamental and practical points of view. We address here the effect of the excited electron tunneling from the emitter into a metallic nanoparticle(s) in the optical response. When close to a plasmonic nanoparticle, the excited state localized on a quantum emitter becomes short-lived because of the electronic coupling with metal conduction band states. We show that as a consequence, the characteristic features associated with the quantum emitter disappear from the optical absorption spectrum. Thus, for the hybrid nanostructure studied here and comprising quantum emitter in the narrow gap of a plasmonic dimer nanoantenna, the quantum tunneling might quench the plexcitonic states. Under certain conditions the optical response of the system approaches that of the individual plasmonic dimer. Excitation decay via resonant electron transfer can play an important role in many situations of interest such as in surface-enhanced spectroscopies, photovoltaics, catalysis, or quantum information, among others.

Femtosecond pulse shaping using plasmonic snowflake nanoantennas

Energy Technology Data Exchange (ETDEWEB)

Tok, Ruestue Umut; Sendur, Kuersat [Sabanci University, Orhanli-Tuzla, 34956, Istanbul (Turkey)

2011-09-15

We have theoretically demonstrated femtosecond pulse manipulation at the nanoscale using the plasmonic snowflake antenna's ability to localize light over a broad spectrum. To analyze the interaction of the incident femtosecond pulse with the plasmonic nanoantenna, we first decompose the diffraction limited incident femtosecond pulse into its spectral components. The interaction of each spectral component with the nanoantenna is analyzed using finite element technique. The time domain response of the plasmonic antenna is obtained using inverse Fourier transformation. It is shown that the rich spectral characteristics of the plasmonic snowflake nanoantenna allow manipulation of the femtosecond pulses over a wide spectrum. Light localization around the gap region of the nanoantenna is shown for femtosecond pulses. As the alignment of incident light polarization is varied, different antenna elements oscillate, which in turn creates a different spectrum and a distinct femtosecond response.

All-silicon-based nano-antennas for wavelength and polarization demultiplexing.

Science.gov (United States)

Panmai, Mingcheng; Xiang, Jin; Sun, Zhibo; Peng, Yuanyuan; Liu, Hongfeng; Liu, Haiying; Dai, Qiaofeng; Tie, Shaolong; Lan, Sheng

2018-05-14

We propose an all-silicon-based nano-antenna that functions as not only a wavelength demultiplexer but also a polarization one. The nano-antenna is composed of two silicon cuboids with the same length and height but with different widths. The asymmetric structure of the nano-antenna with respect to the electric field of the incident light induced an electric dipole component in the propagation direction of the incident light. The interference between this electric dipole and the magnetic dipole induced by the magnetic field parallel to the long side of the cuboids is exploited to manipulate the radiation direction of the nano-antenna. The radiation direction of the nano-antenna at a certain wavelength depends strongly on the phase difference between the electric and magnetic dipoles interacting coherently, offering us the opportunity to realize wavelength demultiplexing. By varying the polarization of the incident light, the interference of the magnetic dipole induced by the asymmetry of the nano-antenna and the electric dipole induced by the electric field parallel to the long side of the cuboids can also be used to realize polarization demultiplexing in a certain wavelength range. More interestingly, the interference between the dipole and quadrupole modes of the nano-antenna can be utilized to shape the radiation directivity of the nano-antenna. We demonstrate numerically that radiation with adjustable direction and high directivity can be realized in such a nano-antenna which is compatible with the current fabrication technology of silicon chips.

Infrared nanoantenna apparatus and method for the manufacture thereof

Science.gov (United States)

Peters, David W.; Davids, Paul; Leonhardt, Darin; Kim, Jin K.; Wendt, Joel R.; Klem, John F.

2014-06-10

An exemplary embodiment of the present invention is a photodetector comprising a semiconductor body, a periodically patterned metal nanoantenna disposed on a surface of the semiconductor body, and at least one electrode separate from the nanoantenna. The semiconductor body comprises an active layer in sufficient proximity to the nanoantenna for plasmonic coupling thereto. The nanoantenna is dimensioned to absorb electromagnetic radiation in at least some wavelengths not more than 12 .mu.m that are effective for plasmonic coupling into the active layer. The electrode is part of an electrode arrangement for obtaining a photovoltage or photocurrent in operation under appropriate stimulation.

Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering

Energy Technology Data Exchange (ETDEWEB)

Sikdar, Debabrata, E-mail: debabrata.sikdar@monash.edu; Premaratne, Malin [Advanced Computing and Simulation Laboratory (A chi L), Department of Electrical and Computer Systems Engineering, Monash University, Clayton 3800, Victoria (Australia); Cheng, Wenlong [Department of Chemical Engineering, Faculty of Engineering, Monash University, Clayton 3800, Victoria (Australia); The Melbourne Centre for Nanofabrication, 151 Wellington Road, Clayton 3168, Victoria (Australia)

2015-02-28

Cubic dielectric nanoparticles are promising candidates for futuristic low-loss, ultra-compact, nanophotonic applications owing to their larger optical coefficients, greater packing density, and relative ease of fabrication as compared to spherical nanoparticles; besides possessing negligible heating at nanoscale in contrast to their metallic counterparts. Here, we present the first theoretical demonstration of azimuthally symmetric, ultra-directional Kerker's-type scattering of simple dielectric nanocubes in visible and near-infrared regions via simultaneous excitation and interference of optically induced electric- and magnetic-resonances up to quadrupolar modes. Unidirectional forward-scattering by individual nanocubes is observed at the first generalized-Kerker's condition for backward-scattering suppression, having equal electric- and magnetic-dipolar responses. Both directionality and magnitude of these unidirectional-scattering patterns get enhanced where matching electric- and magnetic-quadrupolar responses spectrally overlap. While preserving azimuthal-symmetry and backscattering suppression, a nanocube homodimer provides further directionality improvement for increasing interparticle gap, but with reduced main-lobe magnitude due to emergence of side-scattering lobes from diffraction-grating effect. We thoroughly investigate the influence of interparticle gap on scattering patterns and propose optimal range of gap for minimizing side-scattering lobes. Besides suppressing undesired side-lobes, significant enhancement in scattering magnitude and directionality is attained with increasing number of nanocubes forming a linear chain. Optimal directionality, i.e., the narrowest main-scattering lobe, is found at the wavelength of interfering quadrupolar resonances; whereas the largest main-lobe magnitude is observed at the wavelength satisfying the first Kerker's condition. These unique optical properties of dielectric nanocubes thus can

Vectorial control of nonlinear emission via chiral butterfly nanoantennas: generation of pure high order nonlinear vortex beams.

Science.gov (United States)

Lesina, Antonino Cala'; Berini, Pierre; Ramunno, Lora

2017-02-06

We report on a chiral gap-nanostructure, which we term a "butterfly nanoantenna," that offers full vectorial control over nonlinear emission. The field enhancement in its gap occurs for only one circular polarization but for every incident linear polarization. As the polarization, phase and amplitude of the linear field in the gap are highly controlled, the linear field can drive nonlinear emitters within the gap, which behave as an idealized Huygens source. A general framework is thereby proposed wherein the butterfly nanoantennas can be arranged in a metasurface, and the nonlinear Huygens sources exploited to produce a highly structured far-field optical beam. Nonlinearity allows us to shape the light at shorter wavelengths, not accessible by linear plasmonics, and resulting in high purity beams. The chirality of the butterfly allows us to create orbital angular momentum states using a linearly polarized excitation. A third harmonic Laguerre-Gauss beam carrying an optical orbital angular momentum of 41 is demonstrated as an example, through large-scale simulations on a high-performance computing platform of the full plasmonic metasurface with an area large enough to contain up to 3600 nanoantennas.

Babinet's principle for optical frequency metamaterials and nanoantennas

Science.gov (United States)

Zentgraf, T.; Meyrath, T. P.; Seidel, A.; Kaiser, S.; Giessen, H.; Rockstuhl, C.; Lederer, F.

2007-07-01

We consider Babinet’s principle for metamaterials at optical frequencies and include realistic conditions which deviate from the theoretical assumptions of the classic principle such as an infinitely thin and perfectly conducting metal layer. It is shown that Babinet’s principle associates not only transmission and reflection between a structure and its complement but also the field modal profiles of the electromagnetic resonances as well as effective material parameters—a critical concept for metamaterials. Also playing an important role in antenna design, Babinet’s principle is particularly interesting to consider in this case where the metasurfaces and their complements can be regarded as variations on a folded dipole antenna array and patch antenna array, respectively.

A hybrid nanoantenna for highly enhanced directional spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Chou, R. Yuanying; Lu, Guowei, E-mail: guowei.lu@pku.edu.cn; Shen, Hongming; He, Yingbo; Cheng, Yuqing [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Perriat, Pascal [MATEIS, UMR 5510 CNRS, INSA-Lyon, Université de Lyon, Villeurbanne Cedex 69621 (France); Martini, Matteo; Tillement, Olivier [ILM, UMR 5306 CNRS, Université de Lyon, Villeurbanne Cedex 69622 (France); Gong, Qihuang [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

2014-06-28

Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO{sub 2} thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

A hybrid nanoantenna for highly enhanced directional spontaneous emission

International Nuclear Information System (INIS)

Chou, R. Yuanying; Lu, Guowei; Shen, Hongming; He, Yingbo; Cheng, Yuqing; Perriat, Pascal; Martini, Matteo; Tillement, Olivier; Gong, Qihuang

2014-01-01

Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO 2 thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

SERS investigations and electrical recording of neuronal networks with three-dimensional plasmonic nanoantennas (Conference Presentation)

Science.gov (United States)

De Angelis, Francesco

2017-06-01

SERS investigations and electrical recording of neuronal networks with three-dimensional plasmonic nanoantennas Michele Dipalo, Valeria Caprettini, Anbrea Barbaglia, Laura Lovato, Francesco De Angelis e-mail: francesco.deangelis@iit.it Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova Biological systems are analysed mainly by optical, chemical or electrical methods. Normally each of these techniques provides only partial information about the environment, while combined investigations could reveal new phenomena occurring in complex systems such as in-vitro neuronal networks. Aiming at the merging of optical and electrical investigations of biological samples, we introduced three-dimensional plasmonic nanoantennas on CMOS-based electrical sensors [1]. The overall device is then capable of enhanced Raman Analysis of cultured cells combined with electrical recording of neuronal activity. The Raman measurements show a much higher sensitivity when performed on the tip of the nanoantenna in respect to the flat substrate [2]; this effect is a combination of the high plasmonic field enhancement and of the tight adhesion of cells on the nanoantenna tip. Furthermore, when plasmonic opto-poration is exploited [3] the 3D nanoelectrodes are able to penetrate through the cell membrane thus accessing the intracellular environment. Our latest results (unpublished) show that the technique is completely non-invasive and solves many problems related to state-of-the-art intracellular recording approaches on large neuronal networks. This research received funding from ERC-IDEAS Program: "Neuro-Plasmonics" [Grant n. 616213]. References: [1] M. Dipalo, G. C. Messina, H. Amin, R. La Rocca, V. Shalabaeva, A. Simi, A. Maccione, P. Zilio, L. Berdondini, F. De Angelis, Nanoscale 2015, 7, 3703. [2] R. La Rocca, G. C. Messina, M. Dipalo, V. Shalabaeva, F. De Angelis, Small 2015, 11, 4632. [3] G. C. Messina et al., Spatially, Temporally, and Quantitatively Controlled Delivery of

Numerical conversion efficiency of thermally isolated Seebeck nanoantennas

Directory of Open Access Journals (Sweden)

Edgar Briones

2016-11-01

Full Text Available In this letter, we evaluate the conversion efficiency of thermally isolated Seebeck nanoantennas by numerical simulations and discuss their uses and scope for energy harvesting applications. This analysis includes the simple case of titanium-nickel dipoles suspended in air above the substrate by a 200 nm silicon dioxide membrane to isolate the heat dissipation. Results show that substantially thermal gradients are induced along the devices leading to a harvesting efficiency around 10-4 %, 400 % higher than the previously reported Seebeck nanoantennas. In the light of these results, different optimizing strategies should be considered in order to make the Seebeck nanoantennas useful for harvesting applications.

New Frontiers in Passive and Active Nanoantennas

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, Richard W.

2017-01-01

The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers.......The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers....

Mode matching in multiresonant plasmonic nanoantennas for enhanced second harmonic generation

Science.gov (United States)

Celebrano, Michele; Wu, Xiaofei; Baselli, Milena; Großmann, Swen; Biagioni, Paolo; Locatelli, Andrea; de Angelis, Costantino; Cerullo, Giulio; Osellame, Roberto; Hecht, Bert; Duò, Lamberto; Ciccacci, Franco; Finazzi, Marco

2015-05-01

Boosting nonlinear frequency conversion in extremely confined volumes remains a challenge in nano-optics research, but can enable applications in nanomedicine, photocatalysis and background-free biosensing. To obtain brighter nonlinear nanoscale sources, approaches that enhance the electromagnetic field intensity and counter the lack of phase matching in nanoplasmonic systems are often employed. However, the high degree of symmetry in the crystalline structure of plasmonic materials (metals in particular) and in nanoantenna designs strongly quenches second harmonic generation. Here, we describe doubly-resonant single-crystalline gold nanostructures with no axial symmetry displaying spatial mode overlap at both the excitation and second harmonic wavelengths. The combination of these features allows the attainment of a nonlinear coefficient for second harmonic generation of ˜5 × 10-10 W-1, enabling a second harmonic photon yield higher than 3 × 106 photons per second. Theoretical estimations point toward the use of our nonlinear plasmonic nanoantennas as efficient platforms for label-free molecular sensing.

Direct determination of the resonance properties of metallic conical nanoantennas

KAUST Repository

Tuccio, Salvatore; Razzari, Luca; Alabastri, Alessandro; Toma, Andrea; Liberale, Carlo; De Angelis, Francesco De; Candeloro, Patrizio; Das, Gobind; Giugni, Andrea; Di Fabrizio, Enzo M.; Proietti Zaccaria, Remo

2014-01-01

We present a simple method that is able to predict the resonant frequencies of a metallic conical nanoantenna. The alculation is based on an integral relation that takes into account the dependence of the effective refractive index of the plasmonic mode on the cone radius. Numerical simulations retrieving the near field properties of nanocones with different lengths are also performed for comparison. The fine agreement between the two approaches demonstrates the validity of our method. © 2014 Optical Society of America.

Metalenses based on the non-parallel double-slit arrays

Science.gov (United States)

Shao, Hongyan; Chen, Chen; Wang, Jicheng; Pan, Liang; Sang, Tian

2017-09-01

Metalenses based on surface plasmon polaritons have played an indispensable role in ultra-thin devices designing. The amplitude, phase and polarization of electromagnetic waves all can be controlled easily by modifying the metasurface structures. Here we propose and investigate a new type of structure with Babinet-inverted nano-antennas which can provide a series of unit-cells with phase-shifts covering 2π and ensure almost same transmittance simultaneously. As a result, the wavefront can be manipulated by arraying the units in course. Metalenses with the linear asymmetrical double slit unit-cell arrays are designed and the simulative results exhibit their perfect focusing characteristics, including single-focus lenses and multi-focus lenses. The small focus size and high numerical aperture make them stand out from the traditional counterparts in application of precision sensing devices. We expect our designs will provide new insights in the practical applications for metasurfaces in data storages, optical information processing and optical holography.

Modeling of absorption and scattering properties of core -shell nanoparticles for application as nanoantenna in optical domain

Science.gov (United States)

Devi, Jutika; Saikia, Rashmi; Datta, Pranayee

2016-10-01

The present paper describes the study of core-shell nanoparticles for application as nanoantenna in the optical domain. To obtain the absorption and extinction efficiencies as well as the angular distribution of the far field radiation pattern and the resonance wavelengths for these metal-dielectric, dielectric-metal and metal-metal core-shell nanoparticles in optical domain, we have used Finite Element Method based COMSOL Multiphysics Software and Mie Theory. From the comparative study of the extinction efficiencies of core-shell nanoparticles of different materials, it is found that for silica - gold core - shell nanoparticles, the resonant wavelength is greater than that of the gold - silver, silver-gold and gold-silica core - shell nanoparticles and also the radiation pattern of the silica-gold core-shell nanoparticle is the most suitable one from the point of view of directivity. The dielectric functions of the core and shell material as well as of the embedded matrix are extremely important and plays a very major role to tune the directivity and resonance wavelength. Such highly controllable parameters of the dielectric - metal core - shell nanoparticles make them suitable for efficient coupling of optical radiation into nanoscale structures for a broad range of applications in the field of communications.

Modeling of absorption and scattering properties of core -shell nanoparticles for application as nanoantenna in optical domain

International Nuclear Information System (INIS)

Devi, Jutika; Datta, Pranayee; Saikia, Rashmi

2016-01-01

The present paper describes the study of core-shell nanoparticles for application as nanoantenna in the optical domain. To obtain the absorption and extinction efficiencies as well as the angular distribution of the far field radiation pattern and the resonance wavelengths for these metal-dielectric, dielectric-metal and metal-metal core-shell nanoparticles in optical domain, we have used Finite Element Method based COMSOL Multiphysics Software and Mie Theory. From the comparative study of the extinction efficiencies of core-shell nanoparticles of different materials, it is found that for silica - gold core - shell nanoparticles, the resonant wavelength is greater than that of the gold - silver, silver-gold and gold-silica core - shell nanoparticles and also the radiation pattern of the silica-gold core-shell nanoparticle is the most suitable one from the point of view of directivity. The dielectric functions of the core and shell material as well as of the embedded matrix are extremely important and plays a very major role to tune the directivity and resonance wavelength. Such highly controllable parameters of the dielectric - metal core - shell nanoparticles make them suitable for efficient coupling of optical radiation into nanoscale structures for a broad range of applications in the field of communications. (paper)

Directional absorption by phased arrays of plasmonic nanoantennae probed with time-reversed Fourier microscopy

International Nuclear Information System (INIS)

Lozano, Gabriel; Barten, Tommy; Grzela, Grzegorz; Rivas, Jaime Gómez

2014-01-01

We demonstrate that an ordered array of aluminum nanopyramids, behaving as a phased array of optical antennae, strongly modifies light absorption in thin layers of dye molecules. Photoluminescence measurements as a function of the illumination angle are performed using a time-reversed Fourier microscope. This technique enables a variable-angle plane-wave illumination of nanostructures in a microscope-based setup. Our measurements reveal an enhancement of the light conversion in certain directions of illumination, which indicate the efficient diffractive coupling between the free space radiation and the surface plasmons. Numerical simulations confirm that surface modes supported by the periodic array enhance the intensity of the pump field in the space between particles, where the dye molecules are located, yielding a directional plasmonic-mediated enhancement of the optical absorption. This combined experimental and numerical characterization of the angular dependence of light absorption in nanostructures can be beneficial for the design and optimization of devices in which the harvesting of light plays a major role. (paper)

Nanoantenna harmonic sensor: theoretical analysis of contactless detection of molecules with light

KAUST Repository

Farhat, Mohamed

2015-09-25

The nonlinear harmonic sensor is a popular wireless sensor and radiofrequency identification (RFID) technique, which allows high-performance sensing in a severe interference/clutter background by transmitting a radio wave and detecting its modulated higher-order harmonics. Here we introduce the concept and design of optical harmonic tags based on nonlinear nanoantennas that can contactlessly detect electronic (e.g. electron affinity) and optical (e.g. relative permittivity) characteristics of molecules. By using a dual-resonance gold-molecule–silver nanodipole antenna within the quantum mechanical realm, the spectral form of the second-harmonic scattering can sensitively reveal the physical properties of molecules, paving a new route towards optical molecular sensors and optical identification (OPID) of biological, genetic, and medical events for the \\'Internet of Nano-Things\\'.

Nanoantenna harmonic sensor: theoretical analysis of contactless detection of molecules with light

KAUST Repository

Farhat, Mohamed; Cheng, Mark M C; Le, Khai Q; Chen, Pai-Yen

2015-01-01

The nonlinear harmonic sensor is a popular wireless sensor and radiofrequency identification (RFID) technique, which allows high-performance sensing in a severe interference/clutter background by transmitting a radio wave and detecting its modulated higher-order harmonics. Here we introduce the concept and design of optical harmonic tags based on nonlinear nanoantennas that can contactlessly detect electronic (e.g. electron affinity) and optical (e.g. relative permittivity) characteristics of molecules. By using a dual-resonance gold-molecule–silver nanodipole antenna within the quantum mechanical realm, the spectral form of the second-harmonic scattering can sensitively reveal the physical properties of molecules, paving a new route towards optical molecular sensors and optical identification (OPID) of biological, genetic, and medical events for the 'Internet of Nano-Things'.

Nanoantenna harmonic sensor: theoretical analysis of contactless detection of molecules with light

International Nuclear Information System (INIS)

Farhat, Mohamed; Cheng, Mark M C; Chen, Pai-Yen; Le, Khai Q

2015-01-01

The nonlinear harmonic sensor is a popular wireless sensor and radiofrequency identification (RFID) technique, which allows high-performance sensing in a severe interference/clutter background by transmitting a radio wave and detecting its modulated higher-order harmonics. Here we introduce the concept and design of optical harmonic tags based on nonlinear nanoantennas that can contactlessly detect electronic (e.g. electron affinity) and optical (e.g. relative permittivity) characteristics of molecules. By using a dual-resonance gold-molecule–silver nanodipole antenna within the quantum mechanical realm, the spectral form of the second-harmonic scattering can sensitively reveal the physical properties of molecules, paving a new route towards optical molecular sensors and optical identification (OPID) of biological, genetic, and medical events for the ‘Internet of Nano-Things’. (paper)

Bidirectional waveguide coupling with plasmonic Fano nanoantennas

Energy Technology Data Exchange (ETDEWEB)

Guo, Rui; Decker, Manuel, E-mail: manuel.decker@anu.edu.au; Staude, Isabelle; Neshev, Dragomir N.; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

2014-08-04

We introduce the concept of a bidirectional, compact single-element Fano nanoantenna that allows for directional coupling of light in opposite directions of a high-index dielectric waveguide for two different operation wavelengths. We utilize a Fano resonance to tailor the radiation phases of a gold nanodisk and a nanoslit that is inscribed into the nanodisk to realize bidirectional scattering. We show that this Fano nanoantenna operates as a bidirectional waveguide coupler at telecommunication wavelengths and, thus, is ideally suitable for integrated wavelength-selective light demultiplexing.

Design and analyses of an ultra-thin flat lens for wave front shaping in the visible

International Nuclear Information System (INIS)

Huang, Kai; Li, Yiyan; Tian, Xuelong; Zeng, Dajun; Gao, Xueli

2015-01-01

An ultra-thin flat lens is proposed for focusing circularly polarized light in the visible range. Anisotropic C-shaped nanoantennas with phase discontinuities are used to form the metasurface of the lens. The phase response of the C-shaped nanoantennas can be manipulated by simply rotating the angle of the unit nanoantenna. A 600 nm incident circularly polarized light is focused by the proposed techniques. Good agreements are observed by using our MoM and a commercial FDTD software package. The computation time spent by using MoM is approximately 10–100 times smaller than using FDTD. All the results show the proposed nanoantenna array has a great potential for nanoscale optical microscopy, solar cell energy conversion enhancement, as well as integrated optical circuits. - Highlights: • Successfully focusing a 600 nm light using a circularly C-shaped nanoantenna array. • The computation time spent by using MoM is approximately 10–100 times smaller than FDTD. • A good agreement is observed using our MoM to the classic FDTD method.

Imaging spectroscopy using embedded diffractive optical arrays

Science.gov (United States)

Hinnrichs, Michele; Hinnrichs, Bradford

2017-09-01

Pacific Advanced Technology (PAT) has developed an infrared hyperspectral camera based on diffractive optic arrays. This approach to hyperspectral imaging has been demonstrated in all three infrared bands SWIR, MWIR and LWIR. The hyperspectral optical system has been integrated into the cold-shield of the sensor enabling the small size and weight of this infrared hyperspectral sensor. This new and innovative approach to an infrared hyperspectral imaging spectrometer uses micro-optics that are made up of an area array of diffractive optical elements where each element is tuned to image a different spectral region on a common focal plane array. The lenslet array is embedded in the cold-shield of the sensor and actuated with a miniature piezo-electric motor. This approach enables rapid infrared spectral imaging with multiple spectral images collected and processed simultaneously each frame of the camera. This paper will present our optical mechanical design approach which results in an infrared hyper-spectral imaging system that is small enough for a payload on a small satellite, mini-UAV, commercial quadcopter or man portable. Also, an application of how this spectral imaging technology can easily be used to quantify the mass and volume flow rates of hydrocarbon gases. The diffractive optical elements used in the lenslet array are blazed gratings where each lenslet is tuned for a different spectral bandpass. The lenslets are configured in an area array placed a few millimeters above the focal plane and embedded in the cold-shield to reduce the background signal normally associated with the optics. The detector array is divided into sub-images covered by each lenslet. We have developed various systems using a different number of lenslets in the area array. Depending on the size of the focal plane and the diameter of the lenslet array will determine the number of simultaneous different spectral images collected each frame of the camera. A 2 x 2 lenslet array will image

Nanoantennas for surface enhanced infrared spectroscopy: Effects of interaction and higher order resonant excitations

Directory of Open Access Journals (Sweden)

J. Aizpurua

2011-09-01

Full Text Available The sensitivity in surface enhanced infrared spectroscopy (SEIRS strongly depends on where the resonant excitation is spectrally located compared to the molecular vibration that is to be enhanced. In this contribution, we study the effect of coupling in the electromagnetic properties of 2D gold nanorod arrays in the IR. We also study the SEIRS activity of higher order resonant excitations in long nanoantennas to identify polaritonic signals of a supporting SiO2 layer with nanometer thickness (3 nm on a silicon substrate.

The Big Optical Array

International Nuclear Information System (INIS)

Mozurkewich, D.; Johnston, K.J.; Simon, R.S.

1990-01-01

This paper describes the design and the capabilities of the Naval Research Laboratory Big Optical Array (BOA), an interferometric optical array for high-resolution imaging of stars, stellar systems, and other celestial objects. There are four important differences between the BOA design and the design of Mark III Optical Interferometer on Mount Wilson (California). These include a long passive delay line which will be used in BOA to do most of the delay compensation, so that the fast delay line will have a very short travel; the beam combination in BOA will be done in triplets, to allow measurement of closure phase; the same light will be used for both star and fringe tracking; and the fringe tracker will use several wavelength channels

Optical Epitaxial Growth of Gold Nanoparticle Arrays.

Science.gov (United States)

Huang, Ningfeng; Martínez, Luis Javier; Jaquay, Eric; Nakano, Aiichiro; Povinelli, Michelle L

2015-09-09

We use an optical analogue of epitaxial growth to assemble gold nanoparticles into 2D arrays. Particles are attracted to a growth template via optical forces and interact through optical binding. Competition between effects determines the final particle arrangements. We use a Monte Carlo model to design a template that favors growth of hexagonal particle arrays. We experimentally demonstrate growth of a highly stable array of 50 gold particles with 200 nm diameter, spaced by 1.1 μm.

Highly efficient and broadband wide-angle holography using patch-dipole nanoantenna reflectarrays.

Science.gov (United States)

Yifat, Yuval; Eitan, Michal; Iluz, Zeev; Hanein, Yael; Boag, Amir; Scheuer, Jacob

2014-05-14

We demonstrate wide-angle, broadband, and efficient reflection holography by utilizing coupled dipole-patch nanoantenna cells to impose an arbitrary phase profile on the reflected light. High-fidelity images were projected at angles of 45 and 20° with respect to the impinging light with efficiencies ranging between 40-50% over an optical bandwidth exceeding 180 nm. Excellent agreement with the theoretical predictions was found at a wide spectral range. The demonstration of such reflectarrays opens new avenues toward expanding the limits of large-angle holography.

An optical nanoantenna made of plasmonic chain resonators

International Nuclear Information System (INIS)

Lester, Marcelo; Skigin, Diana C

2011-01-01

We propose a novel structure that behaves like an optical antenna and converts evanescent waves into propagating waves. The system comprises metallic subwavelength cylinders distributed in a dual-period array. It is illuminated by an evanescent wave generated by total internal reflection in a close interface. For particular wavelengths, the system exhibits resonances and the inhomogeneous wave is converted into propagating waves that radiate to the far field. This effect can be controlled by varying the geometrical parameters of the structure, such as the period and the inclination angle. Therefore, the transmitted intensity can be sent to a predesigned direction. This structure could be used in highly sensitive detection devices, among other applications

Integrated Miniature Arrays of Optical Biomolecule Detectors

Science.gov (United States)

Iltchenko, Vladimir; Maleki, Lute; Lin, Ying; Le, Thanh

2009-01-01

Integrated miniature planar arrays of optical sensors for detecting specific biochemicals in extremely small quantities have been proposed. An array of this type would have an area of about 1 cm2. Each element of the array would include an optical microresonator that would have a high value of the resonance quality factor (Q . 107). The surface of each microresonator would be derivatized to make it bind molecules of a species of interest, and such binding would introduce a measurable change in the optical properties of the microresonator. Because each microresonator could be derivatized for detection of a specific biochemical different from those of the other microresonators, it would be possible to detect multiple specific biochemicals by simultaneous or sequential interrogation of all the elements in the array. Moreover, the derivatization would make it unnecessary to prepare samples by chemical tagging. Such interrogation would be effected by means of a grid of row and column polymer-based optical waveguides that would be integral parts of a chip on which the array would be fabricated. The row and column polymer-based optical waveguides would intersect at the elements of the array (see figure). At each intersection, the row and column waveguides would be optically coupled to one of the microresonators. The polymer-based waveguides would be connected via optical fibers to external light sources and photodetectors. One set of waveguides and fibers (e.g., the row waveguides and fibers) would couple light from the sources to the resonators; the other set of waveguides and fibers (e.g., the column waveguides and fibers) would couple light from the microresonators to the photodetectors. Each microresonator could be addressed individually by row and column for measurement of its optical transmission. Optionally, the chip could be fabricated so that each microresonator would lie inside a microwell, into which a microscopic liquid sample could be dispensed.

Babinet-Inverted Optical Yagi-Uda Antenna for Unidirectional Radiation to Free Space

Science.gov (United States)

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Choe, Jong-Ho; Lee, Jongcheon; Lee, Jaesoong; Jeong, Heejeong; Kim, Un Jeong; Park, Yeonsang; Song, In Yong; Park, Q.-Han; Hwang, Sung Woo; Kim, Kinam; Lee, Chang-Won

2014-06-01

Plasmonic nanoantennas are key elements in nanophotonics capable of directing radiation or enhancing the transition rate of a quantum emitter. Slot-type magnetic-dipole nanoantennas, which are complementary structures of typical electric-dipole-type antennas, have received little attention, leaving their antenna properties largely unexplored. Here we present a novel magnetic-dipole-fed multi-slot optical Yagi-Uda antenna. By engineering the relative phase of the interacting surface plasmon polaritons between the slot elements, we demonstrate that the optical antenna exhibits highly unidirectional radiation to free space. The unique features of the slot-based magnetic nanoantenna provide a new possibility of achieving integrated features such as energy transfer from one waveguide to another by working as a future optical via.

Understanding and controlling plasmon-induced convection

Science.gov (United States)

Roxworthy, Brian J.; Bhuiya, Abdul M.; Vanka, Surya P.; Toussaint, Kimani C.

2014-01-01

The heat generation and fluid convection induced by plasmonic nanostructures is attractive for optofluidic applications. However, previously published theoretical studies predict only nanometre per second fluid velocities that are inadequate for microscale mass transport. Here we show both theoretically and experimentally that an array of plasmonic nanoantennas coupled to an optically absorptive indium-tin-oxide (ITO) substrate can generate >micrometre per second fluid convection. Crucially, the ITO distributes thermal energy created by the nanoantennas generating an order of magnitude increase in convection velocities compared with nanoantennas on a SiO2 base layer. In addition, the plasmonic array alters absorption in the ITO, causing a deviation from Beer-Lambert absorption that results in an optimum ITO thickness for a given system. This work elucidates the role of convection in plasmonic optical trapping and particle assembly, and opens up new avenues for controlling fluid and mass transport on the micro- and nanoscale.

Capillarity-based preparation system for optical colorimetric sensor arrays.

Science.gov (United States)

Luo, Xiao-Gang; Yi, Xin; Bu, Xiang-Nan; Hou, Chang-Jun; Huo, Dan-Qun; Yang, Mei; Fa, Huan-Bao; Lei, Jin-Can

2017-03-01

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.

Enhanced localized fluorescence in plasmonic nanoantennae

DEFF Research Database (Denmark)

Bakker, R.M.; Yuan, H.-K.; Liu, Z.

2008-01-01

in fluorescence that reaches 100 times enhancement. Near-field excitation shows enhanced fluorescence from a single nanoantenna localized in a subwavelength area of similar to 0.15 mu m(2). The polarization of enhanced emission is along the main antenna axis. These observed experimental results are important...

Dynamic array of dark optical traps

DEFF Research Database (Denmark)

Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

2004-01-01

A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase......-encoded coherent light source. Two-dimensional input phase distributions corresponding to the trapping patterns are encoded using a computer-programmable spatial light modulator, enabling each trap to be shaped and moved arbitrarily within the plane of observation. We demonstrate the generation of multiple dark...... optical traps for simultaneous manipulation of hollow "air-filled" glass microspheres suspended in an aqueous medium. (C) 2004 American Institute of Physics....

Demultiplexing Surface Waves With Silicon Nanoantennas

DEFF Research Database (Denmark)

Sinev, I.; Bogdanov, A.; Komissarenko, F.

2017-01-01

We demonstrate directional launching of surface plasmon polaritons on thin gold film with a single silicon nanosphere. The directivity pattern of the excited surface waves exhibits rapid switching from forward to backward excitation within extremely narrow spectral hand (! 50 nm), which is driven...... by the mutual interference of magnetic and electric dipole moments supported by the dielectric nanoantenna....

Functionalizing large nanoparticles for small gaps in dimer nanoantennas

Science.gov (United States)

Vietz, Carolin; Lalkens, Birka; Acuna, Guillermo P.; Tinnefeld, Philip

2016-04-01

The process of functionalizing gold nanoparticles with DNA commonly competes with nanoparticle aggregation, especially for larger particles of more than 80 nm diameter. Longer DNA strands reduce the tendency for aggregation but commonly lead to larger gaps when applied in certain geometrical arrangements such as gap nanoantennas. Here, we demonstrate that reversing the polarization of one of the strands for hybridization (yielding a zipper-like geometry) is sterically possible with uncompromised yields. Using the single dye molecule’s fluorescence lifetime as an indicator of the proximity of the nanoparticle in combination with electrodynamic simulations, we determine the distance between the nanoparticle and the dye placed in a DNA origami pillar. Importantly, compared to the common shear geometry smaller distances between the connected structures are obtained which are independent of the length of the DNA connector. Using the zipper geometry, we then arranged nanoparticles of 100 and 150 nm diameter on DNA origami and formed gap nanoantennas. We find that the previously reported trend of increased fluorescence enhancement of ATTO647N with increasing particle size for 20-100 nm nanoparticles is stopped. Gap nanoantennas built with 150 nm nanoparticles exhibit smaller enhancement than those with 100 nm nanoparticles. These results are discussed with the aid of electrodynamic simulations.

An Array of Optical Receivers for Deep-Space Communications

Science.gov (United States)

Vilnrotter, Chi-Wung; Srinivasan, Meera; Andrews, Kenneth

2007-01-01

An array of small optical receivers is proposed as an alternative to a single large optical receiver for high-data-rate communications in NASA s Deep Space Network (DSN). Because the telescope for a single receiver capable of satisfying DSN requirements must be greater than 10 m in diameter, the design, building, and testing of the telescope would be very difficult and expensive. The proposed array would utilize commercially available telescopes of 1-m or smaller diameter and, therefore, could be developed and verified with considerably less difficulty and expense. The essential difference between a single-aperture optical-communications receiver and an optical-array receiver is that a single-aperture receiver focuses all of the light energy it collects onto the surface of an optical detector, whereas an array receiver focuses portions of the total collected energy onto separate detectors, optically detects each fractional energy component, then combines the electrical signal from the array of detector outputs to form the observable, or "decision statistic," used to decode the transmitted data. A conceptual block diagram identifying the key components of the optical-array receiver suitable for deep-space telemetry reception is shown in the figure. The most conspicuous feature of the receiver is the large number of small- to medium-size telescopes, with individual apertures and number of telescopes selected to make up the desired total collecting area. This array of telescopes is envisioned to be fully computer- controlled via the user interface and prediction-driven to achieve rough pointing and tracking of the desired spacecraft. Fine-pointing and tracking functions then take over to keep each telescope pointed toward the source, despite imperfect pointing predictions, telescope-drive errors, and vibration caused by wind.

Optical properties of titanium dioxide nanotube arrays

Energy Technology Data Exchange (ETDEWEB)

Abdelmoula, Mohamed [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States); Department of Materials Science, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Sokoloff, Jeffrey; Lu, Wen-Tao; Menon, Latika [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States); Close, Thomas; Richter, Christiaan, E-mail: christiaan.richter@rit.edu [Department of Chemical Engineering, Rochester Institute of Technology, Rochester, New York, 14623 (United States)

2014-01-07

We present experimental measurements and a theoretical analysis of the near UV to NIR optical properties of free standing titania nanotube arrays. An improved understanding of the optical physics of this type of nanostructure is important to several next generation solar energy conversion technologies. We measured the transmission, reflection, and absorption of the electromagnetic spectrum from 300 nm to 1000 nm (UV to NIR) of titania nanotube arrays. We measured the total, specular, and diffuse reflection and transmission using both single point detection and an integrating sphere spectrometer. We find that the transmission, but not the reflection, of light (UV to NIR) through the nanotube array is well-explained by classic geometric optics using an effective medium model taking into account the conical geometry of the nanotubes. For wavelengths shorter than ∼500 nm, we find the surprising result that the reflection coefficient for light incident on the open side of the nanotube array is greater than the reflection coefficient for light incident on the closed “floor” of the nanotube array. We consider theoretical models based on the eikonal approximation, photonic crystal band theory, and a statistical treatment of scattering to explain the observed data. We attribute the fact that light with wavelengths shorter than 500 nm is more highly reflected from the open than the closed tube side as being due to disorder scattering inside the nanotube array.

Resonance spectra of diabolo optical antenna arrays

Directory of Open Access Journals (Sweden)

Hong Guo

2015-10-01

Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

Nonlinear optical localization in embedded chalcogenide waveguide arrays

International Nuclear Information System (INIS)

Li, Mingshan; Huang, Sheng; Wang, Qingqing; Chen, Kevin P.; Petek, Hrvoje

2014-01-01

We report the nonlinear optical localization in an embedded waveguide array fabricated in chalcogenide glass. The array, which consists of seven waveguides with circularly symmetric cross sections, is realized by ultrafast laser writing. Light propagation in the chalcogenide waveguide array is studied with near infrared laser pulses centered at 1040 nm. The peak intensity required for nonlinear localization for the 1-cm long waveguide array was 35.1 GW/cm 2 , using 10-nJ pulses with 300-fs pulse width, which is 70 times lower than that reported in fused silica waveguide arrays and with over 7 times shorter interaction distance. Results reported in this paper demonstrated that ultrafast laser writing is a viable tool to produce 3D all-optical switching waveguide circuits in chalcogenide glass

Gold dimer nanoantenna with slanted gap for tunable LSPR and improved SERS

KAUST Repository

Kessentini, Sameh

2014-02-13

We focus on improving the surface-enhanced Raman scattering (SERS) of dimer nanoantenna by tailoring the shape of the coupled nanoantennas extremities from rounded to straight or slanted ones. A numerical model based on the discrete dipole approximation method-taking into account periodicity, adhesion layer, and roughness-is first validated by comparison with localized surface plasmon resonance (LSPR) and SERS experiments on round-edged dimer nanoantennas and then used to investigate the effect of the straight or slanted gap in the dimer antenna. Simulations show that both LSPR and SERS can be tuned by changing the gap slanting angle. The SERS enhancement factor can also be improved by 2 orders of magnitude compared to the one reached using a rounded gap. Therefore, the slanting angle can be used as a new control parameter in the design of SERS substrates to guarantee stronger field confinement and higher sensitivity, especially as its feasibility is demonstrated. © 2014 American Chemical Society.

Gold dimer nanoantenna with slanted gap for tunable LSPR and improved SERS

KAUST Repository

Kessentini, Sameh; Barchiesi, Dominique; D'Andrea, Cristiano; Toma, Andrea; Guillot, Nicolas; Di Fabrizio, Enzo M.; Fazio, Barbara; Maragó , Onofrio M.; Gucciardi, Pietro Giuseppe; Lamy De La Chapelle, Marc L.

2014-01-01

We focus on improving the surface-enhanced Raman scattering (SERS) of dimer nanoantenna by tailoring the shape of the coupled nanoantennas extremities from rounded to straight or slanted ones. A numerical model based on the discrete dipole approximation method-taking into account periodicity, adhesion layer, and roughness-is first validated by comparison with localized surface plasmon resonance (LSPR) and SERS experiments on round-edged dimer nanoantennas and then used to investigate the effect of the straight or slanted gap in the dimer antenna. Simulations show that both LSPR and SERS can be tuned by changing the gap slanting angle. The SERS enhancement factor can also be improved by 2 orders of magnitude compared to the one reached using a rounded gap. Therefore, the slanting angle can be used as a new control parameter in the design of SERS substrates to guarantee stronger field confinement and higher sensitivity, especially as its feasibility is demonstrated. © 2014 American Chemical Society.

Active Micro structured Optical Arrays of Grazing Incidence Reflectors

International Nuclear Information System (INIS)

Willingale, R.; Feldman, Ch.; Michette, A.; Hart, D.; McFaul, Ch; Morrison, G.R.; Pfauntsch, S.; Powell, A.K.; Sahraei, Sh.; Shand, M.T.; Button, T.; Rodriguez-Sanmartin, D.; Zhang, D.; Dunare, C.; Parkes, W.; Stevenson, T.; Folkard, M.; Vojnovic, B.; Vojnovic, B.

2011-01-01

The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is micro structured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to poly capillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the micro probing of biological cells and tissue samples using Ti Ka radiation (4.5?keV) in studies related to radiation-induced cancers. This paper discusses the optical design, modelling, and manufacture of such optics

Ring-array processor distribution topology for optical interconnects

Science.gov (United States)

Li, Yao; Ha, Berlin; Wang, Ting; Wang, Sunyu; Katz, A.; Lu, X. J.; Kanterakis, E.

1992-01-01

The existing linear and rectangular processor distribution topologies for optical interconnects, although promising in many respects, cannot solve problems such as clock skews, the lack of supporting elements for efficient optical implementation, etc. The use of a ring-array processor distribution topology, however, can overcome these problems. Here, a study of the ring-array topology is conducted with an aim of implementing various fast clock rate, high-performance, compact optical networks for digital electronic multiprocessor computers. Practical design issues are addressed. Some proof-of-principle experimental results are included.

Efficiency roll-off suppression in organic light-emitting diodes using size-tunable bimetallic bowtie nanoantennas at high current densities

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yukun [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Yun, Feng, E-mail: fyun2010@mail.xjtu.edu.cn; Li, Yufeng; Feng, Lungang; Ding, Wen [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Huang, Yi [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Wu, Zhaoxin; Jiao, Bo; Li, Sanfeng [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Zhang, Ye [Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

2016-07-04

Size-tunable bimetallic bowtie nanoantennas have been utilized to suppress the efficiency roll-off characteristics in organic light-emitting diodes (OLEDs) using both the numerical and experimental approaches. The resonant range can be widened by the strong dual-atomic couplings in bimetallic bowtie nanoantennas. Compared with the green OLED with conventional bowtie nanoantennas at a high current density of 800 mA/cm{sup 2}, the measured efficiency roll-off ratio of the OLED with size-modulated bowtie nanoantennas is decreased from 53.2% to 41.8%, and the measured current efficiency is enhanced by 29.9%. When the size-modulated bowtie nanoantennas are utilized in blue phosphorescent OLEDs, the experimental roll-off ratio is suppressed from 43.6% to 25.9% at 250 mA/cm{sup 2}, and the measured current efficiency is also enhanced significantly. It is proposed that the efficiency roll-off suppression is mainly related to the enhanced localized surface plasmon effect, which leads to a shorter radiative lifetime.

Efficiency roll-off suppression in organic light-emitting diodes using size-tunable bimetallic bowtie nanoantennas at high current densities

International Nuclear Information System (INIS)

Zhao, Yukun; Yun, Feng; Li, Yufeng; Feng, Lungang; Ding, Wen; Huang, Yi; Wu, Zhaoxin; Jiao, Bo; Li, Sanfeng; Zhang, Ye

2016-01-01

Size-tunable bimetallic bowtie nanoantennas have been utilized to suppress the efficiency roll-off characteristics in organic light-emitting diodes (OLEDs) using both the numerical and experimental approaches. The resonant range can be widened by the strong dual-atomic couplings in bimetallic bowtie nanoantennas. Compared with the green OLED with conventional bowtie nanoantennas at a high current density of 800 mA/cm"2, the measured efficiency roll-off ratio of the OLED with size-modulated bowtie nanoantennas is decreased from 53.2% to 41.8%, and the measured current efficiency is enhanced by 29.9%. When the size-modulated bowtie nanoantennas are utilized in blue phosphorescent OLEDs, the experimental roll-off ratio is suppressed from 43.6% to 25.9% at 250 mA/cm"2, and the measured current efficiency is also enhanced significantly. It is proposed that the efficiency roll-off suppression is mainly related to the enhanced localized surface plasmon effect, which leads to a shorter radiative lifetime.

Controlling the near-field excitation of nano-antennas with phase-change materials.

Science.gov (United States)

Kao, Tsung Sheng; Chen, Yi Guo; Hong, Ming Hui

2013-01-01

By utilizing the strongly induced plasmon coupling between discrete nano-antennas and quantitatively controlling the crystalline proportions of an underlying Ge2Sb2Te5 (GST) phase-change thin layer, we show that nanoscale light localizations in the immediate proximity of plasmonic nano-antennas can be spatially positioned. Isolated energy hot-spots at a subwavelength scale can be created and adjusted across the landscape of the plasmonic system at a step resolution of λ/20. These findings introduce a new approach for nano-circuitry, bio-assay addressing and imaging applications.

Optical performance of prototype horn-coupled TES bolometer arrays for SAFARI

Science.gov (United States)

Audley, Michael D.; de Lange, Gert; Gao, Jian-Rong; Khosropanah, Pourya; Hijmering, Richard; Ridder, Marcel L.

2016-07-01

The SAFARI Detector Test Facility is an ultra-low background optical testbed for characterizing ultra-sensitive prototype horn-coupled TES bolmeters for SAFARI, the grating spectrometer on board the proposed SPICA satellite. The testbed contains internal cold and hot black-body illuminators and a light-pipe for illumination with an external source. We have added reimaging optics to facilitate array optical measurements. The system is now being used for optical testing of prototype detector arrays read out with frequency-domain multiplexing. We present our latest optical measurements of prototype arrays and discuss these in terms of the instrument performance.

Miniaturized optical sensors based on lens arrays

DEFF Research Database (Denmark)

Hanson, Steen Grüner; Jakobsen, M.L.; Larsen, H.E.

2005-01-01

A suite of optical sensors based on the use of lenticular arrays for probing mechanical deflections will be displayed. The optical systems are well suited for miniaturization, and utilize speckles as the information-carriers. This implementation allows for acquiring directional information...

Remote artificial eyes using micro-optical circuit for long-distance 3D imaging perception.

Science.gov (United States)

Thammawongsa, Nopparat; Yupapin, Preecha P

2016-01-01

A small-scale optical device incorporated with an optical nano-antenna is designed to operate as the remote artificial eye using a tiny conjugate mirror. A basic device known as a conjugate mirror can be formed using the artificial eye device, the partially reflected light intensities from input source are interfered and the 3D whispering gallery modes formed within the ring centers, which can be modulated and propagated to the object. The image pixel is obtained at the center ring and linked with the optic nerve in the remote area via the nano-antenna, which is useful for blind people.

Photoacoustic projection imaging using an all-optical detector array

Science.gov (United States)

Bauer-Marschallinger, J.; Felbermayer, K.; Berer, T.

2018-02-01

We present a prototype for all-optical photoacoustic projection imaging. By generating projection images, photoacoustic information of large volumes can be retrieved with less effort compared to common photoacoustic computed tomography where many detectors and/or multiple measurements are required. In our approach, an array of 60 integrating line detectors is used to acquire photoacoustic waves. The line detector array consists of fiber-optic MachZehnder interferometers, distributed on a cylindrical surface. From the measured variation of the optical path lengths of the interferometers, induced by photoacoustic waves, a photoacoustic projection image can be reconstructed. The resulting images represent the projection of the three-dimensional spatial light absorbance within the imaged object onto a two-dimensional plane, perpendicular to the line detector array. The fiber-optic detectors achieve a noise-equivalent pressure of 24 Pascal at a 10 MHz bandwidth. We present the operational principle, the structure of the array, and resulting images. The system can acquire high-resolution projection images of large volumes within a short period of time. Imaging large volumes at high frame rates facilitates monitoring of dynamic processes.

Full control of far-field radiation via photonic integrated circuits decorated with plasmonic nanoantennas.

Science.gov (United States)

Sun, Yi-Zhi; Feng, Li-Shuang; Bachelot, Renaud; Blaize, Sylvain; Ding, Wei

2017-07-24

We theoretically develop a hybrid architecture consisting of photonic integrated circuit and plasmonic nanoantennas to fully control optical far-field radiation with unprecedented flexibility. By exploiting asymmetric and lateral excitation from silicon waveguides, single gold nanorod and cascaded nanorod pair can function as component radiation pixels, featured by full 2π phase coverage and nanoscale footprint. These radiation pixels allow us to design scalable on-chip devices in a wavefront engineering fashion. We numerically demonstrate beam collimation with 30° out of the incident plane and nearly diffraction limited divergence angle. We also present high-numerical-aperture (NA) beam focusing with NA ≈0.65 and vector beam generation (the radially-polarized mode) with the mode similarity greater than 44%. This concept and approach constitutes a designable optical platform, which might be a future bridge between integrated photonics and metasurface functionalities.

Depscor-95 Agile Optical Phased Arrays for Microspacecraft

National Research Council Canada - National Science Library

Fork, Richard

1999-01-01

... average power beams with little or no mechanical movement are especially interesting. Recent advances in semiconductor and optical fiber lasers suggest lightweight compact optical phased arrays suitable for microspacecraft are feasible...

Hybrid reflection type metasurface of nano-antennas designed for optical needle field generation

Science.gov (United States)

Wang, Shiyi; Zhan, Qiwen

2015-03-01

We propose a reflection type metal-insulator-metal (MIM) metasurface composed of hybrid optical antennas for comprehensive spatial engineering the properties of optical fields. Its capability is illustrated with an example to create a radially polarized vectorial beam for optical needle field generation. Functioning as local quarter-wave-plates (QWP), the MIM metasurface is designed to convert circularly polarized incident into local linear polarization to create an overall radial polarization with corresponding binary phases and desired normalized amplitude modulation ranged from 0.07 to 1. To obtain enough degrees of freedom, the optical-antenna layer comprises periodic arrangements of double metallic nano-bars with perpendicular placement and single nano-bars respectively for different amplitude modulation requirements. Both of the antennas enable to introduce π/2 retardation while reaching the desired modulation range both for phase and amplitude. Through adjusting the antennas' geometry and array carefully, we shift the gap-surface plasmon resonances facilitated by optical antennas to realize the manipulation of vectorial properties. Designed at 1064 nm wavelength, the particularly generated vectorial light output can be further tightly focused by a high numerical aperture objective to obtain longitudinally polarized flat-top focal field. The so-called optical needle field is a promising candidate for novel applications that transcend disciplinary boundaries. The proposed metasurface establishes a new class of compact optical components based on nano-scale structures, leading to compound functions for vectorial light generation.

Optical analogue of relativistic Dirac solitons in binary waveguide arrays

Energy Technology Data Exchange (ETDEWEB)

Tran, Truong X., E-mail: truong.tran@mpl.mpg.de [Department of Physics, Le Quy Don University, 236 Hoang Quoc Viet str., 10000 Hanoi (Viet Nam); Max Planck Institute for the Science of Light, Günther-Scharowsky str. 1, 91058 Erlangen (Germany); Longhi, Stefano [Department of Physics, Politecnico di Milano and Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, I-20133 Milano (Italy); Biancalana, Fabio [Max Planck Institute for the Science of Light, Günther-Scharowsky str. 1, 91058 Erlangen (Germany); School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom)

2014-01-15

We study analytically and numerically an optical analogue of Dirac solitons in binary waveguide arrays in the presence of Kerr nonlinearity. Pseudo-relativistic soliton solutions of the coupled-mode equations describing dynamics in the array are analytically derived. We demonstrate that with the found soliton solutions, the coupled mode equations can be converted into the nonlinear relativistic 1D Dirac equation. This paves the way for using binary waveguide arrays as a classical simulator of quantum nonlinear effects arising from the Dirac equation, something that is thought to be impossible to achieve in conventional (i.e. linear) quantum field theory. -- Highlights: •An optical analogue of Dirac solitons in nonlinear binary waveguide arrays is suggested. •Analytical solutions to pseudo-relativistic solitons are presented. •A correspondence of optical coupled-mode equations with the nonlinear relativistic Dirac equation is established.

Replication of optical microlens arrays using photoresist coated molds

DEFF Research Database (Denmark)

Chakrabarti, Maumita; Dam-Hansen, Carsten; Stubager, Jørgen

2016-01-01

A cost reduced method of producing injection molding tools is reported and demonstrated for the fabrication of optical microlens arrays. A standard computer-numerical-control (CNC) milling machine was used to make a rough mold in steel. Surface treatment of the steel mold by spray coating...... with photoresist is used to smooth the mold surface providing good optical quality. The tool and process are demonstrated for the fabrication of an ø50 mm beam homogenizer for a color mixing LED light engine. The acceptance angle of the microlens array is optimized, in order to maximize the optical efficiency from...

Direct transfer of subwavelength plasmonic nanostructures on bioactive silk films.

Science.gov (United States)

Lin, Dianmin; Tao, Hu; Trevino, Jacob; Mondia, Jessica P; Kaplan, David L; Omenetto, Fiorenzo G; Dal Negro, Luca

2012-11-27

By a reusable transfer fabrication technique, we demonstrate high-fidelity fabrication of metal nanoparticles, optical nanoantennas, and nanohole arrays directly on a functional silk biopolymer. The ability to reproducibly pattern silk biopolymers with arbitrarily complex plasmonic arrays is of importance for a variety of applications in optical biosensing, tissue engineering, cell biology, and the development of novel bio-optoelectronic medical devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Beat Noise Cancellation in 2-D Optical Code-Division Multiple-Access Systems Using Optical Hard-Limiter Array

Science.gov (United States)

Dang, Ngoc T.; Pham, Anh T.; Cheng, Zixue

We analyze the beat noise cancellation in two-dimensional optical code-division multiple-access (2-D OCDMA) systems using an optical hard-limiter (OHL) array. The Gaussian shape of optical pulse is assumed and the impact of pulse propagation is considered. We also take into account the receiver noise and multiple access interference (MAI) in the analysis. The numerical results show that, when OHL array is employed, the system performance is greatly improved compared with the cases without OHL array. Also, parameters needed for practical system design are comprehensively analyzed.

Optical networks for wideband sensor array

Science.gov (United States)

Sheng, Lin Horng

2011-12-01

This thesis presents the realization of novel systems for optical sensing networks with an array of long-period grating (LPG) sensors. As a launching point of the thesis, the motivation to implement optical sensing network in precisely catering LPG sensors is presented. It highlights the flexibility of the sensing network to act as the foundation in order to boost the application of the various LPG sensor design in biological and chemical sensing. After the thorough study on the various optical sensing networks, sub-carrier multiplexing (SCM) and optical time division multiplexing (OTDM) schemes are adopted in conjunction with tunable laser source (TLS) to facilitate simultaneous interrogation of the LPG sensors array. In fact, these systems are distinct to have the capability to accommodate wideband optical sensors. Specifically, the LPG sensors which is in 20nm bandwidth are identified to operate in these systems. The working principles of the systems are comprehensively elucidated in this thesis. It highlights the mathematical approach to quantify the experimental setup of the optical sensing network. Additionally, the system components of the designs are identified and methodically characterized so that the components well operate in the designed environment. A mockup has been setup to demonstrate the application in sensing of various liquid indices and analyse the response of the LPG sensors in order to evaluate the performance of the systems. Eventually, the resemblance of the demultiplexed spectral response to the pristine spectral response are quantified to have excellent agreement. Finally, the promising result consistency of the systems is verified through repeatability test.

Design of a sector bowtie nano-rectenna for optical power and infrared detection

Science.gov (United States)

Wang, Kai; Hu, Haifeng; Lu, Shan; Guo, Lingju; He, Tao

2015-10-01

We designed a sector bowtie nanoantenna integrated with a rectifier (Au-TiO x -Ti diode) for collecting infrared energy. The optical performance of the metallic bowtie nanoantenna was numerically investigated at infrared frequencies (5-30 μm) using three-dimensional frequency-domain electromagnetic field calculation software based on the finite element method. The simulation results indicate that the resonance wavelength and local field enhancement are greatly affected by the shape and size of the bowtie nanoantenna, as well as the relative permittivity and conductivity of the dielectric layer. The output current of the rectified nano-rectenna is substantially at nanoampere magnitude with an electric field intensity of 1 V/m. Moreover, the power conversion efficiency for devices with three different substrates illustrates that a substrate with a larger refractive index yields a higher efficiency and longer infrared response wavelength. Consequently, the optimized structure can provide theoretical support for the design of novel optical rectennas and fabrication of optoelectronic devices.

bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

Energy Technology Data Exchange (ETDEWEB)

Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Hui, H. [Department of Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Barkats, D. [Joint ALMA Observatory, ESO, Santiago (Chile); Benton, S. J. [Department of Physics, University of Toronto, Toronto, ON (Canada); Bischoff, C. A.; Bradford, K. J.; Buder, I. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS 42, Cambridge, MA 02138 (United States); Bullock, E. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Dowell, C. D. [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Duband, L. [Université Grenoble Alpes, CEA INAC-SBT, F-38000 Grenoble (France); Fliescher, S. [Department of Physics, University of Minnesota, Minneapolis, MN 55455 (United States); Halpern, M.; Hasselfield, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC (Canada); Hilton, G. C., E-mail: avieregg@kicp.uchicago.edu [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Collaboration: bicep2 and Keck Array Collaborations; and others

2015-06-20

bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

Micromirror Arrays for Adaptive Optics; TOPICAL

International Nuclear Information System (INIS)

Carr, E.J.

2000-01-01

The long-range goal of this project is to develop the optical and mechanical design of a micromirror array for adaptive optics that will meet the following criteria: flat mirror surface ((lambda)/20), high fill factor ( and gt; 95%), large stroke (5-10(micro)m), and pixel size(approx)-200(micro)m. This will be accomplished by optimizing the mirror surface and actuators independently and then combining them using bonding technologies that are currently being developed

Fabrication of Metallic Quantum Dot Arrays For Nanoscale Nonlinear Optics

Science.gov (United States)

McMahon, M. D.; Hmelo, A. B.; Lopez Magruder, R., III; Weller Haglund, R. A., Jr.; Feldman, L. C.

2003-03-01

Ordered arrays of metal nanocrystals embedded in or sequestered on dielectric hosts have potential applications as elements of nonlinear or near-field optical circuits, as sensitizers for fluorescence emitters and photo detectors, and as anchor points for arrays of biological molecules. Metal nanocrystals are strongly confined electronic systems with size-, shape and spatial orientation-dependent optical responses. At the smallest scales (below about 15 nm diameter), their band structure is drastically altered by the small size of the system, and the reduced population of conduction-band electrons. Here we report on the fabrication of two-dimensional ordered metallic nanocrystal arrays, and one-dimensional nanocrystal-loaded waveguides for optical investigations. We have employed strategies for synthesizing metal nanocrystal composites that capitalize on the best features of focused ion beam (FIB) machining and pulsed laser deposition (PLD). The FIB generates arrays of specialized sites; PLD vapor deposition results in the directed self-assembly of Ag nanoparticles nucleated at the FIB generated sites on silicon substrates. We present results based on the SEM, AFM and optical characterization of prototype composites. This research has been supported by the U.S. Department of Energy under grant DE-FG02-01ER45916.

SEIRS with gold nanoantennas towards health diagnostics

Energy Technology Data Exchange (ETDEWEB)

Neubrech, Frank; Weber, Daniel; Bochterle, Joerg; Petrich, Wolfgang; Pucci, Annemarie [Kirchhoff Institute for Physics, Heidelberg (Germany); Aizpurua, Javier [Donostia International Physics Center, Donostia-San Sebastian (Spain); Di Fabrizio, Enzo [Italian Institute of Technology, Genoa (Italy); La Chapelle, Marc Lamy de [University Paris 13, Bobigny (France)

2011-07-01

It is well established, that plasmonic oscillations in metal nanorods efficiently enhance near-field under resonant conditions. In the infrared, fundamental antenna-like resonance can be used for surface-enhanced infrared spectroscopic (SEIRS) studies. In the project NANOANTENNA we optimize such system for application of SEIRS to the detection of rare biomolecular disease indicators in the human blood. Accordingly, as first step, a biocompatible material combination was identified and secondly, the resonance condition is optimized.

Fiber optic modification of a diode array spectrophotometer

International Nuclear Information System (INIS)

Van Hare, D.R.; Prather, W.S.

1986-01-01

Fiber optics were adapted to a Hewlett-Packard diode array spectrophotometer to permit the analysis of radioactive samples without risking contamination of the instrument. Instrument performance was not compromised by the fiber optics. The instrument is in routine use at the Savannah River Plant control laboratories

Cylindrical and Spherical Active Coated Nanoparticles as Nanoantennas: Active nanoparticles as nanoantennas

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, Richard W.

2017-01-01

In this article, we review the fundamental properties of several spherical and cylindrical, passive, and active coated nanoparticles (CNPs) with an emphasis on their potential for nanoantenna and nanoamplifier synthesis. For the spherical geometries, the nanoparticles are excited by an electric...... Hertzian dipole (EHD), which represents, e.g., a stimulated atom or molecule. The cylindrical nanoparticles are excited by a magnetic line source (MLS). In the active cases, gain is added to the core region of the particle. For simplicity, it is represented by a canonical, frequency-independent gain model....... We demonstrate that specific CNPs can be designed to be resonant and well matched to their respective excitation sources. With active cores, these designs can lead to extremely large total radiated powers. For both configurations, insights into the effects of the nanoparticle material composition...

Switchable directional excitation surface plasmon polaritons with dielectric nanoantennas

DEFF Research Database (Denmark)

Sinev, I.; Komissarenko, F.; Bogdanov, A.

2017-01-01

We demonstrate directional launching of surface plasmon polaritons on thin goldfilm with a single silicon nanosphere. The directivity pattern of the excited surface waves exhibits rapid switching from forward to backward excitation, which is driven by the mutual interference of magnetic and elect...... and electric dipole moments supported by the dielectric nanoantenna....

Conformal array design on arbitrary polygon surface with transformation optics

Energy Technology Data Exchange (ETDEWEB)

Deng, Li, E-mail: dengl@bupt.edu.cn; Hong, Weijun, E-mail: hongwj@bupt.edu.cn; Zhu, Jianfeng; Peng, Biao; Li, Shufang [Beijing Key Laboratory of Network System Architecture and Convergence, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, 100876 Beijing (China); Wu, Yongle, E-mail: wuyongle138@gmail.com [Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, 100876 Beijing (China)

2016-06-15

A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

Conformal array design on arbitrary polygon surface with transformation optics

International Nuclear Information System (INIS)

Deng, Li; Hong, Weijun; Zhu, Jianfeng; Peng, Biao; Li, Shufang; Wu, Yongle

2016-01-01

A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

Fiber Optic Pressure Sensor Array, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

Nanoantenna enhanced terahertz spectroscopy of a monolayer of cadmium selenide quantum dots

KAUST Repository

Razzari, Luca; Toma, Andrea; Tuccio, Salvatore; Prato, Mirko; De Donato, Francesco; Perucchi, Andrea; Di Pietro, Paola; Marras, Sergio; Liberale, Carlo; Proietti Zaccaria, Remo; De Angelis, Francesco De; Manna, Liberato; Lupi, Stefano; Di Fabrizio, Enzo M.

2014-01-01

Exploiting the localization and enhancement capabilities of terahertz resonant dipole nanoantennas coupled through nanogaps, we present an effective method to perform terahertz spectroscopy on an extremely small number of nano-objects.

Optically addressed ultra-wideband phased antenna array

Science.gov (United States)

Bai, Jian

Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of ultra-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled oscillators (VCO) cannot provide a tunable range of several octaves, distribution of wideband local oscillator signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides ultra-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an ultra-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization

Application of optical processing to adaptive phased array radar

Science.gov (United States)

Carroll, C. W.; Vijaya Kumar, B. V. K.

1988-01-01

The results of the investigation of the applicability of optical processing to Adaptive Phased Array Radar (APAR) data processing will be summarized. Subjects that are covered include: (1) new iterative Fourier transform based technique to determine the array antenna weight vector such that the resulting antenna pattern has nulls at desired locations; (2) obtaining the solution of the optimal Wiener weight vector by both iterative and direct methods on two laboratory Optical Linear Algebra Processing (OLAP) systems; and (3) an investigation of the effects of errors present in OLAP systems on the solution vectors.

Apparatuses and method for converting electromagnetic radiation to direct current

Science.gov (United States)

Kotter, Dale K; Novack, Steven D

2014-09-30

An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

Graphene-based fine-tunable optical delay line for optical beamforming in phased-array antennas.

Science.gov (United States)

Tatoli, Teresa; Conteduca, Donato; Dell'Olio, Francesco; Ciminelli, Caterina; Armenise, Mario N

2016-06-01

The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=920  ps) together with a compact footprint (4.15  mm2) and optical loss graphene-based Mach-Zehnder interferometer switches and two vertically stacked microring resonators between which a graphene capacitor is placed. The tuning range is obtained by varying the value of the voltage applied to the graphene electrodes, which controls the optical path of the light propagation and therefore the delay time. The graphene provides a faster reconfigurable time and low values of energy dissipation. Such significant advantages, together with a negligible beam-squint effect, allow us to overcome the limitations of conventional RF beamformers. A highly efficient fine-tunable optical delay line for the beamsteering of 20 radiating elements up to ±20° in the azimuth direction of a tile in a phased-array antenna of an X-band synthetic aperture radar has been designed.

Experimental demonstration of conformal phased array antenna via transformation optics.

Science.gov (United States)

Lei, Juan; Yang, Juxing; Chen, Xi; Zhang, Zhiya; Fu, Guang; Hao, Yang

2018-02-28

Transformation Optics has been proven a versatile technique for designing novel electromagnetic devices and it has much wider applicability in many subject areas related to general wave equations. Among them, quasi-conformal transformation optics (QCTO) can be applied to minimize anisotropy of transformed media and has opened up the possibility to the design of broadband antennas with arbitrary geometries. In this work, a wide-angle scanning conformal phased array based on all-dielectric QCTO lens is designed and experimentally demonstrated. Excited by the same current distribution as such in a conventional planar array, the conformal system in presence of QCTO lens can preserve the same radiation characteristics of a planar array with wide-angle beam-scanning and low side lobe level (SLL). Laplace's equation subject to Dirichlet-Neumann boundary conditions is adopted to construct the mapping between the virtual and physical spaces. The isotropic lens with graded refractive index is realized by all-dielectric holey structure after an effective parameter approximation. The measurements of the fabricated system agree well with the simulated results, which demonstrate its excellent wide-angle beam scanning performance. Such demonstration paves the way to a robust but efficient array synthesis, as well as multi-beam and beam forming realization of conformal arrays via transformation optics.

Light-emitting waveguide-plasmon polaritions

NARCIS (Netherlands)

Rodriguez, S.R.K.; Murai, S.; Verschuuren, M.A.; Gómez Rivas, J.

2012-01-01

We demonstrate the generation of light in an optical waveguide strongly coupled to a periodic array of metallic nanoantennas. This coupling gives rise to hybrid waveguide-plasmon polaritons (WPPs), which undergo a transmutation from plasmon to waveguide mode and vice versa as the eigenfrequency

Smart photodetector arrays for error control in page-oriented optical memory

Science.gov (United States)

Schaffer, Maureen Elizabeth

1998-12-01

Page-oriented optical memories (POMs) have been proposed to meet high speed, high capacity storage requirements for input/output intensive computer applications. This technology offers the capability for storage and retrieval of optical data in two-dimensional pages resulting in high throughput data rates. Since currently measured raw bit error rates for these systems fall several orders of magnitude short of industry requirements for binary data storage, powerful error control codes must be adopted. These codes must be designed to take advantage of the two-dimensional memory output. In addition, POMs require an optoelectronic interface to transfer the optical data pages to one or more electronic host systems. Conventional charge coupled device (CCD) arrays can receive optical data in parallel, but the relatively slow serial electronic output of these devices creates a system bottleneck thereby eliminating the POM advantage of high transfer rates. Also, CCD arrays are "unintelligent" interfaces in that they offer little data processing capabilities. The optical data page can be received by two-dimensional arrays of "smart" photo-detector elements that replace conventional CCD arrays. These smart photodetector arrays (SPAs) can perform fast parallel data decoding and error control, thereby providing an efficient optoelectronic interface between the memory and the electronic computer. This approach optimizes the computer memory system by combining the massive parallelism and high speed of optics with the diverse functionality, low cost, and local interconnection efficiency of electronics. In this dissertation we examine the design of smart photodetector arrays for use as the optoelectronic interface for page-oriented optical memory. We review options and technologies for SPA fabrication, develop SPA requirements, and determine SPA scalability constraints with respect to pixel complexity, electrical power dissipation, and optical power limits. Next, we examine data

Ultradense, Deep Subwavelength Nanowire Array Photovoltaics As Engineered Optical Thin Films

KAUST Repository

Tham, Douglas; Heath, James R.

2010-01-01

A photovoltaic device comprised of an array of 20 nm wide, 32 nm pitch array of silicon nanowires is modeled as an optical material. The nanowire array (NWA) has characteristic device features that are deep in the subwavelength regime for light

Ultradense, Deep Subwavelength Nanowire Array Photovoltaics As Engineered Optical Thin Films

KAUST Repository

Tham, Douglas

2010-11-10

A photovoltaic device comprised of an array of 20 nm wide, 32 nm pitch array of silicon nanowires is modeled as an optical material. The nanowire array (NWA) has characteristic device features that are deep in the subwavelength regime for light, which permits a number of simplifying approximations. Using photocurrent measurements as a probe of the absorptance, we show that the NWA optical properties can be accurately modeled with rigorous coupled-wave analysis. The densely structured NWAs behave as homogeneous birefringent materials into the ultraviolet with effective optical properties that are accurately modeled using the dielectric functions of bulk Si and SiO 2, coupled with a physical model for the NWA derived from ellipsometry and transmission electron microscopy. © 2010 American Chemical Society.

Reconfigurable c-Si/Au hybrid nanoantenna

Science.gov (United States)

Chebykin, A. V.; Zalogina, A. S.; Zuev, D. A.; Makarov, S. V.

2017-09-01

We have performed numerical optimization of hybrid c-Si/Au nanoantenna's geometry to improve efficiency of NV-centers radiation. We have shown that Purcell factor at the wavelength 635 nm can be as much as 4550 for point light emitter placed in the gap between gold spherical nanoparticle and truncated silicon nanocone. We have demonstrated that electric field enhancement can reach a value of 12.9 at the wavelength of NV-center pumping, 532 nm. Our results can be useful for the development of more efficient sources of single photons based on NV-centers in nanodiamonds.

Review on structured optical field generated from array beams

Science.gov (United States)

Hou, Tianyue; Zhou, Pu; Ma, Yanxing; Zhi, Dong

2018-03-01

Structured optical field (SOF), which includes vortex beams, non-diffraction beams, cylindrical vector beams and so on, has been under intensive investigation theoretically and experimentally in recent years. Generally, current research focus on the extraordinary properties (non-diffraction propagation, helical wavefront, rotation of electrical field, et al), which can be widely applied in micro-particle manipulation, super-resolution imaging, free-space communication and so on. There are mainly two technical routes, that is, inner-cavity and outer-cavity (spatial light modulators, diffractive phase holograms, q-plates). To date, most of the SOFs generated from both technical routes involves with single monolithic beam. As a novel technical route, SOF based on array beams has the advantage in more flexible freedom degree and power scaling potential. In this paper, research achievements in SOF generation based on array beams are arranged and discussed in detail. Moreover, experiment of generating exotic beam by array beams is introduced, which illustrates that SOF generated from array beams is theoretically valid and experimentally feasible. SOF generated from array beams is also beneficial for capacity increasing and data receiving for free-space optical communication systems at long distance.

32 x 16 CMOS smart pixel array for optical interconnects

Science.gov (United States)

Kim, Jongwoo; Guilfoyle, Peter S.; Stone, Richard V.; Hessenbruch, John M.; Choquette, Kent D.; Kiamilev, Fouad E.

2000-05-01

Free space optical interconnects can increase throughput capacities and eliminate much of the energy consumption required for `all electronic' systems. High speed optical interconnects can be achieved by integrating optoelectronic devices with conventional electronics. Smart pixel arrays have been developed which use optical interconnects. An individual smart pixel cell is composed of a vertical cavity surface emitting laser (VCSEL), a photodetector, an optical receiver, a laser driver, and digital logic circuitry. Oxide-confined VCSELs are being developed to operate at 850 nm with a threshold current of approximately 1 mA. Multiple quantum well photodetectors are being fabricated from AlGaAs for use with the 850 nm VCSELs. The VCSELs and photodetectors are being integrated with complementary metal oxide semiconductor (CMOS) circuitry using flip-chip bonding. CMOS circuitry is being integrated with a 32 X 16 smart pixel array. The 512 smart pixels are serially linked. Thus, an entire data stream may be clocked through the chip and output electrically by the last pixel. Electrical testing is being performed on the CMOS smart pixel array. Using an on-chip pseudo random number generator, a digital data sequence was cycled through the chip verifying operation of the digital circuitry. Although, the prototype chip was fabricated in 1.2 micrometers technology, simulations have demonstrated that the array can operate at 1 Gb/s per pixel using 0.5 micrometers technology.

Optical Sensing with Simultaneous Electrochemical Control in Metal Nanowire Arrays

Directory of Open Access Journals (Sweden)

Janos Vörös

2010-11-01

Full Text Available This work explores the alternative use of noble metal nanowire systems in large-scale array configurations to exploit both the nanowires’ conductive nature and localized surface plasmon resonance (LSPR. The first known nanowire-based system has been constructed, with which optical signals are influenced by the simultaneous application of electrochemical potentials. Optical characterization of nanowire arrays was performed by measuring the bulk refractive index sensitivity and the limit of detection. The formation of an electrical double layer was controlled in NaCl solutions to study the effect of local refractive index changes on the spectral response. Resonance peak shifts of over 4 nm, a bulk refractive index sensitivity up to 115 nm/RIU and a limit of detection as low as 4.5 × 10−4 RIU were obtained for gold nanowire arrays. Simulations with the Multiple Multipole Program (MMP confirm such bulk refractive index sensitivities. Initial experiments demonstrated successful optical biosensing using a novel form of particle-based nanowire arrays. In addition, the formation of an ionic layer (Stern-layer upon applying an electrochemical potential was also monitored by the shift of the plasmon resonance.

Fiber optic spectrophotometer with photodiode linear array

International Nuclear Information System (INIS)

Blanc, F.; Vernet, P.

1988-01-01

Spectrophotometric measurements are used in a great number of industrial processes, in nuclear environment and with optical precision components. Especially the evolution of a chemical process or of an optical coating could be followed by these measurements. Spectrophotometers, using optical fibers to transport the signal out of the instrument make possible the measurement ''in-situ'' and in real time. The advantage of using a diode array to detect the signal is an instantaneous measurement all over the spectral range without moving parts. It allows an excellent reproductibility. The instrument is controlled by a micro computer. The spectrophotometer is described and technical performance presented. An extension using optical fibers on a ''classical'' spectrophotometer (a H.P. one) is also described and technical performance presented

Generation of Optical Vortex Arrays Using Single-Element Reversed-Wavefront Folding Interferometer

Directory of Open Access Journals (Sweden)

Brijesh Kumar Singh

2012-01-01

Full Text Available Optical vortex arrays have been generated using simple, novel, and stable reversed-wavefront folding interferometer. Two new interferometric configurations were used for generating a variety of optical vortex lattices. In the first interferometric configuration one cube beam splitter (CBS was used in one arm of Mach-Zehnder interferometer for splitting and combining the collimated beam, and one mirror of another arm is replaced by second CBS. At the output of interferometer, three-beam interference gives rise to optical vortex arrays. In second interferometric configuration, a divergent wavefront was made incident on a single CBS which splits and combines wavefronts leading to the generation of vortex arrays due to four-beam interference. It was found that the orientation and structure of the optical vortices can be stably controlled by means of changing the rotation angle of CBS.

Optical Fiber Array Assemblies for Space Flight on the Lunar Reconnaissance Orbiter

Science.gov (United States)

Ott, Jelanie; Matuszeski, Adam

2011-01-01

Custom fiber optic bundle array assemblies developed by the Photonics Group at NASA Goddard Space Flight Center were an enabling technology for both the Lunar Orbiter Laser Altimeter (LOLA) and the Laser Ranging (LR) Investigation on the Lunar Reconnaissance Orbiter (LRO) currently in operation. The unique assembly array designs provided considerable decrease in size and weight and met stringent system level requirements. This is the first time optical fiber array bundle assemblies were used in a high performance space flight application. This innovation was achieved using customized Diamond Switzerland AVIM optical connectors. For LOLA, a five fiber array was developed for the receiver telescope to maintain precise alignment for each of the 200/220 micron optical fibers collecting 1,064 nm wavelength light being reflected back from the moon. The array splits to five separate detectors replacing the need for multiple telescopes. An image illustration of the LOLA instrument can be found at the top of the figure. For the laser ranging, a seven-optical-fiber array of 400/440 micron fibers was developed to transmit light from behind the LR receiver telescope located on the end of the high gain antenna system (HGAS). The bundle was routed across two moving gimbals, down the HGAS boom arm, over a deployable mandrel and across the spacecraft to a detector on the LOLA instrument. The routing of the optical fiber bundle and its end locations is identified in the figure. The Laser Ranging array and bundle is currently accepting light at a wavelength of 532 nm sent to the moon from laser stations at Greenbelt MD and other stations around the world to gather precision ranging information from the Earth to the LRO spacecraft. The LR bundle assembly is capable of withstanding temperatures down to -55 C at the connectors, and 20,000 mechanical gimbal cycles at temperatures as cold as -20 C along the length of the seven-fiber bundle (that is packaged into the gimbals). The total

Multi-spectral optical absorption in substrate-free nanowire arrays

Energy Technology Data Exchange (ETDEWEB)

Zhang, Junpeng; Chia, Andrew; Boulanger, Jonathan; LaPierre, Ray, E-mail: lapierr@mcmaster.ca [Department of Engineering Physics, McMaster University, 1280 Main St. West, Hamilton, Ontario L8S 4L7 (Canada); Dhindsa, Navneet; Khodadad, Iman; Saini, Simarjeet [Department of Electrical and Computer Engineering, University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1 (Canada); Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1 (Canada)

2014-09-22

A method is presented of fabricating gallium arsenide (GaAs) nanowire arrays of controlled diameter and period by reactive ion etching of a GaAs substrate containing an indium gallium arsenide (InGaP) etch stop layer, allowing the precise nanowire length to be controlled. The substrate is subsequently removed by selective etching, using the same InGaP etch stop layer, to create a substrate-free GaAs nanowire array. The optical absorptance of the nanowire array was then directly measured without absorption from a substrate. We directly observe absorptance spectra that can be tuned by the nanowire diameter, as explained with rigorous coupled wave analysis. These results illustrate strong optical absorption suitable for nanowire-based solar cells and multi-spectral absorption for wavelength discriminating photodetectors. The solar-weighted absorptance above the bandgap of GaAs was 94% for a nanowire surface coverage of only 15%.

Dynamic array generation and pattern formation for optical tweezers

DEFF Research Database (Denmark)

Mogensen, P.C.; Glückstad, J.

2000-01-01

The generalised phase contrast approach is used for the generation of optical arrays of arbitrary beam shape, suitable for applications in optical tweezers for the manipulation of biological specimens. This approach offers numerous advantages over current techniques involving the use of computer......-generated holograms or diffractive optical elements. We demonstrate a low-loss system for generating intensity patterns suitable for the trapping and manipulation of small particles or specimens....

Characteristics of VCSELs and VCSEL arrays for optical data links

Science.gov (United States)

Gaw, Craig A.; Jiang, Wenbin; Lebby, Michael S.; Kiely, Philip A.; Claisse, Paul R.

1997-05-01

High performance, low cost, and highly reliable vertical cavity surface emitting lasers (VCSELs) have been developed and are currently being used in both parallel and serial optical interconnect applications. For example, Motorola's OPTOBUSTM parallel optical interconnect relies heavily on the unique characteristics of arrays of GaAs based VCSELs emitting at 850 nm to achieve its stringent performance goals at low cost. Representative parametric results of discrete VCSELs and VCSEL arrays will be compared, including `optical power output-current' and `current-voltage' curves, optical wall plug efficiencies, and modulation characteristics. The use of statistical parameter analysis across a wafer and subsequent parametric wafer maps has proven to be a valuable tool for maintaining control of the fabrication process. The consistency of VCSEL parameters across individual VCSEL arrays will be discussed. VCSELs are very robust devices. Life times at room ambient in excess of 3E6 hours have been reported by several groups. Degradation behavior of selected device parameters will be discussed. Failure analysis demonstrating the effect of proton implant depth on reliability will be presented. ESD damage at forward bias is shown to be process related, while ESD damage at reverse bias is shown to be material related. These VCSELs are ESD Class 1 devices.

Numerical study of the properties of optical vortex array laser tweezers.

Science.gov (United States)

Kuo, Chun-Fu; Chu, Shu-Chun

2013-11-04

Chu et al. constructed a kind of Ince-Gaussian modes (IGM)-based vortex array laser beams consisting of p x p embedded optical vortexes from Ince-Gaussian modes, IG(e)(p,p) modes [Opt. Express 16, 19934 (2008)]. Such an IGM-based vortex array laser beams maintains its vortex array profile during both propagation and focusing, and is applicable to optical tweezers. This study uses the discrete dipole approximation (DDA) method to study the properties of the IGM-based vortex array laser tweezers while it traps dielectric particles. This study calculates the resultant force exerted on the spherical dielectric particles of different sizes situated at the IGM-based vortex array laser beam waist. Numerical results show that the number of trapping spots of a structure light (i.e. IGM-based vortex laser beam), is depended on the relation between the trapped particle size and the structure light beam size. While the trapped particle is small comparing to the beam size of the IGM-based vortex array laser beams, the IGM-based vortex array laser beams tweezers are suitable for multiple traps. Conversely, the tweezers is suitable for single traps. The results of this study is useful to the future development of the vortex array laser tweezers applications.

bicep2/ KECK ARRAY . IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

Energy Technology Data Exchange (ETDEWEB)

Ade, P.A.R.; Aikin, R.W.; Barkats, D.; Benton, S.J.; Bischoff, C.A.; Bock, J.J.; Bradford, K.J.; Brevik, J.A.; Buder, I.; Bullock, E.; Dowell, C.D.; Duband, L.; Filippini, J.P.; Fliescher, S.; Golwala, S.R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S.R.; Hilton, G.C.; Hui, H.; Irwin, K.D.

2015-06-18

bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS P. A. R. Ade1, R. W. Aikin2, D. Barkats3, S. J. Benton4, C. A. Bischoff5, J. J. Bock2,6, K. J. Bradford5, J. A. Brevik2, I. Buder5, E. Bullock7Show full author list Published 2015 June 18 • © 2015. The American Astronomical Society. All rights reserved. The Astrophysical Journal, Volume 806, Number 2 Article PDF Figures Tables References Citations 273 Total downloads Cited by 6 articles Turn on MathJax Share this article Get permission to re-use this article Article information Abstract bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

Large arrays of discrete ionizing radiation detectors multiplexed using fluorescent optical converters

International Nuclear Information System (INIS)

Koslow, E.E.; Edelman, R.R.

1985-01-01

This invention provides a radiation imaging system employing arrays of scintillators. An object of the invention is to produce a detector with high spatial resolution, high gamma-photon absorption efficiency, excellent source and detector scatter rejection, and utilizing low-cost solid state opto-electronic devices. In one embodiment, it provides a radiation detection and conversion apparatus having an array of optically isolated radiation sensitive elements that emit optical radiation upon absorption of ionizing radiation. An array of channels, comprising a material that absorbs and traps the radiation emitted and transports it or radiation that has been shifted to longer wavelengths, is placed near the radiation-sensitive elements. Electro-optical detectors that convert the transported radiation into electrical signals are coupled to the channels. The activation of one of the electro-optical devices by radiation from one of the channels indicates that at least one of the radiation-sensitive elements near that channel has absorbed a quantity of radiation

Reconfigurable optical interconnection network for multimode optical fiber sensor arrays

Science.gov (United States)

Chen, R. T.; Robinson, D.; Lu, H.; Wang, M. R.; Jannson, T.; Baumbick, R.

1992-01-01

A single-source, single-detector architecture has been developed to implement a reconfigurable optical interconnection network multimode optical fiber sensor arrays. The network was realized by integrating LiNbO3 electrooptic (EO) gratings working at the Raman Na regime and a massive fan-out waveguide hologram (WH) working at the Bragg regime onto a multimode glass waveguide. The glass waveguide utilized the whole substrate as a guiding medium. A 1-to-59 massive waveguide fan-out was demonstrated using a WH operating at 514 nm. Measured diffraction efficiency of 59 percent was experimentally confirmed. Reconfigurability of the interconnection was carried out by generating an EO grating through an externally applied electric field. Unlike conventional single-mode integrated optical devices, the guided mode demonstrated has an azimuthal symmetry in mode profile which is the same as that of a fiber mode.

Optical Techniques for Millimeter-Wave Phased Array Communications Antennas

National Research Council Canada - National Science Library

Edge, Colin

1998-01-01

The scope of this program was to study the application of optical techniques to signal distribution and beamforming networks in phased array antennas for Army mobile tactical communications systems...

Optical demodulation system for digitally encoded suspension array in fluoroimmunoassay

Science.gov (United States)

He, Qinghua; Li, Dongmei; He, Yonghong; Guan, Tian; Zhang, Yilong; Shen, Zhiyuan; Chen, Xuejing; Liu, Siyu; Lu, Bangrong; Ji, Yanhong

2017-09-01

A laser-induced breakdown spectroscopy and fluorescence spectroscopy-coupled optical system is reported to demodulate digitally encoded suspension array in fluoroimmunoassay. It takes advantage of the plasma emissions of assembled elemental materials to digitally decode the suspension array, providing a more stable and accurate recognition to target biomolecules. By separating the decoding procedure of suspension array and adsorption quantity calculation of biomolecules into two independent channels, the cross talk between decoding and label signals in traditional methods had been successfully avoided, which promoted the accuracy of both processes and realized more sensitive quantitative detection of target biomolecules. We carried a multiplexed detection of several types of anti-IgG to verify the quantitative analysis performance of the system. A limit of detection of 1.48×10-10 M was achieved, demonstrating the detection sensitivity of the optical demodulation system.

All optical programmable logic array (PLA)

Science.gov (United States)

Hiluf, Dawit

2018-03-01

A programmable logic array (PLA) is an integrated circuit (IC) logic device that can be reconfigured to implement various kinds of combinational logic circuits. The device has a number of AND and OR gates which are linked together to give output or further combined with more gates or logic circuits. This work presents the realization of PLAs via the physics of a three level system interacting with light. A programmable logic array is designed such that a number of different logical functions can be combined as a sum-of-product or product-of-sum form. We present an all optical PLAs with the aid of laser light and observables of quantum systems, where encoded information can be considered as memory chip. The dynamics of the physical system is investigated using Lie algebra approach.

Lipid Multilayer Grating Arrays Integrated by Nanointaglio for Vapor Sensing by an Optical Nose

Directory of Open Access Journals (Sweden)

Troy W. Lowry

2015-08-01

Full Text Available Lipid multilayer gratings are recently invented nanomechanical sensor elements that are capable of transducing molecular binding to fluid lipid multilayers into optical signals in a label free manner due to shape changes in the lipid nanostructures. Here, we show that nanointaglio is suitable for the integration of chemically different lipid multilayer gratings into a sensor array capable of distinguishing vapors by means of an optical nose. Sensor arrays composed of six different lipid formulations are integrated onto a surface and their optical response to three different vapors (water, ethanol and acetone in air as well as pH under water is monitored as a function of time. Principal component analysis of the array response results in distinct clustering indicating the suitability of the arrays for distinguishing these analytes. Importantly, the nanointaglio process used here is capable of producing lipid gratings out of different materials with sufficiently uniform heights for the fabrication of an optical nose.

Lipid Multilayer Grating Arrays Integrated by Nanointaglio for Vapor Sensing by an Optical Nose

Science.gov (United States)

Lowry, Troy W.; Prommapan, Plengchart; Rainer, Quinn; Van Winkle, David; Lenhert, Steven

2015-01-01

Lipid multilayer gratings are recently invented nanomechanical sensor elements that are capable of transducing molecular binding to fluid lipid multilayers into optical signals in a label free manner due to shape changes in the lipid nanostructures. Here, we show that nanointaglio is suitable for the integration of chemically different lipid multilayer gratings into a sensor array capable of distinguishing vapors by means of an optical nose. Sensor arrays composed of six different lipid formulations are integrated onto a surface and their optical response to three different vapors (water, ethanol and acetone) in air as well as pH under water is monitored as a function of time. Principal component analysis of the array response results in distinct clustering indicating the suitability of the arrays for distinguishing these analytes. Importantly, the nanointaglio process used here is capable of producing lipid gratings out of different materials with sufficiently uniform heights for the fabrication of an optical nose. PMID:26308001

Strong Coupling and Entanglement of Quantum Emitters Embedded in a Nanoantenna-Enhanced Plasmonic Cavity

Energy Technology Data Exchange (ETDEWEB)

Hensen, Matthias [Institut; Heilpern, Tal [Center; Gray, Stephen K. [Center; Pfeiffer, Walter [Fakultät

2017-10-12

Establishing strong coupling between spatially separated and thus selectively addressable quantum emitters is a key ingredient to complex quantum optical schemes in future technologies. Insofar as many plasmonic nanostructures are concerned, however, the energy transfer and mutual interaction strength between distant quantum emitters can fail to provide strong coupling. Here, based on mode hybridization, the longevity and waveguide character of an elliptical plasmon cavity are combined with intense and highly localized field modes of suitably designed nanoantennas. Based on FDTD simulations a quantum emitter-plasmon coupling strength hg = 16.7 meV is reached while simultaneously keeping a small plasmon resonance line width h gamma(s) = 33 meV. This facilitates strong coupling, and quantum dynamical simulations reveal an oscillatory exchange of excited state population arid a notable degree of entanglement between the quantum emitters spatially separated by 1.8 mu m, i.e., about twice the operating wavelength.

Quasi-optical antenna-mixer-array design for terahertz frequencies

Science.gov (United States)

Guo, Yong; Potter, Kent A.; Rutledge, David B.

1992-01-01

A new quasi-optical antenna-mixer-array design for terahertz frequencies is presented. In the design, antenna and mixer are combined into an entity, based on the technology in which millimeter-wave horn antenna arrays have been fabricated in silicon wafers. It consists of a set of forward- and backward-looking horns made with a set of silicon wafers. The front side is used to receive incoming signal, and the back side is used to feed local oscillator signal. Intermediate frequency is led out from the side of the array. Signal received by the horn array is picked up by antenna probes suspended on thin silicon-oxynitride membranes inside the horns. Mixer diodes will be located on the membranes inside the horns. Modeling of such an antenna-mixer-array design is done on a scaled model at microwave frequencies. The impedance matching, RF and LO isolation, and patterns of the array have been tested and analyzed.

Optical techniques to feed and control GaAs MMIC modules for phased array antenna applications

Science.gov (United States)

Bhasin, K. B.; Anzic, G.; Kunath, R. R.; Connolly, D. J.

1986-01-01

A complex signal distribution system is required to feed and control GaAs monolithic microwave integrated circuits (MMICs) for phased array antenna applications above 20 GHz. Each MMIC module will require one or more RF lines, one or more bias voltage lines, and digital lines to provide a minimum of 10 bits of combined phase and gain control information. In a closely spaced array, the routing of these multiple lines presents difficult topology problems as well as a high probability of signal interference. To overcome GaAs MMIC phased array signal distribution problems optical fibers interconnected to monolithically integrated optical components with GaAs MMIC array elements are proposed as a solution. System architecture considerations using optical fibers are described. The analog and digital optical links to respectively feed and control MMIC elements are analyzed. It is concluded that a fiber optic network will reduce weight and complexity, and increase reliability and performance, but higher power will be required.

Meta-tips for lab-on-fiber optrodes

Science.gov (United States)

Principe, M.; Consales, M.; Micco, A.; Crescitelli, A.; Castaldi, G.; Esposito, E.; La Ferrara, V.; Cutolo, A.; Galdi, V.; Cusano, A.

2016-05-01

We realize the first optical-fiber "meta-tip" that integrates a metasurface on the tip of an optical fiber. In our proposed configuration a Babinet-inverted plasmonic metasurface is fabricated by patterning (via focused-ion-beam) an array of rectangular aperture nanoantennas in a thin gold film. Via spatial modulation of the nanoantennas size, we properly tune their resonances so as to impress abrupt arbitrary phase variations in the transmitted field wavefront. As a proof-of-principle, we fabricate and characterize several prototypes implementing in the near-infrared the beam-steering with various angles. We also explore the limit case where surface waves are excited, and its capability to work as refractive index sensors. Notably, its sensitivity overwhelms that of the corresponding gradient-free plasmonic array, thus paving the way to the use of metasurfaces for label-free chemical and biological sensing. Our experimental results, in fairly good agreement with numerical predictions, demonstrate the practical feasibility of the meta-tip concept, and set the stage for the integration of metasurfaces, and their exceptional capabilities to manipulate light, in fiber-optics technological platforms, within the emerging "lab-on-fiber" paradigm.

Development of nanostencil lithography and its applications for plasmonics and vibrational biospectroscopy

Science.gov (United States)

Aksu, Serap

Development of low cost nanolithography tools for precisely creating a variety of nanostructure shapes and arrangements in a high-throughput fashion is crucial for next generation biophotonic technologies. Although existing lithography techniques offer tremendous design flexibility, they have major drawbacks such as low-throughput and fabrication complexity. In addition the demand for the systematic fabrication of sub-100 nm structures on flexible, stretchable, non-planar nanoelectronic/photonic systems and multi-functional materials has fueled the research for innovative fabrication methods in recent years. This thesis research investigates a novel lithography approach for fabrication of engineered plasmonic nanostructures and metamaterials operating at visible and infrared wavelengths. The technique is called Nanostencil Lithography (NSL) and relies on direct deposition of materials through nanoapertures on a stencil. NSL enables high throughput fabrication of engineered antenna arrays with optical qualities similar to the ones fabricated by standard electron beam lithography. Moreover, nanostencils can be reused multiple times to fabricate series of plasmonic nanoantenna arrays with identical optical responses enabling high throughput manufacturing. Using nanostencils, very precise nanostructures could be fabricated with 10 nm accuracy. Furthermore, this technique has flexibility and resolution to create complex plasmonic nanostructure arrays on the substrates that are difficult to work with e-beam and ion beam lithography tools. Combining plasmonics with polymeric materials, biocompatible surfaces or curvilinear and non-planar objects enable unique optical applications since they can preserve normal device operation under large strain. In this work, mechanically tunable flexible optical materials and spectroscopy probes integrated on fiber surfaces that could be used for a wide range of applications are demonstrated. Finally, the first application of NSL

Ultrafast optical control of terahertz surface plasmons in subwavelength hole-arrays at room temperature

Energy Technology Data Exchange (ETDEWEB)

Azad, Abul Kalam [Los Alamos National Laboratory; Chen, Hou - Tong [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; O' Hara, John [Los Alamos National Laboratory

2010-12-10

Extraordinary optical transmission through subwavelength metallic hole-arrays has been an active research area since its first demonstration. The frequency selective resonance properties of subwavelength metallic hole arrays, generally known as surface plasmon polaritons, have potential use in functional plasmonic devices such as filters, modulators, switches, etc. Such plasmonic devices are also very promising for future terahertz applications. Ultrafast switching or modulation of the resonant behavior of the 2-D metallic arrays in terahertz frequencies is of particular interest for high speed communication and sensing applications. In this paper, we demonstrate optical control of surface plasmon enhanced resonant terahertz transmission in two-dimensional subwavelength metallic hole arrays fabricated on gallium arsenide based substrates. Optically pumping the arrays creates a conductive layer in the substrate reducing the terahertz transmission amplitude of both the resonant mode and the direct transmission. Under low optical fluence, the terahertz transmission is more greatly affected by resonance damping than by propagation loss in the substrate. An ErAs:GaAs nanoisland superlattice substrate is shown to allow ultrafast control with a switching recovery time of {approx}10 ps. We also present resonant terahertz transmission in a hybrid plasmonic film comprised of an integrated array of subwavelength metallic islands and semiconductor holes. A large dynamic transition between a dipolar localized surface plasmon mode and a surface plasmon resonance near 0.8 THz is observed under near infrared optical excitation. The reversal in transmission amplitude from a stopband to a passband and up to {pi}/2 phase shift achieved in the hybrid plasmonic film make it promising in large dynamic phase modulation, optical changeover switching, and active terahertz plasmonics.

Periodic Arrays of Film-Coupled Cubic Nanoantennas as Tunable Plasmonic Metasurfaces

Directory of Open Access Journals (Sweden)

Vassilios Yannopapas

2015-03-01

Full Text Available We show theoretically that a two-dimensional periodic array of metallic nanocubes in close proximity to a metallic film acts as a metasurface with tunable absorbance. The presence of a metallic film underneath the array of plasmonic nanocubes leads to an impedance matched plasmonic metasurface enhancing up to 4 times the absorbance of incident radiation, in the spectral region below 500 nm. The absorbance spectrum is weakly dependent on the angle of incidence and state of polarization of incident light a functionality which can find application in thermo-photovoltaics. Our calculations are based on a hybrid layer-multiple-scattering (hLMS method based on a discrete-dipole approximation (DDA/T-matrix point matching method.

Realistic full wave modeling of focal plane array pixels.

Energy Technology Data Exchange (ETDEWEB)

Campione, Salvatore [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Jorgenson, Roy E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Davids, Paul [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.; Peters, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.

2017-11-01

Here, we investigate full-wave simulations of realistic implementations of multifunctional nanoantenna enabled detectors (NEDs). We focus on a 2x2 pixelated array structure that supports two wavelengths of operation. We design each resonating structure independently using full-wave simulations with periodic boundary conditions mimicking the whole infinite array. We then construct a supercell made of a 2x2 pixelated array with periodic boundary conditions mimicking the full NED; in this case, however, each pixel comprises 10-20 antennas per side. In this way, the cross-talk between contiguous pixels is accounted for in our simulations. We observe that, even though there are finite extent effects, the pixels work as designed, each responding at the respective wavelength of operation. This allows us to stress that realistic simulations of multifunctional NEDs need to be performed to verify the design functionality by taking into account finite extent and cross-talk effects.

Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays

International Nuclear Information System (INIS)

Sathishkumar, P.; Punyabrahma, P.; Sri Muthu Mrinalini, R.; Jayanth, G. R.

2015-01-01

A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array

Detection and Mapping of the September 2017 Mexico Earthquakes Using DAS Fiber-Optic Infrastructure Arrays

Science.gov (United States)

Karrenbach, M. H.; Cole, S.; Williams, J. J.; Biondi, B. C.; McMurtry, T.; Martin, E. R.; Yuan, S.

2017-12-01

Fiber-optic distributed acoustic sensing (DAS) uses conventional telecom fibers for a wide variety of monitoring purposes. Fiber-optic arrays can be located along pipelines for leak detection; along borders and perimeters to detect and locate intruders, or along railways and roadways to monitor traffic and identify and manage incidents. DAS can also be used to monitor oil and gas reservoirs and to detect earthquakes. Because thousands of such arrays are deployed worldwide and acquiring data continuously, they can be a valuable source of data for earthquake detection and location, and could potentially provide important information to earthquake early-warning systems. In this presentation, we show that DAS arrays in Mexico and the United States detected the M8.1 and M7.2 Mexico earthquakes in September 2017. At Stanford University, we have deployed a 2.4 km fiber-optic DAS array in a figure-eight pattern, with 600 channels spaced 4 meters apart. Data have been recorded continuously since September 2016. Over 800 earthquakes from across California have been detected and catalogued. Distant teleseismic events have also been recorded, including the two Mexican earthquakes. In Mexico, fiber-optic arrays attached to pipelines also detected these two events. Because of the length of these arrays and their proximity to the event locations, we can not only detect the earthquakes but also make location estimates, potentially in near real time. In this presentation, we review the data recorded for these two events recorded at Stanford and in Mexico. We compare the waveforms recorded by the DAS arrays to those recorded by traditional earthquake sensor networks. Using the wide coverage provided by the pipeline arrays, we estimate the event locations. Such fiber-optic DAS networks can potentially play a role in earthquake early-warning systems, allowing actions to be taken to minimize the impact of an earthquake on critical infrastructure components. While many such fiber-optic

Nanoparticle array based optical frequency selective surfaces: theory and design.

Science.gov (United States)

Saeidi, Chiya; van der Weide, Daniel

2013-07-01

We demonstrate a synthesis procedure for designing a bandstop optical frequency selective surface (FSS) composed of nanoparticle (NP) elements. The proposed FSS uses two-dimensional (2-D) periodic arrays of NPs with subwavelength unit-cell dimensions. We derive equivalent circuit for a nanoparticle array (NPA) using the closed-form solution for a 2-D NPA excited by a plane wave in the limit of the dipole approximation, which includes contribution from both individual and collective plasmon modes. Using the extracted equivalent circuit, we demonstrate synthesis of an optical FSS using cascaded NPA layers as coupled resonators, which we validate with both circuit model and full-wave simulation for a third-order Butterworth bandstop prototype.

Geometrical optics, electrostatics, and nanophotonic resonances in absorbing nanowire arrays.

Science.gov (United States)

Anttu, Nicklas

2013-03-01

Semiconductor nanowire arrays have shown promise for next-generation photovoltaics and photodetection, but enhanced understanding of the light-nanowire interaction is still needed. Here, we study theoretically the absorption of light in an array of vertical InP nanowires by moving continuously, first from the electrostatic limit to the nanophotonic regime and then to the geometrical optics limit. We show how the absorption per volume of semiconductor material in the array can be varied by a factor of 200, ranging from 10 times weaker to 20 times stronger than in a bulk semiconductor sample.

Optical spin-to-orbital angular momentum conversion in ultra-thin metasurfaces with arbitrary topological charges

Energy Technology Data Exchange (ETDEWEB)

Bouchard, Frédéric; De Leon, Israel; Schulz, Sebastian A.; Upham, Jeremy; Karimi, Ebrahim, E-mail: ekarimi@uottawa.ca [Department of Physics, University of Ottawa, 25 Templeton, Ottawa, Ontario K1N 6N5 Canada (Canada); Boyd, Robert W. [Department of Physics, University of Ottawa, 25 Templeton, Ottawa, Ontario K1N 6N5 Canada (Canada); Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

2014-09-08

Orbital angular momentum associated with the helical phase-front of optical beams provides an unbounded “space” for both classical and quantum communications. Among the different approaches to generate and manipulate orbital angular momentum states of light, coupling between spin and orbital angular momentum allows a faster manipulation of orbital angular momentum states because it depends on manipulating the polarisation state of light, which is simpler and generally faster than manipulating conventional orbital angular momentum generators. In this work, we design and fabricate an ultra-thin spin-to-orbital angular momentum converter, based on plasmonic nano-antennas and operating in the visible wavelength range that is capable of converting spin to an arbitrary value of orbital angular momentum ℓ. The nano-antennas are arranged in an array with a well-defined geometry in the transverse plane of the beam, possessing a specific integer or half-integer topological charge q. When a circularly polarised light beam traverses this metasurface, the output beam polarisation switches handedness and the orbital angular momentum changes in value by ℓ=±2qℏ per photon. We experimentally demonstrate ℓ values ranging from ±1 to ±25 with conversion efficiencies of 8.6% ± 0.4%. Our ultra-thin devices are integratable and thus suitable for applications in quantum communications, quantum computations, and nano-scale sensing.

Optical spin-to-orbital angular momentum conversion in ultra-thin metasurfaces with arbitrary topological charges

International Nuclear Information System (INIS)

Bouchard, Frédéric; De Leon, Israel; Schulz, Sebastian A.; Upham, Jeremy; Karimi, Ebrahim; Boyd, Robert W.

2014-01-01

Orbital angular momentum associated with the helical phase-front of optical beams provides an unbounded “space” for both classical and quantum communications. Among the different approaches to generate and manipulate orbital angular momentum states of light, coupling between spin and orbital angular momentum allows a faster manipulation of orbital angular momentum states because it depends on manipulating the polarisation state of light, which is simpler and generally faster than manipulating conventional orbital angular momentum generators. In this work, we design and fabricate an ultra-thin spin-to-orbital angular momentum converter, based on plasmonic nano-antennas and operating in the visible wavelength range that is capable of converting spin to an arbitrary value of orbital angular momentum ℓ. The nano-antennas are arranged in an array with a well-defined geometry in the transverse plane of the beam, possessing a specific integer or half-integer topological charge q. When a circularly polarised light beam traverses this metasurface, the output beam polarisation switches handedness and the orbital angular momentum changes in value by ℓ=±2qℏ per photon. We experimentally demonstrate ℓ values ranging from ±1 to ±25 with conversion efficiencies of 8.6% ± 0.4%. Our ultra-thin devices are integratable and thus suitable for applications in quantum communications, quantum computations, and nano-scale sensing.

Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

Energy Technology Data Exchange (ETDEWEB)

Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it [Istituto Italiano di Tecnologia, Via Morego, 30, I-16163 Genova (Italy); Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr [Centre for Nanoscience and Nanotechnology (C2N Orsay), CNRS UMR9001, Univ. Paris Sud, Univ. Paris Saclay, 91405 Orsay (France)

2016-07-11

We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

Microfabricated optically pumped magnetometer arrays for biomedical imaging

Science.gov (United States)

Perry, A. R.; Sheng, D.; Krzyzewski, S. P.; Geller, S.; Knappe, S.

2017-02-01

Optically-pumped magnetometers have demonstrated magnetic field measurements as precise as the best superconducting quantum interference device magnetometers. Our group develops miniature alkali atom-based magnetic sensors using microfabrication technology. Our sensors do not require cryogenic cooling, and can be positioned very close to the sample, making these sensors an attractive option for development in the medical community. We will present our latest chip-scale optically-pumped gradiometer developed for array applications to image magnetic fields from the brain noninvasively. These developments should lead to improved spatial resolution, and potentially sensitive measurements in unshielded environments.

Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

Science.gov (United States)

Seto, Daisaku; Watanabe, Minoru

2015-09-01

In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

Quantitative modeling of the third harmonic emission spectrum of plasmonic nanoantennas.

Science.gov (United States)

Hentschel, Mario; Utikal, Tobias; Giessen, Harald; Lippitz, Markus

2012-07-11

Plasmonic dimer nanoantennas are characterized by a strong enhancement of the optical field, leading to large nonlinear effects. The third harmonic emission spectrum thus depends strongly on the antenna shape and size as well as on its gap size. Despite the complex shape of the nanostructure, we find that for a large range of different geometries the nonlinear spectral properties are fully determined by the linear response of the antenna. We find excellent agreement between the measured spectra and predictions from a simple nonlinear oscillator model. We extract the oscillator parameters from the linear spectrum and use the amplitude of the nonlinear perturbation only as scaling parameter of the third harmonic spectra. Deviations from the model only occur for gap sizes below 20 nm, indicating that only for these small distances the antenna hot spot contributes noticeable to the third harmonic generation. Because of its simplicity and intuitiveness, our model allows for the rational design of efficient plasmonic nonlinear light sources and is thus crucial for the design of future plasmonic devices that give substantial enhancement of nonlinear processes such as higher harmonics generation as well as difference frequency mixing for plasmonically enhanced terahertz generation.

Microlens array processor with programmable weight mask and direct optical input

Science.gov (United States)

Schmid, Volker R.; Lueder, Ernst H.; Bader, Gerhard; Maier, Gert; Siegordner, Jochen

1999-03-01

We present an optical feature extraction system with a microlens array processor. The system is suitable for online implementation of a variety of transforms such as the Walsh transform and DCT. Operating with incoherent light, our processor accepts direct optical input. Employing a sandwich- like architecture, we obtain a very compact design of the optical system. The key elements of the microlens array processor are a square array of 15 X 15 spherical microlenses on acrylic substrate and a spatial light modulator as transmissive mask. The light distribution behind the mask is imaged onto the pixels of a customized a-Si image sensor with adjustable gain. We obtain one output sample for each microlens image and its corresponding weight mask area as summation of the transmitted intensity within one sensor pixel. The resulting architecture is very compact and robust like a conventional camera lens while incorporating a high degree of parallelism. We successfully demonstrate a Walsh transform into the spatial frequency domain as well as the implementation of a discrete cosine transform with digitized gray values. We provide results showing the transformation performance for both synthetic image patterns and images of natural texture samples. The extracted frequency features are suitable for neural classification of the input image. Other transforms and correlations can be implemented in real-time allowing adaptive optical signal processing.

Growth of compact arrays of optical quality single crystalline ZnO

Indian Academy of Sciences (India)

We report the synthesis and optical properties of compact and aligned ZnO nanorod arrays (dia, ∼ 50–200 nm) grown on a glass substrate with varying seed particle density. The suspension of ZnO nanoparticles (size, ∼ 15 nm) of various concentrations are used as seed layer for the growth of nanorod arrays via ...

The CHARA array adaptive optics I: common-path optical and mechanical design, and preliminary on-sky results

Science.gov (United States)

Che, Xiao; Sturmann, Laszlo; Monnier, John D.; ten Brummelaar, Theo A.; Sturmann, Judit; Ridgway, Stephen T.; Ireland, Michael J.; Turner, Nils H.; McAlister, Harold A.

2014-07-01

The CHARA array is an optical interferometer with six 1-meter diameter telescopes, providing baselines from 33 to 331 meters. With sub-milliarcsecond angular resolution, its versatile visible and near infrared combiners offer a unique angle of studying nearby stellar systems by spatially resolving their detailed structures. To improve the sensitivity and scientific throughput, the CHARA array was funded by NSF-ATI in 2011 to install adaptive optics (AO) systems on all six telescopes. The initial grant covers Phase I of the AO systems, which includes on-telescope Wavefront Sensors (WFS) and non-common-path (NCP) error correction. Meanwhile we are seeking funding for Phase II which will add large Deformable Mirrors on telescopes to close the full AO loop. The corrections of NCP error and static aberrations in the optical system beyond the WFS are described in the second paper of this series. This paper describes the design of the common-path optical system and the on-telescope WFS, and shows the on-sky commissioning results.

Online analysis by a fiber-optic diode array spectrophotometer

International Nuclear Information System (INIS)

Van Hare, D.R.; Prather, W.S.; O'Rourke, P.E.

1987-01-01

An online photometric analyzer has been developed which can make remote measurements over the 350 to 900 nm region at distances of up to 100 feet. The analyzer consists of a commercially available diode array spectrophotometer interfaced to a fiber-optic multiplexer to allow online monitoring of up to ten locations sequentially. The development of the fiber-optic interface is discussed and data from several online applications are presented to demonstrate the capabilities of the measurement system

Multicore optical fiber grating array fabrication for medical sensing applications

Science.gov (United States)

Westbrook, Paul S.; Feder, K. S.; Kremp, T.; Taunay, T. F.; Monberg, E.; Puc, G.; Ortiz, R.

2015-03-01

In this work we report on a fiber grating fabrication platform suitable for parallel fabrication of Bragg grating arrays over arbitrary lengths of multicore optical fiber. Our system exploits UV transparent coatings and has precision fiber translation that allows for quasi-continuous grating fabrication. Our system is capable of both uniform and chirped fiber grating array spectra that can meet the demands of medical sensors including high speed, accuracy, robustness and small form factor.

Transition-edge sensor arrays for UV-optical-IR astrophysics

International Nuclear Information System (INIS)

Burney, J.; Bay, T.J.; Barral, J.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Miller, A.J.; Nam, S.; Rosenberg, D.; Romani, R.W.; Tomada, A.

2006-01-01

Our research group has developed and characterized transition-edge sensor (TES) arrays for near IR-optical-near UV astrophysical observations. These detectors have a time-stamp accuracy of 0.3μs and an energy resolution of 0.16eV for 2.33eV photons at very high rates (30kHz). We have installed a 6x6 array of these TESs in an adiabatic demagnetization refrigerator equipped with windows for direct imaging. We discuss new instrumentation progress and current data in all aspects related to successful operation of this camera system, including: detector and array performance, position dependence and cross-talk, low-temperature and readout electronics, quantum and system efficiency, IR filtering, and focus and imaging

Designing Plasmonic Materials and Optical Metasurfaces for Light Manipulation and Optical Sensing

Science.gov (United States)

Chen, Wenxiang

Metamaterials are artificial materials designed to create optical properties that do not exist in nature. They are assemblies of subwavelength structures that are tailored in size, shape, composition, and orientation to realize the desired property. Metamaterials are promising for applications in diverse areas: optical filters, lenses, holography, sensors, photodetectors, photovoltaics, photocatalysts, medical devices, and many more, because of their excellent abilities in bending, absorbing, enhancing and blocking light. However, the practical use of metamaterials is challenged by the lack of plasmonic materials with proper permittivity for different applications and the slow and expensive fabrication methods available to pattern sub-wavelength structures. We have also only touched the surface in exploring the innovative uses of metamaterials to solve world problems. In this thesis, we study the fundamental optical properties of metamaterial building blocks by designing material permittivity. We continuously tune the interparticle distance in colloidal Au nanocrystal (NC) solids via the partial ligand exchange process. Then we combine top-down nanoimprint lithography with bottom-up assembly of colloidal NCs to develop a large-area, low-cost fabrication method for subwavelength nanostructures. Via this method, we fabricate and characterize nano-antenna arrays of different sizes and demonstrate metasurface quarter wave-plates of different bandwidth, and compare their performances with simulation results. We also integrate the metasurfaces with chemically- and mechanically-responsive polymers for strong-signal sensing. In the first design, we combine ultrathin plasmonic nanorods with hydrogel to fabricate optical moisture sensors for agricultural use. In the second application, we design mechanically tunable Au grating resonances on a polydimethylsiloxane (PDMS) substrate. The dimensions of Au grating are carefully engineered to achieve a hybridized, ultrasharp, and

Demonstration of an optical phased array using electro-optic polymer phase shifters

Science.gov (United States)

Hirano, Yoshikuni; Motoyama, Yasushi; Tanaka, Katsu; Machida, Kenji; Yamada, Toshiki; Otomo, Akira; Kikuchi, Hiroshi

2018-03-01

We have been investigating an optical phased array (OPA) using electro-optic (EO) polymers in phase shifters to achieve ultrafast optical beam steering. In this paper, we describe the basic structures of the OPA using EO polymer phase shifters and show the beam steering capability of the OPA. The designed OPA has a multimode interference (MMI) beam splitter and 8-channel polymer waveguides with EO polymer phase shifters. We compare 1 × 8 MMI and cascaded 1 × 2 MMI beam splitters numerically and experimentally, and then obtain uniform intensity outputs from the 1 × 8 beam splitter. We fabricate the EO polymer OPA with a 1 × 8 MMI beam splitter to prevent intensity dispersion due to radiation loss in bending waveguides. We also evaluate the optical beam steering capability of the fabricated OPA and found a 2.7° deflection of far-field patterns when applying a voltage difference of 25 V in adjacent phase shifters.

Development and characterization of a TES optical imaging array for astrophysics applications

International Nuclear Information System (INIS)

Burney, J.; Bay, T.J.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Romani, R.W.; Tomada, A.; Nam, S.W.; Miller, A.J.; Martinis, J.; Wang, E.; Kenny, T.; Young, B.A.

2004-01-01

Our research group has successfully developed photon detectors capable of both time-stamping and energy-resolving individual photons at very high rates in a wide band from the near-IR through optical and into the near-UV. We have fabricated 32-pixel arrays of these Transition-Edge Sensor (TES) devices and have mounted them in an adiabatic demagnetization refrigerator equipped with windows for direct imaging. We have characterized single pixel behavior; we have also begun operating multiple pixels simultaneously, starting the scaling process towards use of the full array. We emphasize the development of a metalized mask for our array that blocks photons from hitting the inter-pixel areas and reflects them onto the TESs. We also present calibration data on detector resolution, electronics noise, and optical alignment

Numerical analysis of ALADIN optics contamination due to outgassing of solar array materials

Energy Technology Data Exchange (ETDEWEB)

Markelov, G [Advanced Operations and Engineering Services (AOES) Group BV, Postbus 342, 2300 AH Leiden (Netherlands); Endemann, M [ESA-ESTEC/EOP-PAS, Postbus 299, 2200 AG Noordwijk (Netherlands); Wernham, D [ESA-ESTEC/EOP-PAQ, Postbus 299, 2200 AG Noordwijk (Netherlands)], E-mail: Gennady.Markelov@aoes.com

2008-03-01

ALADIN is the very first space-based lidar that will provide global wind profile and a special attention has been paid to contamination of ALADIN optics. The paper presents a numerical approach, which is based on the direct simulation Monte Carlo method. The method allows one to accurately compute collisions between various species, in the case under consideration, free-stream flow and outgassing from solar array materials. The collisions create a contamination flux onto the optics despite there is no line-of-sight from the solar arrays to the optics. Comparison of obtained results with a simple analytical model prediction shows that the analytical model underpredicts mass fluxes.

Numerical analysis of ALADIN optics contamination due to outgassing of solar array materials

International Nuclear Information System (INIS)

Markelov, G; Endemann, M; Wernham, D

2008-01-01

ALADIN is the very first space-based lidar that will provide global wind profile and a special attention has been paid to contamination of ALADIN optics. The paper presents a numerical approach, which is based on the direct simulation Monte Carlo method. The method allows one to accurately compute collisions between various species, in the case under consideration, free-stream flow and outgassing from solar array materials. The collisions create a contamination flux onto the optics despite there is no line-of-sight from the solar arrays to the optics. Comparison of obtained results with a simple analytical model prediction shows that the analytical model underpredicts mass fluxes

Molecular transport network security using multi-wavelength optical spins.

Science.gov (United States)

Tunsiri, Surachai; Thammawongsa, Nopparat; Mitatha, Somsak; Yupapin, Preecha P

2016-01-01

Multi-wavelength generation system using an optical spin within the modified add-drop optical filter known as a PANDA ring resonator for molecular transport network security is proposed. By using the dark-bright soliton pair control, the optical capsules can be constructed and applied to securely transport the trapped molecules within the network. The advantage is that the dark and bright soliton pair (components) can securely propagate for long distance without electromagnetic interference. In operation, the optical intensity from PANDA ring resonator is fed into gold nano-antenna, where the surface plasmon oscillation between soliton pair and metallic waveguide is established.

Smart-phone based computational microscopy using multi-frame contact imaging on a fiber-optic array.

Science.gov (United States)

Navruz, Isa; Coskun, Ahmet F; Wong, Justin; Mohammad, Saqib; Tseng, Derek; Nagi, Richie; Phillips, Stephen; Ozcan, Aydogan

2013-10-21

We demonstrate a cellphone based contact microscopy platform, termed Contact Scope, which can image highly dense or connected samples in transmission mode. Weighing approximately 76 grams, this portable and compact microscope is installed on the existing camera unit of a cellphone using an opto-mechanical add-on, where planar samples of interest are placed in contact with the top facet of a tapered fiber-optic array. This glass-based tapered fiber array has ~9 fold higher density of fiber optic cables on its top facet compared to the bottom one and is illuminated by an incoherent light source, e.g., a simple light-emitting-diode (LED). The transmitted light pattern through the object is then sampled by this array of fiber optic cables, delivering a transmission image of the sample onto the other side of the taper, with ~3× magnification in each direction. This magnified image of the object, located at the bottom facet of the fiber array, is then projected onto the CMOS image sensor of the cellphone using two lenses. While keeping the sample and the cellphone camera at a fixed position, the fiber-optic array is then manually rotated with discrete angular increments of e.g., 1-2 degrees. At each angular position of the fiber-optic array, contact images are captured using the cellphone camera, creating a sequence of transmission images for the same sample. These multi-frame images are digitally fused together based on a shift-and-add algorithm through a custom-developed Android application running on the smart-phone, providing the final microscopic image of the sample, visualized through the screen of the phone. This final computation step improves the resolution and also removes spatial artefacts that arise due to non-uniform sampling of the transmission intensity at the fiber optic array surface. We validated the performance of this cellphone based Contact Scope by imaging resolution test charts and blood smears.

Infrared rectification in a nanoantenna-coupled metal-oxide-semiconductor tunnel diode.

Science.gov (United States)

Davids, Paul S; Jarecki, Robert L; Starbuck, Andrew; Burckel, D Bruce; Kadlec, Emil A; Ribaudo, Troy; Shaner, Eric A; Peters, David W

2015-12-01

Direct rectification of electromagnetic radiation is a well-established method for wireless power conversion in the microwave region of the spectrum, for which conversion efficiencies in excess of 84% have been demonstrated. Scaling to the infrared or optical part of the spectrum requires ultrafast rectification that can only be obtained by direct tunnelling. Many research groups have looked to plasmonics to overcome antenna-scaling limits and to increase the confinement. Recently, surface plasmons on heavily doped Si surfaces were investigated as a way of extending surface-mode confinement to the thermal infrared region. Here we combine a nanostructured metallic surface with a heavily doped Si infrared-reflective ground plane designed to confine infrared radiation in an active electronic direct-conversion device. The interplay of strong infrared photon-phonon coupling and electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast electronic tunnelling in metal-oxide-semiconductor (MOS) structures. Infrared dispersion of SiO2 near a longitudinal optical (LO) phonon mode gives large transverse-field confinement in a nanometre-scale oxide-tunnel gap as the wavelength-dependent permittivity changes from 1 to 0, which leads to enhanced electromagnetic fields at material interfaces and a rectified displacement current that provides a direct conversion of infrared radiation into electric current. The spectral and electrical signatures of the nanoantenna-coupled tunnel diodes are examined under broadband blackbody and quantum-cascade laser (QCL) illumination. In the region near the LO phonon resonance, we obtained a measured photoresponsivity of 2.7 mA W(-1) cm(-2) at -0.1 V.

A wideband connection to sperm whales: A fiber-optic, deep-sea hydrophone array

DEFF Research Database (Denmark)

Heerfordt, Anders; Møhl, Bertel; Wahlberg, Magnus

2007-01-01

A 10-element, 950 m long, vertical hydrophone array based on fiber-optic data transmission has been developed primarily for studying the beam pattern from deep diving cetaceans emitting sonar pulses. The array elements have a configurable sampling rate and resolution with a maximum signal bandwidth...

Monolithic, High-Speed Fiber-Optic Switching Array for Lidar

Science.gov (United States)

Suckow, Will; Roberts, Tony; Switzer, Gregg; Terwilliger, Chelle

2011-01-01

Current fiber switch technologies use mechanical means to redirect light beams, resulting in slow switch time, as well as poor reliability due to moving parts wearing out quickly at high speeds. A non-mechanical ability to switch laser output into one of multiple fibers within a fiber array can provide significant power, weight, and costs savings to an all-fiber system. This invention uses an array of crystals that act as miniature prisms to redirect light as an electric voltage changes the prism s properties. At the heart of the electro-optic fiber-optic switch is an electro- optic crystal patterned with tiny prisms that can deflect the beam from the input fiber into any one of the receiving fibers arranged in a linear array when a voltage is applied across the crystal. Prism boundaries are defined by a net dipole moment in the crystal lattice that has been poled opposite to the surrounding lattice fabricated using patterned, removable microelectrodes. When a voltage is applied across the crystal, the resulting electric field changes the index of refraction within the prism boundaries relative to the surrounding substrate, causing light to deflect slightly according to Snell s Law. There are several materials that can host the necessary monolithic poled pattern (including, but not limited to, SLT, KTP, LiNbO3, and Mg:LiNbO3). Be cause this is a solid-state system without moving parts, it is very fast, and does not wear down easily. This invention is applicable to all fiber networks, as well as industries that use such networks. The unit comes in a compact package, can handle both low and high voltages, and has a high reliability (100,000 hours without maintenance).

Engineering shadows to fabricate optical metasurfaces.

Science.gov (United States)

Nemiroski, Alex; Gonidec, Mathieu; Fox, Jerome M; Jean-Remy, Philip; Turnage, Evan; Whitesides, George M

2014-11-25

Optical metasurfaces-patterned arrays of plasmonic nanoantennas that enable the precise manipulation of light-matter interactions-are emerging as critical components in many nanophotonic materials, including planar metamaterials, chemical and biological sensors, and photovoltaics. The development of these materials has been slowed by the difficulty of efficiently fabricating patterns with the required combinations of intricate nanoscale structure, high areal density, and/or heterogeneous composition. One convenient strategy that enables parallel fabrication of periodic nanopatterns uses self-assembled colloidal monolayers as shadow masks; this method has, however, not been extended beyond a small set of simple patterns and, thus, has remained incompatible with the broad design requirements of metasurfaces. This paper demonstrates a technique-shadow-sphere lithography (SSL)-that uses sequential deposition from multiple angles through plasma-etched microspheres to expand the variety and complexity of structures accessible by colloidal masks. SSL harnesses the entire, relatively unexplored, space of shadow-derived shapes and-with custom software to guide multiangled deposition-contains sufficient degrees of freedom to (i) design and fabricate a wide variety of metasurfaces that incorporate complex structures with small feature sizes and multiple materials and (ii) generate, in parallel, thousands of variations of structures for high-throughput screening of new patterns that may yield unexpected optical spectra. This generalized approach to engineering shadows of spheres provides a new strategy for efficient prototyping and discovery of periodic metasurfaces.

Optical microwave filter based on spectral slicing by use of arrayed waveguide gratings.

Science.gov (United States)

Pastor, Daniel; Ortega, Beatriz; Capmany, José; Sales, Salvador; Martinez, Alfonso; Muñoz, Pascual

2003-10-01

We have experimentally demonstrated a new optical signal processor based on the use of arrayed waveguide gratings. The structure exploits the concept of spectral slicing combined with the use of an optical dispersive medium. The approach presents increased flexibility from previous slicing-based structures in terms of tunability, reconfiguration, and apodization of the samples or coefficients of the transversal optical filter.

Synthesis and optical characterization of carbon nanotube arrays

Energy Technology Data Exchange (ETDEWEB)

Rahman, Md. Mahfuzur, E-mail: mrahman@masdar.ac.ae [Institute Centre for Energy (iEnergy), Mechanical and Materials Engineering Department, Masdar Institute of Science and Technology (MIST), P.O. Box 54224, Abu Dhabi (United Arab Emirates); Younes, Hammad [Institute Centre for Energy (iEnergy), Mechanical and Materials Engineering Department, Masdar Institute of Science and Technology (MIST), P.O. Box 54224, Abu Dhabi (United Arab Emirates); Ni, George [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Zhang, TieJun [Institute Centre for Energy (iEnergy), Mechanical and Materials Engineering Department, Masdar Institute of Science and Technology (MIST), P.O. Box 54224, Abu Dhabi (United Arab Emirates); Al Ghaferi, Amal, E-mail: aalghaferi@masdar.ac.ae [Institute Centre for Energy (iEnergy), Mechanical and Materials Engineering Department, Masdar Institute of Science and Technology (MIST), P.O. Box 54224, Abu Dhabi (United Arab Emirates)

2016-05-15

Highlights: • Controlling metallicity and vertical alignment of CNT forest by changing hydrogen catalyst annealing time and growth pressure. • Verifying metallicity using Raman spectroscopy of top CNT layer. • Optical characterization of CNT forest using UV–vis–NIR spectrophotometer. - Abstract: Catalyst annealing time and growth pressure play a crucial role in the chiral selective and high-efficiency growth of single-walled carbon nanotubes (SWCNTs) during low pressure chemical vapor deposition (LPCVD). We achieved a high growth rates for SWCNTs and a change the chiral distribution towards metallic (n, m) increasing the catalyst annealing time in hydrogen. A strong correlation is revealed between the catalyst annealing time at lower growth pressures and the shape of the G band, which indicates the metallic or semiconducting nature of the SWCNT and predict the chirality distribution. Under a 15 min annealing time and 10 mbar of growth pressure, the bottom of the G band is broadened with a sharp G{sup −} peak, and the G-band exhibited asymmetrical Breit–Wigner–Fano (BWF) shape. In addition, the growth of SWCNTs with smaller diameters and rich in metallic character is confirmed by the shift of the G-band to a smaller Raman frequency. Homogeneity and vertical alignment of as-grown SWCNT arrays are optically studied using UV/vis/NIR Spectrophotometer. Wavelength-independent and low reflectance resulted from the growth of uniform arrays of SWCNTs. Because of their tunable electronic and optical properties, selective growth of SWCNTs promises great application potential, particularly in electronics and solar industries.

Electric radiation mapping of silver/zinc oxide nanoantennas by using electron holography

Energy Technology Data Exchange (ETDEWEB)

Sanchez, J. E.; Mendoza-Santoyo, F.; Cantu-Valle, J.; Velazquez-Salazar, J.; José Yacaman, M.; Ponce, A. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio 78249 (United States); González, F. J. [Coordinación para la Innovación y la Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luís Potosí, San Luis Potosí 78210 (Mexico); Diaz de Leon, R. [Instituto Tecnológico de San Luis Potosí, San Luis Potosi 78437 (Mexico)

2015-01-21

In this work, we report the fabrication of self-assembled zinc oxide nanorods grown on pentagonal faces of silver nanowires by using microwaves irradiation. The nanostructures resemble a hierarchal nanoantenna and were used to study the far and near field electrical metal-semiconductor behavior from the electrical radiation pattern resulting from the phase map reconstruction obtained using off-axis electron holography. As a comparison, we use electric numerical approximations methods for a finite number of ZnO nanorods on the Ag nanowires and show that the electric radiation intensities maps match closely the experimental results obtained with electron holography. The time evolution of the radiation pattern as generated from the nanostructure was recorded under in-situ radio frequency signal stimulation, in which the generated electrical source amplitude and frequency were varied from 0 to 5 V and from 1 to 10 MHz, respectively. The phase maps obtained from electron holography show the change in the distribution of the electric radiation pattern for individual nanoantennas. The mapping of this electrical behavior is of the utmost importance to gain a complete understanding for the metal-semiconductor (Ag/ZnO) heterojunction that will help to show the mechanism through which these receiving/transmitting structures behave at nanoscale level.

An optical tunable filter array based on LCOS phase grating

Science.gov (United States)

Feng, Dong; Wan, Zhujun; Chen, Xu; Yan, Shijia; Luo, Zhixiang

2018-01-01

This paper reports an optical tunable filter array (TFA) based on a LCOS (liquid crystal on silicon) chip. The input broadband optical beam is first dispersed by a bulk grating and then incident on the LCOS chip. The LCOS chip is phase-only modulated and constructed as a dynamic reflective phase grating. The phase modulation is adjusted to meet the Littrow angle for a specified passband wavelength and thus the optical beam corresponding to this wavelength is steered to the output. The input/output optical beams are coupled to optical fibers with a dual-fiber collimator. Four dualfiber collimators are vertically aligned as the inputs/outputs and the pixels of the LCOS chip are vertically allocated as four independent zones. Thus the device can act as a 4-channel TFA, which is assembled and functionally demonstrated.

Low threshold all-optical crossbar switch on GaAs-GaAlAs channel waveguide arrays

Science.gov (United States)

Jannson, Tomasz; Kostrzewski, Andrew

1994-09-01

During the Phase 2 project entitled 'Low Threshold All-Optical Crossbar Switch on GaAs - GaAlAs Channel Waveguide Array,' Physical Optics Corporation (POC) developed the basic principles for the fabrication of all-optical crossbar switches. Based on this development. POC fabricated a 2 x 2 GaAs/GaAlAs switch that changes the direction of incident light with minimum insertion loss and nonlinear distortion. This unique technology can be used in both analog and digital networks. The applications of this technology are widespread. Because the all-optical network does not have any speed limitations (RC time constant), POC's approach will be beneficial to SONET networks, phased array radar networks, very high speed oscilloscopes, all-optical networks, IR countermeasure systems, BER equipment, and the fast growing video conferencing network market. The novel all-optical crossbar switch developed in this program will solve interconnect problems. and will be a key component in the widely proposed all-optical 200 Gb/s SONET/ATM networks.

Optical Communications With A Geiger Mode APD Array

Science.gov (United States)

2016-02-09

practical performance of a Geiger mode avalanche photodiode ( GM -APD, or Geiger mode APD) array for use in optical com- munications systems. I designed and...signal quality in the first half of the frame. These shorter reset times also did not offer any advantage in the maximum number of counts able to be...pattern was advantageous for the modifications being made in post-processing on the benchmark data. In particular, this allowed post-processing results

Two-dimensional optical phased array antenna on silicon-on-insulator.

Science.gov (United States)

Van Acoleyen, Karel; Rogier, Hendrik; Baets, Roel

2010-06-21

Optical wireless links can offer a very large bandwidth and can act as a complementary technology to radiofrequency links. Optical components nowadays are however rather bulky. Therefore, we have investigated the potential of silicon photonics to fabricated integrated components for wireless optical communication. This paper presents a two-dimensional phased array antenna consisting of grating couplers that couple light off-chip. Wavelength steering of $0.24 degrees /nm is presented reducing the need of active phase modulators. The needed steering range is $1.5 degrees . The 3dB angular coverage range of these antennas is about $0.007pi sr with a directivity of more than 38dBi and antenna losses smaller than 3dB.

Optical Doppler tomography based on a field programmable gate array

DEFF Research Database (Denmark)

Larsen, Henning Engelbrecht; Nilsson, Ronnie Thorup; Thrane, Lars

2008-01-01

We report the design of and results obtained by using a field programmable gate array (FPGA) to digitally process optical Doppler tomography signals. The processor fits into the analog signal path in an existing optical coherence tomography setup. We demonstrate both Doppler frequency and envelope...... extraction using the Hilbert transform, all in a single FPGA. An FPGA implementation has certain advantages over general purpose digital signal processor (DSP) due to the fact that the processing elements operate in parallel as opposed to the DSP. which is primarily a sequential processor....

10-channel fiber array fabrication technique for parallel optical coherence tomography system

Science.gov (United States)

Arauz, Lina J.; Luo, Yuan; Castillo, Jose E.; Kostuk, Raymond K.; Barton, Jennifer

2007-02-01

Optical Coherence Tomography (OCT) shows great promise for low intrusive biomedical imaging applications. A parallel OCT system is a novel technique that replaces mechanical transverse scanning with electronic scanning. This will reduce the time required to acquire image data. In this system an array of small diameter fibers is required to obtain an image in the transverse direction. Each fiber in the array is configured in an interferometer and is used to image one pixel in the transverse direction. In this paper we describe a technique to package 15μm diameter fibers on a siliconsilica substrate to be used in a 2mm endoscopic probe tip. Single mode fibers are etched to reduce the cladding diameter from 125μm to 15μm. Etched fibers are placed into a 4mm by 150μm trench in a silicon-silica substrate and secured with UV glue. Active alignment was used to simplify the lay out of the fibers and minimize unwanted horizontal displacement of the fibers. A 10-channel fiber array was built, tested and later incorporated into a parallel optical coherence system. This paper describes the packaging, testing, and operation of the array in a parallel OCT system.

Spectroscopic studies of resonant coupling of silver optical antenna arrays to a near-surface quantum well

International Nuclear Information System (INIS)

Gehl, Michael; Zandbergen, Sander; Gibson, Ricky; Nader, Nima; Sears, Jasmine; Keiffer, Patrick; Khitrova, Galina; Béchu, Muriel; Wegener, Martin; Hendrickson, Joshua

2014-01-01

The coupling of radiation emitted on semiconductor inter-band transitions to resonant optical-antenna arrays allows for enhanced light–matter interaction via the Purcell effect. Semiconductor optical gain also potentially allows for loss reduction in metamaterials. Here we extend our previous work on optically pumped individual near-surface InGaAs quantum wells coupled to silver split-ring-resonator arrays to wire and square-antenna arrays. By comparing the transient pump-probe experimental results with the predictions of a simple model, we find that the effective coupling is strongest for the split rings, even though the split rings have the weakest dipole moment. The effect of the latter must thus be overcompensated by a smaller effective mode volume of the split rings. Furthermore, we also present a systematic variation of the pump-pulse energy, which was fixed in our previous experiments. (paper)

Planar location of the simulative acoustic source based on fiber optic sensor array

Science.gov (United States)

Liang, Yi-Jun; Liu, Jun-feng; Zhang, Qiao-ping; Mu, Lin-lin

2010-06-01

A fiber optic sensor array which is structured by four Sagnac fiber optic sensors is proposed to detect and locate a simulative source of acoustic emission (AE). The sensing loops of Sagnac interferometer (SI) are regarded as point sensors as their small size. Based on the derived output light intensity expression of SI, the optimum work condition of the Sagnac fiber optic sensor is discussed through the simulation of MATLAB. Four sensors are respectively placed on a steel plate to structure the sensor array and the location algorithms are expatiated. When an impact is generated by an artificial AE source at any position of the plate, the AE signal will be detected by four sensors at different times. With the help of a single chip microcomputer (SCM) which can calculate the position of the AE source and display it on LED, we have implemented an intelligent detection and location.

Room temperature synthesis and optical properties of small diameter (5 nm) ZnO nanorod arrays.

Science.gov (United States)

Cho, Seungho; Jang, Ji-Wook; Lee, Jae Sung; Lee, Kun-Hong

2010-10-01

We report a simple wet-chemical synthesis of ∼5 nm diameter ZnO nanorod arrays at room temperature (20 °C) and normal atmospheric pressure (1 atm) and their optical properties. They were single crystalline in nature, and grew in the [001] direction. These small diameter ZnO nanorod arrays can also be synthesized at 0 °C. Control experiments were also conducted. On the basis of the results, we propose a mechanism for the spontaneous growth of the small diameter ZnO structures. The optical properties of the 5 nm diameter ZnO nanorod arrays synthesized using this method were probed by UV-Visible diffuse reflectance spectroscopy. A clear blue-shift, relative to the absorption band from 50 nm diameter ZnO nanorod arrays, was attributed to the quantum confinement effects caused by the small nanocrystal size in the 5 nm diameter ZnO nanorods.

Optically Controlled Reconfigurable Antenna Array Based on E-Shaped Elements

Directory of Open Access Journals (Sweden)

Arismar Cerqueira Sodré Junior

2014-01-01

Full Text Available This work presents the development of optically controlled reconfigurable antenna arrays. They are based on two patch elements with E-shaped slots, a printed probe, and a photoconductive switch made from an intrinsic silicon die. Numerical simulations and experiments have been shown to be in agreement, and both demonstrate that the frequency response of the antenna arrays can be efficiently reconfigured over two different frequency ISM bands, namely, 2.4 and 5 GHz. A measured gain of 12.5 dBi has been obtained through the use of two radiating elements printed in a low-cost substrate and a dihedral corner reflector.

Enhanced density of optical data storage using near-field concept: fabrication and test of nanometric aperture array

International Nuclear Information System (INIS)

Cha, J.; Park, J. H.; Kim, Myong R.; Jhe, W.

1999-01-01

We have tried to enhance the density of the near-field optical memory and to improve the recording/readout speed. The current optical memory has the limitation in both density and speed. This barrier due to the far-field nature can be overcome by the use of near-field. The optical data storage density can be increased by reducing the size of the nanometric aperture where the near-field is obtained. To fabricate the aperture in precise dimension, we applied the orientation-dependent / anisotropic etching property of crystal Si often employed in the field of MEMS. And so we fabricated the 10 x 10 aperture array. This array will be also the indispensable part for speeding up. One will see the possibility of the multi-tracking pickup in the phase changing type memory through this array. This aperture array will be expected to write the bit-mark whose size is about 100 nm. We will show the recent result obtained. (author)

Optical True Time Delay for Phased Array Antennas Composed of 2×2 Optical MEMS Switches and Fiber Delay Lines

Institute of Scientific and Technical Information of China (English)

Back-Song; Lee; Jong-Dug; Shin; Boo-Gyoun; Kim

2003-01-01

We proposed an optical true time delay (TTD) for phased array antennas (PAAs) composed of 2×2 optical MEMS switches, single-mode fiber delay lines, and a fixed wavelength laser diode. A 3-bit TTD for 10 GHz PAAs was implemented with a time delay error less than ± 0.2 ps.

All-optical LAN architectures based on arrayed waveguide grating multiplexers

Science.gov (United States)

Woesner, Hagen

1998-10-01

The paper presents optical LAN topologies which are made possible using an Arrayed Waveguide Grating Multiplexer (AWGM) instead of a passive star coupler to interconnect stations in an all-optical LAN. Due to the collision-free nature of an AWGM it offers the n-fold bandwidth compared to the star coupler. Virtual ring topologies appear (one ring on each wavelength) if the number of stations attached to the AWGM is a prime number. A method to construct larger networks using Cayley graphs is shown. An access protocol to avoid collisions on the proposed network is outlined.

P3-7: On Prototyping a Visual Prosthesis System with Artificial Retina and Optic Nerve Based on Arrayed Microfibers

Directory of Open Access Journals (Sweden)

Jian Hong Chen

2012-10-01

Full Text Available The traditional visual prosthesis system combines both a camera and a microelectrode array implanted on the visual neural network including retina, optic nerve, and visual cortex. Here, we introduce a new visual prosthesis system in which an artificial retina and optic nerve are demonstrated. The prototype of optic nerve for image transmission is comprised of arrayed PMMA microfibers with both ends connected with two planes, one functioned as retina for light reception and another attached to visual cortex. The microfibers are drawn from the thin film prepared by PMMA/chlorobenzene solution. Each micro fiber serves as an optical waveguide for the delivery of a single image pixel. It is demonstrated that with proper imaging optics, arrayed micro fibers could be lit as discrete light spots in accordance with the input image. Each micro fiber is expected to function as a stimulation unit for optical neural modulation in a visual prosthesis system.

Functionalization of optical nanotip arrays with an electrochemical microcantilever for multiplexed DNA detection.

Science.gov (United States)

Descamps, Emeline; Duroure, Nathalie; Deiss, Frédérique; Leichlé, Thierry; Adam, Catherine; Mailley, Pascal; Aït-Ikhlef, Ali; Livache, Thierry; Nicu, Liviu; Sojic, Neso

2013-08-07

Optical nanotip arrays fabricated on etched fiber bundles were functionalized with DNA spots. Such unconventional substrates (3D and non-planar) are difficult to pattern with standard microfabrication techniques but, using an electrochemical cantilever, up to 400 spots were electrodeposited on the nanostructured optical surface in 5 min. This approach allows each spot to be addressed individually and multiplexed fluorescence detection is demonstrated. Finally, remote fluorescence detection was performed by imaging through the optical fiber bundle itself after hybridisation with the complementary sequence.

Theranostic Gold Nanoantennas for Simultaneous Multiplexed Raman Imaging of Immunomarkers and Photothermal Therapy.

Science.gov (United States)

Webb, Joseph A; Ou, Yu-Chuan; Faley, Shannon; Paul, Eden P; Hittinger, Joseph P; Cutright, Camden C; Lin, Eugene C; Bellan, Leon M; Bardhan, Rizia

2017-07-31

In this study, we demonstrate the theranostic capability of actively targeted, site-specific multibranched gold nanoantennas (MGNs) in triple-negative breast cancer (TNBC) cells in vitro. By utilizing multiplexed surface-enhanced Raman scattering (SERS) imaging, enabled by the narrow peak widths of Raman signatures, we simultaneously targeted immune checkpoint receptor programmed death ligand 1 (PDL1) and the epidermal growth factor receptor (EGFR) overexpressed in TNBC cells. A 1:1 mixture of MGNs functionalized with anti-PDL1 antibodies and Raman tag 5,5-dithio-bis-(2-nitrobenzoic acid) (DTNB) and MGNs functionalized with anti-EGFR antibodies and Raman tag para -mercaptobenzoic acid ( p MBA) were incubated with the cells. SERS imaging revealed a cellular traffic map of MGN localization by surface binding and receptor-mediated endocytosis, enabling targeted diagnosis of both biomarkers. Furthermore, cells incubated with anti-EGFR- p MBA-MGNs and illuminated with an 808 nm laser for 15 min at 4.7 W/cm 2 exhibited photothermal cell death only within the laser spot (indicated by live/dead cell fluorescence assay). Therefore, this study not only provides an optical imaging platform that can track immunomarkers with spatiotemporal control but also demonstrates an externally controlled light-triggered therapeutic approach enabling receptor-specific treatment with biocompatible theranostic nanoprobes.

64 x 64 thresholding photodetector array for optical pattern recognition

Science.gov (United States)

Langenbacher, Harry; Chao, Tien-Hsin; Shaw, Timothy; Yu, Jeffrey W.

1993-10-01

A high performance 32 X 32 peak detector array is introduced. This detector consists of a 32 X 32 array of thresholding photo-transistor cells, manufactured with a standard MOSIS digital 2-micron CMOS process. A built-in thresholding function that is able to perform 1024 thresholding operations in parallel strongly distinguishes this chip from available CCD detectors. This high speed detector offers responses from one to 10 milliseconds that is much higher than the commercially available CCD detectors operating at a TV frame rate. The parallel multiple peaks thresholding detection capability makes it particularly suitable for optical correlator and optoelectronically implemented neural networks. The principle of operation, circuit design and the performance characteristics are described. Experimental demonstration of correlation peak detection is also provided. Recently, we have also designed and built an advanced version of a 64 X 64 thresholding photodetector array chip. Experimental investigation of using this chip for pattern recognition is ongoing.

Optical fiber Bragg gratings. Part II. Modeling of finite-length gratings and grating arrays.

Science.gov (United States)

Passaro, Vittorio M N; Diana, Roberto; Armenise, Mario N

2002-09-01

A model of both uniform finite-length optical fiber Bragg gratings and grating arrays is presented. The model is based on the Floquet-Bloch formalism and allows rigorous investigation of all the physical aspects in either single- or multiple-periodic structures realized on the core of a monomodal fiber. Analytical expressions of reflectivity and transmittivity for both single gratings and grating arrays are derived. The influence of the grating length and the index modulation amplitude on the reflected and transmitted optical power for both sinusoidal and rectangular profiles is evaluated. Good agreement between our method and the well-known coupled-mode theory (CMT) approach has been observed for both single gratings and grating arrays only in the case of weak index perturbation. Significant discrepancies exist there in cases of strong index contrast because of the increasing approximation of the CMT approach. The effects of intragrating phase shift are also shown and discussed.

Indirect optical crosstalk reduction by highly-doped backside layer in single-photon avalanche diode arrays

NARCIS (Netherlands)

Osrečki, Željko; Knežević, Tihomir; Nanver, Lis K.; Suligoj, Tomislav

2018-01-01

A method of reducing indirect optical crosstalk in single-photon avalanche diode arrays is investigated by TCAD simulations. The reduction is accomplished by taking advantage of an enhanced optical absorption in a highly-doped Si layer on the backside of the wafer. A simulation environment was

Detection system of capillary array electrophoresis microchip based on optical fiber

Science.gov (United States)

Yang, Xiaobo; Bai, Haiming; Yan, Weiping

2009-11-01

To meet the demands of the post-genomic era study and the large parallel detections of epidemic diseases and drug screening, the high throughput micro-fluidic detection system is needed urgently. A scanning laser induced fluorescence detection system based on optical fiber has been established by using a green laser diode double-pumped solid-state laser as excitation source. It includes laser induced fluorescence detection subsystem, capillary array electrophoresis micro-chip, channel identification unit and fluorescent signal processing subsystem. V-shaped detecting probe composed with two optical fibers for transmitting the excitation light and detecting induced fluorescence were constructed. Parallel four-channel signal analysis of capillary electrophoresis was performed on this system by using Rhodamine B as the sample. The distinction of different samples and separation of samples were achieved with the constructed detection system. The lowest detected concentration is 1×10-5 mol/L for Rhodamine B. The results show that the detection system possesses some advantages, such as compact structure, better stability and higher sensitivity, which are beneficial to the development of microminiaturization and integration of capillary array electrophoresis chip.

Design and optical analyses of an arrayed microfluidic tunable prism panel for enhancing solar energy collection

International Nuclear Information System (INIS)

Narasimhan, Vinayak; Jiang, Dongyue; Park, Sung-Yong

2016-01-01

Highlights: • We present an arrayed tunable prism panel enabling wide tracking and high solar concentration. • A microfluidic technology allows a low-cost, lightweight and precise solar tracking system. • Our prism panel enables high solar concentration up to 2032× factor. • Various liquid prism configurations (stacked prism arrays) and optical materials are considered. • Their impacts on solar beam steering, reflection losses and beam concentration are studied. - Abstract: We present the design and optical analyses of an arrayed microfluidic tunable prism panel that enables wide solar tracking and high solar concentration while minimizing energy loss. Each of the liquid prism modules is implemented by a microfluidic (i.e. non-mechanical) technology based on electrowetting for adaptive solar beam steering. Therefore the proposed platform offers a low-cost, lightweight and precise solar tracking system while obviating the need for bulky and heavy mechanical moving parts essentially required for a conventional motor-driven solar tracker. In this paper, various liquid prism configurations in terms of design (single, double, triple and quad-stacked prism arrays) as well as optical materials are considered and their impact on optical performance aspects such as solar beam steering, reflection losses and beam concentration is studied. Our system is able to achieve a wide solar tracking covering the whole-day movement of the Sun and a reflection loss below 4.4% with a Rayleigh’s film for a quad-stacked prism configuration. Furthermore, an arrayed prism panel is proposed to increase the aperture area and thus allows for the collection of large amounts of sunlight. Our simulation study based on the optical design software, ZEMAX, indicates that the prism panel is capable of high solar concentration up to 2032× factor even without conventional solar tracking devices. We also deal with dispersion characteristics of the materials and their corresponding effect on

Babinet-Inverted Optical Nanoantenna Analogue of Electromagnetically Induced Transparency

Science.gov (United States)

Ding, Yin-Xing; Wang, Lu-Lu; Yu, Li

2018-01-01

Not Available Supported by the National Key Research and Development Program of China under Grant No 2016YFA0301300, the National Natural Science Foundation of China under Grant Nos 11374041, 11574035 and 11404030, and the State Key Laboratory of Information Photonics and Optical Communications.

Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

Directory of Open Access Journals (Sweden)

Heck Martijn J.R.

2016-06-01

Full Text Available Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

Science.gov (United States)

Heck, Martijn J. R.

2017-01-01

Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

Remote online process measurements by a fiber optic diode array spectrometer

International Nuclear Information System (INIS)

Van Hare, D.R.; Prather, W.S.; O'Rourke, P.E.

1986-01-01

The development of remote online monitors for radioactive process streams is an active research area at the Savannah River Laboratory (SRL). A remote offline spectrophotometric measurement system has been developed and used at the Savannah River Plant (SRP) for the past year to determine the plutonium concentration of process solution samples. The system consists of a commercial diode array spectrophotometer modified with fiber optic cables that allow the instrument to be located remotely from the measurement cell. Recently, a fiber optic multiplexer has been developed for this instrument, which allows online monitoring of five locations sequentially. The multiplexer uses a motorized micrometer to drive one of five sets of optical fibers into the optical path of the instrument. A sixth optical fiber is used as an external reference and eliminates the need to flush out process lines to re-reference the spectrophotometer. The fiber optic multiplexer has been installed in a process prototype facility to monitor uranium loading and breakthrough of ion exchange columns. The design of the fiber optic multiplexer is discussed and data from the prototype facility are presented to demonstrate the capabilities of the measurement system

Stretchable Transparent Electrode Arrays for Simultaneous Electrical and Optical Interrogation of Neural Circuits in Vivo.

Science.gov (United States)

Zhang, Jing; Liu, Xiaojun; Xu, Wenjing; Luo, Wenhan; Li, Ming; Chu, Fangbing; Xu, Lu; Cao, Anyuan; Guan, Jisong; Tang, Shiming; Duan, Xiaojie

2018-04-09

Recent developments of transparent electrode arrays provide a unique capability for simultaneous optical and electrical interrogation of neural circuits in the brain. However, none of these electrode arrays possess the stretchability highly desired for interfacing with mechanically active neural systems, such as the brain under injury, the spinal cord, and the peripheral nervous system (PNS). Here, we report a stretchable transparent electrode array from carbon nanotube (CNT) web-like thin films that retains excellent electrochemical performance and broad-band optical transparency under stretching and is highly durable under cyclic stretching deformation. We show that the CNT electrodes record well-defined neuronal response signals with negligible light-induced artifacts from cortical surfaces under optogenetic stimulation. Simultaneous two-photon calcium imaging through the transparent CNT electrodes from cortical surfaces of GCaMP-expressing mice with epilepsy shows individual activated neurons in brain regions from which the concurrent electrical recording is taken, thus providing complementary cellular information in addition to the high-temporal-resolution electrical recording. Notably, the studies on rats show that the CNT electrodes remain operational during and after brain contusion that involves the rapid deformation of both the electrode array and brain tissue. This enables real-time, continuous electrophysiological monitoring of cortical activity under traumatic brain injury. These results highlight the potential application of the stretchable transparent CNT electrode arrays in combining electrical and optical modalities to study neural circuits, especially under mechanically active conditions, which could potentially provide important new insights into the local circuit dynamics of the spinal cord and PNS as well as the mechanism underlying traumatic injuries of the nervous system.

Mapping the electromagnetic field confinement in the gap of germanium nanoantennas with plasma wavelength of 4.5 micrometers

NARCIS (Netherlands)

Calandrini, Eugenio; Venanzi, Tommaso; Appugliese, Felice; Badioli, Michela; Giliberti, Valeria; Baldassarre, Leonetta; Biagioni, Paolo; De Angelis, Francesco; Klesse, Wolfgang M.; Scappucci, G.; Ortolani, Michele

2016-01-01

We study plasmonic nanoantennas for molecular sensing in the mid-infrared made of heavily doped germanium, epitaxially grown with a bottom-up doping process and featuring free carrier density in excess of 10²⁰ cm^-3. The dielectric function of the 250 nm thick germanium film

Optical response of large-area aluminum-coated nano-bucket arrays on flexible PET substrates

Science.gov (United States)

Hohertz, Donna; Chuo, Yindar; Omrane, Badr; Landrock, Clint; Kavanagh, Karen L.

2014-09-01

The high-cost of fabrication of nanohole arrays for extraordinary optical transmission, surface-plasmon-resonance-based sensors, inhibits their widespread commercial adoption. Production typically involves the application of small-area patterning techniques, such as focused-ion-beam milling, and electron-beam lithography onto high-cost gold-coated substrates. Moving to lower-cost manufacturing is a critical step for applications such as the detection of environmental oil-leaks, or water quality assurance. In these applications, the sensitivity requirements are relatively low, and a bio-compatible inert surface, such as gold, is unnecessary. We report on the optical response of aluminum-coated nano-bucket arrays fabricated on flexible polyethylene terephthalate substrates. The arrays are fabricated using an economical roll-to-roll UV-casting process from large sheets of nickel templates generated from master quartz stamps. The nano-featured surface is subsequently coated with 50 nm of thermally-evaporated aluminum. The roll-to-roll production process has a 97% yield over a 600 m roll producing nano-buckets with 240 nm diameters, 300 nm deep, with a 70° taper. When exposed to a series of refractive index standards (glucose solutions), changes in the locations of the resonance transmission peaks result in optical sensitivities as high as 390 ± 20 nm/RIU. The peak transmission is approximately 5% of illumination, well within the sensitivity requirements of most common low-cost detectors.

Point-source reconstruction with a sparse light-sensor array for optical TPC readout

International Nuclear Information System (INIS)

Rutter, G; Richards, M; Bennieston, A J; Ramachers, Y A

2011-01-01

A reconstruction technique for sparse array optical signal readout is introduced and applied to the generic challenge of large-area readout of a large number of point light sources. This challenge finds a prominent example in future, large volume neutrino detector studies based on liquid argon. It is concluded that the sparse array option may be ruled out for reasons of required number of channels when compared to a benchmark derived from charge readout on wire-planes. Smaller-scale detectors, however, could benefit from this technology.

Nanoantennas for enhancing and confining the magnetic optical field

Science.gov (United States)

Grosjean, Thierry; Mivelle, Mathieu; Baida, Fadi I.; Burr, Geoffrey W.; Fischer, Ulrich C.

2011-05-01

We propose different optical antenna structures for enhancing and confining the magnetic optical field. A common feature of these structures are concave corners in thin metal films as locations of the enhanced magnetic field. This proposal is inspired by Babinet's principle as the concave edges are the complementary structures to convex metal corners, which are known to be locations of a strongly enhanced electric field. Bowtie antennas and the bowtie apertures of appropriate size were shown to exhibit resonances in the infrared frequency range with an especially strong enhancement of the electrical field in the gap between 2 convex metal corners. We show by numerical calculations, that the complementary structures, the complementary bowtie aperture - the diabolo antenna - and the complementary bow tie antenna - two closely spaced triangular apertures in a metal film with a narrow gap between two opposing concave corners - exhibit resonances with a strongly enhanced magnetic field at the narrow metal constriction between the concave corners. We suggest sub-wavelength circuits of concave and convex corners as building blocks of planar metamaterials.

Composite silicon nanostructure arrays fabricated on optical fibre by chemical etching of multicrystal silicon film

International Nuclear Information System (INIS)

Zuo, Zewen; Zhu, Kai; Ning, Lixin; Cui, Guanglei; Qu, Jun; Huang, Wanxia; Shi, Yi; Liu, Hong

2015-01-01

Integrating nanostructures onto optical fibers presents a promising strategy for developing new-fashioned devices and extending the scope of nanodevices’ applications. Here we report the first fabrication of a composite silicon nanostructure on an optical fiber. Through direct chemical etching using an H 2 O 2 /HF solution, multicrystal silicon films with columnar microstructures are etched into a vertically aligned, inverted-cone-like nanorod array embedded in a nanocone array. A faster dissolution rate of the silicon at the void-rich boundary regions between the columns is found to be responsible for the separation of the columns, and thus the formation of the nanostructure array. The morphology of the nanorods primarily depends on the microstructure of the columns in the film. Through controlling the microstructure of the as-grown film and the etching parameters, the structural control of the nanostructure is promising. This fabrication method can be extended to a larger length scale, and it even allows roll-to-roll processing. (paper)

Composite silicon nanostructure arrays fabricated on optical fibre by chemical etching of multicrystal silicon film.

Science.gov (United States)

Zuo, Zewen; Zhu, Kai; Ning, Lixin; Cui, Guanglei; Qu, Jun; Huang, Wanxia; Shi, Yi; Liu, Hong

2015-04-17

Integrating nanostructures onto optical fibers presents a promising strategy for developing new-fashioned devices and extending the scope of nanodevices' applications. Here we report the first fabrication of a composite silicon nanostructure on an optical fiber. Through direct chemical etching using an H2O2/HF solution, multicrystal silicon films with columnar microstructures are etched into a vertically aligned, inverted-cone-like nanorod array embedded in a nanocone array. A faster dissolution rate of the silicon at the void-rich boundary regions between the columns is found to be responsible for the separation of the columns, and thus the formation of the nanostructure array. The morphology of the nanorods primarily depends on the microstructure of the columns in the film. Through controlling the microstructure of the as-grown film and the etching parameters, the structural control of the nanostructure is promising. This fabrication method can be extended to a larger length scale, and it even allows roll-to-roll processing.

Role of photonic angular momentum states in nonreciprocal diffraction from magneto-optical cylinder arrays

Directory of Open Access Journals (Sweden)

Tian-Jing Guo

2014-07-01

Full Text Available Optical eigenstates in a concentrically symmetric resonator are photonic angular momentum states (PAMSs with quantized optical orbital angular momentums (OAMs. Nonreciprocal optical phenomena can be obtained if we lift the degeneracy of PAMSs. In this article, we provide a comprehensive study of nonreciprocal optical diffraction of various orders from a magneto-optical cylinder array. We show that nonreciprocal diffraction can be obtained only for these nonzero orders. Role of PAMSs, the excitation of which is sensitive to the directions of incidence, applied magnetic field, and arrangement of the cylinders, are studied. Some interesting phenomena such as a dispersionless quasi-omnidirectional nonreciprocal diffraction and spikes associated with high-OAM PAMSs are present and discussed.

Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas

International Nuclear Information System (INIS)

Fromm, David P.; Sundaramurthy, Arvind; Kinkhabwala, Anika; Schuck, P. James; Kino, Gordon S.; Moerner, W.E.

2006-01-01

Single metallic bowtie nanoantennas provide a controllable environment for surface-enhanced Raman scattering (SERS) of adsorbed molecules. Bowties have experimentally measured electromagnetic enhancements, enabling estimation of chemical enhancement for both the bulk and the few-molecule regime. Strong fluctuations of selected Raman lines imply that a small number of p-mercaptoaniline molecules on a single bowtie show chemical enhancement >10 7 , much larger than previously believed, likely due to charge transfer between the Au surface and the molecule. This chemical sensitivity of SERS has significant implications for ultra-sensitive detection of single molecules

In vivo photothermal treatment with real-time monitoring by optical fiber-needle array.

Science.gov (United States)

Yang, Taeseok Daniel; Park, Kwanjun; Kim, Hyung-Jin; Im, Nu-Ri; Kim, Byoungjae; Kim, TaeHoon; Seo, Sohyun; Lee, Jae-Seung; Kim, Beop-Min; Choi, Youngwoon; Baek, Seung-Kuk

2017-07-01

Photothermal treatment (PTT) using gold nanoshells (gold-NSs) is accepted as a method for treating cancer. However, owing to restrictions in therapeutic depth and skin damage caused by excessive light exposure, its application has been limited to lesions close to the epidermis. Here, we demonstrate an in vivo PTT method that uses gold-NSs with a flexible optical fiber-needle array (OFNA), which is an array of multiple needles in which multimode optical fibers are inserted, one in each, for light delivery. The light for PTT was directly administrated to subcutaneous tissues through the OFNA, causing negligible thermal damage to the skin. Enhancement of light energy delivery assisted by the OFNA in a target area was confirmed by investigation using artificial tissues. The ability of OFNA to treat cancer without causing cutaneous thermal damage was also verified by hematoxylin and eosin (H&E) staining and optical coherence tomography in cancer models in mice. In addition, the OFNA allowed for observation of the target site through an imaging fiber bundle. By imaging the activation of the injected gold-NSs, we were able to obtain information on the PTT process in real-time.

'Optical' soft x-ray arrays for fluctuation diagnostics in magnetic fusion energy experiments

International Nuclear Information System (INIS)

Delgado-Aparicio, L.F.; Stutman, D.; Tritz, K.; Finkenthal, M.; Kaita, R.; Roquemore, L.; Johnson, D.; Majeski, R.

2004-01-01

We are developing large pixel count, fast (≥100 kHz) and continuously sampling soft x-ray (SXR) array for the diagnosis of magnetohydrodynamics (MHD) and turbulent fluctuations in magnetic fusion energy plasmas. The arrays are based on efficient scintillators, high thoughput multiclad fiber optics, and multichannel light amplification and integration. Compared to conventional x-ray diode arrays, such systems can provide vastly increased spatial coverage, and access to difficult locations with small neutron noise and damage. An eight-channel array has been built using columnar CsI:Tl as an SXR converter and a multianode photomultiplier tube as photoamplifier. The overall system efficiency is measured using laboratory SXR sources, while the time response and signal-to-noise performance have been evaluated by recording MHD activity from the spherical tori (ST) Current Drive Experiment-Upgrade and National Spherical Torus Experiment, both at Princeton Plasma Physics Laboratory

High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

KAUST Repository

Du, Qing Guo; Yue, Weisheng; Wang, Zhihong; Lau, Wah Tung; Ren, Hengjiang; Li, Er-Ping

2016-01-01

We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips. © 2016 Optical Society of America.

High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

KAUST Repository

Du, Qing Guo

2016-02-24

We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips. © 2016 Optical Society of America.

Stacked optical antennas for plasmon propagation in a 5 nm-confined cavity

KAUST Repository

Saeed, A.; Panaro, S.; Zaccaria, R. Proietti; Raja, W.; Liberale, Carlo; Dipalo, M.; Messina, G. C.; Wang, H.; De Angelis, F.; Toma, A.

2015-01-01

The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding. © 2015, Nature Publishing Group. All rights reserved.

Stacked optical antennas for plasmon propagation in a 5 nm-confined cavity

KAUST Repository

Saeed, A.

2015-06-09

The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding. © 2015, Nature Publishing Group. All rights reserved.

Array-type miniature interferometer as the core optical microsystem of an optical coherence tomography device for tissue inspection

Science.gov (United States)

Passilly, Nicolas; Perrin, Stéphane; Lullin, Justine; Albero, Jorge; Bargiel, Sylwester; Froehly, Luc; Gorecki, Christophe; Krauter, Johann; Osten, Wolfgang; Wang, Wei-Shan; Wiemer, Maik

2016-04-01

Some of the critical limitations for widespread use in medical applications of optical devices, such as confocal or optical coherence tomography (OCT) systems, are related to their cost and large size. Indeed, although quite efficient systems are available on the market, e.g. in dermatology, they equip only a few hospitals and hence, are far from being used as an early detection tool, for instance in screening of patients for early detection of cancers. In this framework, the VIAMOS project aims at proposing a concept of miniaturized, batch-fabricated and lower-cost, OCT system dedicated to non-invasive skin inspection. In order to image a large skin area, the system is based on a full-field approach. Moreover, since it relies on micro-fabricated devices whose fields of view are limited, 16 small interferometers are arranged in a dense array to perform multi-channel simultaneous imaging. Gaps between each channel are then filled by scanning of the system followed by stitching. This approach allows imaging a large area without the need of large optics. It also avoids the use of very fast and often expensive laser sources, since instead of a single point detector, almost 250 thousands pixels are used simultaneously. The architecture is then based on an array of Mirau interferometers which are interesting for their vertical arrangement compatible with vertical assembly at the wafer-level. Each array is consequently a local part of a stack of seven wafers. This stack includes a glass lens doublet, an out-of-plane actuated micro-mirror for phase shifting, a spacer and a planar beam-splitter. Consequently, different materials, such as silicon and glass, are bonded together and well-aligned thanks to lithographic-based fabrication processes.

A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

Directory of Open Access Journals (Sweden)

Ivan Aldaya

2015-01-01

Full Text Available Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

Development of Infrared Phase Closure Capability in the Infrared-Optical Telescope Array (IOTA)

Science.gov (United States)

Traub, Wesley A.

2002-01-01

We completed all major fabrication and testing for the third telescope and phase-closure operation at the Infrared-Optical Telescope Array (IOTA) during this period. In particular we successfully tested the phase-closure operation, using a laboratory light source illuminating the full delay-line optical paths, and using an integrated-optic beam combiner coupled to our Picnic-detector camera. This demonstration is an important and near-final milestone achievement. As of this writing, however, several tasks yet remain, owing to development snags and weather, so the final proof of success, phase-closure observation of a star, is now expected to occur in early 2002, soon after this report has been submitted.

Optical properties of anisotropic 3D nanoparticles arrays

Science.gov (United States)

Santiago, E. Y.; Esquivel-Sirvent, R.

2017-07-01

The optical properties of 3D periodic arrays of spheroidal Au nanoparticles are calculated using a Bruggeman effective medium approximation. The optical response of the supra-crystal depends on the volume fraction of the nanoparticles and their aspect or size ratio (major/minor axis). All the nanoparticles have the same orientation, and this defines an anisotropic dielectric function of the crystal. As a function of the filling fraction, while keeping the size ratio fixed, the maximum in the extinction spectra along the major and minor axes does not show a significant change. However, for a fixed filling fraction, varying the aspect ratio of the particles induces a shift of several hundred of nanometers in the maximum of the extinction spectra along the major axis and almost no changes along the minor axis. Depending on the aspect ratio and the filling fraction, we show that the supra-crystal has three regimes with different values of an effective plasma frequency. Contribution to the Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.

GaN-based micro-LED arrays on flexible substrates for optical cochlear implants

International Nuclear Information System (INIS)

Goßler, Christian; Bierbrauer, Colin; Moser, Rüdiger; Kunzer, Michael; Holc, Katarzyna; Pletschen, Wilfried; Köhler, Klaus; Wagner, Joachim; Schwarz, Ulrich T; Schwaerzle, Michael; Ruther, Patrick; Paul, Oliver; Neef, Jakob; Keppeler, Daniel; Hoch, Gerhard; Moser, Tobias

2014-01-01

Currently available cochlear implants are based on electrical stimulation of the spiral ganglion neurons. Optical stimulation with arrays of micro-sized light-emitting diodes (µLEDs) promises to increase the number of distinguishable frequencies. Here, the development of a flexible GaN-based micro-LED array as an optical cochlear implant is reported for application in a mouse model. The fabrication of 15 µm thin and highly flexible devices is enabled by a laser-based layer transfer process of the GaN-LEDs from sapphire to a polyimide-on-silicon carrier wafer. The fabricated 50 × 50 µm 2 LEDs are contacted via conducting paths on both p- and n-sides of the LEDs. Up to three separate channels could be addressed. The probes, composed of a linear array of the said µLEDs bonded to the flexible polyimide substrate, are peeled off the carrier wafer and attached to flexible printed circuit boards. Probes with four µLEDs and a width of 230 µm are successfully implanted in the mouse cochlea both in vitro and in vivo. The LEDs emit 60 µW at 1 mA after peel-off, corresponding to a radiant emittance of 6 mW mm −2 . (paper)

Metasurface-Enabled Remote Quantum Interference.

Science.gov (United States)

Jha, Pankaj K; Ni, Xingjie; Wu, Chihhui; Wang, Yuan; Zhang, Xiang

2015-07-10

An anisotropic quantum vacuum (AQV) opens novel pathways for controlling light-matter interaction in quantum optics, condensed matter physics, etc. Here, we theoretically demonstrate a strong AQV over macroscopic distances enabled by a judiciously designed array of subwavelength-scale nanoantennas-a metasurface. We harness the phase-control ability and the polarization-dependent response of the metasurface to achieve strong anisotropy in the decay rate of a quantum emitter located over distances of hundreds of wavelengths. Such an AQV induces quantum interference among radiative decay channels in an atom with orthogonal transitions. Quantum vacuum engineering with metasurfaces holds promise for exploring new paradigms of long-range light-matter interaction for atom optics, solid-state quantum optics, quantum information processing, etc.

Optical absorption enhancement in silicon nanowire arrays with a large lattice constant for photovoltaic applications.

Science.gov (United States)

Lin, Chenxi; Povinelli, Michelle L

2009-10-26

In this paper, we use the transfer matrix method to calculate the optical absorptance of vertically-aligned silicon nanowire (SiNW) arrays. For fixed filling ratio, significant optical absorption enhancement occurs when the lattice constant is increased from 100 nm to 600 nm. The enhancement arises from an increase in field concentration within the nanowire as well as excitation of guided resonance modes. We quantify the absorption enhancement in terms of ultimate efficiency. Results show that an optimized SiNW array with lattice constant of 600 nm and wire diameter of 540 nm has a 72.4% higher ultimate efficiency than a Si thin film of equal thickness. The enhancement effect can be maintained over a large range of incidence angles.

Nonlinear dynamics of solitary and optically injected two-element laser arrays with four different waveguide structures: a numerical study.

Science.gov (United States)

Li, Nianqiang; Susanto, H; Cemlyn, B R; Henning, I D; Adams, M J

2018-02-19

We study the nonlinear dynamics of solitary and optically injected two-element laser arrays with a range of waveguide structures. The analysis is performed with a detailed direct numerical simulation, where high-resolution dynamic maps are generated to identify regions of dynamic instability in the parameter space of interest. Our combined one- and two-parameter bifurcation analysis uncovers globally diverse dynamical regimes (steady-state, oscillation, and chaos) in the solitary laser arrays, which are greatly influenced by static design waveguiding structures, the amplitude-phase coupling factor of the electric field, i.e. the linewidth-enhancement factor, as well as the control parameter, e.g. the pump rate. When external optical injection is introduced to one element of the arrays, we show that the whole system can be either injection-locked simultaneously or display rich, different dynamics outside the locking region. The effect of optical injection is to significantly modify the nature and the regions of nonlinear dynamics from those found in the solitary case. We also show similarities and differences (asymmetry) between the oscillation amplitude of the two elements of the array in specific well-defined regions, which hold for all the waveguiding structures considered. Our findings pave the way to a better understanding of dynamic instability in large arrays of lasers.

Optimization of gold nanoring arrays for biosensing in the fiber-optic communication window

International Nuclear Information System (INIS)

Jiang, Hao; Sabarinathan, Jayshri; Li, Tingjie; Yang, Jun; Mittler, Silvia

2013-01-01

To improve the limit of detection in a nanoplasmonic sensor system, the optical performance of the metal nanostructures should be optimized according to the best spectral window of the measurement instrument. We propose that the spectral window from 1460 to 1610 nm can potentially provide ultrahigh instrumental resolution for biosensing. We optimized gold nanoring arrays such that the extinction peak position is inside the proposed window, the extinction peak is sharp enough to track the peak shift with high resolution and the figure of merit (sensitivity/linewidth) of the array is optimized at the same time. The peak-sharpening effect of the array caused by coherent interaction plays a central role in the optimization. The optimized array has a lattice constant in the range [1000 nm,1060 nm], a bulk index sensitivity of around 450 nm/RIU and a figure of merit larger than 4. It is an enabling sensor element for a near-infrared sensor chip with ultrahigh resolution. (paper)

Optical diffraction by ordered 2D arrays of silica microspheres

Science.gov (United States)

Shcherbakov, A. A.; Shavdina, O.; Tishchenko, A. V.; Veillas, C.; Verrier, I.; Dellea, O.; Jourlin, Y.

2017-03-01

The article presents experimental and theoretical studies of angular dependent diffraction properties of 2D monolayer arrays of silica microspheres. High-quality large area defect-free monolayers of 1 μm diameter silica microspheres were deposited by the Langmuir-Blodgett technique under an accurate optical control. Measured angular dependencies of zeroth and one of the first order diffraction efficiencies produced by deposited samples were simulated by the rigorous Generalized Source Method taking into account particle size dispersion and lattice nonideality.

Improvement of the optical and morphological properties of microlens arrays fabricated by laser using a sol–gel coating

International Nuclear Information System (INIS)

Nieto, Daniel; Gómez-Varela, Ana Isabel; Martín, Yolanda Castro; O’Connor, Gerard M.; Flores-Arias, María Teresa

2015-01-01

Highlights: • Microlens arrays were fabricated on soda-lime glass using a Ti:Sapphire laser. • A SiO 2 coating prepared via sol–gel route was used to improve the microlens quality. • The sol–gel coating was deposited at the microlens top surface using a dip coating. • Optical properties of the microlenses were improved by the coating. - Abstract: We present a simple, repeatable and non-contaminant method to improve the optical and morphological properties of microlens arrays. It consists on depositing hybrid SiO 2 (TEOS, MTES) coatings via sol–gel route onto microlens arrays fabricated using a Ti:Sapphire Femtosecond Amplitude Systems S-pulse HP laser operating at 1030 nm. The deposited silica sol–gel layer reduces the surface roughness (quantified as the root mean square) and increases the quality of the interstices between the microlenses generated by the ablation process, thus improving the contrast and homogeneity of the foci of the microlens array. The proposed technique allows us to obtain microlenses with a diameter in the range of 15–20 μm and a depth of 1.5–15 μm. For the characterization of the micro-optical structures, the UV–visible spectroscopy, spectral ellipsometry, confocal microscopy and beam profilometry were used. The proof-of-principle presented in this paper can be used to improve the optical and morphological properties of micro-optical systems of different nature by tailoring the parameters involved in both the laser ablation and sol–gel processes comprising the starting materials, solvent and catalysts nature and concentration, hydrolysis ratio, aging time and/or deposition conditions

Improvement of the optical and morphological properties of microlens arrays fabricated by laser using a sol–gel coating

Energy Technology Data Exchange (ETDEWEB)

Nieto, Daniel, E-mail: daniel.nieto@usc.es [Microoptics and GRIN Optics Group, Applied Physics Department, Faculty of Physics, University of Santiago de Compostela, Santiago de Compostela E15782 (Spain); Gómez-Varela, Ana Isabel [Microoptics and GRIN Optics Group, Applied Physics Department, Faculty of Physics, University of Santiago de Compostela, Santiago de Compostela E15782 (Spain); Martín, Yolanda Castro [Instituto de Cerámica y Vidrio (CSIC), Kelsen 5, Campus de Cantoblanco, 28049 Madrid (Spain); O’Connor, Gerard M. [School of Physics, National Centre for Laser Applications, National University of Ireland, University Road, Galway (Ireland); Flores-Arias, María Teresa, E-mail: maite.flores@usc.es [Microoptics and GRIN Optics Group, Applied Physics Department, Faculty of Physics, University of Santiago de Compostela, Santiago de Compostela E15782 (Spain)

2015-10-01

Highlights: • Microlens arrays were fabricated on soda-lime glass using a Ti:Sapphire laser. • A SiO{sub 2} coating prepared via sol–gel route was used to improve the microlens quality. • The sol–gel coating was deposited at the microlens top surface using a dip coating. • Optical properties of the microlenses were improved by the coating. - Abstract: We present a simple, repeatable and non-contaminant method to improve the optical and morphological properties of microlens arrays. It consists on depositing hybrid SiO{sub 2} (TEOS, MTES) coatings via sol–gel route onto microlens arrays fabricated using a Ti:Sapphire Femtosecond Amplitude Systems S-pulse HP laser operating at 1030 nm. The deposited silica sol–gel layer reduces the surface roughness (quantified as the root mean square) and increases the quality of the interstices between the microlenses generated by the ablation process, thus improving the contrast and homogeneity of the foci of the microlens array. The proposed technique allows us to obtain microlenses with a diameter in the range of 15–20 μm and a depth of 1.5–15 μm. For the characterization of the micro-optical structures, the UV–visible spectroscopy, spectral ellipsometry, confocal microscopy and beam profilometry were used. The proof-of-principle presented in this paper can be used to improve the optical and morphological properties of micro-optical systems of different nature by tailoring the parameters involved in both the laser ablation and sol–gel processes comprising the starting materials, solvent and catalysts nature and concentration, hydrolysis ratio, aging time and/or deposition conditions.

Toward a nanoimprinted nanoantenna to perform optical rectification through molecular diodes

Science.gov (United States)

Reynaud, C. A.; Duché, D.; Ruiz, C. M.; Palanchoke, U.; Patrone, L.; Le Rouzo, J.; Labau, S.; Frolet, N.; Gourgon, C.; Alfonso, C.; Charaï, A.; Lebouin, C.; Simon, J.-J.; Escoubas, L.

2017-12-01

This work presents investigations about the realization and modelization of rectenna solar cells. Rectennas are antennas coupled with a rectifier to convert the alternative current originating from the antenna into direct current that can be harvested and stored. By reducing the size of the antennas to the nanoscale, interactions with visible and near-infrared light become possible. If techniques such as nanoimprint lithography make possible the fabrication of sufficiently small plasmonic structures to act as optical antennas, the concept of rectenna still faces several challenges. One of the most critical point is to achieve rectification at optical frequencies. To address this matter, we propose to use molecular diodes (ferrocenyl-alkanethiol) that can be self-assembled on metallic surfaces such as gold or silver. In this paper, we present a basic rectenna theory as well as finite-difference time-domain (FDTD) optical simulations of plasmonic structures and experimental results of both nanoimprint fabrication of samples and characterizations by electron microscopy, Raman spectroscopy, and cyclic voltammetry techniques.

Enhancement of magneto-optical Faraday effects and extraordinary optical transmission in a tri-layer structure with rectangular annular arrays.

Science.gov (United States)

Lei, Chengxin; Chen, Leyi; Tang, Zhixiong; Li, Daoyong; Cheng, Zhenzhi; Tang, Shaolong; Du, Youwei

2016-02-15

The properties of optics and magneto-optical Faraday effects in a metal-dielectric tri-layer structure with subwavelength rectangular annular arrays are investigated. It is noteworthy that we obtained the strongly enhanced Faraday rotation of the desired sign along with high transmittance by optimizing the parameters of the nanostructure in the visible spectral ranges. In this system, we obtained two extraordinary optical transmission (EOT) resonant peaks with enhanced Faraday rotations, whose signs are opposite, which may provide the possibility of designing multi-channel magneto-optical devices. Study results show that the maximum of the figure of merit (FOM) of the structure can be obtained between two EOT resonant peaks accompanied by an enhanced Faraday rotation. The positions of the maximum value of the FOM and resonant peaks of transmission along with a large Faraday rotation can be tailored by simply adjusting the geometric parameters of our models. These research findings are of great importance for future applications of magneto-optical devices.

Processes for design, construction and utilisation of arrays of light-emitting diodes and light-emitting diode-coupled optical fibres for multi-site brain light delivery.

Science.gov (United States)

Bernstein, Jacob G; Allen, Brian D; Guerra, Alexander A; Boyden, Edward S

2015-05-01

Optogenetics enables light to be used to control the activity of genetically targeted cells in the living brain. Optical fibers can be used to deliver light to deep targets, and LEDs can be spatially arranged to enable patterned light delivery. In combination, arrays of LED-coupled optical fibers can enable patterned light delivery to deep targets in the brain. Here we describe the process flow for making LED arrays and LED-coupled optical fiber arrays, explaining key optical, electrical, thermal, and mechanical design principles to enable the manufacturing, assembly, and testing of such multi-site targetable optical devices. We also explore accessory strategies such as surgical automation approaches as well as innovations to enable low-noise concurrent electrophysiology.

Optical response of a flat metallic surface coated with a monolayer array of latex spheres

International Nuclear Information System (INIS)

Shi Lei; Liu Xiaohan; Yin Haiwei; Zi Jian

2010-01-01

We report on the fabrication, characterization and simulation of a structure consisting of a flat metallic surface coated with a monolayer array of latex spheres. This structure shows interesting optical response: over flat metallic surfaces a series of reflection minima appear in reflection spectra. Numerical simulations revealed that the structure can support two types of surface modes: surface plasmon-polaritons bound at the metallic surface and guided modes confined to the array of latex spheres, or their hybrids. Both experimental and theoretical results indicated that these surface modes show well-defined band structures due to the introduced periodicity by the monolayer array of latex spheres.

Effect of Refractive Index of Substrate on Fabrication and Optical Properties of Hybrid Au-Ag Triangular Nanoparticle Arrays

Directory of Open Access Journals (Sweden)

Jing Liu

2015-05-01

Full Text Available In this study, the nanosphere lithography (NSL method was used to fabricate hybrid Au-Ag triangular periodic nanoparticle arrays. The Au-Ag triangular periodic arrays were grown on different substrates, and the effect of the refractive index of substrates on fabrication and optical properties was systematically investigated. At first, the optical spectrum was simulated by the discrete dipole approximation (DDA numerical method as a function of refractive indexes of substrates and mediums. Simulation results showed that as the substrates had the refractive indexes of 1.43 (quartz and 1.68 (SF5 glass, the nanoparticle arrays would have better refractive index sensitivity (RIS and figure of merit (FOM. Simulation results also showed that the peak wavelength of the extinction spectra had a red shift when the medium’s refractive index n increased. The experimental results also demonstrated that when refractive indexes of substrates were 1.43 and 1.68, the nanoparticle arrays and substrate had better adhesive ability. Meanwhile, we found the nanoparticles formed a large-scale monolayer array with the hexagonally close-packed structure. Finally, the hybrid Au-Ag triangular nanoparticle arrays were fabricated on quartz and SF5 glass substrates and their experiment extinction spectra were compared with the simulated results.

SU-E-T-111: Development of Proton Dosimetry System Using Fiber-Optic Cerenkov Radiation Sensor Array

Energy Technology Data Exchange (ETDEWEB)

Son, J [National Cancer Center, Ilsan, Gyeonggi-do, Korea University, Seoul (Korea, Republic of); Kim, M; Shin, D; Lim, Y; Lee, S; Kim, J; Kim, J [National Cancer Center, Goyangsi, Gyeonggi-do (Korea, Republic of); Hwang, U [National Medical Center in Korea, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

2014-06-01

Purpose: We had developed and evaluated a new dosimetric system for proton therapy using array of fiber-optic Cerenkov radiation sensor (FOCRS) which can measure a percent depth dose (PDD) instantly. In this study, the Bragg peaks and spread out Bragg peak (SOBP) of the proton beams measured by FOCRS array were compared with those measured by an ion chamber. Methods and Method: We fabricated an optical fiber array of FOCRS in a handmade phantom which is composed of poly-methyl methacrylate (PMMA). There are 75 holes of 1mm diameter inside the phantom which is designed to be exposed in direction of beam when it is emerged in water phantom. The proton beam irradiation was carried out using IBA cyclotron PROTEUS 235 at national cancer center in Korea and a commercial data acquisition system was used to digitize the analog signal. Results: The measured Bragg peak and SOBP for the proton ranges of 7∼ 20 cm were well matched with the result from ion chamber. The comparison results show that the depth of proton beam ranges and the width of SOBP measured by array of FOCRS are comparable with the measurement from multi-layer ion chamber (MLIC) although there are some uncertainty in the measurement of FOCRS array for some specific beam ranges. Conclusion: The newly developed FOCRS array based dosimetric system for proton therapy can efficiently reduce the time and effort needed for proton beam range measurement compared to the conventional method and has the potential to be used for the proton pencil beam application.

Fiber-optic microsphere-based antibody array for the analysis of inflammatory cytokines in saliva.

Science.gov (United States)

Blicharz, Timothy M; Siqueira, Walter L; Helmerhorst, Eva J; Oppenheim, Frank G; Wexler, Philip J; Little, Frédéric F; Walt, David R

2009-03-15

Antibody microarrays have emerged as useful tools for high-throughput protein analysis and candidate biomarker screening. We describe here the development of a multiplexed microsphere-based antibody array capable of simultaneously measuring 10 inflammatory protein mediators. Cytokine-capture microspheres were fabricated by covalently coupling monoclonal antibodies specific for cytokines of interest to fluorescently encoded 3.1 microm polymer microspheres. An optical fiber bundle containing approximately 50,000 individual 3.1 microm diameter fibers was chemically etched to create microwells in which cytokine-capture microspheres could be deposited. Microspheres were randomly distributed in the wells to produce an antibody array for performing a multiplexed sandwich immunoassay. The array responded specifically to recombinant cytokine solutions in a concentration-dependent fashion. The array was also used to examine endogenous mediator patterns in saliva supernatants from patients with pulmonary inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD). This array technology may prove useful as a laboratory-based platform for inflammatory disease research and diagnostics, and its small footprint could also enable integration into a microfluidic cassette for use in point-of-care testing.

Indirect optical crosstalk reduction by highly-doped backside layer in PureB single-photon avalanche diode arrays

NARCIS (Netherlands)

Osrečki, Željko; Knežević, Tihomir; Nanver, Lis K.; Suligoj, Tomislav

2017-01-01

A method of reducing indirect optical crosstalk in a PureB single-photon avalanche diode (SPAD) array is investigated by TCAD simulations. The reduction is accomplished by taking advantage of the enhanced optical absorption of a highly-doped Si layer (p-type, 3×1020 cm-3) on the backside of the

Design of optical element combining Fresnel lens with microlens array for uniform light-emitting diode lighting.

Science.gov (United States)

Wang, Guangzhen; Wang, Lili; Li, Fuli; Kong, Depeng

2012-09-01

One kind of optical element combining Fresnel lens with microlens array is designed simply for LED lighting based on geometrical optics and nonimaging optics. This design method imposes no restriction on the source intensity pattern. The designed element has compact construction and can produce multiple shapes of illumination distribution. Taking square lighting as an example, tolerance analysis is carried out to determine tolerance limits for applying the element in the assembly process. This element can produce on-axis lighting and off-axis lighting.

Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications

KAUST Repository

Yue, Weisheng; Wang, Zhihong; Yang, Yang; Li, Jingqi; Wu, Ying; Chen, Longqing; Ooi, Boon S.; Wang, Xianbin; Zhang, Xixiang

2014-01-01

Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration

Construction of 3D Arrays of Cylindrically Hierarchical Structures with ZnO Nanorods Hydrothermally Synthesized on Optical Fiber Cores

Directory of Open Access Journals (Sweden)

Weixuan Jing

2014-01-01

Full Text Available With ZnO nanorods hydrothermally synthesized on manually assembled arrays of optical fiber cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+ concentration of the growth solution but also were anisotropic due to different curvature radii of the optical fiber core at side and front view.

Bit-error-rate testing of fiber optic data links for MMIC-based phased array antennas

Science.gov (United States)

Shalkhauser, K. A.; Kunath, R. R.; Daryoush, A. S.

1990-01-01

The measured bit-error-rate (BER) performance of a fiber optic data link to be used in satellite communications systems is presented and discussed. In the testing, the link was measured for its ability to carry high burst rate, serial-minimum shift keyed (SMSK) digital data similar to those used in actual space communications systems. The fiber optic data link, as part of a dual-segment injection-locked RF fiber optic link system, offers a means to distribute these signals to the many radiating elements of a phased array antenna. Test procedures, experimental arrangements, and test results are presented.

Bit error rate testing of fiber optic data links for MMIC-based phased array antennas

Science.gov (United States)

Shalkhauser, K. A.; Kunath, R. R.; Daryoush, A. S.

1990-01-01

The measured bit-error-rate (BER) performance of a fiber optic data link to be used in satellite communications systems is presented and discussed. In the testing, the link was measured for its ability to carry high burst rate, serial-minimum shift keyed (SMSK) digital data similar to those used in actual space communications systems. The fiber optic data link, as part of a dual-segment injection-locked RF fiber optic link system, offers a means to distribute these signals to the many radiating elements of a phased array antenna. Test procedures, experimental arrangements, and test results are presented.

Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

NARCIS (Netherlands)

Tijmes, M.R.; Meijerink, Arjan; Roeloffzen, C.G.H.; Bentum, Marinus Jan

2009-01-01

A new simulator tool is described that can be used in the field of RF photonics. It has been developed on the basis of a broadband, continuously tunable optical beamformer system for phased array receive antennas. The application that is considered in this paper is airborne satellite reception of

Cell manipulation tool with combined microwell array and optical tweezers for cell isolation and deposition

International Nuclear Information System (INIS)

Wang, Xiaolin; Gou, Xue; Chen, Shuxun; Yan, Xiao; Sun, Dong

2013-01-01

Isolation from rare cells and deposition of sorted cells with high accuracy for further study are critical to a wide range of biomedical applications. In the current paper, we report an automated cell manipulation tool with combined optical tweezers and a uniquely designed microwell array, which functions for recognition, isolation, assembly, transportation and deposition of the interesting cells. The microwell array allows the passive hydrodynamic docking of cells, while offering the opportunity to inspect the interesting cell phenotypes with high spatio-temporal resolution based on the flexible image processing technique. In addition, dynamic and parallel cell manipulation in three dimensions can realize the target cell levitation from microwell and pattern assembly with multiple optical traps. Integrated with the programmed motorized stage, the optically levitated and assembled cells can be transported and deposited to the predefined microenvironment, so the tool can facilitate the integration of other on-chip functionalities for further study without removing these isolated cells from the chip. Experiments on human embryonic stem cells and yeast cells are performed to demonstrate the effectiveness of the proposed cell manipulation tool. Besides the application to cell isolation and deposition, three other biological applications with this tool are also presented. (paper)

Design of a ring resonator-based optical beam forming network for phased array receive antennas

NARCIS (Netherlands)

van 't Klooster, J.W.J.R.; Roeloffzen, C.G.H.; Meijerink, Arjan; Zhuang, L.; Marpaung, D.A.I.; van Etten, Wim; Heideman, Rene; Leinse, Arne; Schippers, H.; Verpoorte, J.; Wintels, M.

2008-01-01

A novel squint-free ring resonator-based optical beam forming network (OBFN) for phased array antennas (PAA) is proposed. It is intended to provide broadband connectivity to airborne platforms via geostationary satellites. In this paper, we present the design of the OBFN and its control system. Our

An automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope

International Nuclear Information System (INIS)

Lin, Chern-Sheng; Loh, Guo-Hao; Fu, Shu-Hsien; Chang, Hsun-Kai; Yang, Shih-Wei; Yeh, Mau-Shiun

2010-01-01

In this paper, an automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope is presented. For inspecting the microlens array, an XY-table is used to position it. With a He–Ne laser beam and optical fiber as a probing light, the measured image is sent to the computer to analyze the surface profile. By binary image slicing and area recognition, this study located the center of each ring and determined the substrate of the microlens array image through the background of the entire microlens array interference image. The maximum and minimum values of every segment brightness curve were determined corresponding to the change in the segment phase angle from 0° to 180°. According to the ratio of the actual ring area and the ideal ring area, the area ratio method was adopted to find the phase-angle variation of the interference ring. Based on the ratio of actual ring brightness and the ideal ring brightness, the brightness ratio method was used to determine the phase-angle variation of the interference ring fringe. The area ratio method and brightness ratio method are interchangeable in precisely determining the phase angles of the innermost and outermost rings of the interference fringe and obtaining different microlens surface altitudes of respective pixels in the segment, to greatly increase the microlens array surface profile inspection accuracy and quality

A Portable Array-Type Optical Fiber Sensing Instrument for Real-Time Gas Detection

Directory of Open Access Journals (Sweden)

San-Shan Hung

2016-12-01

Full Text Available A novel optical fiber array-type of sensing instrument with temperature compensation for real-time detection was developed to measure oxygen, carbon dioxide, and ammonia simultaneously. The proposed instrument is multi-sensing array integrated with real-time measurement module for portable applications. The sensing optical fibers were etched and polished before coating to increase sensitivities. The ammonia and temperature sensors were each composed of a dye-coated single-mode fiber with constructing a fiber Bragg grating and a long-period filter grating for detecting light intensity. Both carbon dioxide and oxygen sensing structures use multimode fibers where 1-hydroxy-3,6,8-pyrene trisulfonic acid trisodium salt is coated for carbon dioxide sensing and Tris(2,2′-bipyridyl dichlororuthenium(II hexahydrate and Tris(bipyridineruthenium(II chloride are coated for oxygen sensing. Gas-induced fluorescent light intensity variation was applied to detect gas concentration. The portable gas sensing array was set up by integrating with photo-electronic measurement modules and a human-machine interface to detect gases in real time. The measured data have been processed using piecewise-linear method. The sensitivity of the oxygen sensor were 1.54%/V and 9.62%/V for concentrations less than 1.5% and for concentrations between 1.5% and 6%, respectively. The sensitivity of the carbon dioxide sensor were 8.33%/V and 9.62%/V for concentrations less than 2% and for concentrations between 2% and 5%, respectively. For the ammonia sensor, the sensitivity was 27.78%/V, while ammonia concentration was less than 2%.

A Portable Array-Type Optical Fiber Sensing Instrument for Real-Time Gas Detection.

Science.gov (United States)

Hung, San-Shan; Chang, Hsing-Cheng; Chang, I-Nan

2016-12-08

A novel optical fiber array-type of sensing instrument with temperature compensation for real-time detection was developed to measure oxygen, carbon dioxide, and ammonia simultaneously. The proposed instrument is multi-sensing array integrated with real-time measurement module for portable applications. The sensing optical fibers were etched and polished before coating to increase sensitivities. The ammonia and temperature sensors were each composed of a dye-coated single-mode fiber with constructing a fiber Bragg grating and a long-period filter grating for detecting light intensity. Both carbon dioxide and oxygen sensing structures use multimode fibers where 1-hydroxy-3,6,8-pyrene trisulfonic acid trisodium salt is coated for carbon dioxide sensing and Tris(2,2'-bipyridyl) dichlororuthenium(II) hexahydrate and Tris(bipyridine)ruthenium(II) chloride are coated for oxygen sensing. Gas-induced fluorescent light intensity variation was applied to detect gas concentration. The portable gas sensing array was set up by integrating with photo-electronic measurement modules and a human-machine interface to detect gases in real time. The measured data have been processed using piecewise-linear method. The sensitivity of the oxygen sensor were 1.54%/V and 9.62%/V for concentrations less than 1.5% and for concentrations between 1.5% and 6%, respectively. The sensitivity of the carbon dioxide sensor were 8.33%/V and 9.62%/V for concentrations less than 2% and for concentrations between 2% and 5%, respectively. For the ammonia sensor, the sensitivity was 27.78%/V, while ammonia concentration was less than 2%.

Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

Directory of Open Access Journals (Sweden)

S.M. Popov

2018-06-01

Full Text Available A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been applied for precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration. Keywords: Tapered optical fibers, Fiber Bragg gratings, Random lasers

Fully CMOS-compatible titanium nitride nanoantennas

Energy Technology Data Exchange (ETDEWEB)

Briggs, Justin A., E-mail: jabriggs@stanford.edu [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305 (United States); Naik, Gururaj V.; Baum, Brian K.; Dionne, Jennifer A. [Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305 (United States); Petach, Trevor A.; Goldhaber-Gordon, David [Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305 (United States)

2016-02-01

CMOS-compatible fabrication of plasmonic materials and devices will accelerate the development of integrated nanophotonics for information processing applications. Using low-temperature plasma-enhanced atomic layer deposition (PEALD), we develop a recipe for fully CMOS-compatible titanium nitride (TiN) that is plasmonic in the visible and near infrared. Films are grown on silicon, silicon dioxide, and epitaxially on magnesium oxide substrates. By optimizing the plasma exposure per growth cycle during PEALD, carbon and oxygen contamination are reduced, lowering undesirable loss. We use electron beam lithography to pattern TiN nanopillars with varying diameters on silicon in large-area arrays. In the first reported single-particle measurements on plasmonic TiN, we demonstrate size-tunable darkfield scattering spectroscopy in the visible and near infrared regimes. The optical properties of this CMOS-compatible material, combined with its high melting temperature and mechanical durability, comprise a step towards fully CMOS-integrated nanophotonic information processing.

UV plasmonic enhancement through three dimensional nano-cavity antenna array in aluminum

Science.gov (United States)

Mao, Jieying; Stevenson, Peter; Montanaric, Danielle; Wang, Yunshan; Shumaker-Parry, Jennifer S.; Harris, Joel M.; Blair, Steve

2017-08-01

Metallic nanostructure can enhance fluorescence through excited surface plasmons which increase the local field as well as improve its quantum efficiency. When coupling to cavity resonance with proper gap dimension, gap hot spots can be generated to interact with fluorescence at their excitation/emission region in UV. A 3D nano-cavity antenna array in Aluminum has been conducted to generate local hot spot resonant at fluorescence emission resonance. Giant field enhancement has been achieved through coupling fundamental resonance modes of nanocavity into surface plasmons polaritons (SPPs). In this work, two distinct plasmonic structure of 3D resonant cavity nanoantenna has been studied and its plasmonic response has been scaled down to the UV regime through finite-difference-time-domain (FDTD) method. Two different strategies for antenna fabrication will be conducted to obtain D-coupled Dots-on-Pillar Antenna array (D2PA) through Focus Ion Beam (FIB) and Cap- Hole Pair Antenna array (CHPA) through nanosphere template lithography (NTL). With proper optimization of the structures, D2PA and CHPA square array with 280nm pitch have achieved distinct enhancement at fluorophore emission wavelength 350nm and excitation wavelength 280nm simultaneously. Maximum field enhancement can reach 20 and 65 fold in the gap of D2PA and CHPA when light incident from substrate, which is expected to greatly enhance fluorescent quantum efficiency that will be confirmed in fluorescence lifetime measurement.

2D director calculation for liquid crystal optical phased array

International Nuclear Information System (INIS)

Xu, L; Zhang, J; Wu, L Y

2005-01-01

A practical numerical model for a liquid crystal cell is set up based on the geometrical structure of liquid crystal optical phased arrays. Model parameters include width and space of electrodes, thickness of liquid crystal layer, alignment layers and glass substrates, pre-tilted angles, dielectric constants, elastic constants and so on. According to electrostatic field theory and Frank-Oseen elastic continuum theory, 2D electric potential distribution and 2D director distribution are calculated by means of the finite difference method on non-uniform grids. The influence of cell sizes on director distribution is analyzed. The fringe field effect between electrodes is also discussed

Smart time-pulse coding photoconverters as basic components 2D-array logic devices for advanced neural networks and optical computers

Science.gov (United States)

Krasilenko, Vladimir G.; Nikolsky, Alexander I.; Lazarev, Alexander A.; Michalnichenko, Nikolay N.

2004-04-01

The article deals with a conception of building arithmetic-logic devices (ALD) with a 2D-structure and optical 2D-array inputs-outputs as advanced high-productivity parallel basic operational training modules for realization of basic operation of continuous, neuro-fuzzy, multilevel, threshold and others logics and vector-matrix, vector-tensor procedures in neural networks, that consists in use of time-pulse coding (TPC) architecture and 2D-array smart optoelectronic pulse-width (or pulse-phase) modulators (PWM or PPM) for transformation of input pictures. The input grayscale image is transformed into a group of corresponding short optical pulses or time positions of optical two-level signal swing. We consider optoelectronic implementations of universal (quasi-universal) picture element of two-valued ALD, multi-valued ALD, analog-to-digital converters, multilevel threshold discriminators and we show that 2D-array time-pulse photoconverters are the base elements for these devices. We show simulation results of the time-pulse photoconverters as base components. Considered devices have technical parameters: input optical signals power is 200nW_200μW (if photodiode responsivity is 0.5A/W), conversion time is from tens of microseconds to a millisecond, supply voltage is 1.5_15V, consumption power is from tens of microwatts to a milliwatt, conversion nonlinearity is less than 1%. One cell consists of 2-3 photodiodes and about ten CMOS transistors. This simplicity of the cells allows to carry out their integration in arrays of 32x32, 64x64 elements and more.

A Comparative Study on Structural and Optical Properties of ZnO Micro-Nanorod Arrays Grown on Seed Layers Using Chemical Bath Deposition and Spin Coating Methods

Directory of Open Access Journals (Sweden)

Sibel MORKOÇ KARADENİZ

2016-11-01

Full Text Available In this study, Zinc Oxide (ZnO seed layers were prepared on Indium Tin Oxide (ITO substrates by using Chemical Bath Deposition (CBD method and Sol-gel Spin Coating (SC method. ZnO micro-nanorod arrays were grown on ZnO seed layers by using Hydrothermal Synthesis method. Seed layer effects of structural and optical properties of ZnO arrays were characterized. X-ray diffractometer (XRD, Scanning Electron Microscopy (SEM and Ultraviolet Visible (UV-Vis Spectrometer were used for analyses. ZnO micro-nanorod arrays consisted of a single crystalline wurtzite ZnO structure for each seed layer. Besides, ZnO rod arrays were grown smoothly and vertically on SC seed layer, while ZnO rod arrays were grown randomly and flower like structures on CBD seed layer. The optical absorbance peaks found at 422 nm wavelength in the visible region for both ZnO arrays. Optical bandgap values were determined by using UV-Vis measurements at 3.12 and 3.15 eV for ZnO micro-nanorod arrays on CBD seed layer and for ZnO micro-nanorod arrays on SC-seed layer respectively.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.13443

Fabrication of long linear arrays of plastic optical fibers with squared ends for the use of code mark printing lithography

Science.gov (United States)

Horiuchi, Toshiyuki; Watanabe, Jun; Suzuki, Yuta; Iwasaki, Jun-ya

2017-05-01

Two dimensional code marks are often used for the production management. In particular, in the production lines of liquid-crystal-display panels and others, data on fabrication processes such as production number and process conditions are written on each substrate or device in detail, and they are used for quality managements. For this reason, lithography system specialized in code mark printing is developed. However, conventional systems using lamp projection exposure or laser scan exposure are very expensive. Therefore, development of a low-cost exposure system using light emitting diodes (LEDs) and optical fibers with squared ends arrayed in a matrix is strongly expected. In the past research, feasibility of such a new exposure system was demonstrated using a handmade system equipped with 100 LEDs with a central wavelength of 405 nm, a 10×10 matrix of optical fibers with 1 mm square ends, and a 10X projection lens. Based on these progresses, a new method for fabricating large-scale arrays of finer fibers with squared ends was developed in this paper. At most 40 plastic optical fibers were arranged in a linear gap of an arraying instrument, and simultaneously squared by heating them on a hotplate at 120°C for 7 min. Fiber sizes were homogeneous within 496+/-4 μm. In addition, average light leak was improved from 34.4 to 21.3% by adopting the new method in place of conventional one by one squaring method. Square matrix arrays necessary for printing code marks will be obtained by piling the newly fabricated linear arrays up.

A High-Performance Optical Memory Array Based on Inhomogeneity of Organic Semiconductors.

Science.gov (United States)

Pei, Ke; Ren, Xiaochen; Zhou, Zhiwen; Zhang, Zhichao; Ji, Xudong; Chan, Paddy Kwok Leung

2018-03-01

Organic optical memory devices keep attracting intensive interests for diverse optoelectronic applications including optical sensors and memories. Here, flexible nonvolatile optical memory devices are developed based on the bis[1]benzothieno[2,3-d;2',3'-d']naphtho[2,3-b;6,7-b']dithiophene (BBTNDT) organic field-effect transistors with charge trapping centers induced by the inhomogeneity (nanosprouts) of the organic thin film. The devices exhibit average mobility as high as 7.7 cm 2 V -1 s -1 , photoresponsivity of 433 A W -1 , and long retention time for more than 6 h with a current ratio larger than 10 6 . Compared with the standard floating gate memory transistors, the BBTNDT devices can reduce the fabrication complexity, cost, and time. Based on the reasonable performance of the single device on a rigid substrate, the optical memory transistor is further scaled up to a 16 × 16 active matrix array on a flexible substrate with operating voltage less than 3 V, and it is used to map out 2D optical images. The findings reveal the potentials of utilizing [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives as organic semiconductors for high-performance optical memory transistors with a facile structure. A detailed study on the charge trapping mechanism in the derivatives of BTBT materials is also provided, which is closely related to the nanosprouts formed inside the organic active layer. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of a 1 x N Fiber Optic Sensor Array for Carbon Sequestration Site Monitoring

Energy Technology Data Exchange (ETDEWEB)

Repasky, Kevin [Montana State Univ., Bozeman, MT (United States)

2014-02-01

A fiber sensor array for sub-surface CO₂ concentrations measurements was developed for monitoring geologic carbon sequestration sites. The fiber sensor array uses a single temperature tunable distributed feedback (DFB) laser operating with a nominal wavelength of 2.004 μm. Light from this DFB laser is direct to one of the 4 probes via an in-line 1 x 4 fiber optic switch. Each of the 4 probes are buried and allow the sub-surface CO₂ to enter the probe through Millipore filters that allow the soil gas to enter the probe but keeps out the soil and water. Light from the DFB laser interacts with the CO₂ before it is directed back through the in-line fiber optic switch. The DFB laser is tuned across two CO₂ absorption features where a transmission measurement is made allowing the CO₂ concentration to be retrieved. The fiber optic switch then directs the light to the next probe where this process is repeated allowing sub-surface CO₂ concentration measurements at each of the probes to be made as a function of time. The fiber sensor array was deployed for fifty-eight days beginning June 19, 2012 at the Zero Emission Research Technology (ZERT) field site where sub-surface CO₂ concentrations were monitored. Background measurements indicate the fiber sensor array can monitor background levels as low as 1,000 parts per million (ppm). A thirty four day sub-surface release of 0.15 tones CO₂/day began on July 10, 2012. The elevated subsurface CO₂ concentration was easily detected by each of the four probes with values ranging to over 60,000 ppm, a factor of greater than 6 higher than background measurements. The fiber sensor array was also deploy at the Big Sky Carbon Sequestration Partnership (BSCSP) site in north-central Montana between July 9th and August 7th, 2013 where background measurements were made in a remote sequestration site with minimal infrastructure. The project

High performance architecture design for large scale fibre-optic sensor arrays using distributed EDFAs and hybrid TDM/DWDM

Science.gov (United States)

Liao, Yi; Austin, Ed; Nash, Philip J.; Kingsley, Stuart A.; Richardson, David J.

2013-09-01

A distributed amplified dense wavelength division multiplexing (DWDM) array architecture is presented for interferometric fibre-optic sensor array systems. This architecture employs a distributed erbium-doped fibre amplifier (EDFA) scheme to decrease the array insertion loss, and employs time division multiplexing (TDM) at each wavelength to increase the number of sensors that can be supported. The first experimental demonstration of this system is reported including results which show the potential for multiplexing and interrogating up to 4096 sensors using a single telemetry fibre pair with good system performance. The number can be increased to 8192 by using dual pump sources.

Protein Functionalized Nanodiamond Arrays

Directory of Open Access Journals (Sweden)

Liu YL

2010-01-01

Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

Fiber-optic transmission system information for the testing of active phased antenna arrays in an anechoic chamber.

Science.gov (United States)

Saveleiv, I. K.; Sharova, N. V.; Tarasenko, M. Yu; Yalunina, T. R.; Davydov, V. V.; Rud', V. Yu

2017-11-01

The results of the research of the developed fiber-optic transmission systems for analog high frequency signal are represented. On its basis, a new method to identify various structural defects in the active phased antenna arrays is elaborated.

Plasmonic non-concentric nanorings array as an unidirectional nano-optical conveyor belt actuated by polarization rotation.

Science.gov (United States)

Jiang, Min; Wang, Guanghui; Jiao, Wenxiang; Ying, Zhoufeng; Zou, Ningmu; Ho, Ho-Pui; Sun, Tianyu; Zhang, Xuping

2017-01-15

We report a nano-optical conveyor belt containing an array of gold plasmonic non-concentric nanorings (PNNRs) for the realization of trapping and unidirectional transportation of nanoparticles through rotating the polarization of an excitation beam. The location of hot spots within an asymmetric plasmonic nanostructure is polarization dependent, thus making it possible to manipulate a trapped target by rotating the incident polarization state. In the case of PNNR, the two poles have highly unbalanced trap potential. This greatly enhances the chance of transferring trapped particles between adjacent PNNRs in a given direction through rotating the polarization. As confirmed by three-dimensional finite-difference time-domain analysis, an array of PNNRs forms an unidirectional nano-optical conveyor belt, which delivers target nanoparticles or biomolecules over a long distance with nanometer accuracy. With the capacity to trap and to transfer, our design offers a versatile scheme for conducting mechanical sample manipulation in many on-chip optofluidic applications.

Optical second harmonic generation from V-shaped chromium nanohole arrays

Science.gov (United States)

Khoa Quang, Ngo; Miyauchi, Yoshihiro; Mizutani, Goro; Charlton, Martin D.; Chen, Ruiqi; Boden, Stuart; Rutt, Harvey

2014-02-01

We observed rotational anisotropy of optical second harmonic generation (SHG) from an array of V-shaped chromium nanoholes fabricated by electron beam lithography. Phenomenological analysis indicated that the effective nonlinear susceptibility element \\chi _{313}^{(2)} had a characteristic contribution to the observed anisotropic SHG intensity patterns. Here, coordinate 1 is in the direction of the tip of V shapes in the substrate plane, and 3 indicates the direction perpendicular to the sample surface. The SHG intensity for the S-polarized output light was very weak, probably owing to the cancellation effect of the image dipoles generated at the metal-air boundary. The possible origin of the observed nonlinearity is discussed in terms of the susceptibility elements obtained.

Patterned Diblock Co-Polymer Thin Films as Templates for Advanced Anisotropic Metal Nanostructures.

Science.gov (United States)

Roth, Stephan V; Santoro, Gonzalo; Risch, Johannes F H; Yu, Shun; Schwartzkopf, Matthias; Boese, Torsten; Döhrmann, Ralph; Zhang, Peng; Besner, Bastian; Bremer, Philipp; Rukser, Dieter; Rübhausen, Michael A; Terrill, Nick J; Staniec, Paul A; Yao, Yuan; Metwalli, Ezzeldin; Müller-Buschbaum, Peter

2015-06-17

We demonstrate glancing-angle deposition of gold on a nanostructured diblock copolymer, namely polystyrene-block-poly(methyl methacrylate) thin film. Exploiting the selective wetting of gold on the polystyrene block, we are able to fabricate directional hierarchical structures. We prove the asymmetric growth of the gold nanoparticles and are able to extract the different growth laws by in situ scattering methods. The optical anisotropy of these hierarchical hybrid materials is further probed by angular resolved spectroscopic methods. This approach enables us to tailor functional hierarchical layers in nanodevices, such as nanoantennae arrays, organic photovoltaics, and sensor electronics.

Frequency-addressed tunable transmission in optically thin metallic nanohole arrays with dual-frequency liquid crystals

International Nuclear Information System (INIS)

Hao Qingzhen; Zhao Yanhui; Juluri, Bala Krishna; Kiraly, Brian; Huang, Tony Jun; Liou, Justin; Khoo, Iam Choon

2011-01-01

Frequency-addressed tunable transmission is demonstrated in optically thin metallic nanohole arrays embedded in dual-frequency liquid crystals (DFLCs). The optical properties of the composite system are characterized by the transmission spectra of the nanoholes, and a prominent transmission peak is shown to originate from the resonance of localized surface plasmons at the edges of the nanoholes. An ∼17 nm shift in the transmission peak is observed between the two alignment configurations of the liquid crystals. This DFLC-based active plasmonic system demonstrates excellent frequency-dependent switching behavior and could be useful in future nanophotonic applications.

Zero-crossing detection algorithm for arrays of optical spatial filtering velocimetry sensors

DEFF Research Database (Denmark)

Jakobsen, Michael Linde; Pedersen, Finn; Hanson, Steen Grüner

2008-01-01

This paper presents a zero-crossing detection algorithm for arrays of compact low-cost optical sensors based on spatial filtering for measuring fluctuations in angular velocity of rotating solid structures. The algorithm is applicable for signals with moderate signal-to-noise ratios, and delivers...... repeating the same measurement error for each revolution of the target, and to gain high performance measurement of angular velocity. The traditional zero-crossing detection is extended by 1) inserting an appropriate band-pass filter before the zero-crossing detection, 2) measuring time periods between zero...

Complementary Walsh-Hadamard coded optical CDMA coder/decoders structured over arrayed-waveguide grating routers

Science.gov (United States)

Huang, Jen-Fa; Yang, Chao-Chin; Tseng, Shin-Pin

2004-01-01

In this paper, an optical code-division multiple-access (OCDMA) system with complementary Walsh-Hadamard coded optical encoder/decoder configuration structured over arrayed-waveguide grating (AWG) routers is examined. In the proposed system, each network user requires only two AWG routers to accomplish spectral encoding and decoding for complementary keying, thus, resulting a simpler and low cost system. Performance of the proposed system is analyzed by taking the effect of phase-induced intensity noise into account. The result indicates that the established system not only preserves the capability of suppressing multiple-access interference (MAI), but also improves bit-error-rate performance as compared to the conventional coders employing simple on-off keying.

Programming Nanoparticles in Multiscale: Optically Modulated Assembly and Phase Switching of Silicon Nanoparticle Array.

Science.gov (United States)

Wang, Letian; Rho, Yoonsoo; Shou, Wan; Hong, Sukjoon; Kato, Kimihiko; Eliceiri, Matthew; Shi, Meng; Grigoropoulos, Costas P; Pan, Heng; Carraro, Carlo; Qi, Dongfeng

2018-03-27

Manipulating and tuning nanoparticles by means of optical field interactions is of key interest for nanoscience and applications in electronics and photonics. We report scalable, direct, and optically modulated writing of nanoparticle patterns (size, number, and location) of high precision using a pulsed nanosecond laser. The complex nanoparticle arrangement is modulated by the laser pulse energy and polarization with the particle size ranging from 60 to 330 nm. Furthermore, we report fast cooling-rate induced phase switching of crystalline Si nanoparticles to the amorphous state. Such phase switching has usually been observed in compound phase change materials like GeSbTe. The ensuing modification of atomic structure leads to dielectric constant switching. Based on these effects, a multiscale laser-assisted method of fabricating Mie resonator arrays is proposed. The number of Mie resonators, as well as the resonance peaks and dielectric constants of selected resonators, can be programmed. The programmable light-matter interaction serves as a mechanism to fabricate optical metasurfaces, structural color, and multidimensional optical storage devices.

Optical diffraction by ordered 2D arrays of silica microspheres

International Nuclear Information System (INIS)

Shcherbakov, A.A.; Shavdina, O.; Tishchenko, A.V.; Veillas, C.; Verrier, I.; Dellea, O.; Jourlin, Y.

2017-01-01

The article presents experimental and theoretical studies of angular dependent diffraction properties of 2D monolayer arrays of silica microspheres. High-quality large area defect-free monolayers of 1 μm diameter silica microspheres were deposited by the Langmuir-Blodgett technique under an accurate optical control. Measured angular dependencies of zeroth and one of the first order diffraction efficiencies produced by deposited samples were simulated by the rigorous Generalized Source Method taking into account particle size dispersion and lattice nonideality. - Highlights: • High quality silica microsphere monolayer was fabricated. • Accurate measurements of diffraction efficiency angular dependencies. • Rigorous diffraction simulation of both ideal hexagonal and realistic microsphere arrangements. • Qualitative rationalization of the obtained results and the observed differences between the experiment and the theory.

ScintSim1: a new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors

International Nuclear Information System (INIS)

Mosleh-Shirazi, Mohammad Amin; Karbasi, Sareh; Zarrini-Monfared, Zinat; Zamani, Ali

2014-01-01

Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization. (author)

Integration of Fiber-Optic Sensor Arrays into a Multi-Modal Tactile Sensor Processing System for Robotic End-Effectors

Directory of Open Access Journals (Sweden)

Peter Kampmann

2014-04-01

Full Text Available With the increasing complexity of robotic missions and the development towards long-term autonomous systems, the need for multi-modal sensing of the environment increases. Until now, the use of tactile sensor systems has been mostly based on sensing one modality of forces in the robotic end-effector. The use of a multi-modal tactile sensory system is motivated, which combines static and dynamic force sensor arrays together with an absolute force measurement system. This publication is focused on the development of a compact sensor interface for a fiber-optic sensor array, as optic measurement principles tend to have a bulky interface. Mechanical, electrical and software approaches are combined to realize an integrated structure that provides decentralized data pre-processing of the tactile measurements. Local behaviors are implemented using this setup to show the effectiveness of this approach.

Gold Nanohole Array with Sub-1 nm Roughness by Annealing for Sensitivity Enhancement of Extraordinary Optical Transmission Biosensor

Science.gov (United States)

Zhang, Jian; Irannejad, Mehrdad; Yavuz, Mustafa; Cui, Bo

2015-05-01

Nanofabrication technology plays an important role in the performance of surface plasmonic devices such as extraordinary optical transmission (EOT) sensor. In this work, a double liftoff process was developed to fabricate a series of nanohole arrays of a hole diameter between 150 and 235 nm and a period of 500 nm in a 100-nm-thick gold film on a silica substrate. To improve the surface quality of the gold film, thermal annealing was conducted, by which an ultra-smooth gold film with root-mean-square (RMS) roughness of sub-1 nm was achieved, accompanied with a hole diameter shrinkage. The surface sensitivity of the nanohole arrays was measured using a monolayer of 16-mercaptohexadecanoic acid (16-MHA) molecule, and the surface sensitivity was increased by 2.5 to 3 times upon annealing the extraordinary optical transmission (EOT) sensor.

Ultra-fast dynamics in the nonlinear optical response of silver nanoprism ordered arrays.

Science.gov (United States)

Sánchez-Esquivel, Héctor; Raygoza-Sanchez, Karen Y; Rangel-Rojo, Raúl; Kalinic, Boris; Michieli, Niccolò; Cesca, Tiziana; Mattei, Giovanni

2018-03-15

In this work we present the study of the ultra-fast dynamics of the nonlinear optical response of a honeycomb array of silver triangular nanoprisms, performed using a femtosecond pulsed laser tuned with the dipolar surface plasmon resonance of the nanoarray. Nonlinear absorption and refraction, and their time-dependence, were explored using the z-scan and time-resolved excite-probe techniques. Nonlinear absorption is shown to change sign with the input irradiance and the behavior was explained on the basis of a three-level model. The response time was determined to be in the picosecond regime. A technique based on a variable frequency chopper was also used in order to discriminate the thermal and electronic contributions to the nonlinearity, which were found to have opposite signs. All these findings propel the investigated nanoprism arrays as good candidates for applications in advanced ultra-fast nonlinear nanophotonic devices.

Complementary bowtie aperture for localizing and enhancing optical magnetic field

Science.gov (United States)

Zhou, Nan; Kinzel, Edward C.; Xu, Xianfan

2011-08-01

Nanoscale bowtie antenna and bowtie aperture antenna have been shown to generate strongly enhanced and localized electric fields below the diffraction limit in the optical frequency range. According to Babinet's principle, their complements will be efficient for concentrating and enhancing magnetic fields. In this Letter, we discuss the enhancement of magnetic field intensity of nanoscale complementary bowtie aperture as well as complementary bowtie aperture antenna, or diabolo nanoantenna. We show that the complementary bowtie antenna resonates at a smaller wavelength and thus is more suitable for applications near visible wavelengths. The near-field magnetic intensity can be further enhanced by the addition of groove structures that scatter surface plasmon.

Reflectivity quenching of ESR multilayer polymer film reflector in optically bonded scintillator arrays

Science.gov (United States)

Loignon-Houle, Francis; Pepin, Catherine M.; Charlebois, Serge A.; Lecomte, Roger

2017-04-01

The 3M-ESR multilayer polymer film is a widely used reflector in scintillation detector arrays. As specified in the datasheet and confirmed experimentally by measurements in air, it is highly reflective (> 98 %) over the entire visible spectrum (400-1000 nm) for all angles of incidence. Despite these outstanding characteristics, it was previously found that light crosstalk between pixels in a bonded LYSO scintillator array with ESR reflector can be as high as ∼30-35%. This unexplained light crosstalk motivated further investigation of ESR optical performance. Analytical simulation of a multilayer structure emulating the ESR reflector showed that the film becomes highly transparent to incident light at large angles when surrounded on both sides by materials of refractive index higher than air. Monte Carlo simulations indicate that a considerable fraction (∼25-35%) of scintillation photons are incident at these leaking angles in high aspect ratio LYSO scintillation crystals. The film transparency was investigated experimentally by measuring the scintillation light transmission through the ESR film sandwiched between a scintillation crystal and a photodetector with or without layers of silicone grease. Strong light leakage, up to nearly 30%, was measured through the reflector when coated on both sides with silicone, thus elucidating the major cause of light crosstalk in bonded arrays. The reflector transparency was confirmed experimentally for angles of incidence larger than 60 ° using a custom designed setup allowing illumination of the bonded ESR film at selected grazing angles. The unsuspected ESR film transparency can be beneficial for detector arrays exploiting light sharing schemes, but it is highly detrimental for scintillator arrays designed for individual pixel readout.

An Optical Wavefront Sensor Based on a Double Layer Microlens Array

Directory of Open Access Journals (Sweden)

Hsiang-Chun Wei

2011-10-01

Full Text Available In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA to divide the incident light into small parts and focus them onto image planes. In this paper, we present the design and fabrication of long focal length MLA with various shapes and arrangements based on a double layer structure for optical wavefront sensing applications. A longer focal length MLA could provide high sensitivity in determining the average slope across each microlens under a given wavefront, and spatial resolution of a wavefront sensor is increased by numbers of microlenses across a detector. In order to extend focal length, we used polydimethysiloxane (PDMS above MLA on a glass substrate. Because of small refractive index difference between PDMS and MLA interface (UV-resin, the incident light is less refracted and focused in further distance. Other specific focal lengths could also be realized by modifying the refractive index difference without changing the MLA size. Thus, the wavefront sensor could be improved with better sensitivity and higher spatial resolution.

Double-Arched LD Array Stagger Pumped Electro-Optic Q-Switched Nd:YAG Laser without Water Cooling

International Nuclear Information System (INIS)

Xin-Yu, Chen; Guang-Yong, Jin; Yong-Ji, Yu; Chao, Wang; Da-Wei, Hao; Yi-Bo, Wang

2010-01-01

We report an experimental study on a double-arched LD array stagger pumped electro-optic Q-switched Nd:YAG laser without water cooling by using a convex-concave compensate resonator. Perfect matching of the gain field inside the rod and the fundamental mode of the cavity is made by this structure. When the repetition rate is 20 Hz, A maximum output energy at 1064 nm wavelength of 176 mJ (M 2 = 1.55) and 9.6 ns FWHM pulse width in fundamental mode Q-switch operation is obtained with LD injection current 120 A. The optical-optical conversion efficiency is 14.7%, the divergence angle of the output beam is about 1.8 mrad. (fundamental areas of phenomenology(including applications))

Investigation of a nanostrip patch antenna in optical frequencies

Science.gov (United States)

Kashyap, Nitesh; Wani, Zamir Ahmad; Jain, Rishi; Khusboo; Dinesh Kumar, V.

2014-08-01

This is the first report and investigation of a patch antenna in optical frequency range. Variety of plasmonic nanoantenna reported so far is good at enhancing the local field intensity of light by orders of magnitude. However, their far-field radiation efficiency is very poor. The proposed patch antenna emits a directional beam with high efficacy in addition to enhancing the intensity of near field. The nano-patch antenna (NPA) consists of a square patch of gold film of dimension 480 nm2, placed on a substrate of dielectric constant \\varepsilon_{{r}} = 3.9 and thickness 150 nm with a ground plane of gold film of dimension 1,080 nm2. The NPA resonates at 210 THz and has gain nearly 2 dB and radiation efficiency 45.18 %. The NPA might be useful in variety of applications such as optical communication, nano-photonics, biosensing, and spectroscopy.

Theoretical model and experimental verification on the PID tracking method using liquid crystal optical phased array

Science.gov (United States)

Wang, Xiangru; Xu, Jianhua; Huang, Ziqiang; Wu, Liang; Zhang, Tianyi; Wu, Shuanghong; Qiu, Qi

2017-02-01

Liquid crystal optical phased array (LC-OPA) has been considered with great potential on the non-mechanical laser deflector because it is fabricated using photolithographic patterning technology which has been well advanced by the electronics and display industry. As a vital application of LC-OPA, free space laser communication has demonstrated its merits on communication bandwidth. Before data communication, ATP (acquisition, tracking and pointing) process costs relatively long time to result in a bottle-neck of free space laser communication. Meanwhile, dynamic real time accurate tracking is sensitive to keep a stable communication link. The electro-optic medium liquid crystal with low driving voltage can be used as the laser beam deflector. This paper presents a fast-track method using liquid crystal optical phased array as the beam deflector, CCD as a beacon light detector. PID (Proportion Integration Differentiation) loop algorithm is introduced as the controlling algorithm to generate the corresponding steering angle. To achieve the goal of fast and accurate tracking, theoretical analysis and experimental verification are demonstrated that PID closed-loop system can suppress the attitude random vibration. Meanwhile, theoretical analysis shows that tracking accuracy can be less than 6.5μrad, with a relative agreement with experimental results which is obtained after 10 adjustments that the tracking accuracy is less than12.6μrad.

Optical diffraction tomography microscopy with transport of intensity equation using a light-emitting diode array

Science.gov (United States)

Li, Jiaji; Chen, Qian; Zhang, Jialin; Zhang, Zhao; Zhang, Yan; Zuo, Chao

2017-08-01

Optical diffraction tomography (ODT) is an effective label-free technique for quantitatively refractive index imaging, which enables long-term monitoring of the internal three-dimensional (3D) structures and molecular composition of biological cells with minimal perturbation. However, existing optical tomographic methods generally rely on interferometric configuration for phase measurement and sophisticated mechanical systems for sample rotation or beam scanning. Thereby, the measurement is suspect to phase error coming from the coherent speckle, environmental vibrations, and mechanical error during data acquisition process. To overcome these limitations, we present a new ODT technique based on non-interferometric phase retrieval and programmable illumination emitting from a light-emitting diode (LED) array. The experimental system is built based on a traditional bright field microscope, with the light source replaced by a programmable LED array, which provides angle-variable quasi-monochromatic illumination with an angular coverage of ±37 degrees in both x and y directions (corresponding to an illumination numerical aperture of ∼0.6). Transport of intensity equation (TIE) is utilized to recover the phase at different illumination angles, and the refractive index distribution is reconstructed based on the ODT framework under first Rytov approximation. The missing-cone problem in ODT is addressed by using the iterative non-negative constraint algorithm, and the misalignment of the LED array is further numerically corrected to improve the accuracy of refractive index quantification. Experiments on polystyrene beads and thick biological specimens show that the proposed approach allows accurate refractive index reconstruction while greatly reduced the system complexity and environmental sensitivity compared to conventional interferometric ODT approaches.

A novel optical freezing array for the examination of cooling rate dependence in heterogeneous ice nucleation

Science.gov (United States)

Budke, Carsten; Dreischmeier, Katharina; Koop, Thomas

2014-05-01

Homogeneous ice nucleation is a stochastic process, implying that it is not only temperature but also time dependent. For heterogeneous ice nucleation it is still under debate whether there is a significant time dependence or not. In case of minor time dependence it is probably sufficient to use a singular or slightly modified singular approach, which mainly supposes temperature dependence and just small stochastic variations. We contribute to this discussion using a novel optical freezing array termed BINARY (Bielefeld Ice Nucleation ARraY). The setup consists of an array of microliter-sized droplets on a Peltier cooling stage. The droplets are separated from each other with a polydimethylsiloxane (PDMS) spacer to prevent a Bergeron-Findeisen process, in which the first freezing droplets grow at the expense of the remaining liquid ones due to their vapor pressure differences. An automatic detection of nucleation events is realized optically by the change in brightness during freezing. Different types of ice nucleating agents were tested with the presented setup, e. g. pollen and clay mineral dust. Exemplarily, cooling rate dependent measurements are shown for the heterogeneous ice nucleation induced by Snomax®. The authors gratefully acknowledge funding by the German Research Foundation (DFG) through the project BIOCLOUDS (KO 2944/1-1) and through the research unit INUIT (FOR 1525) under KO 2944/2-1. We particularly thank our INUIT partners for fruitful collaboration and sharing of ideas and IN samples.

Resonant surface-enhanced Raman scattering by optical phonons in a monolayer of CdSe nanocrystals on Au nanocluster arrays

Energy Technology Data Exchange (ETDEWEB)

Milekhin, Alexander G., E-mail: milekhin@isp.nsc.ru [A.V. Rzhanov Institute of Semiconductor Physics, pr. Lavrentjeva, 13, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogov str. 2, 630090 Novosibirsk (Russian Federation); Sveshnikova, Larisa L.; Duda, Tatyana A. [A.V. Rzhanov Institute of Semiconductor Physics, pr. Lavrentjeva, 13, 630090 Novosibirsk (Russian Federation); Rodyakina, Ekaterina E. [A.V. Rzhanov Institute of Semiconductor Physics, pr. Lavrentjeva, 13, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogov str. 2, 630090 Novosibirsk (Russian Federation); Dzhagan, Volodymyr M. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Sheremet, Evgeniya [Solid Surfaces Analysis, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Gordan, Ovidiu D. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Himcinschi, Cameliu [Institut für Theoretische Physik, TU Bergakademie Freiberg, 09596 Freiberg (Germany); Latyshev, Alexander V. [A.V. Rzhanov Institute of Semiconductor Physics, pr. Lavrentjeva, 13, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogov str. 2, 630090 Novosibirsk (Russian Federation); Zahn, Dietrich R.T. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany)

2016-05-01

Highlights: • Regular Au nanocluster and dimer arrays as well as single Au dimers are fabricated. • Resonant SERS by monolayers of CdSe nanocrystals deposited on the Au nanostructures is observed. • LO energy change for CdSe NCs on different single Au dimers indicates SERS by single or a few NCs. - Abstract: Here we present the results on an investigation of resonant Stokes and anti- Stokes surface-enhanced Raman scattering (SERS) by optical phonons in colloidal CdSe nanocrystals (NCs) homogeneously deposited on arrays of Au nanoclusters using the Langmuir–Blodgett technology. The thickness of deposited NCs, determined by transmission and scanning electron microscopy, amounts to approximately 1 monolayer. Special attention is paid to the determination of the localized surface plasmon resonance (LSPR) energy in the arrays of Au nanoclusters as a function of the nanocluster size by means of micro-ellipsometry. SERS by optical phonons in CdSe NCs shows a significant enhancement factor with a maximal value of 2 × 10{sup 3} which depends resonantly on the Au nanocluster size and thus on the LSPR energy. The deposition of CdSe NCs on the arrays of Au nanocluster dimers enabled us to study the polarization dependence of SERS. It was found that a maximal SERS signal is observed for the light polarization along the dimer axis. Finally, SERS by optical phonons was observed for CdSe NCs deposited on the structures with a single Au dimer. A difference of the LO phonon energy is observed for CdSe NCs on different single dimers. This effect is explained as the confinement-induced shift which depends on the CdSe nanocrystal size and indicates quasi-single NC Raman spectra being obtained.

Field programmable gate array based reconfigurable scanning probe/optical microscope.

Science.gov (United States)

Nowak, Derek B; Lawrence, A J; Dzegede, Zechariah K; Hiester, Justin C; Kim, Cliff; Sánchez, Erik J

2011-10-01

The increasing popularity of nanometrology and nanospectroscopy has pushed researchers to develop complex new analytical systems. This paper describes the development of a platform on which to build a microscopy tool that will allow for flexibility of customization to suit research needs. The novelty of the described system lies in its versatility of capabilities. So far, one version of this microscope has allowed for successful near-field and far-field fluorescence imaging with single molecule detection sensitivity. This system is easily adapted for reflection, polarization (Kerr magneto-optical (MO)), Raman, super-resolution techniques, and other novel scanning probe imaging and spectroscopic designs. While collecting a variety of forms of optical images, the system can simultaneously monitor topographic information of a sample with an integrated tuning fork based shear force system. The instrument has the ability to image at room temperature and atmospheric pressure or under liquid. The core of the design is a field programmable gate array (FPGA) data acquisition card and a single, low cost computer to control the microscope with analog control circuitry using off-the-shelf available components. A detailed description of electronics, mechanical requirements, and software algorithms as well as examples of some different forms of the microscope developed so far are discussed.

Optical parameters of ITO/TPD/Alq3/Al luminescent structures, containing arrays of CdSe/ZnS colloidal quantum dots

Science.gov (United States)

Mikhailov, I. I.; Tarasov, S. A.; Lamkin, I. A.; Tadtaev, P. O.; Kozlovich, L. I.; Solomonov, A. V.; Stepanov, E. M.

2016-08-01

The luminescent organic ITO/TPD/Alq3/Al structures and CdSe/ZnS quantum dots (QD) arrays were created. Electrical and optical properties of the samples were examined. The luminescence of the layers and QD arrays was shown in the range of wavelengths from 400 to 680 nm. Luminescent structures with phosphors corresponding to the emission standards with CRI>98 and with color temperature of 5500 K and 6504 K were created.

Imaging RF Phased Array Receivers using Optically-Coherent Up-conversion for High Beam-Bandwidth Processing

Science.gov (United States)

2017-03-01

It does so by using an optical lens to perform an inverse spatial Fourier Transform on the up-converted RF signals, thereby rendering a real-time... simultaneous beams or other engineered beam patterns. There are two general approaches to array-based beam forming: digital and analog. In digital beam...of significantly limiting the number of beams that can be formed simultaneously and narrowing the operational bandwidth. An alternate approach that

Metal-filled carbon nanotube based optical nanoantennas: bubbling, reshaping, and in situ characterization.

Science.gov (United States)

Fan, Zheng; Tao, Xinyong; Cui, Xudong; Fan, Xudong; Zhang, Xiaobin; Dong, Lixin

2012-09-21

Controlled fabrication of metal nanospheres on nanotube tips for optical antennas is investigated experimentally. Resembling soap bubble blowing using a straw, the fabrication process is based on nanofluidic mass delivery at the attogram scale using metal-filled carbon nanotubes (m@CNTs). Two methods have been investigated including electron-beam-induced bubbling (EBIB) and electromigration-based bubbling (EMBB). EBIB involves the bombardment of an m@CNT with a high energy electron beam of a transmission electron microscope (TEM), with which the encapsulated metal is melted and flowed out from the nanotube, generating a metallic particle on a nanotube tip. In the case where the encapsulated materials inside the CNT have a higher melting point than what the beam energy can reach, EMBB is an optional process to apply. Experiments show that, under a low bias (2.0-2.5 V), nanoparticles can be formed on the nanotube tips. The final shape and crystallinity of the nanoparticles are determined by the cooling rate. Instant cooling occurs with a relatively large heat sink and causes the instant shaping of the solid deposit, which is typically similar to the shape of the molten state. With a smaller heat sink as a probe, it is possible to keep the deposit in a molten state. Instant cooling by separating the deposit from the probe can result in a perfect sphere. Surface and volume plasmons characterized with electron energy loss spectroscopy (EELS) prove that resonance occurs between a pair of as-fabricated spheres on the tip structures. Such spheres on pillars can serve as nano-optical antennas and will enable devices such as scanning near-field optical microscope (SNOM) probes, scanning anodes for field emitters, and single molecule detectors, which can find applications in bio-sensing, molecular detection, and high-resolution optical microscopy.

Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays

National Research Council Canada - National Science Library

Yang, Kyoung

2005-01-01

This final report summarizes the progress during the Phase I SBIR project entitled "Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays...

Quantum simulation of 2D topological physics in a 1D array of optical cavities.

Science.gov (United States)

Luo, Xi-Wang; Zhou, Xingxiang; Li, Chuan-Feng; Xu, Jin-Shi; Guo, Guang-Can; Zhou, Zheng-Wei

2015-07-06

Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration.

Nanoparticle sorting in silicon waveguide arrays

Science.gov (United States)

Zhao, H. T.; Zhang, Y.; Chin, L. K.; Yap, P. H.; Wang, K.; Ser, W.; Liu, A. Q.

2017-08-01

This paper presents the optical fractionation of nanoparticles in silicon waveguide arrays. The optical lattice is generated by evanescent coupling in silicon waveguide arrays. The hotspot size is tunable by changing the refractive index of surrounding liquids. In the experiment, 0.2-μm and 0.5-μm particles are separated with a recovery rate of 95.76%. This near-field approach is a promising candidate for manipulating nanoscale biomolecules and is anticipated to benefit the biomedical applications such as exosome purification, DNA optical mapping, cell-cell interaction, etc.

A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

Science.gov (United States)

Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

2008-03-01

This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

Mapping the electromagnetic field confinement in the gap of germanium nanoantennas with plasma wavelength of 4.5 micrometers

Science.gov (United States)

Calandrini, Eugenio; Venanzi, Tommaso; Appugliese, Felice; Badioli, Michela; Giliberti, Valeria; Baldassarre, Leonetta; Biagioni, Paolo; De Angelis, Francesco; Klesse, Wolfgang M.; Scappucci, Giordano; Ortolani, Michele

2016-09-01

We study plasmonic nanoantennas for molecular sensing in the mid-infrared made of heavily doped germanium, epitaxially grown with a bottom-up doping process and featuring free carrier density in excess of 1020 cm-3. The dielectric function of the 250 nm thick germanium film is determined, and bow-tie antennas are designed, fabricated, and embedded in a polymer. By using a near-field photoexpansion mapping technique at λ = 5.8 μm, we demonstrate the existence in the antenna gap of an electromagnetic energy density hotspot of diameter below 100 nm and confinement volume 105 times smaller than λ3.

Jammed-array wideband sawtooth filter.

Science.gov (United States)

Tan, Zhongwei; Wang, Chao; Goda, Keisuke; Malik, Omer; Jalali, Bahram

2011-11-21

We present an all-optical passive low-cost spectral filter that exhibits a high-resolution periodic sawtooth spectral pattern without the need for active optoelectronic components. The principle of the filter is the partial masking of a phased array of virtual light sources with multiply jammed diffraction orders. We utilize the filter's periodic linear map between frequency and intensity to demonstrate fast sensitive interrogation of fiber Bragg grating sensor arrays and ultrahigh-frequency electrical sawtooth waveform generation. © 2011 Optical Society of America

Thermal poling of multi-wire array optical fiber

DEFF Research Database (Denmark)

Huang, Lin; An, Honglin; Hayashi, Juliano G.

2018-01-01

We demonstrate in this paper thermal poling of multi-wire array fibers, which extends poling of fibers with two anodes to similar to 50 and similar to 500 wire array anodes. The second harmonic microscopy observations show that second order nonlinearity (SON) layers are developed surrounding all...... the rings of wires in the similar to 50 anode array fiber with poling of 1.8kV, 250 degrees C and 30min duration, and the outer rings of the similar to 500 anode array fiber at lower poling temperature. Our simulations based on a two-dimensional charge dynamics model confirm this can be explained...

Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

Science.gov (United States)

Popov, S. M.; Butov, O. V.; Chamorovskiy, Y. K.; Isaev, V. A.; Kolosovskiy, A. O.; Voloshin, V. V.; Vorob'ev, I. L.; Vyatkin, M. Yu.; Mégret, P.; Odnoblyudov, M.; Korobko, D. A.; Zolotovskii, I. O.; Fotiadi, A. A.

2018-06-01

A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG) inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been applied for precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration.

Effects of heat treatment on optical absorption properties of Ni-P/AAO nano-array composite structure

Energy Technology Data Exchange (ETDEWEB)

Liu, Yi-Fan; Wang, Feng-Hua; Guo, Dong-Lai; Huang, Sheng-You; Zou, Xian-Wu [Wuhan University, Department of Physics, Wuhan (China); Sang, Jian-Ping [Wuhan University, Department of Physics, Wuhan (China); Jianghan University, Department of Physics, Wuhan (China)

2009-11-15

Ni-P/AAO nano-array composite structure assemblies with Ni and P grown in the pores of anodic aluminum oxide (AAO) membranes were prepared by electroless deposition. The results of SEM, TEM and SAED show that as-deposited Ni-P nanowires have an amorphous structure and a few nanocrystallites form after annealing. The optical absorption spectra reveal that, as the annealing temperature increases, the absorption band edge of the Ni-P/AAO composite structure is obviously blue shifted, which is attributed to a decrease of the internal pressure after heat treatment. Meanwhile, the annealed Ni-P/AAO nano-array composite structure exhibits the absorption behavior of a direct band gap semiconductor. Details of this behavior are discussed together with the implications for potential device applications. (orig.)

Method and system for homogenizing diode laser pump arrays

Science.gov (United States)

Bayramian, Andy J

2013-10-01

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

CCD and IR array controllers

Science.gov (United States)

Leach, Robert W.; Low, Frank J.

2000-08-01

A family of controllers has bene developed that is powerful and flexible enough to operate a wide range of CCD and IR focal plane arrays in a variety of ground-based applications. These include fast readout of small CCD and IR arrays for adaptive optics applications, slow readout of large CCD and IR mosaics, and single CCD and IR array operation at low background/low noise regimes as well as high background/high speed regimes. The CCD and IR controllers have a common digital core based on user- programmable digital signal processors that are used to generate the array clocking and signal processing signals customized for each application. A fiber optic link passes image data and commands to VME or PCI interface boards resident in a host computer to the controller. CCD signal processing is done with a dual slope integrator operating at speeds of up to one Megapixel per second per channel. Signal processing of IR arrays is done either with a dual channel video processor or a four channel video processor that has built-in image memory and a coadder to 32-bit precision for operating high background arrays. Recent developments underway include the implementation of a fast fiber optic data link operating at a speed of 12.5 Megapixels per second for fast image transfer from the controller to the host computer, and supporting image acquisition software and device drivers for the PCI interface board for the Sun Solaris, Linux and Windows 2000 operating systems.

Optical technology for microwave applications VI and optoelectronic signal processing for phased-array antennas III; Proceedings of the Meeting, Orlando, FL, Apr. 20-23, 1992

Science.gov (United States)

Yao, Shi-Kay; Hendrickson, Brian M.

The following topics related to optical technology for microwave applications are discussed: advanced acoustooptic devices, signal processing device technologies, optical signal processor technologies, microwave and optomicrowave devices, advanced lasers and sources, wideband electrooptic modulators, and wideband optical communications. The topics considered in the discussion of optoelectronic signal processing for phased-array antennas include devices, signal processing, and antenna systems.

Morphologies and optical and electrical properties of InGaN/GaN micro-square array light-emitting diode chips.

Science.gov (United States)

Han, Dan; Ma, Shufang; Jia, Zhigang; Liu, Peizhi; Jia, Wei; Shang, Lin; Zhai, Guangmei; Xu, Bingshe

2018-04-10

InGaN/GaN micro-square array light-emitting diode (LED) chips (micro-chips) have been prepared via the focused ion beam (FIB) etching technique, which can not only reduce ohmic contact degradation but also control the aspect ratio precisely in three-dimensional (3D) structure LED (3D-LED) device fabrication. The effects of FIB beam current and micro-square array depth on morphologies and optical and electrical properties of the micro-chips have been studied. Our results show that sidewall surface morphology and optical and electrical properties of the micro-chips degrade with increased beam current. After potassium hydroxide etching with different times, an optimal current-voltage and luminescence performance can be obtained. Combining the results of cathodoluminescence mappings and light output-current characteristics, the light extraction efficiency of the micro-chips is reduced as FIB etch depth increases. The mechanisms of micro-square depth on light extraction have been revealed by 3D finite difference time domain.

Wettability, structural and optical properties investigation of TiO{sub 2} nanotubular arrays

Energy Technology Data Exchange (ETDEWEB)

Zalnezhad, E., E-mail: erfan@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Maleki, E. [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Banihashemian, S.M. [Low Dimensional Materials Research Center, Department of Physics, Science Faculty, University Malaya, 50603 Kuala Lumpur (Malaysia); Park, J.W. [Department of Materials Science and Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Y.B. [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Sarraf, M.; Sarhan, A.A.D.M.; Ramesh, S. [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2016-06-15

Graphical abstract: FESEM images of the TiO 2 nanotube layers formed at 0.5 wt% NH4F/ glycerol. - Highlights: • Structural property investigation of TiO{sub 2} nanotube. • Evaluation of wettability of TiO{sub 2} nanotube. • Study on optical properties of TiO{sub 2} nanotube. • The effect of anatase phase on optical and wettability properties of TiO{sub 2.} - Abstract: In this study, the effect of microstructural evolution of TiO{sub 2} nanotubular arrays on wettability and optical properties was investigated. Pure titanium was deposited on silica glass by PVD magnetron sputtering technique. The Ti coated substrates were anodized in an electrolyte containing NH{sub 4}F/glycerol. The structures of the ordered anodic TiO{sub 2} nanotubes (ATNs) as long as 175 nm were studied using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The result shows a sharp peak in the optical absorbance spectra around the band gap energy, 3.49–3.42 eV for annealed and non-annealed respectively. The thermal process induced growth of the grain size, which influence on the density of particles and the index of refraction. Furthermore, the wettability tests' result displays that the contact angle of intact substrate (θ = 74.7°) was decreased to 31.4° and 17.4° after anodization for amorphous and heat treated (450 °C) ANTs coated substrate, respectively.

Optical characterization of nonimaging dish concentrator for the application of dense-array concentrator photovoltaic system.

Science.gov (United States)

Tan, Ming-Hui; Chong, Kok-Keong; Wong, Chee-Woon

2014-01-20

Optimization of the design of a nonimaging dish concentrator (NIDC) for a dense-array concentrator photovoltaic system is presented. A new algorithm has been developed to determine configuration of facet mirrors in a NIDC. Analytical formulas were derived to analyze the optical performance of a NIDC and then compared with a simulated result obtained from a numerical method. Comprehensive analysis of optical performance via analytical method has been carried out based on facet dimension and focal distance of the concentrator with a total reflective area of 120 m2. The result shows that a facet dimension of 49.8 cm, focal distance of 8 m, and solar concentration ratio of 411.8 suns is the most optimized design for the lowest cost-per-output power, which is US$1.93 per watt.

Light Trapping with Silicon Light Funnel Arrays

Directory of Open Access Journals (Sweden)

Ashish Prajapati

2018-03-01

Full Text Available Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase. This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization.

Optically Controlled Phased Array Antenna

National Research Council Canada - National Science Library

Garafalo, David

1998-01-01

.... The antenna is a 3-foot by 9 foot phased array capable of a scan angle of 120 degrees. The antenna was designed to be conformal to the cargo door of a large aircraft and is designed to operate in the frequency range of 830 - 1400 MHz with a 30...

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

Science.gov (United States)

Starko-Bowes, Ryan; Pramanik, Sandipan

2013-01-01

In recent years π-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication. A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently π-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important π-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors

Improving the optical performance of InGaN light-emitting diodes by altering light reflection and refraction with triangular air prism arrays.

Science.gov (United States)

Kang, Ji Hye; Kim, Hyung Gu; Chandramohan, S; Kim, Hyun Kyu; Kim, Hee Yun; Ryu, Jae Hyoung; Park, Young Jae; Beak, Yun Seon; Lee, Jeong-Sik; Park, Joong Seo; Lysak, Volodymyr V; Hong, Chang-Hee

2012-01-01

The effect of triangular air prism (TAP) arrays with different distance-to-width (d/w) ratios on the enhancement of light extraction efficiency (LEE) of InGaN light-emitting diodes (LEDs) is investigated. The TAP arrays embedded at the sapphire/GaN interface act as light reflectors and refractors, and thereby improve the light output power due to the redirection of light into escape cones on both the front and back sides of the LED. Enhancement in radiometric power as high as 117% and far-field angle as low as 129° are realized with a compact arrangement of TAP arrays compared with that of a conventional LED made without TAP arrays under an injection current of 20 mA. © 2012 Optical Society of America

Misalignment corrections in optical interconnects

Science.gov (United States)

Song, Deqiang

Optical interconnects are considered a promising solution for long distance and high bitrate data transmissions, outperforming electrical interconnects in terms of loss and dispersion. Due to the bandwidth and distance advantage of optical interconnects, longer links have been implemented with optics. Recent studies show that optical interconnects have clear advantages even at very short distances---intra system interconnects. The biggest challenge for such optical interconnects is the alignment tolerance. Many free space optical components require very precise assembly and installation, and therefore the overall cost could be increased. This thesis studied the misalignment tolerance and possible alignment correction solutions for optical interconnects at backplane or board level. First the alignment tolerance for free space couplers was simulated and the result indicated the most critical alignments occur between the VCSEL, waveguide and microlens arrays. An in-situ microlens array fabrication method was designed and experimentally demonstrated, with no observable misalignment with the waveguide array. At the receiver side, conical lens arrays were proposed to replace simple microlens arrays for a larger angular alignment tolerance. Multilayer simulation models in CodeV were built to optimized the refractive index and shape profiles of the conical lens arrays. Conical lenses fabricated with micro injection molding machine and fiber etching were characterized. Active component VCSOA was used to correct misalignment in optical connectors between the board and backplane. The alignment correction capability were characterized for both DC and AC (1GHz) optical signal. The speed and bandwidth of the VCSOA was measured and compared with a same structure VCSEL. Based on the optical inverter being studied in our lab, an all-optical flip-flop was demonstrated using a pair of VCSOAs. This memory cell with random access ability can store one bit optical signal with set or

A 4×8-Gbps VCSEL array driver ASIC and integration with a custom array transmitter module for the LHC front-end transmission

International Nuclear Information System (INIS)

Guo, Di; Liu, Chonghan; Chen, Jinghong; Chramowicz, John; Gong, Datao; He, Huiqin; Hou, Suen; Liu, Tiankuan; Prosser, Alan; Teng, Ping-Kun; Xiang, Annie C.; Xiao, Le; Ye, Jingbo

2016-01-01

This paper describes the design, fabrication and experiment results of a 4×8-Gbps Vertical-Cavity Surface-Emitting Laser (VCSEL) array driver ASIC with the adjustable active-shunt peaking technique and the novel balanced output structure under the Silicon-on-Sapphire (SOS) process, and a custom array optical transmitter module, featuring a compact size of 10 mm×15 mm×5.3 mm. Both the array driver ASIC and the module have been fully tested after integration as a complete parallel transmitter. Optical eye diagram of each channel passes the eye mask at 8 Gbps/ch with adjacent channel working simultaneously with a power consumption of 150 mW/ch. The optical transmission of Bit-Error Rate (BER) less than 10E-12 is achieved at an aggregated data rate of 4×8-Gbps. - Highlights: • An anode-driven VCSEL Array driver ASIC with the configurable active-shunt peaking technique in pre-driving stages. • A novel full-differential balanced output structure is used to minimize the noise and crosstalk from the power. • A custom array optical transmitter module with custom low-cost reliable alignment method.

A 4×8-Gbps VCSEL array driver ASIC and integration with a custom array transmitter module for the LHC front-end transmission

Energy Technology Data Exchange (ETDEWEB)

Guo, Di [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei Anhui 230026 (China); Liu, Chonghan [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Chen, Jinghong [Department of Electrical and Computer Engineering, University of Houston, Houston, TX 77004 (United States); Chramowicz, John [Real-Time Systems Engineering Department, Fermi National Laboratory, Batavia, IL 60510 (United States); Gong, Datao [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); He, Huiqin [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Shenzhen Polytechnic, Shenzhen 518055 (China); Hou, Suen [Institute of Physics, Academia Sinica, Nangang 11529, Taipei, Taiwan (China); Liu, Tiankuan [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Prosser, Alan [Real-Time Systems Engineering Department, Fermi National Laboratory, Batavia, IL 60510 (United States); Teng, Ping-Kun [Institute of Physics, Academia Sinica, Nangang 11529, Taipei, Taiwan (China); Xiang, Annie C. [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Xiao, Le [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Department of Physics, Central China Normal University, Wuhan, Hubei 430079 (China); Ye, Jingbo [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States)

2016-09-21

This paper describes the design, fabrication and experiment results of a 4×8-Gbps Vertical-Cavity Surface-Emitting Laser (VCSEL) array driver ASIC with the adjustable active-shunt peaking technique and the novel balanced output structure under the Silicon-on-Sapphire (SOS) process, and a custom array optical transmitter module, featuring a compact size of 10 mm×15 mm×5.3 mm. Both the array driver ASIC and the module have been fully tested after integration as a complete parallel transmitter. Optical eye diagram of each channel passes the eye mask at 8 Gbps/ch with adjacent channel working simultaneously with a power consumption of 150 mW/ch. The optical transmission of Bit-Error Rate (BER) less than 10E-12 is achieved at an aggregated data rate of 4×8-Gbps. - Highlights: • An anode-driven VCSEL Array driver ASIC with the configurable active-shunt peaking technique in pre-driving stages. • A novel full-differential balanced output structure is used to minimize the noise and crosstalk from the power. • A custom array optical transmitter module with custom low-cost reliable alignment method.

Dumand-array data-acquisition system

International Nuclear Information System (INIS)

Brenner, A.E.; Theriot, D.; Dau, W.D.; Geelhood, B.D.; Harris, F.; Learned, J.G.; Stenger, V.; March, R.; Roos, C.; Shumard, E.

1982-04-01

An overall data acquisition approach for DUMAND is described. The scheme assumes one array to shore optical fiber transmission line for each string of the array. The basic event sampling period is approx. 13 μsec. All potentially interesting data is transmitted to shore where the major processing is performed

Fabrication of microlens array with controllable high NA and tailored optical characteristics using confined ink-jetting

Science.gov (United States)

Wang, Li; Luo, Yu; Liu, ZengZeng; Feng, Xueming; Lu, Bingheng

2018-06-01

This work presents an economic and controllable fabricating method of high numerical aperture (NA) polymer microlens array (MLA) based on ink-jetting technology. The MLAs are ink-jetted to align on micro platforms patterned flexible PDMS substrate. The shape of a sole lens is constructed by the ink-jetted pre-cured polymer volume confined on a micro platform. In this way, MLAs with targeted geometries-as well as tailored optical characteristics-can be printed, leading to freely designed optical properties. High NA from 0.446 to 0.885 and focal lengths between 99.26 μm and 39.45 μm are demonstrated, confirming theoretical predictions. Particularly, both the simulations and experimental measurements in optical properties are carried out, demonstrating that microlenses with shapes beyond a hemisphere (CA > 90°) exhibits higher light utilization efficiency and wider viewing angle. Meanwhile, the MLAs are fabricated on flexible PDMS substrates and can be attached to other curved surfaces for wider field of view imaging and higher sensitivity.

Optical fiber array for the delivery of high peak-power laser pulses for fluid flow measurements

International Nuclear Information System (INIS)

Parry, Jonathan P.; Shephard, Jonathan D.; Thomson, Martin J.; Taghizadeh, Mohammad R.; Jones, Julian D. C.; Hand, Duncan P.

2007-01-01

Fiber delivery of 64.7 mJ laser pulses (∼6 ns duration) from a Q-switched Nd:YAG laseroperating at532 nm is demonstrated. A custom diffractive optical element was used toshape the laser beam and facilitate coupling into a linear fiber array. This launcharrangement achieves an improvement in launch efficiency compared with a circular fiberbundle evaluated in previous work and the delivery of higher pulse energies isdemonstrated. The bundle is capable of delivering light of sufficient pulse energy and,importantly, with suitable focusability, to generate a thin light sheet for the fluid flowmeasurement technique of particle image velocimetry (PIV). Fiber delivery offers anadvantage, in terms of optical access, for the application of PIV to enclosed measurementvolumes, such as the cylinder of a combustion engine

Arrayed waveguide Sagnac interferometer.

Science.gov (United States)

Capmany, José; Muñoz, Pascual; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz; Martinez, Alfonso

2003-02-01

We present a novel device, an arrayed waveguide Sagnac interferometer, that combines the flexibility of arrayed waveguides and the wide application range of fiber or integrated optics Sagnac loops. We form the device by closing an array of wavelength-selective light paths provided by two arrayed waveguides with a single 2 x 2 coupler in a Sagnac configuration. The equations that describe the device's operation in general conditions are derived. A preliminary experimental demonstration is provided of a fiber prototype in passive operation that shows good agreement with the expected theoretical performance. Potential applications of the device in nonlinear operation are outlined and discussed.

Micromirror array nanostructures for anticounterfeiting applications

Science.gov (United States)

Lee, Robert A.

2004-06-01

The optical characteristics of pixellated passive micro mirror arrays are derived and applied in the context of their use as reflective optically variable device (OVD) nanostructures for the protection of documents from counterfeiting. The traditional design variables of foil based diffractive OVDs are shown to be able to be mapped to a corresponding set of design parameters for reflective optical micro mirror array (OMMA) devices. The greatly increased depth characteristics of micro mirror array OVDs provides an opportunity for directly printing the OVD microstructure onto the security document in-line with the normal printing process. The micro mirror array OVD architecture therefore eliminates the need for hot stamping foil as the carrier of the OVD information, thereby reducing costs. The origination of micro mirror array devices via a palette based data format and a combination electron beam lithography and photolithography techniques is discussed via an artwork example and experimental tests. Finally the application of the technology to the design of a generic class of devices which have the interesting property of allowing for both application and customer specific OVD image encoding and data encoding at the end user stage of production is described. Because of the end user nature of the image and data encoding process these devices are particularly well suited to ID document applications and for this reason we refer this new OVD concept as biometric OVD technology.

Filter arrays

Science.gov (United States)

Page, Ralph H.; Doty, Patrick F.

2017-08-01

The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

Synthesis and optical properties modulation of ZnO/Eu2O3 nanocable arrays

Science.gov (United States)

Yang, Lei; She, Yajuan; Zhao, Shihua; Yue, Shihai; Wang, Qian; Hu, Aiping; Zhang, Wei

2010-11-01

White-light-emitting materials have attracted considerable attention because of their applications, such as large-surface emitting devices and displays. However, simply mixing nanoparticles would result in uneven color. Nanocables are expected to improve the chemical stability and color uniformity. Herein we demonstrate the synthesis of Eu2O3/ZnO nanocable arrays embedded in anodic alumina template via a versatile, simple, and cheap method. In order to control the composition of the cable with low cost, a two-step synthesis including an electric field deposition and a sol-gel template approach is used to fabricate the nanocable. The product is investigated by x-ray powder diffraction, transmission electron microscopy, selected area electron diffraction, and photoluminescence (PL) spectrum. The results show that ordered Eu2O3/ZnO nanocable arrays with an average inside diameter of 20-40 nm and wall thickness of 20-40 nm were prepared. By adjusting the excitation wavelength, change of the emitting color of the cables from blue to white could be obtained. Energy and charge transfer were found by investigating the electronic transition and recombination in the PL process. These arrays are promising for applications in display, white phosphors, and ultraviolet detectors owing to the special optical properties. And this method may be of much significance in the synthesis of nanocables with the controllable composition.

Theory of tailorable optical response of two-dimensional arrays of plasmonic nanoparticles at dielectric interfaces.

Science.gov (United States)

Sikdar, Debabrata; Kornyshev, Alexei A

2016-09-22

Two-dimensional arrays of plasmonic nanoparticles at interfaces are promising candidates for novel optical metamaterials. Such systems materialise from 'top-down' patterning or 'bottom-up' self-assembly of nanoparticles at liquid/liquid or liquid/solid interfaces. Here, we present a comprehensive analysis of an extended effective quasi-static four-layer-stack model for the description of plasmon-resonance-enhanced optical responses of such systems. We investigate in detail the effects of the size of nanoparticles, average interparticle separation, dielectric constants of the media constituting the interface, and the nanoparticle position relative to the interface. Interesting interplays of these different factors are explored first for normally incident light. For off-normal incidence, the strong effects of the polarisation of light are found at large incident angles, which allows to dynamically tune the reflectance spectra. All the predictions of the theory are tested against full-wave simulations, proving this simplistic model to be adequate within the quasi-static limit. The model takes seconds to calculate the system's optical response and makes it easy to unravel the effect of each system parameter. This helps rapid rationalization of experimental data and understanding of the optical signals from these novel 'metamaterials', optimised for light reflection or harvesting.

Tunneling effect in cavity-resonator-coupled arrays

International Nuclear Information System (INIS)

Ma Hua; Xu Zhuo; Qu Shao-Bo; Zhang Jie-Qiu; Wang Jia-Fu; Liang Chang-Hong

2013-01-01

The quantum tunneling effect (QTE) in a cavity-resonator-coupled (CRC) array was analytically and numerically investigated. The underlying mechanism was interpreted by treating electromagnetic waves as photons, and then was generalized to acoustic waves and matter waves. It is indicated that for the three kinds of waves, the QTE can be excited by cavity resonance in a CRC array, resulting in sub-wavelength transparency through the narrow splits between cavities. This opens up opportunities for designing new types of crystals based on CRC arrays, which may find potential applications such as quantum devices, micro-optic transmission, and acoustic manipulation. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Vision communications based on LED array and imaging sensor

Science.gov (United States)

Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

BINARY: an optical freezing array for assessing temperature and time dependence of heterogeneous ice nucleation

Directory of Open Access Journals (Sweden)

C. Budke

2015-02-01

Full Text Available A new optical freezing array for the study of heterogeneous ice nucleation in microliter-sized droplets is introduced, tested and applied to the study of immersion freezing in aqueous Snomax® suspensions. In the Bielefeld Ice Nucleation ARraY (BINARY ice nucleation can be studied simultaneously in 36 droplets at temperatures down to −40 °C (233 K and at cooling rates between 0.1 and 10 K min−1. The droplets are separated from each other in individual compartments, thus preventing a Wegener–Bergeron–Findeisen type water vapor transfer between droplets as well as avoiding the seeding of neighboring droplets by formation and surface growth of frost halos. Analysis of freezing and melting occurs via an automated real-time image analysis of the optical brightness of each individual droplet. As an application ice nucleation in water droplets containing Snomax® at concentrations from 1 ng mL−1 to 1 mg mL−1 was investigated. Using different cooling rates, a small time dependence of ice nucleation induced by two different classes of ice nucleators (INs contained in Snomax® was detected and the corresponding heterogeneous ice nucleation rate coefficient was quantified. The observed time dependence is smaller than those of other types of INs reported in the literature, suggesting that the BINARY setup is suitable for quantifying time dependence for most other INs of atmospheric interest, making it a useful tool for future investigations.

BINARY: an optical freezing array for assessing temperature and time dependence of heterogeneous ice nucleation

Science.gov (United States)

Budke, C.; Koop, T.

2015-02-01

A new optical freezing array for the study of heterogeneous ice nucleation in microliter-sized droplets is introduced, tested and applied to the study of immersion freezing in aqueous Snomax® suspensions. In the Bielefeld Ice Nucleation ARraY (BINARY) ice nucleation can be studied simultaneously in 36 droplets at temperatures down to -40 °C (233 K) and at cooling rates between 0.1 and 10 K min-1. The droplets are separated from each other in individual compartments, thus preventing a Wegener-Bergeron-Findeisen type water vapor transfer between droplets as well as avoiding the seeding of neighboring droplets by formation and surface growth of frost halos. Analysis of freezing and melting occurs via an automated real-time image analysis of the optical brightness of each individual droplet. As an application ice nucleation in water droplets containing Snomax® at concentrations from 1 ng mL-1 to 1 mg mL-1 was investigated. Using different cooling rates, a small time dependence of ice nucleation induced by two different classes of ice nucleators (INs) contained in Snomax® was detected and the corresponding heterogeneous ice nucleation rate coefficient was quantified. The observed time dependence is smaller than those of other types of INs reported in the literature, suggesting that the BINARY setup is suitable for quantifying time dependence for most other INs of atmospheric interest, making it a useful tool for future investigations.

Time-resolved optical spectrometer based on a monolithic array of high-precision TDCs and SPADs

Science.gov (United States)

Tamborini, Davide; Markovic, Bojan; Di Sieno, Laura; Contini, Davide; Bassi, Andrea; Tisa, Simone; Tosi, Alberto; Zappa, Franco

2013-12-01

We present a compact time-resolved spectrometer suitable for optical spectroscopy from 400 nm to 1 μm wavelengths. The detector consists of a monolithic array of 16 high-precision Time-to-Digital Converters (TDC) and Single-Photon Avalanche Diodes (SPAD). The instrument has 10 ps resolution and reaches 70 ps (FWHM) timing precision over a 160 ns full-scale range with a Differential Non-Linearity (DNL) better than 1.5 % LSB. The core of the spectrometer is the application-specific integrated chip composed of 16 pixels with 250 μm pitch, containing a 20 μm diameter SPAD and an independent TDC each, fabricated in a 0.35 μm CMOS technology. In front of this array a monochromator is used to focus different wavelengths into different pixels. The spectrometer has been used for fluorescence lifetime spectroscopy: 5 nm spectral resolution over an 80 nm bandwidth is achieved. Lifetime spectroscopy of Nile blue is demonstrated.

Plasmonic enhancement of a silicon-vacancy center in a nanodiamond crystal

Science.gov (United States)

Meng, Xiang; Liu, Shang; Dadap, Jerry I.; Osgood, Richard M.

2017-06-01

This work reports a rigorous and comprehensive three-dimensional electromagnetic computation to investigate and design photoluminescence enhancement from a single silicon-vacancy center (SVC) in a nanodiamond crystal embedded in various metallic nanoantennae, each having a different geometry. The study demonstrates how each antenna design enhances the photoluminescence of SVCs in diamond. In particular, our report discusses how the 2D or 3D curvature of the nanoantenna and the control of the local environment of the SVC can lead to significant field enhancement of its optical field. Our calculated optimal photoluminescence for each design enhances the emission intensity by 15 -300 × that of a single SVC without antenna. The enhancement mechanisms are investigated using four representative structures that can be fabricated under feasible and realistic growth conditions, i.e., spherical-, nanorod-, nanodisk-dimer, and bow-tie nanoantennae. These results demonstrate a method for rationally designing arbitrary metallic nanoantenna/emitter assemblies to achieve optimal SVC photoluminescence.

Smart X-ray optics

International Nuclear Information System (INIS)

Michette, A G; Pfauntsch, S J; Sahraei, S; Shand, M; Morrison, G R; Hart, D; Vojnovic, B; Stevenson, T; Parkes, W; Dunare, C; Willingale, R; Feldman, C; Button, T; Zhang, D; Rodriguez-Sanmartin, D; Wang, H

2009-01-01

This paper describes reflective adaptive/active optics for applications including studies of biological radiation damage. The optics work on the polycapillary principle, but use arrays of channels in thin silicon. For optimum performance the x-rays should reflect once off a channel wall in each of two successive arrays. This reduces aberrations since then the Abbe sine condition is approximately satisfied. Adaptivity is achieved by flexing the arrays via piezo actuation, providing further aberration reduction and controllable focal length.

High energy erbium laser end-pumped by a laser diode bar array coupled to a Nonimaging Optic Concentrator

OpenAIRE

Tanguy , Eric; Feugnet , Gilles; Pocholle , Jean-Paul; Blondeau , R.; Poisson , M.A.; Duchemin , J.P.

1998-01-01

International audience; A high energy Er3+, Yb3+:glass laser end pumped by a laser diode array emitting at 980 nm coupled to a Nonimaging Optic Concentrator (NOC) is demonstrated. Energy up to 100 mJ and a 16% slope efficiency are achieved in a plano-plano laser cavity. The energy transfer coefficient from Yb3+ to Er3+ is estimated by a new method.

Large-area, high-intensity PV arrays for systems using dish concentrating optics

Energy Technology Data Exchange (ETDEWEB)

Ward, J.S.; Duda, A.; Zweibel, K.; Coutts, T.J. [National Renewable Energy Lab., Golden, CO (United States)

1998-09-01

In this paper, the authors report on efforts to fabricate monolithic interconnected modules (MIMs) using III-V semiconductors with bandgaps appropriate for the terrestrial solar spectrum. The small size of the component cells comprising the MIM allows for operation at extremely high flux densities and relaxes the requirement for a small spot size to be generated by the optics. This makes possible a PV option for the large dish concentrator systems that have been developed by the solar thermal community for use with Stirling engines. Additionally, the highly effective back-surface reflector integrated into the MIM design is an effective tool for thermal management of the array. Development of this technology would radically alter the projections for PV manufacturing capacity because of the potential for extremely high power generation per unit area of semiconductor material.

Health monitoring of unmanned aerial vehicle based on optical fiber sensor array

Science.gov (United States)

Luo, Yuxiang; Shen, Jingshi; Shao, Fei; Guo, Chunhui; Yang, Ning; Zhang, Jiande

2017-10-01

The unmanned aerial vehicle (UAV) in flight needs to face the complicated environment, especially to withstand harsh weather conditions, such as the temperature and pressure. Compared with conventional sensors, fiber Bragg grating (FBG) sensor has the advantages of small size, light weight, high reliability, high precision, anti-electromagnetic interference, long lift-span, moistureproof and good resistance to causticity. It's easy to be embedded in composite structural components of UAVs. In the paper, over 1000 FBG sensors distribute regularly on a wide range of UAVs body, combining wavelength division multiplexing (WDM), time division multiplexing (TDM) and multichannel parallel architecture. WDM has the advantage of high spatial resolution. TDM has the advantage of large capacity and wide range. It is worthful to constitute a sensor network by different technologies. For the signal demodulation of FBG sensor array, WDM works by means of wavelength scanning light sources and F-P etalon. TDM adopts the technology of optical time-domain reflectometry. In order to demodulate efficiently, the most proper sensor multiplex number with some reflectivity is given by the curves fitting. Due to the regular array arrangement of FBG sensors on the UAVs, we can acquire the health state of UAVs in the form of 3D visualization. It is helpful to master the information of health status rapidly and give a real-time health evaluation.

Development of the optical system for the SST-1M telescope of the Cherenkov Telescope Array observatory

CERN Document Server

Ostrowski, Michael; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Curyło, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, Ł.; Grudzińska, M.; Heller, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandat, D.; Marszałek, A.; Michałowski, J.; Moderski, R.; Montaruli, T.; Neronov, A.; Niemiec, J.; Paśko, P.; Pech, M.; Porcelli, A.; Prandini, E.; Pueschel, E.; Rajda, P.; Rameez, M.; Schioppa, E. jr; Schovanek, P.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Troyano Pujadas, I.; Walter, R.; Wiȩcek, M.; Zagdański, A.; Ziȩtara, K.; Żychowski, P.; Barciński, T.; Karczewski, M.; Kukliński, J. Nicolau; Płatos, Ł.; Rataj, M.; Wawer, P.; Wawrzaszek, R.

2016-01-01

The prototype of a Davies-Cotton small size telescope (SST-1M) has been designed and developed by a consortium of Polish and Swiss institutions and proposed for the Cherenkov Telescope Array (CTA) observatory. The main purpose of the optical system is to focus the Cherenkov light emitted by extensive air showers in the atmosphere onto the focal plane detectors. The main component of the system is a dish consisting of 18 hexagonal mirrors with a total effective collection area of 6.47 m2 (including the shadowing and estimated mirror reflectivity). Such a solution was chosen taking into account the analysis of the Cherenkov light propagation and based on optical simulations. The proper curvature and stability of the dish is ensured by the mirror alignment system and the isostatic interface to the telescope structure. Here we present the design of the optical subsystem together with the performance measurements of its components.

Thermo-optical vacuum testing of IRNSS laser retroreflector array qualification model

Science.gov (United States)

Porcelli, L.; Boni, A.; Ciocci, E.; Contessa, S.; Dell'Agnello, S.; Delle Monache, G.; Intaglietta, N.; Martini, M.; Mondaini, C.; Patrizi, G.; Salvatori, L.; Tibuzzi, M.; Lops, C.; Cantone, C.; Tuscano, P.; Maiello, M.; Venkateswaran, R.; Chakraborty, P.; Ramana Reddy, C. V.; Sriram, K. V.

2017-09-01

We describe the activities performed by SCF_Lab (Satellite/lunar/GNSS laser ranging/altimetry and cube/microsat Characterization Facilities Laboratory) of INFN-LNF for the thermo-optical vacuum testing activity of a IRNSS (Indian Regional Navigation Satellite System) LRA (Laser Retroreflector Array), under contract for ISRO-LEOS. To our knowledge, this is the first publication on the characterization of the optical performance of an LRA operating at about 36,000 km altitude (typical of regional GNSS segments, namely QZSS, COMPASS-G) executed in fully representative, carefully lab-simulated space conditions. In particular, this is the only such publication concerning IRNSS. Since laser ranging to its altitude is more challenging than to GNSS altitudes (from about 19,100 km for GLONASS to about 23,200 km for Galileo), comparative measurements were long awaited by ILRS (International Laser Ranging Service) and we present measurements of the absolute laser return to ground stations of the ILRS in terms of lidar OCS (Optical Cross Section) at the IRNSS relevant value of velocity aberration, in turn derived from measurements of the full FFDP (Far Field Diffraction Pattern) over a very large range of velocity aberrations. These measurements were acquired: (i) on a full-size qualification model of a IRNSS CCR (Cube Corner Retroreflector) LRA that ISRO-LEOS provided to INFN-LNF; (ii) during the lab-simulation of a 1/4 orbit segment, in which the LRA CCRs are exposed to the perturbation of the sun heat at varying angles, from grazing incidence (90° with respect to the direction perpendicular to the plane of array), up to the perpendicular to the LRA, with a same time variation consistent with the actual space orbit. In this 1/4 orbit condition, the LRA experiences potentially large thermal degradations of the OCS, depending on the detailed thermal and mechanical design of the LRA. Since all GNSS constellations have different LRA designs or configurations, this is another

Multiparallel Three-Dimensional Optical Microscopy

Science.gov (United States)

Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

2010-01-01

Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

Control of light scattering by nanoparticles with optically-induced magnetic responses

International Nuclear Information System (INIS)

Liu Wei; Miroshnichenko, Andrey E.; Kivshar, Yuri S.

2014-01-01

Conventional approaches to control and shape the scattering patterns of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support only electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. We discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both electric and magnetic responses, based on the interference of both spectrally separated (with different resonant wavelengths) and overlapped dipoles (with the same resonant wavelength), and also other higher-order modes. Finally, we discuss the scattering control utilizing Fano resonances associated with the magnetic responses. (topical review - plasmonics and metamaterials)

Spatiotemporal polarization modulation microscopy with a microretarder array

Science.gov (United States)

Ding, Changqin; Ulcickas, James R. W.; Simpson, Garth J.

2018-02-01

A patterned microretarder array positioned in the rear conjugate plane of a microscope enables rapid polarizationdependent nonlinear optical microscopy. The pattern introduced to the array results in periodic modulation of the polarization-state of the incident light as a function of position within the field of view with no moving parts or active control. Introduction of a single stationary optical element and a fixed polarizer into the beam of a nonlinear optical microscope enabled nonlinear optical tensor recovery, which informs on local structure and orientation. Excellent agreement was observed between the measured and predicted second harmonic generation (SHG) of z-cut quartz, selected as a test system with well-established nonlinear optical properties. Subsequent studies of spatially varying samples further support the general applicability of this relatively simple strategy for detailed polarization analysis in both conventional and nonlinear optical imaging of structurally diverse samples.

Fabrication and optical properties of TiO sub 2 nanowire arrays made by sol-gel electrophoresis deposition into anodic alumina membranes

CERN Document Server

Lin, Y; Yuan, X Y; Xie, T; Zhang, L D

2003-01-01

Ordered TiO sub 2 nanowire arrays have been successfully fabricated into the nanochannels of a porous anodic alumina membrane by sol-gel electrophoretic deposition. After annealing at 500 deg. C, the TiO sub 2 nanowire arrays and the individual nanowires were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and x-ray diffraction (XRD). SEM and TEM images show that these nanowires are dense and continuous with a uniform diameter throughout their entire length. XRD and SAED analysis together indicate that these TiO sub 2 nanowires crystallize in the anatase polycrystalline structure. The optical absorption band edge of TiO sub 2 nanowire arrays exhibits a blue shift with respect of that of the bulk TiO sub 2 owing to the quantum size effect.

Multiwall carbon nanotube microcavity arrays

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Rajib; Butt, Haider, E-mail: h.butt@bham.ac.uk [Nanotechnology Laboratory, School of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom); Rifat, Ahmmed A. [Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yetisen, Ali K.; Yun, Seok Hyun [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Dai, Qing [National Center for Nanoscience and Technology, Beijing 100190 (China)

2016-03-21

Periodic highly dense multi-wall carbon nanotube (MWCNT) arrays can act as photonic materials exhibiting band gaps in the visible regime and beyond terahertz range. MWCNT arrays in square arrangement for nanoscale lattice constants can be configured as a microcavity with predictable resonance frequencies. Here, computational analyses of compact square microcavities (≈0.8 × 0.8 μm{sup 2}) in MWCNT arrays were demonstrated to obtain enhanced quality factors (≈170–180) and narrow-band resonance peaks. Cavity resonances were rationally designed and optimized (nanotube geometry and cavity size) with finite element method. Series (1 × 2 and 1 × 3) and parallel (2 × 1 and 3 × 1) combinations of microcavities were modeled and resonance modes were analyzed. Higher order MWCNT microcavities showed enhanced resonance modes, which were red shifted with increasing Q-factors. Parallel microcavity geometries were also optimized to obtain narrow-band tunable filtering in low-loss communication windows (810, 1336, and 1558 nm). Compact series and parallel MWCNT microcavity arrays may have applications in optical filters and miniaturized optical communication devices.

Ultra-wideband WDM VCSEL arrays by lateral heterogeneous integration

Science.gov (United States)

Geske, Jon

Advancements in heterogeneous integration are a driving factor in the development of evermore sophisticated and functional electronic and photonic devices. Such advancements will merge the optical and electronic capabilities of different material systems onto a common integrated device platform. This thesis presents a new lateral heterogeneous integration technology called nonplanar wafer bonding. The technique is capable of integrating multiple dissimilar semiconductor device structures on the surface of a substrate in a single wafer bond step, leaving different integrated device structures adjacent to each other on the wafer surface. Material characterization and numerical simulations confirm that the material quality is not compromised during the process. Nonplanar wafer bonding is used to fabricate ultra-wideband wavelength division multiplexed (WDM) vertical-cavity surface-emitting laser (VCSEL) arrays. The optically-pumped VCSEL arrays span 140 nm from 1470 to 1610 nm, a record wavelength span for devices operating in this wavelength range. The array uses eight wavelength channels to span the 140 nm with all channels separated by precisely 20 nm. All channels in the array operate single mode to at least 65°C with output power uniformity of +/- 1 dB. The ultra-wideband WDM VCSEL arrays are a significant first step toward the development of a single-chip source for optical networks based on coarse WDM (CWDM), a low-cost alternative to traditional dense WDM. The CWDM VCSEL arrays make use of fully-oxidized distributed Bragg reflectors (DBRs) to provide the wideband reflectivity required for optical feedback and lasing across 140 rim. In addition, a novel optically-pumped active region design is presented. It is demonstrated, with an analytical model and experimental results, that the new active-region design significantly improves the carrier uniformity in the quantum wells and results in a 50% lasing threshold reduction and a 20°C improvement in the peak

Matter-wave scattering and guiding by atomic arrays

International Nuclear Information System (INIS)

Vaishnav, J. Y.; Walls, J. D.; Apratim, M.; Heller, E. J.

2007-01-01

We investigate the possibility that linear arrays of atoms can guide matter waves, much as fiber optics guide light. We model the atomic line as a quasi-one-dimensional array of s-wave point scatterers embedded in two-dimensions. Our theoretical study reveals how matter-wave guiding arises from the interplay of scattering phenomena with bands and conduction along the array. We discuss the conditions under which a straight or curved array of atoms can guide a beam focused at one end of the array

Halbach arrays in precision motion control

Energy Technology Data Exchange (ETDEWEB)

Trumper, D.L.; Williams, M.E. [Massachusetts Institute of Technology, Cambridge, MA (United States)

1995-02-01

The Halbach array was developed for use as an optical element in particle accelerators. Following up on a suggestion from Klaus Halbach, the authors have investigated the utility of such arrays as the permanent magnet structure for synchronous machines in cartesian, polar, and cylindrical geometries. Their work has focused on the design of a novel Halbach array linear motor for use in a magnetic suspension stage for photolithography. This paper presents the details of the motor design and its force and power characteristics.

Fibre optic microarrays.

Science.gov (United States)

Walt, David R

2010-01-01

This tutorial review describes how fibre optic microarrays can be used to create a variety of sensing and measurement systems. This review covers the basics of optical fibres and arrays, the different microarray architectures, and describes a multitude of applications. Such arrays enable multiplexed sensing for a variety of analytes including nucleic acids, vapours, and biomolecules. Polymer-coated fibre arrays can be used for measuring microscopic chemical phenomena, such as corrosion and localized release of biochemicals from cells. In addition, these microarrays can serve as a substrate for fundamental studies of single molecules and single cells. The review covers topics of interest to chemists, biologists, materials scientists, and engineers.

An integral field spectrograph utilizing mirrorlet arrays

Science.gov (United States)

Chamberlin, Phillip C.; Gong, Qian

2016-09-01

An integral field spectrograph (IFS) has been developed that utilizes a new and novel optical design to observe two spatial dimensions simultaneously with one spectral dimension. This design employs an optical 2-D array of reflecting and focusing mirrorlets. This mirrorlet array is placed at the imaging plane of the front-end telescope to generate a 2-D array of tiny spots replacing what would be the slit in a traditional slit spectrometer design. After the mirrorlet in the optical path, a grating on a concave mirror surface will image the spot array and provide high-resolution spectrum for each spatial element at the same time; therefore, the IFS simultaneously obtains the 3-D data cube of two spatial and one spectral dimensions. The new mirrorlet technology is currently in-house and undergoing laboratory testing at NASA Goddard Space Flight Center. Section 1 describes traditional classes of instruments that are used in Heliophysics missions and a quick introduction to the new IFS design. Section 2 discusses the details of the most generic mirrorlet IFS, while section 3 presents test results of a lab-based instrument. An example application to a Heliophysics mission to study solar eruptive events in extreme ultraviolet wavelengths is presented in section 4 that has high spatial resolution (0.5 arc sec pixels) in the two spatial dimensions and high spectral resolution (66 mÅ) across a 15 Å spectral window. Section 4 also concludes with some other optical variations that could be employed on the more basic IFS for further capabilities of this type of instrument.

An Integral Field Spectrograph Utilizing Mirrorlet Arrays

Science.gov (United States)

Chamberlin, Phillip C.; Gong, Qian

2016-01-01

An integral field spectrograph (IFS) has been developed that utilizes a new and novel optical design to observe two spatial dimensions simultaneously with one spectral dimension. This design employs an optical 2-D array of reflecting and focusing mirrorlets. This mirrorlet array is placed at the imaging plane of the front-end telescope to generate a 2-D array of tiny spots replacing what would be the slit in a traditional slit spectrometer design. After the mirrorlet in the optical path, a grating on a concave mirror surface will image the spot array and provide high-resolution spectrum for each spatial element at the same time; therefore, the IFS simultaneously obtains the 3-D data cube of two spatial and one spectral dimensions. The new mirrorlet technology is currently in-house and undergoing laboratory testing at NASA Goddard Space Flight Center. Section 1 describes traditional classes of instruments that are used in Heliophysics missions and a quick introduction to the new IFS design. Section 2 discusses the details of the most generic mirrorlet IFS, while section 3 presents test results of a lab-based instrument. An example application to a Heliophysics mission to study solar eruptive events in extreme ultraviolet wavelengths is presented in section 4 that has high spatial resolution (0.5 arc sec pixels) in the two spatial dimensions and high spectral resolution (66 m) across a 15 spectral window. Section 4 also concludes with some other optical variations that could be employed on the more basic IFS for further capabilities of this type of instrument.

X-ray focusing using capillary arrays

International Nuclear Information System (INIS)

Nugent, K.A.; Chapman, H.N.

1990-01-01

A new form of X-ray focusing device based on glass capillary arrays is presented. Theoretical and experimental results for array of circular capillaries and theoretical and computational results for square hole capillaries are given. It is envisaged that devices such as these will find wide applications in X-ray optics as achromatic condensers and collimators. 3 refs., 4 figs

Field programmable gate array-based real-time optical Doppler tomography system for in vivo imaging of cardiac dynamics in the chick embryo

DEFF Research Database (Denmark)

Thrane, Lars; Larsen, Henning Engelbrecht; Norozi, Kambiz

2009-01-01

efficient and compact implementation by combining the conversion to an analytic signal with a pulse shaping function without the need for extra resources as compared to the Hilbert transform method. The conversion of the analytic signal to amplitude and phase is done by use of the coordinate rotation......We demonstrate a field programmable gate-array-based real-time optical Doppler tomography system. A complex-valued bandpass filter is used for the first time in optical coherence tomography signal processing to create the analytic signal. This method simplifies the filter design, and allows...

Thermoelastic expansion vs. piezoelectricity for high-frequency, 2-D arrays.

Science.gov (United States)

Buma, Takashi; Spisar, Monica; O'Donnell, Matthew

2003-08-01

Optical generation using the thermoelastic effect has traditionally suffered from low conversion efficiency. We previously demonstrated increased efficiency of nearly 20 dB with an optical absorbing layer consisting of a mixture of polydimethylsiloxane (PDMS) and carbon black spin coated onto a glass microscope slide. In this paper we show that the radiated power from a black PDMS film is comparable to a 20 MHz piezoelectric two-dimensional (2-D) array element. Furthermore, we predict that a thermoelastic array element can produce similar acoustic power levels compared to ideal piezoelectric 2-D array elements at frequencies in the 100 MHz regime. We believe these results show that thermoelastic generation of ultrasound is a promising alternative to piezoelectricity for high-frequency, 2-D arrays.

Fabrication and Optical Characterization of Silicon Nanostructure Arrays by Laser Interference Lithography and Metal-Assisted Chemical Etching

Directory of Open Access Journals (Sweden)

P. Heydari

2014-10-01

Full Text Available In this paper metal-assisted chemical etching has been applied to pattern porous silicon regions and silicon nanohole arrays in submicron period simply by using positive photoresist as a mask layer. In order to define silicon nanostructures, Metal-assisted chemical etching (MaCE was carried out with silver catalyst. Provided solution (or materiel in combination with laser interference lithography (LIL fabricated different reproducible pillars, holes and rhomboidal structures. As a result, Submicron patterning of porous areas and nanohole arrays on Si substrate with a minimum feature size of 600nm was achieved. Measured reflection spectra of the samples present different optical characteristics which is dependent on the shape, thickness of metal catalyst and periodicity of the structure. These structures can be designed to reach a photonic bandgap in special range or antireflection layer in energy harvesting applications. The resulted reflection spectra of applied method are comparable to conventional expensive and complicated dry etching techniques.

Wide-field two-dimensional multifocal optical-resolution photoacoustic computed microscopy

Science.gov (United States)

Xia, Jun; Li, Guo; Wang, Lidai; Nasiriavanaki, Mohammadreza; Maslov, Konstantin; Engelbach, John A.; Garbow, Joel R.; Wang, Lihong V.

2014-01-01

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technique that directly images optical absorption in tissue at high spatial resolution. To date, the majority of OR-PAM systems are based on single focused optical excitation and ultrasonic detection, limiting the wide-field imaging speed. While one-dimensional multifocal OR-PAM (1D-MFOR-PAM) has been developed, the potential of microlens and transducer arrays has not been fully realized. Here, we present the development of two-dimensional multifocal optical-resolution photoacoustic computed microscopy (2D-MFOR-PACM), using a 2D microlens array and a full-ring ultrasonic transducer array. The 10 × 10 mm2 microlens array generates 1800 optical foci within the focal plane of the 512-element transducer array, and raster scanning the microlens array yields optical-resolution photoacoustic images. The system has improved the in-plane resolution of a full-ring transducer array from ≥100 µm to 29 µm and achieved an imaging time of 36 seconds over a 10 × 10 mm2 field of view. In comparison, the 1D-MFOR-PAM would take more than 4 minutes to image over the same field of view. The imaging capability of the system was demonstrated on phantoms and animals both ex vivo and in vivo. PMID:24322226

Optical Interconnection Via Computer-Generated Holograms

Science.gov (United States)

Liu, Hua-Kuang; Zhou, Shaomin

1995-01-01

Method of free-space optical interconnection developed for data-processing applications like parallel optical computing, neural-network computing, and switching in optical communication networks. In method, multiple optical connections between multiple sources of light in one array and multiple photodetectors in another array made via computer-generated holograms in electrically addressed spatial light modulators (ESLMs). Offers potential advantages of massive parallelism, high space-bandwidth product, high time-bandwidth product, low power consumption, low cross talk, and low time skew. Also offers advantage of programmability with flexibility of reconfiguration, including variation of strengths of optical connections in real time.

Gallium-based avalanche photodiode optical crosstalk

International Nuclear Information System (INIS)

Blazej, Josef; Prochazka, Ivan; Hamal, Karel; Sopko, Bruno; Chren, Dominik

2006-01-01

Solid-state single photon detectors based on avalanche photodiode are getting more attention in various areas of applied physics: optical sensors, quantum key distribution, optical ranging and Lidar, time-resolved spectroscopy, X-ray laser diagnostics, and turbid media imaging. Avalanche photodiodes specifically designed for single photon counting semiconductor avalanche structures have been developed on the basis of various materials: Si, Ge, GaP, GaAsP, and InGaP/InGaAs at the Czech Technical University in Prague during the last 20 years. They have been tailored for numerous applications. Trends in demand are focused on detection array construction recently. Even extremely small arrays containing a few cells are of great importance for users. Electrical crosstalk between individual gating and quenching circuits and optical crosstalk between individual detecting cells are serious limitation for array design and performance. Optical crosstalk is caused by the parasitic light emission of the avalanche which accompanies the photon detection process. We have studied in detail the optical emission of the avalanche photon counting structure in the silicon- and gallium-based photodiodes. The timing properties and spectral distribution of the emitted light have been measured for different operating conditions to quantify optical crosstalk. We conclude that optical crosstalk is an inherent property of avalanche photodiode operated in Geiger mode. The only way to minimize optical crosstalk in avalanche photodiode array is to build active quenching circuit with minimum response time

Fiber optical assembly for fluorescence spectrometry

Science.gov (United States)

Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

2010-12-07

A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Energy Technology Data Exchange (ETDEWEB)

DeVetter, Brent M.; Bernacki, Bruce E.; Bennett, Wendy D.; Schemer-Kohrn, Alan; Alvine, Kyle J.

2017-01-01

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances—collective charge density oscillations on the surface of the nanoparticle—in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-IR was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

Molecular diodes in optical rectennas

Science.gov (United States)

Duché, David; Palanchoke, Ujwol; Terracciano, Luigi; Dang, Florian-Xuan; Patrone, Lionel; Le Rouzo, Judikael; Balaban, Téodore Silviu; Alfonso, Claude; Charai, Ahmed; Margeat, Olivier; Ackermann, Jorg; Gourgon, Cécile; Simon, Jean-Jacques; Escoubas, Ludovic

2016-09-01

The photo conversion efficiencies of the 1st and 2nd generat ion photovoltaic solar cells are limited by the physical phenomena involved during the photo-conversion processes. An upper limit around 30% has been predicted for a monojunction silicon solar cell. In this work, we study 3rd generation solar cells named rectenna which could direct ly convert visible and infrared light into DC current. The rectenna technology is at odds with the actual photovoltaic technologies, since it is not based on the use of semi-conducting materials. We study a rectenna architecture consist ing of plasmonic nano-antennas associated with rectifying self assembled molecular diodes. We first opt imized the geometry of plasmonic nano-antennas using an FDTD method. The optimal antennas are then realized using a nano-imprint process and associated with self assembled molecular diodes in 11- ferrocenyl-undecanethiol. Finally, The I(V) characterist ics in darkness of the rectennas has been carried out using an STM. The molecular diodes exhibit averaged rect ification ratios of 5.

Large scale biomimetic membrane arrays

DEFF Research Database (Denmark)

Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

2009-01-01

To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO2 laser micro......-structured 8 x 8 aperture partition arrays with average aperture diameters of 301 +/- 5 mu m. We addressed the electro-physical properties of the lipid bilayers established across the micro-structured scaffold arrays by controllable reconstitution of biotechnological and physiological relevant membrane...... peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays...

Low power consumption 4-channel variable optical attenuator array based on planar lightwave circuit technique

International Nuclear Information System (INIS)

Ren Mei-Zhen; Zhang Jia-Shun; An Jun-Ming; Wang Yue; Wang Liang-Liang; Li Jian-Guang; Wu Yuan-Da; Yin XiaoJie; Hu Xiong-Wei

2017-01-01

The power consumption of a variable optical attenuator (VOA) array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis. The simulation results showed that the power consumption reduces as the depth of the heat-insulating grooves is deeper, the up-cladding is thinner, the down-cladding is thicker, and the width of the cladding ridge is narrower. The materials component and thickness of the electrodes were also optimized to guarantee the driving voltage under 5 V. The power consumption was successfully reduced to as low as 155 mW at an attenuation of 30 dB in the experiment. (paper)

PROSPECTS FOR THE DEVELOPMENT OF PHASED ANTENNA ARRAYS

Directory of Open Access Journals (Sweden)

A. P. Dzuba

2013-01-01

Full Text Available This article describes the main achievements in the development of phased antenna arrays (par in the past decade. Provides an overview of the most famous systems based on the PAR and PAR based on MMIC technology - PAR in radar stations, PAR to control the laser and optical beams. The existing options for the design of the PAR:ferroelectric antenna array; plasma antenna with electronic scanning; reflective grating on 100-mm semiconductor wafers; wideband antenna arrays with aperture; antenna arrays with digital beam forming.

Tomographic array

International Nuclear Information System (INIS)

1976-01-01

A tomographic array with the following characteristics is described. An X-ray screen serving as detector is placed before a photomultiplier tube which itself is placed in front of a television camera connected to a set of image processors. The detector is concave towards the source and is replacable. Different images of the object are obtained simultaneously. Optical fibers and lenses are used for transmission within the system

Using a Semiconductor-to-Metal Transition to Control Optical Transmission through Subwavelength Hole Arrays

Directory of Open Access Journals (Sweden)

E. U. Donev

2008-01-01

Full Text Available We describe a simple configuration in which the extraordinary optical transmission effect through subwavelength hole arrays in noble-metal films can be switched by the semiconductor-to-metal transition in an underlying thin film of vanadium dioxide. In these experiments, the transition is brought about by thermal heating of the bilayer film. The surprising reverse hysteretic behavior of the transmission through the subwavelength holes in the vanadium oxide suggest that this modulation is accomplished by a dielectric-matching condition rather than plasmon coupling through the bilayer film. The results of this switching, including the wavelength dependence, are qualitatively reproduced by a transfer matrix model. The prospects for effecting a similar modulation on a much faster time scale by using ultrafast laser pulses to trigger the semiconductor-to-metal transition are also discussed.

A self-assembled three-dimensional cloak in the visible

KAUST Repository

Mü hlig, Stefan; Cunningham, Alastair; Dintinger, José ; Farhat, Mohamed; Hasan, Shakeeb Bin; Scharf, Toralf; Bü rgi, Thomas; Lederer, Falk; Rockstuhl, Carsten

2013-01-01

An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object. Such fabrication approach constitutes a further important step towards real world applications of cloaking; leaving the realm of curiosity. The cloak and the way it was fabricated opens an avenue for many spectacular nanooptical applications such as non-disturbing sensors and photo-detectors, highly efficient solar cells, or optical nanoantenna arrays with strongly suppressed cross-talk to mention only a few. Our results rely on the successful combination of concepts from various disciplines, i.e. chemistry, material science, and plasmonics. Consequently, this work will stimulate these fields by unraveling new paths for future research.

A self-assembled three-dimensional cloak in the visible

KAUST Repository

Mühlig, Stefan

2013-08-07

An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object. Such fabrication approach constitutes a further important step towards real world applications of cloaking; leaving the realm of curiosity. The cloak and the way it was fabricated opens an avenue for many spectacular nanooptical applications such as non-disturbing sensors and photo-detectors, highly efficient solar cells, or optical nanoantenna arrays with strongly suppressed cross-talk to mention only a few. Our results rely on the successful combination of concepts from various disciplines, i.e. chemistry, material science, and plasmonics. Consequently, this work will stimulate these fields by unraveling new paths for future research.

Optical interconnects

CERN Document Server

Chen, Ray T

2006-01-01

This book describes fully embedded board level optical interconnect in detail including the fabrication of the thin-film VCSEL array, its characterization, thermal management, the fabrication of optical interconnection layer, and the integration of devices on a flexible waveguide film. All the optical components are buried within electrical PCB layers in a fully embedded board level optical interconnect. Therefore, we can save foot prints on the top real estate of the PCB and relieve packaging difficulty reduced by separating fabrication processes. To realize fully embedded board level optical

Squeezing terahertz light into nanovolumes: Nanoantenna enhanced terahertz spectroscopy (NETS) of semiconductor quantum dots

KAUST Repository

Toma, Andrea

2015-01-14

Terahertz spectroscopy has vast potentialities in sensing a broad range of elementary excitations (e.g., collective vibrations of molecules, phonons, excitons, etc.). However, the large wavelength associated with terahertz radiation (about 300 μm at 1 THz) severely hinders its interaction with nano-objects, such as nanoparticles, nanorods, nanotubes, and large molecules of biological relevance, practically limiting terahertz studies to macroscopic ensembles of these compounds, in the form of thick pellets of crystallized molecules or highly concentrated solutions of nanomaterials. Here we show that chains of terahertz dipole nanoantennas spaced by nanogaps of 20 nm allow retrieving the spectroscopic signature of a monolayer of cadmium selenide quantum dots, a significant portion of the signal arising from the dots located within the antenna nanocavities. A Fano-like interference between the fundamental antenna mode and the phonon resonance of the quantum dots is observed, accompanied by an absorption enhancement factor greater than one million. NETS can find immediate applications in terahertz spectroscopic studies of nanocrystals and molecules at extremely low concentrations. Furthermore, it shows a practicable route toward the characterization of individual nano-objects at these frequencies.

Energy transfer, orbital angular momentum, and discrete current in a double-ring fiber array

International Nuclear Information System (INIS)

Alexeyev, C. N.; Volyar, A. V.; Yavorsky, M. A.

2011-01-01

We study energy transfer and orbital angular momentum of supermodes in a double-ring array of evanescently coupled monomode optical fibers. The structure of supermodes and the spectra of their propagation constants are obtained. The geometrical parameters of the array, at which the energy is mostly confined within the layers, are determined. The developed method for finding the supermodes of concentric arrays is generalized for the case of multiring arrays. The orbital angular momentum carried by a supermode of a double-ring array is calculated. The discrete lattice current is introduced. It is shown that the sum of discrete currents over the array is a conserved quantity. The connection of the total discrete current with orbital angular momentum of discrete optical vortices is made.

Energy transfer, orbital angular momentum, and discrete current in a double-ring fiber array

Energy Technology Data Exchange (ETDEWEB)

Alexeyev, C. N.; Volyar, A. V. [Taurida National V.I. Vernadsky University, Vernadsky Prospekt, 4, Simferopol, 95007, Crimea (Ukraine); Yavorsky, M. A. [Taurida National V.I. Vernadsky University, Vernadsky Prospekt, 4, Simferopol, 95007, Crimea (Ukraine); Universite Bordeaux and CNRS, LOMA, UMR 5798, FR-33400 Talence (France)

2011-12-15

We study energy transfer and orbital angular momentum of supermodes in a double-ring array of evanescently coupled monomode optical fibers. The structure of supermodes and the spectra of their propagation constants are obtained. The geometrical parameters of the array, at which the energy is mostly confined within the layers, are determined. The developed method for finding the supermodes of concentric arrays is generalized for the case of multiring arrays. The orbital angular momentum carried by a supermode of a double-ring array is calculated. The discrete lattice current is introduced. It is shown that the sum of discrete currents over the array is a conserved quantity. The connection of the total discrete current with orbital angular momentum of discrete optical vortices is made.

Oxide-confined 2D VCSEL arrays for high-density inter/intra-chip interconnects

Science.gov (United States)

King, Roger; Michalzik, Rainer; Jung, Christian; Grabherr, Martin; Eberhard, Franz; Jaeger, Roland; Schnitzer, Peter; Ebeling, Karl J.

1998-04-01

We have designed and fabricated 4 X 8 vertical-cavity surface-emitting laser (VCSEL) arrays intended to be used as transmitters in short-distance parallel optical interconnects. In order to meet the requirements of 2D, high-speed optical links, each of the 32 laser diodes is supplied with two individual top contacts. The metallization scheme allows flip-chip mounting of the array modules junction-side down on silicon complementary metal oxide semiconductor (CMOS) chips. The optical and electrical characteristics across the arrays with device pitch of 250 micrometers are quite homogeneous. Arrays with 3 micrometers , 6 micrometers and 10 micrometers active diameter lasers have been investigated. The small devices show threshold currents of 600 (mu) A, single-mode output powers as high as 3 mW and maximum wavelength deviations of only 3 nm. The driving characteristics of all arrays are fully compatible to advanced 3.3 V CMOS technology. Using these arrays, we have measured small-signal modulation bandwidths exceeding 10 GHz and transmitted pseudo random data at 8 Gbit/s channel over 500 m graded index multimode fiber. This corresponds to a data transmission rate of 256 Gbit/s per array of 1 X 2 mm2 footprint area.

Novel optics for conditioning neutron beams. II Focussing neutrons with a 'lobster-eye' optic

International Nuclear Information System (INIS)

Allman, B.E.; Cimmino, A.; Griffin, S.L.; Klein, A.G.; Nugent, K.A.

1998-01-01

Square-channel capillary, or 'Lobster-eye' arrays have been shown to be the optimum geometry for array optics. This configuration leads to a novel class of conditioning devices for X-ray and neutron beams. We present the first results of the focussing of neutrons with a Pb glass square-channel array. (authors)

Integrated ZnO nanotube arrays as efficient dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Xi, Y., E-mail: yxi6@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Wu, W.Z.; Fang, H. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Hu, C.G. [Department of Applied Physics, Chongqing University, Chongqing 400044 (China)

2012-07-15

Highlights: Black-Right-Pointing-Pointer Tuning the reaction parameters, we got the best reaction conditions on ITO glass. Black-Right-Pointing-Pointer Introduce ZnO NTs design of photoanode featuring high aspect ratio structure. Black-Right-Pointing-Pointer The design strategy integrates the optical fibers or ITO with ZnO NTs grown. - Abstract: Zinc oxide (ZnO) is a wide band gap semiconducting material and has been considered as an alternative material in dye-sensitized solar cell (DSSC) applications. A high-performance nanotube (NT) photoanode must have a large surface area for dye adsorption in order to enhance conversion efficiency. In this work, the way of hydrothermally grown ZnO NT arrays on the indium tin oxide (ITO) substrate is presented by utilizing a systematic study. By adjusting the hydrothermal reaction parameters, we attained the optimizing reaction conditions on the ITO substrate. Moreover, ZnO NT arrays are introduced as a photoanode on various substrates, such as optical fiber and ITO glass, for DSSCs applications. We took the contrast test with conversion efficiency of the DSSC based on ZnO NT arrays versus ZnO nanowire arrays on the ITO substrate, which the DSSC based on ZnO NT arrays shows significantly enhanced power conversion efficiency. Furthermore, the conversion efficiency of DSSC based on the ZnO NT arrays grown on an optical fiber substrate is enhanced up to 1.44%.

Active phase correction of high resolution silicon photonic arrayed waveguide gratings.

Science.gov (United States)

Gehl, M; Trotter, D; Starbuck, A; Pomerene, A; Lentine, A L; DeRose, C

2017-03-20

Arrayed waveguide gratings provide flexible spectral filtering functionality for integrated photonic applications. Achieving narrow channel spacing requires long optical path lengths which can greatly increase the footprint of devices. High index contrast waveguides, such as those fabricated in silicon-on-insulator wafers, allow tight waveguide bends which can be used to create much more compact designs. Both the long optical path lengths and the high index contrast contribute to significant optical phase error as light propagates through the device. Therefore, silicon photonic arrayed waveguide gratings require active or passive phase correction following fabrication. Here we present the design and fabrication of compact silicon photonic arrayed waveguide gratings with channel spacings of 50, 10 and 1 GHz. The largest device, with 11 channels of 1 GHz spacing, has a footprint of only 1.1 cm2. Using integrated thermo-optic phase shifters, the phase error is actively corrected. We present two methods of phase error correction and demonstrate state-of-the-art cross-talk performance for high index contrast arrayed waveguide gratings. As a demonstration of possible applications, we perform RF channelization with 1 GHz resolution. Additionally, we generate unique spectral filters by applying non-zero phase offsets calculated by the Gerchberg Saxton algorithm.

Carbon nanotube array actuators

International Nuclear Information System (INIS)

Geier, S; Mahrholz, T; Wierach, P; Sinapius, M

2013-01-01

Experimental investigations of highly vertically aligned carbon nanotubes (CNTs), also known as CNT-arrays, are the main focus of this paper. The free strain as result of an active material behavior is analyzed via a novel experimental setup. Previous test experiences of papers made of randomly oriented CNTs, also called Bucky-papers, reveal comparably low free strain. The anisotropy of aligned CNTs promises better performance. Via synthesis techniques like chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD), highly aligned arrays of multi-walled carbon nanotubes (MWCNTs) are synthesized. Two different types of CNT-arrays are analyzed, morphologically first, and optically tested for their active characteristics afterwards. One type of the analyzed arrays features tube lengths of 750–2000 μm with a large variety of diameters between 20 and 50 nm and a wave-like CNT-shape. The second type features a maximum, almost uniform, length of 12 μm and a constant diameter of 50 nm. Different CNT-lengths and array types are tested due to their active behavior. As result of the presented tests, it is reported that the quality of orientation is the most decisive property for excellent active behavior. Due to their alignment, CNT-arrays feature the opportunity to clarify the actuation mechanism of architectures made of CNTs. (paper)

DSP-Based Focusing over Optical Fiber Using Time Reversal

DEFF Research Database (Denmark)

Piels, Molly; Porto da Silva, Edson; Estaran Tolosa, Jose Manuel

2014-01-01

A time-reversal array in multimode fiber is proposed for lossless switching using passive optical splitters. Numerical investigations are performed, and a two-transmitter array that routes a 3GBd QPSK signal through the physical layer is demonstrated experimentally.......A time-reversal array in multimode fiber is proposed for lossless switching using passive optical splitters. Numerical investigations are performed, and a two-transmitter array that routes a 3GBd QPSK signal through the physical layer is demonstrated experimentally....

Remoting alternatives for a multiple phased-array antenna network

Science.gov (United States)

Shi, Zan; Foshee, James J.

2001-10-01

airplane. Included in these alternatives will be the use of optical modules as the true time delay in the phased array antennas and using a fiber optic bus from the centralized control to drive the optical modules.

Response Characterization of a Fiber Optic Sensor Array with Dye-Coated Planar Waveguide for Detection of Volatile Organic Compounds

Directory of Open Access Journals (Sweden)

Jae-Sung Lee

2014-07-01

Full Text Available We have developed a multi-array side-polished optical-fiber gas sensor for the detection of volatile organic compound (VOC gases. The side-polished optical-fiber coupled with a polymer planar waveguide (PWG provides high sensitivity to alterations in refractive index. The PWG was fabricated by coating a solvatochromic dye with poly(vinylpyrrolidone. To confirm the effectiveness of the sensor, five different sensing membranes were fabricated by coating the side-polished optical-fiber using the solvatochromic dyes Reinhardt’s dye, Nile red, 4-aminophthalimide, 4-amino-N-methylphthalimide, and 4-(dimethylaminocinnamaldehyde, which have different polarities that cause changes in the effective refractive index of the sensing membrane owing to evanescent field coupling. The fabricated gas detection system was tested with five types of VOC gases, namely acetic acid, benzene, dimethylamine, ethanol, and toluene at concentrations of 1, 2,…,10 ppb. Second-regression and principal component analyses showed that the response properties of the proposed VOC gas sensor were linearly shifted bathochromically, and each gas showed different response characteristics.

Infrared laser transillumination CT imaging system using parallel fiber arrays and optical switches for finger joint imaging

Science.gov (United States)

Sasaki, Yoshiaki; Emori, Ryota; Inage, Hiroki; Goto, Masaki; Takahashi, Ryo; Yuasa, Tetsuya; Taniguchi, Hiroshi; Devaraj, Balasigamani; Akatsuka, Takao

2004-05-01

The heterodyne detection technique, on which the coherent detection imaging (CDI) method founds, can discriminate and select very weak, highly directional forward scattered, and coherence retaining photons that emerge from scattering media in spite of their complex and highly scattering nature. That property enables us to reconstruct tomographic images using the same reconstruction technique as that of X-Ray CT, i.e., the filtered backprojection method. Our group had so far developed a transillumination laser CT imaging method based on the CDI method in the visible and near-infrared regions and reconstruction from projections, and reported a variety of tomographic images both in vitro and in vivo of biological objects to demonstrate the effectiveness to biomedical use. Since the previous system was not optimized, it took several hours to obtain a single image. For a practical use, we developed a prototype CDI-based imaging system using parallel fiber array and optical switches to reduce the measurement time significantly. Here, we describe a prototype transillumination laser CT imaging system using fiber-optic based on optical heterodyne detection for early diagnosis of rheumatoid arthritis (RA), by demonstrating the tomographic imaging of acrylic phantom as well as the fundamental imaging properties. We expect that further refinements of the fiber-optic-based laser CT imaging system could lead to a novel and practical diagnostic tool for rheumatoid arthritis and other joint- and bone-related diseases in human finger.

Micro-array collimators for X-rays and neutrons

International Nuclear Information System (INIS)

Cimmino, A.; Allman, B.E.; Klein, A.G.; Bastie, P.

1998-08-01

The authors describe the fabrication techniques of novel, compact optical elements for collimating and/or focusing beams of X-rays or thermal neutrons. These optical elements are solid composite arrays consisting of regular stacks of alternating micro-foils, analogous in action to Soller slit collimators, but up to three orders of magnitude smaller. The arrays are made of alternating metals with suitable refractive indices for reflection and/or absorption of the specific radiation. In one implementation, the arrays are made of stacked micro-foils of transmissive elements (Al, Cu) coated and/or electroplated with absorbing elements (Gd, Cd), which are repeatedly rolled or drawn and restacked to achieve the required collimation parameters. The authors present results of these collimators using both X-rays and neutrons. The performance of the collimating element is limited only by the choice of micro-foil materials and the uniformity of their interfaces

Black GE based on crystalline/amorphous core/shell nanoneedle arrays

Science.gov (United States)

Javey, Ali; Chueh, Yu-Lun; Fan, Zhiyong

2014-03-04

Direct growth of black Ge on low-temperature substrates, including plastics and rubber is reported. The material is based on highly dense, crystalline/amorphous core/shell Ge nanoneedle arrays with ultrasharp tips (.about.4 nm) enabled by the Ni catalyzed vapor-solid-solid growth process. Ge nanoneedle arrays exhibit remarkable optical properties. Specifically, minimal optical reflectance (<1%) is observed, even for high angles of incidence (.about.75.degree.) and for relatively short nanoneedle lengths (.about.1 .mu.m). Furthermore, the material exhibits high optical absorption efficiency with an effective band gap of .about.1 eV. The reported black Ge can have important practical implications for efficient photovoltaic and photodetector applications on nonconventional substrates.

Contact CMOS imaging of gaseous oxygen sensor array.

Science.gov (United States)

Daivasagaya, Daisy S; Yao, Lei; Yi Yung, Ka; Hajj-Hassan, Mohamad; Cheung, Maurice C; Chodavarapu, Vamsy P; Bright, Frank V

2011-10-01

We describe a compact luminescent gaseous oxygen (O 2 ) sensor microsystem based on the direct integration of sensor elements with a polymeric optical filter and placed on a low power complementary metal-oxide semiconductor (CMOS) imager integrated circuit (IC). The sensor operates on the measurement of excited-state emission intensity of O 2 -sensitive luminophore molecules tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) ([Ru(dpp) 3 ] 2+ ) encapsulated within sol-gel derived xerogel thin films. The polymeric optical filter is made with polydimethylsiloxane (PDMS) that is mixed with a dye (Sudan-II). The PDMS membrane surface is molded to incorporate arrays of trapezoidal microstructures that serve to focus the optical sensor signals on to the imager pixels. The molded PDMS membrane is then attached with the PDMS color filter. The xerogel sensor arrays are contact printed on top of the PDMS trapezoidal lens-like microstructures. The CMOS imager uses a 32 × 32 (1024 elements) array of active pixel sensors and each pixel includes a high-gain phototransistor to convert the detected optical signals into electrical currents. Correlated double sampling circuit, pixel address, digital control and signal integration circuits are also implemented on-chip. The CMOS imager data is read out as a serial coded signal. The CMOS imager consumes a static power of 320 µW and an average dynamic power of 625 µW when operating at 100 Hz sampling frequency and 1.8 V DC. This CMOS sensor system provides a useful platform for the development of miniaturized optical chemical gas sensors.

Modeling Charge Collection in Detector Arrays

Science.gov (United States)

Hardage, Donna (Technical Monitor); Pickel, J. C.

2003-01-01

A detector array charge collection model has been developed for use as an engineering tool to aid in the design of optical sensor missions for operation in the space radiation environment. This model is an enhancement of the prototype array charge collection model that was developed for the Next Generation Space Telescope (NGST) program. The primary enhancements were accounting for drift-assisted diffusion by Monte Carlo modeling techniques and implementing the modeling approaches in a windows-based code. The modeling is concerned with integrated charge collection within discrete pixels in the focal plane array (FPA), with high fidelity spatial resolution. It is applicable to all detector geometries including monolithc charge coupled devices (CCDs), Active Pixel Sensors (APS) and hybrid FPA geometries based on a detector array bump-bonded to a readout integrated circuit (ROIC).

Method of separation of air showers initiated by γ-quanta and protons using Cherenkov light angular characteristics in combination and angular resolution estimate for an array of several optical telescopes

International Nuclear Information System (INIS)

Anokhina, A.M.; Galkin, V.I.; Ivanenko, I.P.; Roganova, T.M.

1990-01-01

Computer simulation of optical characteristics of air showers was carried out. On the basis of multidimensional analysis of Cherenkov light angular distribution possibility is considered to distinguish γ-showers from proton showers. Also an estimate for angular resolution is given for an array of five optical telescopes situated at Mt.Aragats. 7 refs.; 10 figs.; 11 tabs

Multiband Photonic Phased-Array Antenna

Science.gov (United States)

Tang, Suning

2015-01-01

A multiband phased-array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. Crystal Research, Inc., has developed a multiband photonic antenna that is based on a high-speed, optical, true-time-delay beamformer. It is capable of simultaneously steering multiple independent radio frequency (RF) beams in less than 1,000 nanoseconds. This high steering speed is 3 orders of magnitude faster than any existing optical beamformer. Unlike other approaches, this technology uses a single controlling device per operation band, eliminating the need for massive optical switches, laser diodes, and fiber Bragg gratings. More importantly, only one beamformer is needed for all antenna elements.

Growth of GaN micro/nanolaser arrays by chemical vapor deposition.

Science.gov (United States)

Liu, Haitao; Zhang, Hanlu; Dong, Lin; Zhang, Yingjiu; Pan, Caofeng

2016-09-02

Optically pumped ultraviolet lasing at room temperature based on GaN microwire arrays with Fabry-Perot cavities is demonstrated. GaN microwires have been grown perpendicularly on c-GaN/sapphire substrates through simple catalyst-free chemical vapor deposition. The GaN microwires are [0001] oriented single-crystal structures with hexagonal cross sections, each with a diameter of ∼1 μm and a length of ∼15 μm. A possible growth mechanism of the vertical GaN microwire arrays is proposed. Furthermore, we report room-temperature lasing in optically pumped GaN microwire arrays based on the Fabry-Perot cavity. Photoluminescence spectra exhibit lasing typically at 372 nm with an excitation threshold of 410 kW cm(-2). The result indicates that these aligned GaN microwire arrays may offer promising prospects for ultraviolet-emitting micro/nanodevices.

Solid state optical microscope

Science.gov (United States)

Young, Ian T.

1983-01-01

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

Optical electronics

CERN Document Server

Yariv, Amnon

1991-01-01

This classic text introduces engineering students to the first principles of major phenomena and devices of optoelectronics and optical communication technology. Yariv's "first principles" approach employs real-life examples and extensive problems. The text includes separate chapters on quantum well and semiconductor lasers, as well as phase conjugation and its applications. Optical fiber amplification, signal and noise considerations in optical fiber systems, laser arrays and distributed feedback lasers all are covered extensively in major sections within chapters.

Fabrication of microlens arrays using a CO2-assisted embossing technique

International Nuclear Information System (INIS)

Huang, Tzu-Chien; Chan, Bin-Da; Ciou, Jyun-Kai; Yang, Sen-Yeu

2009-01-01

This paper reports a method to fabricate microlens arrays with a low processing temperature and a low pressure. The method is based on embossing a softened polymeric substrate over a mold with micro-hole arrays. Due to the effect of capillary and surface tension, microlens arrays can be formed. The embossing medium is CO 2 gas, which supplies a uniform pressing pressure so that large-area microlens arrays can be fabricated. CO 2 gas also acts as a solvent to plasticize the polymer substrates. With the special dissolving ability and isotropic pressing capacity of CO 2 gas, microlens arrays can be fabricated at a low temperature (lower than T g ) and free of thermal-induced residual stress. Such a combined mechanism of dissolving and embossing with CO 2 gas makes the fabrication of microlens arrays direct with complex processes, and is more compatible for optical usage. In the study, it is also found that the sag height of microlens changes when different CO 2 dissolving pressure and time are used. This makes it easy to fabricate microlens arrays of different geometries without using different molds. The quality, uniformity and optical property of the fabricated microlens arrays have been verified with measurements of the dimensions, surface smoothness, focal length, transmittance and light intensity through the fabricated microlens arrays

Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace

International Nuclear Information System (INIS)

Barlier-Salsi, A

2014-01-01

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace. (paper)

Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace.

Science.gov (United States)

Barlier-Salsi, A

2014-12-01

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace.

Broadband High Efficiency Fractal-Like and Diverse Geometry Silicon Nanowire Arrays for Photovoltaic Applications

Science.gov (United States)

AL-Zoubi, Omar H.

Solar energy has many advantages over conventional sources of energy. It is abundant, clean and sustainable. One way to convert solar energy directly into electrical energy is by using the photovoltaic solar cells (PVSC). Despite PVSC are becoming economically competitive, they still have high cost and low light to electricity conversion efficiency. Therefore, increasing the efficiency and reducing the cost are key elements for producing economically more competitive PVSC that would have significant impact on energy market and saving environment. A significant percentage of the PVSC cost is due to the materials cost. For that, thin films PVSC have been proposed which offer the benefits of the low amount of material and fabrication costs. Regrettably, thin film PVSC show poor light to electricity conversion efficiency because of many factors especially the high optical losses. To enhance conversion efficiency, numerous techniques have been proposed to reduce the optical losses and to enhance the absorption of light in thin film PVSC. One promising technique is the nanowire (NW) arrays in general and the silicon nanowire (SiNW) arrays in particular. The purpose of this research is to introduce vertically aligned SiNW arrays with enhanced and broadband absorption covering the entire solar spectrum while simultaneously reducing the amount of material used. To this end, we apply new concept for designing SiNW arrays based on employing diversity of physical dimensions, especially radial diversity within certain lattice configurations. In order to study the interaction of light with SiNW arrays and compute their optical properties, electromagnetic numerical modeling is used. A commercial numerical electromagnetic solver software package, high frequency structure simulation (HFSS), is utilized to model the SiNW arrays and to study their optical properties. We studied different geometries factors that affect the optical properties of SiNW arrays. Based on this study, we

Enhanced depth-of-field of an integral imaging microscope using a bifocal holographic optical element-micro lens array.

Science.gov (United States)

Kwon, Ki-Chul; Lim, Young-Tae; Shin, Chang-Won; Erdenebat, Munkh-Uchral; Hwang, Jae-Moon; Kim, Nam

2017-08-15

We propose and implement an integral imaging microscope with extended depth-of-field (DoF) using a bifocal holographic micro lens array (MLA). The properties of the two MLAs are switched via peristrophic multiplexing, where different properties of the MLA are recorded onto the single holographic optical element (HOE). The recorded MLA properties are perpendicular to each other: after the first mode is recorded, the HOE is rotated by 90° clockwise, and the second mode is recorded. The experimental results confirm that the DoF of the integral imaging microscopy system is extended successfully by using the bifocal MLA.

Quantum optics and nano-optics teaching laboratory for the undergraduate curriculum: teaching quantum mechanics and nano-physics with photon counting instrumentation

Science.gov (United States)

Lukishova, Svetlana G.

2017-08-01

At the Institute of Optics, University of Rochester (UR), we have adapted to the main challenge (the lack of space in the curriculum) by developing a series of modular 3-hour experiments and 20-min-demonstrations based on technical elective, 4-credit-hour laboratory course "Quantum Optics and Nano-Optics Laboratory" (OPT 253/OPT453/PHY434), that were incorporated into a number of required courses ranging from freshman to senior level. Rochester Monroe Community College (MCC) students also benefited from this facility that was supported by four NSF grants. MCC students carried out two 3-hour labs on photon quantum mechanics at the UR. Since 2006, total 566 students passed through the labs with lab reports submission (including 144 MCC students) and more than 250 students through lab demonstrations. In basic class OPT 253, four teaching labs were prepared on generation and characterization of entangled and single (antibunched) photons demonstrating the laws of quantum mechanics: (1) entanglement and Bell's inequalities, (2) single-photon interference (Young's double slit experiment and Mach-Zehnder interferometer), (3) confocal microscope imaging of single-emitter (colloidal nanocrystal quantum dots and NV-center nanodiamonds) fluorescence within photonic (liquid crystal photonic bandgap microcavities) or plasmonic (gold bowtie nanoantennas) nanostructures, (4) Hanbury Brown and Twiss setup. Fluorescence antibunching from nanoemitters. Students also carried out measurements of nanodiamond topography using atomic force microscopy and prepared photonic bandgap materials from cholesteric liquid crystals. Manuals, student reports, presentations, lecture materials and quizzes, as well as some NSF grants' reports are placed on a website http://www.optics.rochester.edu/workgroups/lukishova/QuantumOpticsLab/ . In 2011 UR hosted 6 professors from different US universities in three-days training of these experiments participating in the Immersion Program of the Advanced

Diode lasers and arrays

International Nuclear Information System (INIS)

Streifer, W.

1988-01-01

This paper discusses the principles of operation of III-V semiconductor diode lasers, the use of distributed feedback, and high power laser arrays. The semiconductor laser is a robust, miniature, versatile device, which directly converts electricity to light with very high efficiency. Applications to pumping solid-state lasers and to fiber optic and point-to-point communications are reviewed

MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement

Directory of Open Access Journals (Sweden)

Yonghua Qu

2014-05-01

Full Text Available The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of Optical Sensors (MLAOS, which consists of three above-canopy and nine below-canopy optical sensors that capture plant transmittance at different times of the day. Data communication between the MLAOS node is facilitated by using a ZigBee network, and the data are transmitted from the field MLAOS to a remote data server using the Internet. The choice of the electronic element and design of the MLAOS software is aimed at reducing costs and power consumption. A power consumption test showed that, when a 4000 mAH Li-ion battery is used, a maximum of 8–10 months of work can be achieved. A field experiment on a coniferous forest revealed that the CI of MLAOS may reveal a clumping effect that occurs within the canopy. In further work, measurement of the multi-scale clumping effect can be achieved by utilizing a greater number of MLAOS devices to capture the heterogeneity of the plant canopy.

Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching

Energy Technology Data Exchange (ETDEWEB)

Guo, Peijun; Weimer, Matthew S. [Department; Emery, Jonathan D.; Diroll, Benjamin T.; Chen, Xinqi; Hock, Adam S. [Department; Chang, Robert P. H.; Martinson, Alex B. F.; Schaller, Richard D.

2016-12-19

Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO2), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching.

Science.gov (United States)

Guo, Peijun; Weimer, Matthew S; Emery, Jonathan D; Diroll, Benjamin T; Chen, Xinqi; Hock, Adam S; Chang, Robert P H; Martinson, Alex B F; Schaller, Richard D

2017-01-24

Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium-tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO 2 ), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO 2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

Clinical prototype of a plastic water-equivalent scintillating fiber dosimeter array for QA applications

International Nuclear Information System (INIS)

Lacroix, Frederic; Archambault, Louis; Gingras, Luc; Guillot, Mathieu; Beddar, A. Sam; Beaulieu, Luc

2008-01-01

A clinical prototype of a scintillating fiber dosimeter array for quality assurance applications is presented. The array consists of a linear array of 29 plastic scintillation detectors embedded in a water-equivalent plastic sheet coupled to optical fibers used to guide optical photons to a charge coupled device (CCD) camera. The CCD is packaged in a light-tight, radiation-shielded housing designed for convenient transport. A custom designed connector is used to ensure reproducible mechanical positioning of the optical fibers relative to the CCD. Profile and depth dose characterization measurements are presented and show that the prototype provides excellent dose measurement reproducibility (±0.8%) in-field and good accuracy (±1.6% maximum deviation) relative to the dose measured with an IC10 ionization chamber

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

2008-01-01

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....

Two-dimensional photonic crystal arrays for polymer:fullerene solar cells.

Science.gov (United States)

Nam, Sungho; Han, Jiyoung; Do, Young Rag; Kim, Hwajeong; Yim, Sanggyu; Kim, Youngkyoo

2011-11-18

We report the application of two-dimensional (2D) photonic crystal (PC) array substrates for polymer:fullerene solar cells of which the active layer is made with blended films of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The 2D PC array substrates were fabricated by employing a nanosphere lithography technique. Two different hole depths (200 and 300 nm) were introduced for the 2D PC arrays to examine the hole depth effect on the light harvesting (trapping). The optical effect by the 2D PC arrays was investigated by the measurement of optical transmittance either in the direction normal to the substrate (direct transmittance) or in all directions (integrated transmittance). The results showed that the integrated transmittance was higher for the 2D PC array substrates than the conventional planar substrate at the wavelengths of ca. 400 nm, even though the direct transmittance of 2D PC array substrates was much lower over the entire visible light range. The short circuit current density (J(SC)) was higher for the device with the 2D PC array (200 nm hole depth) than the reference device. However, the device with the 2D PC array (300 nm hole depth) showed a slightly lower J(SC) value at a high light intensity in spite of its light harvesting effect proven at a lower light intensity.

Laser beam shaping design based on micromirror array

Science.gov (United States)

Fang, Han; Su, Bida; Liu, Jiaguo; Fan, Xiaoli; Jing, Wang

2017-10-01

In the practical application of the laser, it is necessary to use the laser beam shaping technology to shape the output beam of laser device to the uniform light intensity distribution. The shaping divergent optical system of compound eye integrator way is composed of beam expanding mirror group and lens array. Its working principle is to expand the output laser to a certain size of caliber, and then divide the beam with lens array into multiple sub beam, where the lens unit of lens array can control the divergence angle of sub beam through the design of focal length, with mutual superposition of the sub beam in far field, to make up for the nonuniformity of beam, so that the radiant exitance on the radiated surface may become uniform. In this paper, we use a reflective microlens array to realize the laser beam shaping. By through of the practical optical path model established, the ray tracing is carried out and the simulation results for single-mode Gaussian beam with noise circumstance is provided. The analysis results show that the laser beam shaping under different inputs can be effectively realized by use of microlens array. All the energy is within the signal window, with a high energy efficiency of more than 90%; The measured surface has a better uniformity, and the uniformity is better than 99.5% at 150m.

Si Wire-Array Solar Cells

Science.gov (United States)

Boettcher, Shannon

2010-03-01

Micron-scale Si wire arrays are three-dimensional photovoltaic absorbers that enable orthogonalization of light absorption and carrier collection and hence allow for the utilization of relatively impure Si in efficient solar cell designs. The wire arrays are grown by a vapor-liquid-solid-catalyzed process on a crystalline (111) Si wafer lithographically patterned with an array of metal catalyst particles. Following growth, such arrays can be embedded in polymethyldisiloxane (PDMS) and then peeled from the template growth substrate. The result is an unusual photovoltaic material: a flexible, bendable, wafer-thickness crystalline Si absorber. In this paper I will describe: 1. the growth of high-quality Si wires with controllable doping and the evaluation of their photovoltaic energy-conversion performance using a test electrolyte that forms a rectifying conformal semiconductor-liquid contact 2. the observation of enhanced absorption in wire arrays exceeding the conventional light trapping limits for planar Si cells of equivalent material thickness and 3. single-wire and large-area solid-state Si wire-array solar cell results obtained to date with directions for future cell designs based on optical and device physics. In collaboration with Michael Kelzenberg, Morgan Putnam, Joshua Spurgeon, Daniel Turner-Evans, Emily Warren, Nathan Lewis, and Harry Atwater, California Institute of Technology.

Optical technology for microwave applications V; Proceedings of the Meeting, Orlando, FL, Apr. 3-5, 1991

Science.gov (United States)

Yao, Shi-Kay

Consideration is given to light modulation technologies, wideband optical links, phased array antenna applications, radar and EW applications, and novel optoelectronic devices and technologies. Particular attention is given to wideband nonlinear optical organic external modulators, ultra-linear electrooptic modulators for microwave fiber-optic communications, coherent optical modulation for antenna remoting, a hybrid optical transmitter for microwave communication, a direct optical phase shifter for phased array systems, acoustooptic architectures for multidimensional phased-array antenna processing, generalized phased-array Bragg interaction in anisotropic crystals, analog optical processing of radio frequency signals, a wideband acoustooptic spectrometer, ring resonators for microwave optoelectronics, optical techniques for microwave monolithic circuit characterization, microwave control using a high-gain bias-free optoelectronic switch, and A/D conversion of microwave signals using a hybrid optical-electronic technique. (For individual items see A93-25727 to A93-25758)

High density micro-pyramids with silicon nanowire array for photovoltaic applications

International Nuclear Information System (INIS)

Rahman, Tasmiat; Navarro-Cía, Miguel; Fobelets, Kristel

2014-01-01

We use a metal assisted chemical etch process to fabricate silicon nanowire arrays (SiNWAs) onto a dense periodic array of pyramids that are formed using an alkaline etch masked with an oxide layer. The hybrid micro-nano structure acts as an anti-reflective coating with experimental reflectivity below 1% over the visible and near-infrared spectral regions. This represents an improvement of up to 11 and 14 times compared to the pyramid array and SiNWAs on bulk, respectively. In addition to the experimental work, we optically simulate the hybrid structure using a commercial finite difference time domain package. The results of the optical simulations support our experimental work, illustrating a reduced reflectivity in the hybrid structure. The nanowire array increases the absorbed carrier density within the pyramid by providing a guided transition of the refractive index along the light path from air into the silicon. Furthermore, electrical simulations which take into account surface and Auger recombination show an efficiency increase for the hybrid structure of 56% over bulk, 11% over pyramid array and 8.5% over SiNWAs. (paper)

Radiation-hard/high-speed parallel optical links

Energy Technology Data Exchange (ETDEWEB)

Gan, K.K., E-mail: gan@mps.ohio-state.edu [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Buchholz, P.; Heidbrink, S. [Fachbereich Physik, Universität Siegen, Siegen (Germany); Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S. [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Vogt, M.; Ziolkowski, M. [Fachbereich Physik, Universität Siegen, Siegen (Germany)

2016-09-21

We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

Heat-rejection design for large concentrating solar arrays

Science.gov (United States)

French, E. P.

1980-01-01

This paper considers the effect of heat rejection devices (radiators) on the performance and cost of large concentrating solar arrays for space application. Overall array characteristics are derived from the weight, cost, and performance of four major components; namely primary structure, optics/secondary structure, radiator, and solar panel. An ideal concentrator analysis is used to establish general cost and performance trends independent of specific array design. Both passive and heat-pipe radiation are evaluated, with an incremental cost-of-power approach used in the evaluation. Passive radiators are found to be more cost effective with silicon than with gallium arsenide (GaAs) arrays. Representative concentrating arrays have been evaluated for both near-term and advanced solar cell technology. Minimum cost of power is achieved at geometric concentration ratios in the range 2 to 6.

Coupling of single nitrogen-vacancy defect centers in diamond nanocrystals to optical antennas and photonic crystal cavities

Energy Technology Data Exchange (ETDEWEB)

Wolters, Janik; Kewes, Guenter; Schell, Andreas W.; Aichele, Thomas; Benson, Oliver [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Nuesse, Nils; Schoengen, Max; Loechel, Bernd [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Hanke, Tobias; Leitenstorfer, Alfred [Department of Physics and Center for Applied Photonics, Universitaet Konstanz, Konstanz (Germany); Bratschitsch, Rudolf [Department of Physics and Center for Applied Photonics, Universitaet Konstanz, Konstanz (Germany); Technische Universitaet Chemnitz, Institut fuer Physik, Chemnitz (Germany)

2012-05-15

We demonstrate the ability to modify the emission properties and enhance the interaction strength of single-photon emitters coupled to nanophotonic structures based on metals and dielectrics. Assembly of individual diamond nanocrystals, metal nanoparticles, and photonic crystal cavities to meta-structures is introduced. Experiments concerning controlled coupling of single defect centers in nanodiamonds to optical nanoantennas made of gold bowtie structures are reviewed. By placing one and the same emitter at various locations with high precision, a map of decay rate enhancements was obtained. Furthermore, we demonstrate the formation of a hybrid cavity quantum electrodynamics system in which a single defect center is coupled to a single mode of a gallium phosphite photonic crystal cavity. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Self-assembly and optical properties of patterned ZnO nanodot arrays

International Nuclear Information System (INIS)

Song Yijian; Zheng Maojun; Ma Li

2007-01-01

Patterned ZnO nanodot (ND) arrays and a ND-cavity microstructure were realized on an anodic alumina membrane (AAM) surface through a spin-coating sol-gel process, which benefits from the morphology and localized negative charge surface of AAM as well as the optimized sol concentration. The growth mechanism is believed to be a self-assembly process. This provides a simple approach to fabricate semiconductor quantum dot (QD) arrays and a QD-cavity system with its advantage in low cost and mass production. Strong ultra-violet emission, a multi-phonon process, and its special structure-related properties were observed in the patterned ZnO ND arrays

Diffractive optics for industrial and commercial applications

Energy Technology Data Exchange (ETDEWEB)

Turunen, J. [Joensuu Univ. (Finland); Wyrowski, F. [eds.] [Jena Univ. (Germany)

1997-12-31

The following topics were dealt with: diffractive optics, diffraction gratings, optical system design with diffractive optics, continuous-relief diffractive lenses and microlens arrays, diffractive bifocal intraocular lenses, diffractive laser resonators, diffractive optics for semiconductor lasers, diffractive elements for optical image processing, photorefractive crystals in optical measurement systems, subwavelenth-structured elements, security applications, diffractive optics for solar cells, holographic microlithography. 999 refs.

Optics of multiple ultrasharp grooves in metal

DEFF Research Database (Denmark)

Skjølstrup, Enok Johannes Haahr; Søndergaard, Thomas

2017-01-01

. When the multiple-groove array is illuminated by a plane wave the out-of-plane scattering is found to be extraordinarily large compared with the expected maximum from a geometric-optics estimate even for array widths of many wavelengths. The out-of-plane scattering is even higher per groove compared......The optics of multiple ultrasharp sub-wavelength grooves in metal is studied theoretically. Focus is on the transition from a single groove, where the scattering cross section is significant and can exceed the groove width, to infinitely many grooves in a periodic array with very low reflectance...

Solar collector array

Science.gov (United States)

Hall, John Champlin; Martins, Guy Lawrence

2015-09-06

A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

Optical sensor array platform based on polymer electronic devices

Science.gov (United States)

Koetse, Marc M.; Rensing, Peter A.; Sharpe, Ruben B. A.; van Heck, Gert T.; Allard, Bart A. M.; Meulendijks, Nicole N. M. M.; Kruijt, Peter G. M.; Tijdink, Marcel W. W. J.; De Zwart, René M.; Houben, René J.; Enting, Erik; van Veen, Sjaak J. J. F.; Schoo, Herman F. M.

2007-10-01

Monitoring of personal wellbeing and optimizing human performance are areas where sensors have only begun to be used. One of the reasons for this is the specific demands that these application areas put on the underlying technology and system properties. In many cases these sensors will be integrated in clothing, be worn on the skin, or may even be placed inside the body. This implies that flexibility and wearability of the systems is essential for their success. Devices based on polymer semiconductors allow for these demands since they can be fabricated with thin film technology. The use of thin film device technology allows for the fabrication of very thin sensors (e.g. integrated in food product packaging), flexible or bendable sensors in wearables, large area/distributed sensors, and intrinsically low-cost applications in disposable products. With thin film device technology a high level of integration can be achieved with parts that analyze signals, process and store data, and interact over a network. Integration of all these functions will inherently lead to better cost/performance ratios, especially if printing and other standard polymer technology such as high precision moulding is applied for the fabrication. In this paper we present an optical transmission sensor array based on polymer semiconductor devices made by thin film technology. The organic devices, light emitting diodes, photodiodes and selective medium chip, are integrated with classic electronic components. Together they form a versatile sensor platform that allows for the quantitative measurement of 100 channels and communicates wireless with a computer. The emphasis is given to the sensor principle, the design, fabrication technology and integration of the thin film devices.

Thermal microphotonic sensor and sensor array

Science.gov (United States)

Watts, Michael R [Albuquerque, NM; Shaw, Michael J [Tijeras, NM; Nielson, Gregory N [Albuquerque, NM; Lentine, Anthony L [Albuquerque, NM

2010-02-23

A thermal microphotonic sensor is disclosed for detecting infrared radiation using heat generated by the infrared radiation to shift the resonant frequency of an optical resonator (e.g. a ring resonator) to which the heat is coupled. The shift in the resonant frequency can be determined from light in an optical waveguide which is evanescently coupled to the optical resonator. An infrared absorber can be provided on the optical waveguide either as a coating or as a plate to aid in absorption of the infrared radiation. In some cases, a vertical resonant cavity can be formed about the infrared absorber to further increase the absorption of the infrared radiation. The sensor can be formed as a single device, or as an array for imaging the infrared radiation.

Analysis of the modal behavior of an antiguide diode laser array with Talbot filter

NARCIS (Netherlands)

van Eijk, P.D.; van Eijk, Pieter D.; Reglat, Muriel; Vassilief, Georges; Krijnen, Gijsbertus J.M.; Driessen, A.; Mouthaan, A.J.

An analysis of the filtering of the array modes in a resonant optical waveguide (ROW) array of antiguides by a diffractive spatial filter (a Talbot filter) is presented. A dispersion relation is derived for the array modes, allowing the calculation of the field distribution. The filtering is

Optical frequency-domain reflectometry using multiple wavelength-swept elements of a DFB laser array

Science.gov (United States)

DiLazaro, Tom; Nehmetallah, Georges

2017-02-01

Coherent optical frequency-domain reflectometry (C-OFDR) is a distance measurement technique with significant sensitivity and detector bandwidth advantages over normal time-of-flight methods. Although several swept-wavelength laser sources exist, many exhibit short coherence lengths, or require precision mechanical tuning components. Semiconductor distributed feedback lasers (DFBs) are advantageous as a mid-to-long range OFDR source because they exhibit a narrow linewidth and can be rapidly tuned simply via injection current. However, the sweep range of an individual DFB is thermally limited. Here, we present a novel high-resolution OFDR system that uses a compact, monolithic 12-element DFB array to create a continuous, gap-free sweep over a wide wavelength range. Wavelength registration is provided by the incorporation of a HCN gas cell and reference interferometer. The wavelength-swept spectra of the 12 DFBs are combined in post-processing to achieve a continuous total wavelength sweep of more than 40 nm (5.4 THz) in the telecommunications C-Band range.

Performance of the Multi-Spectral Solar Telescope Array. III - Optical characteristics of the Ritchey-Chretien and Cassegrain telescopes

Science.gov (United States)

Hoover, Richard B.; Baker, Phillip C.; Hadaway, James B.; Johnson, R. B.; Peterson, Cynthia; Gabardi, David R.; Walker, Arthur B., Jr.; Lindblom, J. F.; Deforest, Craig; O'Neal, R. H.

1991-12-01

The Multi-Spectral Solar Telescope Array (MSSTA), which is a sounding-rocket-borne observatory for investigating the sun in the soft X-ray/EUV and FUV regimes of the electromagnetic spectrum, utilizes single reflection multilayer coated Herschelian telescopes for wavelengths below 100 A, and five doubly reflecting multilayer coated Ritchey-Chretien and two Cassegrain telescopes for selected wavelengths in the EUV region between 100 and 1000 A. The paper discusses the interferometric alignment, testing, focusing, visible light testing, and optical performance characteristics of the Ritchey-Chretien and Cassegrain telescopes of MSSTA. A schematic diagram of the MSSTA Ritchey-Chretien telescope is presented together with diagrams of the system autocollimation testing.

Optical Array Processor: Laboratory Results

Science.gov (United States)

Casasent, David; Jackson, James; Vaerewyck, Gerard

1987-01-01

A Space Integrating (SI) Optical Linear Algebra Processor (OLAP) is described and laboratory results on its performance in several practical engineering problems are presented. The applications include its use in the solution of a nonlinear matrix equation for optimal control and a parabolic Partial Differential Equation (PDE), the transient diffusion equation with two spatial variables. Frequency-multiplexed, analog and high accuracy non-base-two data encoding are used and discussed. A multi-processor OLAP architecture is described and partitioning and data flow issues are addressed.

Engineering surface plasmon based fiber-optic sensors

International Nuclear Information System (INIS)

Dhawan, Anuj; Muth, John F.

2008-01-01

Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors

Engineering surface plasmon based fiber-optic sensors

Energy Technology Data Exchange (ETDEWEB)

Dhawan, Anuj [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States); Muth, John F. [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States)], E-mail: muth@unity.ncsu.edu

2008-04-15

Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors.

Ultrasensitive Broadband Probing of Molecular Vibrational Modes with Multifrequency Optical Antennas

Czech Academy of Sciences Publication Activity Database

Aouani, H.; Šípová, Hana; Rahmani, M.; Navarro-Cia, M.; Hegnerová, Kateřina; Homola, Jiří; Hong, M.; Maier, S. A.

2013-01-01

Roč. 7, č. 1 (2013), s. 669-675 ISSN 1936-0851 R&D Projects: GA MŠk(CZ) LH11102 Institutional support: RVO:67985882 Keywords : plasmonic * nanoantenna * vibrational spectroscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 12.033, year: 2013

Metallic nanocone array photonic substrate for high-uniformity surface deposition and optical detection of small molecules

International Nuclear Information System (INIS)

Coppe, Jean-Philippe; Xu Zhida; Chen Yi; Logan Liu, G

2011-01-01

Molecular probe arrays printed on solid surfaces such as DNA, peptide, and protein microarrays are widely used in chemical and biomedical applications especially genomic and proteomic studies (Pollack et al 1999 Nat. Genet. 23 41-6, Houseman et al 2002 Nat. Biotechnol. 20 270-4, Sauer et al 2005 Nat. Rev. Genet. 6 465-76) as well as surface imaging and spectroscopy (Mori et al 2008 Anal. Biochem. 375 223-31, Liu et al 2006 Nat. Nanotechnol. 1 47-52, Liu 2010 IEEE J. Sel. Top. Quantum Electron. 16 662-71). Unfortunately the printed molecular spots on solid surfaces often suffer low distribution uniformity due to the lingering 'coffee stain' (Deegan et al 1997 Nature 389 827-9) problem of molecular accumulations and blotches, especially around the edge of deposition spots caused by solvent evaporation and convection processes. Here we present, without any surface chemistry modification, a unique solid surface of high-aspect-ratio silver-coated silicon nanocone arrays that allows highly uniform molecular deposition and thus subsequent uniform optical imaging and spectroscopic molecular detection. Both fluorescent Rhodamine dye molecules and unlabeled oligopeptides are printed on the metallic nanocone photonic substrate surface as circular spot arrays. In comparison with the printed results on ordinary glass slides and silver-coated glass slides, not only high printing density but uniform molecular distribution in every deposited spot is achieved. The high-uniformity and repeatability of molecular depositions on the 'coffee stain'-free nanocone surface is confirmed by laser scanning fluorescence imaging and surface enhanced Raman imaging experiments. The physical mechanism for the uniform molecular deposition is attributed to the superhydrophobicity and localized pinned liquid-solid-air interface on the silver-coated silicon nanocone surface. The unique surface properties of the presented nanocone surface enabled high-density, high-uniformity probe spotting beneficial

Design of hybrid two-dimensional and three-dimensional nanostructured arrays for electronic and sensing applications

Science.gov (United States)

Ko, Hyunhyub

This dissertation presents the design of organic/inorganic hybrid 2D and 3D nanostructured arrays via controlled assembly of nanoscale building blocks. Two representative nanoscale building blocks such as carbon nanotubes (one-dimension) and metal nanoparticles (zero-dimension) are the core materials for the study of solution-based assembly of nanostructured arrays. The electrical, mechanical, and optical properties of the assembled nanostructure arrays have been investigated for future device applications. We successfully demonstrated the prospective use of assembled nanostructure arrays for electronic and sensing applications by designing flexible carbon nanotube nanomembranes as mechanical sensors, highly-oriented carbon nanotubes arrays for thin-film transistors, and gold nanoparticle arrays for SERS chemical sensors. In first section, we fabricated highly ordered carbon nanotube (CNT) arrays by tilted drop-casting or dip-coating of CNT solution on silicon substrates functionalized with micropatterned self-assembled monolayers. We further exploited the electronic performance of thin-film transistors based on highly-oriented, densely packed CNT micropatterns and showed that the carrier mobility is largely improved compared to randomly oriented CNTs. The prospective use of Raman-active CNTs for potential mechanical sensors has been investigated by studying the mechano-optical properties of flexible carbon nanotube nanomembranes, which contain freely-suspended carbon nanotube array encapsulated into ultrathin (optical waveguide properties of nano-canals. We demonstrated the ability of this SERS substrate for trace level sensing of nitroaromatic explosives by detecting down to 100 zeptogram (˜330 molecules) of DNT.

Gold Nanoantenna-Mediated Photothermal Drug Delivery from Thermosensitive Liposomes in Breast Cancer.

Science.gov (United States)

Ou, Yu-Chuan; Webb, Joseph A; Faley, Shannon; Shae, Daniel; Talbert, Eric M; Lin, Sharon; Cutright, Camden C; Wilson, John T; Bellan, Leon M; Bardhan, Rizia

2016-08-31

In this work, we demonstrate controlled drug delivery from low-temperature-sensitive liposomes (LTSLs) mediated by photothermal heating from multibranched gold nanoantennas (MGNs) in triple-negative breast cancer (TNBC) cells in vitro. The unique geometry of MGNs enables the generation of mild hyperthermia (∼42 °C) by converting near-infrared light to heat and effectively delivering doxorubicin (DOX) from the LTSLs in breast cancer cells. We confirmed the cellular uptake of MGNs by using both fluorescence confocal Z-stack imaging and transmission electron microscopy (TEM) imaging. We performed a cellular viability assay and live/dead cell fluorescence imaging of the combined therapeutic effects of MGNs with DOX-loaded LTSLs (DOX-LTSLs) and compared them with free DOX and DOX-loaded non-temperature-sensitive liposomes (DOX-NTSLs). Imaging of fluorescent live/dead cell indicators and MTT assay outcomes both demonstrated significant decreases in cellular viability when cells were treated with the combination therapy. Because of the high phase-transition temperature of NTSLs, no drug delivery was observed from the DOX-NTSLs. Notably, even at a low DOX concentration of 0.5 μg/mL, the combination treatment resulted in a higher (33%) cell death relative to free DOX (17% cell death). The results of our work demonstrate that the synergistic therapeutic effect of photothermal hyperthermia of MGNs with drug delivery from the LTSLs can successfully eradicate aggressive breast cancer cells with higher efficacy than free DOX by providing a controlled light-activated approach and minimizing off-target toxicity.

Reliability-centered maintenance for ground-based large optical telescopes and radio antenna arrays

Science.gov (United States)

Marchiori, G.; Formentin, F.; Rampini, F.

2014-07-01

In the last years, EIE GROUP has been more and more involved in large optical telescopes and radio antennas array projects. In this frame, the paper describes a fundamental aspect of the Logistic Support Analysis (LSA) process, that is the application of the Reliability-Centered Maintenance (RCM) methodology for the generation of maintenance plans for ground-based large optical telescopes and radio antennas arrays. This helps maintenance engineers to make sure that the telescopes continue to work properly, doing what their users require them to do in their present operating conditions. The main objective of the RCM process is to establish the complete maintenance regime, with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems. At the same time, a correct application of the RCM allows to increase the cost effectiveness, telescope uptime and items availability, and to provide greater understanding of the level of risk that the organization is managing. At the same time, engineers shall make a great effort since the initial phase of the project to obtain a telescope requiring easy maintenance activities and simple replacement of the major assemblies, taking special care on the accesses design and items location, implementation and design of special lifting equipment and handling devices for the heavy items. This maintenance engineering framework is based on seven points, which lead to the main steps of the RCM program. The initial steps of the RCM process consist of: system selection and data collection (MTBF, MTTR, etc.), definition of system boundaries and operating context, telescope description with the use of functional block diagrams, and the running of a FMECA to address the dominant causes of equipment failure and to lay down the Critical Items List. In the second part of the process the RCM logic is applied, which helps to determine the appropriate maintenance tasks for each identified failure mode. Once

Liquid crystal-based hydrophone arrays

Science.gov (United States)

Brodzeli, Zourab; Silvestri, Leonardo; Michie, Andrew; Chigrinov, Vladimir G.; Guo, Qi; Pozhidaev, Eugene P.; Kiselev, Alexei D.; Ladouceur, Francois

2012-09-01

We describe a fiber optic hydrophone array system that could be used for underwater acoustic surveillance applications (e.g. military, counter terrorist, and customs authorities in protecting ports and harbors), offshore production facilities or coastal approaches as well as various marine applications. In this paper, we propose a new approach to underwater sonar systems using the voltage-controlled liquid crystals and simple multiplexing method. The proposed method permits measurement of sound under water at multiple points along an optical fiber using the low cost components and standard single mode fiber, without complex interferometric measurement techniques, electronics or demodulation software.

Piezo-Phototronic Enhanced UV Sensing Based on a Nanowire Photodetector Array.

Science.gov (United States)

Han, Xun; Du, Weiming; Yu, Ruomeng; Pan, Caofeng; Wang, Zhong Lin

2015-12-22

A large array of Schottky UV photodetectors (PDs) based on vertical aligned ZnO nanowires is achieved. By introducing the piezo-phototronic effect, the performance of the PD array is enhanced up to seven times in photoreponsivity, six times in sensitivity, and 2.8 times in detection limit. The UV PD array may have applications in optoelectronic systems, adaptive optical computing, and communication. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A digital optical phase-locked loop for diode lasers based on field programmable gate array

Science.gov (United States)

Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui

2012-09-01

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad2 and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications

KAUST Repository

Yue, Weisheng

2014-01-01

Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration of the electromagnetic field in the slit between the holes. The geometrical shape and separation of the holes in these pairs of nanoholes affected the intensity of the transmission and the wavelength of resonance. Changing the geometrical shapes of these nanohole pairs from triangles to circles to squares leads to increased transmission intensity as well as red-shifting resonance wavelengths. The performance of bridged nanohole pairs as a plasmonic sensor was investigated. The bridged nanohole pairs were able to distinguish methanol, olive oil and microscope immersion oil for the different surface plasmon resonance in transmission spectra. Numerical simulation results were in agreement with experimental observations. © 2014 the Partner Organisations.

The Fuge Tube Diode Array Spectrophotometer

Science.gov (United States)

Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.

2008-01-01

We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

Method and apparatus for synthesis of arrays of DNA probes

Science.gov (United States)

Cerrina, Francesco; Sussman, Michael R.; Blattner, Frederick R.; Singh-Gasson, Sangeet; Green, Roland

2002-04-23

The synthesis of arrays of DNA probes sequences, polypeptides, and the like is carried out using a patterning process on an active surface of a substrate. An image is projected onto the active surface of the substrate utilizing an image former that includes a light source that provides light to a micromirror device comprising an array of electronically addressable micromirrors, each of which can be selectively tilted between one of at least two positions. Projection optics receives the light reflected from the micromirrors along an optical axis and precisely images the micromirrors onto the active surface of the substrate, which may be used to activate the surface of the substrate. The first level of bases may then be applied to the substrate, followed by development steps, and subsequent exposure of the substrate utilizing a different pattern of micromirrors, with further repeats until the elements of a two dimensional array on the substrate surface have an appropriate base bound thereto. The micromirror array can be controlled in conjunction with a DNA synthesizer supplying appropriate reagents to a flow cell containing the active substrate to control the sequencing of images presented by the micromirror array in coordination of the reagents provided to the substrate.

Biological applications of an LCoS-BASED PROGRAMMABLE ARRAY MICROSCOPE (PAM)

NARCIS (Netherlands)

Hagen, G.M.; Caarls, W.; Thomas, M.; Hill, A.; Lidke, K.A.; Rieger, B.; Fritsch, C.; Van Geest, B.; Jovin, T.M.; Arndt-Jovin, D.J.

2007-01-01

We report on a new generation, commercial prototype of a programmable array optical sectioning fluorescence microscope (PAM) for rapid, light efficient 3D imaging of living specimens. The stand-alone module, including light source(s) and detector(s), features an innovative optical design and a

Excitation of high density surface plasmon polariton vortex array

Science.gov (United States)

Kuo, Chun-Fu; Chu, Shu-Chun

2018-06-01

This study proposes a method to excite surface plasmon polariton (SPP) vortex array of high spatial density on metal/air interface. A doughnut vector beam was incident at four rectangularly arranged slits to excite SPP vortex array. The doughnut vector beam used in this study has the same field intensity distribution as the regular doughnut laser mode, TEM01* mode, but a different polarization distribution. The SPP vortex array is achieved through the matching of both polarization state and phase state of the incident doughnut vector beam with the four slits. The SPP field distribution excited in this study contains stable array-distributed time-varying optical vortices. Theoretical derivation, analytical calculation and numerical simulation were used to discuss the characteristics of the induced SPP vortex array. The period of the SPP vortex array induced by the proposed method had only half SPPs wavelength. In addition, the vortex number in an excited SPP vortex array can be increased by enlarging the structure.

Design and Deployment of a Multichroic Polarimeter Array on the Atacama Cosmology Telescope

Science.gov (United States)

Datta, R.; Austermann, J.; Beall, J. A.; Becker, D.; Coughlin, K. P.; Duff, S. M.; Gallardo, P.A.; Grace, E.; Hasselfield, M.; Henderson, S. W.;

Design and Deployment of a Multichroic Polarimeter Array on the Atacama Cosmology Telescope

Science.gov (United States)

Datta, R.; Austermann, J.; Beall, J. A.; Becker, D.; Coughlin, K. P.; Duff, S. M.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; Koopman, B. J.; Lanen, J. V.; Li, D.; McMahon, J.; Munson, C. D.; Nati, F.; Niemack, M. D.; Page, L.; Pappas, C. G.; Salatino, M.; Schmitt, B. L.; Schillaci, A.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

2016-08-01

We present the design and the preliminary on-sky performance with respect to beams and passbands of a multichroic polarimeter array covering the 90 and 146 GHz cosmic microwave background bands and its enabling broad-band optical system recently deployed on the Atacama Cosmology Telescope (ACT). The constituent pixels are feedhorn-coupled multichroic polarimeters fabricated at NIST. This array is coupled to the ACT telescope via a set of three silicon lenses incorporating novel broad-band metamaterial anti-reflection coatings. This receiver represents the first multichroic detector array deployed for a CMB experiment and paves the way for the extensive use of multichroic detectors and broad-band optical systems in the next generation of CMB experiments.

Nonlinear Optical Fiber Arrays for Limiting Application

National Research Council Canada - National Science Library

Khoo, Iam-Choon

2006-01-01

.... Measurements show that they possess desirable nonlinear optical such as low-freezing pint, non-volatile, transparent for low light level and possess large effective nonlinear absorption coefficients...

The optical design concept of SPICA-SAFARI

Science.gov (United States)

Jellema, Willem; Kruizinga, Bob; Visser, Huib; van den Dool, Teun; Pastor Santos, Carmen; Torres Redondo, Josefina; Eggens, Martin; Ferlet, Marc; Swinyard, Bruce; Dohlen, Kjetil; Griffin, Doug; Gonzalez Fernandez, Luis Miguel; Belenguer, Tomas; Matsuhara, Hideo; Kawada, Mitsunobu; Doi, Yasuo

2012-09-01

The Safari instrument on the Japanese SPICA mission is a zodiacal background limited imaging spectrometer offering a photometric imaging (R ≍ 2), and a low (R = 100) and medium spectral resolution (R = 2000 at 100 μm) spectroscopy mode in three photometric bands covering the 34-210 μm wavelength range. The instrument utilizes Nyquist sampled filled arrays of very sensitive TES detectors providing a 2’x2’ instantaneous field of view. The all-reflective optical system of Safari is highly modular and consists of an input optics module containing the entrance shutter, a calibration source and a pair of filter wheels, followed by an interferometer and finally the camera bay optics accommodating the focal-plane arrays. The optical design is largely driven and constrained by volume inviting for a compact three-dimensional arrangement of the interferometer and camera bay optics without compromising the optical performance requirements associated with a diffraction- and background-limited spectroscopic imaging instrument. Central to the optics we present a flexible and compact non-polarizing Mach-Zehnder interferometer layout, with dual input and output ports, employing a novel FTS scan mechanism based on magnetic bearings and a linear motor. In this paper we discuss the conceptual design of the focal-plane optics and describe how we implement the optical instrument functions, define the photometric bands, deal with straylight control, diffraction and thermal emission in the long-wavelength limit and interface to the large-format FPA arrays at one end and the SPICA telescope assembly at the other end.

Synthesis and characterization of Mn-doped ZnO column arrays

International Nuclear Information System (INIS)

Yang Mei; Guo Zhixing; Qiu Kehui; Long Jianping; Yin Guangfu; Guan Denggao; Liu Sutian; Zhou Shijie

2010-01-01

Mn-doped ZnO column arrays were successfully synthesized by conventional sol-gel process. Effect of Mn/Zn atomic ratio and reaction time were investigated, and the morphology, tropism and optical properties of Mn-doped ZnO column arrays were characterized by SEM, XRD and photoluminescence (PL) spectroscopy. The result shows that a Mn/Zn atomic ratio of 0.1 and growth time of 12 h are the optimal condition for the preparation of densely distributed ZnO column arrays. XRD analysis shows that Mn-doped ZnO column arrays are highly c-axis oriented. As for Mn-doped ZnO column arrays, obvious increase of photoluminescence intensity is observed at the wavelength of ∼395 nm and ∼413 nm, compared to pure ZnO column arrays.

Effects of thermal annealing temperature and duration on hydrothermally grown ZnO nanorod arrays

Energy Technology Data Exchange (ETDEWEB)

Zhao, X.Q.; Kim, C.R.; Lee, J.Y.; Shin, C.M.; Heo, J.H.; Leem, J.Y. [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Obang-dong, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Ryu, H. [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Obang-dong, Gimhae, Gyeongnam 621-749 (Korea, Republic of)], E-mail: hhryu@inje.ac.kr; Chang, J.H. [Major of Nano Semiconductor, Korea Maritime University, 1 Dongsam-dong, Yeongdo-Ku, Busan 606-791 (Korea, Republic of); Lee, H.C. [Department of Mechatronics Engineering, Korea Maritime University, 1 Dongsam-dong, Yeongdo-Ku, Busan 606-791 (Korea, Republic of); Son, C.S. [Department of Electronic Materials Engineering, Silla University, Gwaebeop-dong, Sasang-gu, Busan 617-736 (Korea, Republic of); Shin, B.C.; Lee, W.J. [Department of Nano Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of); Jung, W.G. [School of Advanced Materials Engineering, Kookmin University, 861-1, Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Tan, S.T. [Institute of Microelectronics, 11 Science Park Road, Science Park II, Singapore 117685 (Singapore); Zhao, J.L. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Sun, X.W. [Institute of Microelectronics, 11 Science Park Road, Science Park II, Singapore 117685 (Singapore); School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)

2009-03-15

In this study, the effects of thermal annealing temperature and duration on ZnO nanorod arrays fabricated by hydrothermal method were investigated. The annealed ZnO/Si(1 1 1) substrate was used for ZnO nanorod array growth. The effects of annealing treatment on the structural and optical properties were investigated by scanning electron microscopy, X-ray diffraction, and room-temperature photoluminescence measurements. With the annealing temperature of 750 {sup o}C and the annealing duration of 10 min, both the structural and optical properties of the ZnO nanorod arrays improved significantly, as indicated in the X-ray diffraction and photoluminescence measurement.

Ordered InAs/InP quantum dot arrays at telecom wavelength

NARCIS (Netherlands)

Sritirawisarn, N.

2010-01-01

This dissertation demonstrates the growth and optical characterization of ordered InAs/InP quantum dot (QD) arrays grown by chemical-beam epitaxy (CBE). The creation of InAs/InP QD arrays is governed by self-organized anisotropic strain engineering of InAs/InGaAsP superlattice (SL) templates leading

The LED and fiber based calibration system for the photomultiplier array of SNO+

Science.gov (United States)

Seabra, L.; Alves, R.; Andringa, S.; Bradbury, S.; Carvalho, J.; Clark, K.; Coulter, I.; Descamps, F.; Falk, L.; Gurriana, L.; Kraus, C.; Lefeuvre, G.; Maio, A.; Maneira, J.; Mottram, M.; Peeters, S.; Rose, J.; Sinclair, J.; Skensved, P.; Waterfield, J.; White, R.; Wilson, J.; SNO+ Collaboration

2015-02-01

A new external LED/fiber light injection calibration system was designed for the calibration and monitoring of the photomultiplier array of the SNO+ experiment at SNOLAB. The goal of the calibration system is to allow an accurate and regular measurement of the photomultiplier array's performance, while minimizing the risk of radioactivity ingress. The choice in SNO+ was to use a set of optical fiber cables to convey into the detector the light pulses produced by external LEDs. The quality control was carried out using a modified test bench that was used in QC of optical fibers for TileCal/ATLAS. The optical fibers were characterized for transmission, timing and angular dispersions. This article describes the setups used for the characterization and quality control of the system based on LEDs and optical fibers and their results.

A grating coupler with a trapezoidal hole array for perfectly vertical light coupling between optical fibers and waveguides

Science.gov (United States)

Mizutani, Akio; Eto, Yohei; Kikuta, Hisao

2017-12-01

A grating coupler with a trapezoidal hole array was designed and fabricated for perfectly vertical light coupling between a single-mode optical fiber and a silicon waveguide on a silicon-on-insulator (SOI) substrate. The grating coupler with an efficiency of 53% was computationally designed at a 1.1-µm-thick buried oxide (BOX) layer. The grating coupler and silicon waveguide were fabricated on the SOI substrate with a 3.0-µm-thick BOX layer by a single full-etch process. The measured coupling efficiency was 24% for TE-polarized light at 1528 nm wavelength, which was 0.69 times of the calculated coupling efficiency for the 3.0-µm-thick BOX layer.

Fiber optical asssembly for fluorescence spectrometry

Science.gov (United States)

Piltch, Martin S.; Gray, Perry Clayton; Rubenstein, Richard

2015-08-18

System is provided for detecting the presence of an analyte of interest in a sample, said system comprising an elongated, transparent container for a sample; an excitation source in optical communication with the sample, wherein radiation from the excitation source is directed along the length of the sample, and wherein the radiation induces a signal which is emitted from the sample; and, at least two linear arrays disposed about the sample holder, each linear array comprising a plurality of optical fibers having a first end and a second end, wherein the first ends of the fibers are disposed along the length of the container and in proximity thereto; the second ends of the fibers of each array are bundled together to form a single end port.

Calibration strategies for the Cherenkov Telescope Array

Science.gov (United States)

Gaug, Markus; Berge, David; Daniel, Michael; Doro, Michele; Förster, Andreas; Hofmann, Werner; Maccarone, Maria C.; Parsons, Dan; de los Reyes Lopez, Raquel; van Eldik, Christopher

2014-08-01

The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration efforts of the different telescopes. The latter include LED-based light pulsers, and various methods and instruments to achieve a calibration of the overall optical throughput. On the array level, methods for the inter-telescope calibration and the absolute calibration of the entire observatory are being developed. Additionally, the atmosphere above the telescopes, used as a calorimeter, will be monitored constantly with state-of-the-art instruments to obtain a full molecular and aerosol profile up to the stratosphere. The aim is to provide a maximal uncertainty of 10% on the reconstructed energy-scale, obtained through various independent methods. Different types of LIDAR in combination with all-sky-cameras will provide the observatory with an online, intelligent scheduling system, which, if the sky is partially covered by clouds, gives preference to sources observable under good atmospheric conditions. Wide-field optical telescopes and Raman Lidars will provide online information about the height-resolved atmospheric extinction, throughout the field-of-view of the cameras, allowing for the correction of the reconstructed energy of each gamma-ray event. The aim is to maximize the duty cycle of the observatory, in terms of usable data, while reducing the dead time introduced by calibration activities to an absolute minimum.

Flat dielectric metasurface lens array for three dimensional integral imaging

Science.gov (United States)

Zhang, Jianlei; Wang, Xiaorui; Yang, Yi; Yuan, Ying; Wu, Xiongxiong

2018-05-01

In conventional integral imaging, the singlet refractive lens array limits the imaging performance due to its prominent aberrations. Different from the refractive lens array relying on phase modulation via phase change accumulated along the optical paths, metasurfaces composed of nano-scatters can produce phase abrupt over the scale of wavelength. In this letter, we propose a novel lens array consisting of two neighboring flat dielectric metasurfaces for integral imaging system. The aspherical phase profiles of the metasurfaces are optimized to improve imaging performance. The simulation results show that our designed 5 × 5 metasurface-based lens array exhibits high image quality at designed wavelength 865 nm.

A comparative study with a 755 nm picosecond Alexandrite laser with a diffractive lens array and a 532 nm/1064 nm Nd:YAG with a holographic optic.

Science.gov (United States)

Tanghetti Md, Emil; Jennings, John

2018-01-01

This study was performed to better understand the cutaneous effects of using a fractional picosecond laser at 755 nm with a diffractive lens array and a picosecond Nd:YAG laser at 532 mn and 1064 nm with a holographic optic. We characterized the injuries created by these devices on skin clinically and histologically over 24 hours. With this information we modeled the effects of these devices on a cutaneous target. Eight patients, representing Fitzpatrick skin types I-VI, were treated on their backs with a picosecond Alexandrite laser with a diffractive lens array, as well as a picosecond Nd:YAG laser at 532 nm and 1064 nm with a holographic optic. Photographs were taken 15 minutes and 24 hours after treatments. Punch biopsies were obtained at 24 hours and examined histologically. Treatment with the picosecond Nd:YAG laser at both 532 nm and 1064 nm with the holographic optic revealed erythema and small scatted areas of petechial hemorrhage areas immediately and in many cases at 24 hours after treatment. The 755 nm picosecond Alexandrite laser with diffractive lens array produced erythema immediately after treatment, which largely dissipated 24 hours later. Histologies revealed intra-epidermal vacuoles with all three wavelengths. Fractional picosecond Nd:YAG laser at 532 nm and 1064 nm with the holographic optic showed focal areas of dermal and intra-epidermal hemorrhage with areas of vascular damage in some patients. This study demonstrates that both fractional picosecond devices produce vacuoles in the skin, which are most likely due to areas of laser induced optical breakdown (LIOB). In the patients (skin type II-IV) we observed scatter areas of hemorrhage in the skin, due to vascular damage with the 532 nm and 1064 nm, but not with 755 nm wavelengths. Lasers Surg. Med. 50:37-44, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.