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Sample records for hollow-core photonic-crystal fiber

  1. Control of Dispersion in Hollow Core Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    The dispersion of hollow core photonic crystal fibers can be tailored by modifying a single ring of holes in the cladding. The dispersion can be lowered and flattened, or alternatively greatly increased, in a controlled manner.......The dispersion of hollow core photonic crystal fibers can be tailored by modifying a single ring of holes in the cladding. The dispersion can be lowered and flattened, or alternatively greatly increased, in a controlled manner....

  2. Highly efficient fluorescence sensing with hollow core photonic crystal fibers

    DEFF Research Database (Denmark)

    Smolka, Stephan; Barth, Michael; Benson, Oliver

    2008-01-01

    We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes.......We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes....

  3. Measuring Beam Quality of Hollow Core Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Shephard, J.D.; Roberts, John; Jones, J.D.C.

    2006-01-01

    In this paper, the authors measure the quality of the delivered beam from hollow core photonic crystal fibers (HC-PCFs). The$M^2$parameter is determined, and the near- to far-field transition is examined. The influence on these properties due to the presence of a core surround mode is evaluated.......17 for the same output beam. This highlights the need for careful consideration when measuring and describing the beam quality delivered by these novel photonic fibers....

  4. Compact and Robust Refilling and Connectorization of Hollow Core Photonic Crystal Fiber Gas Reference Cells

    Science.gov (United States)

    Poberezhskiy, Ilya Y.; Meras, Patrick; Chang, Daniel H.; Spiers, Gary D.

    2007-01-01

    This slide presentation reviews a method for refilling and connectorization of hollow core photonic crystal fiber gas reference cells. Thees hollow-core photonic crystal fiber allow optical propagation in air or vacuum and are for use as gas reference cell is proposed and demonstrated. It relies on torch-sealing a quartz filling tube connected to a mechanical splice between regular and hollow-core fibers.

  5. Low Loss and Highly Birefringent Hollow-Core Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Roberts, P. John; Williams, D.P.; Mangan, Brian J.

    2006-01-01

    A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core.......A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core....

  6. Square-lattice large-pitch hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Couny, F.; Roberts, John; Birks, T.A.

    2008-01-01

    We report on the design, fabrication and characterization of silica square-lattice hollow core photonic crystal fibers optimized for low loss guidance over an extended frequency range in the mid-IR region of the optical spectrum. The fiber's linear optical properties include an ultra-low group...... velocity dispersion and a polarization cross-coupling as low as -13.4dB over 10m of fiber....

  7. Hollow-Core Photonic Crystal Fibers for Surface-Enhanced Raman Scattering Probes

    Directory of Open Access Journals (Sweden)

    Xuan Yang

    2011-01-01

    Full Text Available Photonic crystal fiber (PCF sensors based on surface-enhanced Raman scattering (SERS have become increasingly attractive in chemical and biological detections due to the molecular specificity, high sensitivity, and flexibility. In this paper, we review the development of PCF SERS sensors with emphasis on our recent work on SERS sensors utilizing hollow-core photonic crystal fibers (HCPCFs. Specifically, we discuss and compare various HCPCF SERS sensors, including the liquid-filled HCPCF and liquid-core photonic crystal fibers (LCPCFs. We experimentally demonstrate and theoretically analyze the high sensitivity of the HCPCF SERS sensors. Various molecules including Rhodamine B, Rhodamine 6G, human insulin, and tryptophan have been tested to show the excellent performance of these fiber sensors.

  8. Laser-cooled atoms inside a hollow-core photonic-crystal fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Peyronel, Thibault

    2011-01-01

    We describe the loading of laser-cooled rubidium atoms into a single-mode hollow-core photonic-crystal fiber. Inside the fiber, the atoms are confined by a far-detuned optical trap and probed by a weak resonant beam. We describe different loading methods and compare their trade-offs in terms...... of implementation complexity and atom-loading efficiency. The most efficient procedure results in loading of ∼30,000 rubidium atoms, which creates a medium with an optical depth of ∼180 inside the fiber. Compared to our earlier study this represents a sixfold increase in the maximum achieved optical depth...

  9. Identification of Bloch-modes in hollow-core Photonic Crystal Fiber cladding

    DEFF Research Database (Denmark)

    Couny, F.; Benabid, F.; Roberts, John

    2007-01-01

    We report on the experimental visualization of the cladding Bloch-modes of a hollow-core photonic crystal fiber. Both spectral and spatial field information is extracted using the approach, which is based on measurement of the near-field and Fresnel-zone that results after propagation over a short...... length of fiber. A detailed study of the modes near the edges of the band gap shows that it is formed by the influence of three types of resonator: the glass interstitial apex, the silica strut which joins the neighboring apexes, and the air hole. The cladding electromagnetic field which survives...

  10. Design of low-loss and highly birefringent hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, Peter John; Williams, D.P.; Sabert, H.

    2006-01-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each...... feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap, thus minimizing the guided mode field intensity both within the fiber material and at material / air interfaces. A birefringent design, which involves a 2-fold symmetric arrangement of the features...

  11. Linear and nonlinear modeling of light propagation in hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, John; Lægsgaard, Jesper

    2009-01-01

    Hollow core photonic crystal fibers (HC-PCFs) find applications which include quantum and non-linear optics, gas detection and short high-intensity laser pulse delivery. Central to most applications is an understanding of the linear and nonlinear optical properties. These require careful modeling....... The intricacies of modeling various forms of HC-PCF are reviewed. An example of linear dispersion engineering, aimed at reducing and flattening the group velocity dispersion, is then presented. Finally, a study of short high intensity pulse delivery using HC-PCF in both dispersive and nonlinear (solitonic...

  12. Optical trapping and control of nanoparticles inside evacuated hollow core photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Grass, David, E-mail: david.grass@univie.ac.at; Fesel, Julian; Hofer, Sebastian G.; Kiesel, Nikolai; Aspelmeyer, Markus, E-mail: markus.aspelmeyer@univie.ac.at [Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, A-1090 Vienna (Austria)

    2016-05-30

    We demonstrate an optical conveyor belt for levitated nanoparticles over several centimeters inside both air-filled and evacuated hollow-core photonic crystal fibers (HCPCF). Detection of the transmitted light field allows three-dimensional read-out of the particle center-of-mass motion. An additional laser enables axial radiation pressure based feedback cooling over the full fiber length. We show that the particle dynamics is a sensitive local probe for characterizing the optical intensity profile inside the fiber as well as the pressure distribution along the fiber axis. In contrast to some theoretical predictions, we find a linear pressure dependence inside the HCPCF, extending over three orders of magnitude from 0.2 mbar to 100 mbar. A targeted application is the controlled delivery of nanoparticles from ambient pressure into medium vacuum.

  13. Fluorescence-based remote irradiation sensor in liquid-filled hollow-core photonic crystal fiber

    Energy Technology Data Exchange (ETDEWEB)

    Zeltner, R.; Russell, P. St.J. [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Department of Physics, University of Erlangen-Nuremberg, Guenther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Bykov, D. S.; Xie, S. [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Euser, T. G. [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2016-06-06

    We report an irradiation sensor based on a fluorescent “flying particle” that is optically trapped and propelled inside the core of a water-filled hollow-core photonic crystal fiber. When the moving particle passes through an irradiated region, its emitted fluorescence is captured by guided modes of the fiber core and so can be monitored using a filtered photodiode placed at the fiber end. The particle speed and position can be precisely monitored using in-fiber Doppler velocimetry, allowing the irradiation profile to be measured to a spatial resolution of ∼10 μm. The spectral response can be readily adjusted by appropriate choice of particle material. Using dye-doped polystyrene particles, we demonstrate detection of green (532 nm) and ultraviolet (340 nm) light.

  14. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    Science.gov (United States)

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-02

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.

  15. Research on Distributed Gas Detection Based on Hollow-core Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    Gui XIN

    2014-07-01

    Full Text Available We have demonstrated a distributed gas detection system by using hollow-core photonic crystal fiber (HC-PCF as a gas chamber. The HC-PCF gas chamber has several lateral micro- channels fabricated by the femtosecond laser. The HC-PCF is connected to the single mode fiber by thermal splicing, and gas can diffuse in hollow-core of PCF via micro-channels. Compared to the traditional gas chamber, the HC-PCF gas chamber has relatively simpler construction and quite stability. According to experiment results, the system response time of 15 s has been achieved for a 5 cm HC-PCF which has ten channels with 4mm channel distance. It would construct long sensing length fiber gas sensor that the side holes and the splicer have introduced very little loss. Thus make it possible to achieve highly sensitive sensing system without influencing the response time. By using self-reference demodulation algorithm and space division multiplexing technique, distributed gas detection system with fast response was achieved.

  16. Realization of low loss and polarization maintaining hollow core photonic crystal fibers

    DEFF Research Database (Denmark)

    Mangan, Brian Joseph; Lyngsøe, Jens Kristian; Roberts, John

    2008-01-01

    Antiresonant core wals in 7-cell hollow core fibers are used to reduce the attenuation to 9.3dB/km and create an intentionally hightly birefringent fiber with a beatlength as low as 0.2mm......Antiresonant core wals in 7-cell hollow core fibers are used to reduce the attenuation to 9.3dB/km and create an intentionally hightly birefringent fiber with a beatlength as low as 0.2mm...

  17. Detection of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core photonic crystal fiber

    Science.gov (United States)

    Tiwari, Vidhu S.; Khetani, Altaf; Monfared, Ali Momenpour T.; Smith, Brett; Anis, Hanan; Trudeau, Vance L.

    2012-03-01

    The present work explores the feasibility of using surface enhanced Raman scattering (SERS) for detecting the neurotransmitters such as glutamate (GLU) and gamma-amino butyric acid (GABA). These amino acid neurotransmitters that respectively mediate fast excitatory and inhibitory neurotransmission in the brain, are important for neuroendocrine control, and upsets in their synthesis are also linked to epilepsy. Our SERS-based detection scheme enabled the detection of low amounts of GLU (10-7 M) and GABA (10-4 M). It may complement existing techniques for characterizing such kinds of neurotransmitters that include high-performance liquid chromatography (HPLC) or mass spectrography (MS). This is mainly because SERS has other advantages such as ease of sample preparation, molecular specificity and sensitivity, thus making it potentially applicable to characterization of experimental brain extracts or clinical diagnostic samples of cerebrospinal fluid and saliva. Using hollow core photonic crystal fiber (HC-PCF) further enhanced the Raman signal relative to that in a standard cuvette providing sensitive detection of GLU and GABA in micro-litre volume of aqueous solutions.

  18. A Raman cell based on hollow core photonic crystal fiber for human breath analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Kam Kong; Zeng, Haishan, E-mail: hzeng@bccrc.ca [Imaging Unit – Integrative Oncology Department, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada and Medical Physics Program – Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Short, Michael; Lam, Stephen; McWilliams, Annette [Imaging Unit – Integrative Oncology Department, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3 (Canada)

    2014-09-15

    Purpose: Breath analysis has a potential prospect to benefit the medical field based on its perceived advantages to become a point-of-care, easy to use, and cost-effective technology. Early studies done by mass spectrometry show that volatile organic compounds from human breath can represent certain disease states of our bodies, such as lung cancer, and revealed the potential of breath analysis. But mass spectrometry is costly and has slow-turnaround time. The authors’ goal is to develop a more portable and cost effective device based on Raman spectroscopy and hollow core-photonic crystal fiber (HC-PCF) for breath analysis. Methods: Raman scattering is a photon-molecular interaction based on the kinetic modes of an analyte which offers unique fingerprint type signals that allow molecular identification. HC-PCF is a novel light guide which allows light to be confined in a hollow core and it can be filled with a gaseous sample. Raman signals generated by the gaseous sample (i.e., human breath) can be guided and collected effectively for spectral analysis. Results: A Raman-cell based on HC-PCF in the near infrared wavelength range was developed and tested in a single pass forward-scattering mode for different gaseous samples. Raman spectra were obtained successfully from reference gases (hydrogen, oxygen, carbon dioxide gases), ambient air, and a human breath sample. The calculated minimum detectable concentration of this system was ∼15 parts per million by volume, determined by measuring the carbon dioxide concentration in ambient air via the characteristic Raman peaks at 1286 and 1388 cm{sup −1}. Conclusions: The results of this study were compared to a previous study using HC-PCF to trap industrial gases and backward-scatter 514.5 nm light from them. The authors found that the method presented in this paper has an advantage to enhance the signal-to-noise ratio (SNR). This SNR advantage, coupled with the better transmission of HC-PCF in the near-IR than in the

  19. Behavior of a hollow core photonic crystal fiber under high radial pressure for downhole application

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, J., E-mail: j-sadeghi@sbu.ac.ir; Chenari, Z.; Ziaee, F. [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Latifi, H., E-mail: latifi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Department of Physics, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Santos, J. L., E-mail: josantos@fc.up.pt [INESC Porto—Instituto de Engenharia de Sistemas e Computadores do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Departamento de Física, da Faculdade de Ciências, da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

    2014-02-17

    Pressure fiber sensors play an important role in downhole high pressure measurements to withstand long term operation. The purpose of this paper is to present an application of hollow core photonic crystal fiber (HC-PCF) as a high pressure sensor head for downhole application based on dispersion variation. We used a high pressure stainless steel unit to exert pressure on the sensor. The experimental results show that different wavelengths based on sagnac loop interferometer have additive sensitivities from 5 × 10{sup −5} nm/psi at 1480 nm to 1.3 × 10{sup −3} nm/psi at 1680 nm. We developed a simulation to understand the reason for difference in sensitivity of wavelengths and also the relationship between deformation of HC-PCF and dispersion variation under pressure. For this purpose, by using the finite element method, we investigated the effect of structural variation of HC-PCF on spectral transformation of two linear polarizations under 1000 psi pressure. The simulation and experimental results show exponential decay behavior of dispersion variation from −3.4 × 10{sup −6} 1/psi to −1.3 × 10{sup −6} 1/psi and from −5 × 10{sup −6} 1/psi to −1.8 × 10{sup −6} 1/psi, respectively, which were in a good accordance with each other.

  20. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  1. 7-cell core hollow-core photonic crystal fibers with low loss in the spectral region around 2 mu m

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, B.J.; Jakobsen, C.

    2009-01-01

    Several 7 cell core hollow-core photonic crystal fibers with bandgaps in the spectral range of 1.4 μm to 2.3 μm have been fabricated. The transmission loss follows the ≈ λ−3 dependency previously reported, with a minimum measured loss of 9.5 dB/km at 1.99 μm. One fiber with a transmission loss...... of 26 dB/km at 2.3 μm is reported, which is significantly lower than the transmission loss of solid silica fibers at this wavelength....

  2. Ultrafast Mid-IR Nonlinear Optics in Gas-filled Hollow-core Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Habib, Selim

    Invention of hollow-core fiber has been proven an ideal medium to study light-gas interaction. Tight confinement of light inside hollowcore fiber allows unremitting and tailored interaction between light and gas over long distances. In this work, we used a special kind of hollowcore fiberhollow......-core anti-resonant (HC-AR) fiber to study the various nonlinear effects filled with Raman free noble gas. One of the main striking features of HC-AR fiber is that ∼99.99% light can be guided inside the central hollow-core region, which significantly enhances damage threshold level. HC-AR fiber can sustain...... be tuned by simply changing the pressure of the gas while at the same time providing extremely wide transparency ranges. In this thesis, we propose several low-loss broadband guidance HC-AR fibers and investigate soliton-plasma dynamics using HC-AR fiber filled with noble gas in the mid-IR. The combined...

  3. Acousto-optic mode coupling excited by flexural waves in simplified hollow-core photonic crystal fibers

    International Nuclear Information System (INIS)

    Zhang, Hao; Qiu, Minghui; Wu, Zhifang; Dong, Hongguang; Liu, Bo; Miao, Yinping

    2013-01-01

    We have demonstrated the formation of an acoustic grating in a simplified hollow-core photonic crystal fiber, which consists of a hollow hexagonal core and six crown-like air holes, by applying flexural acoustic waves along the fiber axis. The dependence of the resonance wavelength on the applied acoustic frequency has been acquired on the basis of the theoretical calculation of the phase matching curve; it is in good agreement with our experimental observation of the transmission spectral evolution as the applied acoustic frequency varies. Experimental results show that the acoustic grating resonance peak possesses acoustic frequency and strain dependences of 728 nm MHz −1 and −6.98 pm με −1 , respectively, based on which high-performance acousto-optic tunable filters and fiber-optic strain sensors with high sensitivity could be achieved. And furthermore, the research work presented in this paper indicates that microbending rather than physical deformation is the main physical mechanism that leads to the formation of equivalent long-period gratings, which would be of significance for developing related grating devices based on simplified hollow-core photonic crystal fibers. (paper)

  4. Broadband high-resolution multi-species CARS in gas-filled hollow-core photonic crystal fiber.

    Science.gov (United States)

    Trabold, Barbara M; Hupfer, Robert J R; Abdolvand, Amir; St J Russell, Philip

    2017-09-01

    We report the use of coherent anti-Stokes Raman spectroscopy (CARS) in gas-filled hollow-core photonic crystal fiber (HC-PCF) for trace gas detection. The long optical path-lengths yield a 60 dB increase in the signal level compared with free-space arrangements. This enables a relatively weak supercontinuum (SC) to be used as Stokes seed, along with a ns pump pulse, paving the way for broadband (>4000  cm -1 ) single-shot CARS with an unprecedented resolution of ∼100  MHz. A kagomé-style HC-PCF provides broadband guidance, and, by operating close to the pressure-tunable zero dispersion wavelength, we can ensure simultaneous phase-matching of all gas species. We demonstrate simultaneous measurement of the concentrations of multiple trace gases in a gas sample introduced into the core of the HC-PCF.

  5. Control of ultrafast pulses in a hydrogen-filled hollow-core photonic-crystal fiber by Raman coherence

    Science.gov (United States)

    Belli, F.; Abdolvand, A.; Travers, J. C.; Russell, P. St. J.

    2018-01-01

    We present the results of an experimental and numerical investigation into temporally nonlocal coherent interactions between ultrashort pulses, mediated by Raman coherence, in a gas-filled kagome-style hollow-core photonic-crystal fiber. A pump pulse first sets up the Raman coherence, creating a refractive index spatiotemporal grating in the gas that travels at the group velocity of the pump pulse. Varying the arrival time of a second, probe, pulse allows a high degree of control over its evolution as it propagates along the fiber through the grating. Of particular interest are soliton-driven effects such as self-compression and dispersive wave (DW) emission. In the experiments reported, a DW is emitted at ˜300 nm and exhibits a wiggling effect, with its central frequency oscillating periodically with pump-probe delay. The results demonstrate that a strong Raman coherence, created in a broadband guiding gas-filled kagome photonic-crystal fiber, can be used to control the nonlinear dynamics of ultrashort probe pulses, even in difficult-to-access spectral regions such as the deep and vacuum ultraviolet.

  6. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... applications, and places emphasis on the development of polarization maintaining (PM) HC-PCF. The polarization cross-coupling characteristics of PM HC-PCF are very different from those of conventional PM fibers. The former fibers have the advantage of suffering far less from stress-field fluctuations...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  7. Low-loss polarization-maintaining fusion splicing of single-mode fibers and hollow-core photonic crystal fibers, relevant for monolithic fiber laser pulse compression

    DEFF Research Database (Denmark)

    Kristensen, Jesper Toft; Houmann, Andreas; Liu, Xiaomin

    2008-01-01

    of the splicing process. We also demonstrate that the higher splice loss compromises the PM properties of the splice. Our splicing technique was successfully applied to the realization of a low-loss, environmentally stable monolithic PM fiber laser pulse compressor, enabling direct end-of-the-fiber femtosecond......We report on highly reproducible low-loss fusion splicing of polarization-maintaining single-mode fibers (PM-SMFs) and hollow-core photonic crystal fibers (HC-PCFs). The PM-SMF-to-HC-PCF splices are characterized by the loss of 0.62 ± 0.24 dB, and polarization extinction ratio of 19 ± 0.68 d...... pulse delivery...

  8. Optical frequency standard using acetylene-filled hollow-core photonic crystal fibers

    DEFF Research Database (Denmark)

    Triches, Marco; Michieletto, Mattia; Hald, Jan

    2015-01-01

    frequency instability. The locked fiber laser shows a fractional frequency instability below 4×10−12 for averaging time up to 104 s. The lock-point repeatability over more than 1 year is 1.3×10−11, corresponding to a standard deviation of 2.5 kHz. A complete experimental investigation of the light...

  9. Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

    OpenAIRE

    Bromberger, H.; Ermolov, A.; Belli, F.; Liu, H.; Calegari, F.; Chavez-Cervantes, M.; Li, M. T.; Lin, C. T.; Abdolvand, A.; Russell, P. St. J.; Cavalleri, A.; Travers, J. C.; Gierz, I.

    2015-01-01

    A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few {\\mu}J energy generate vacuum ultraviolet (VUV) radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi2Se3 with a signal to noise ratio comparable to ...

  10. Fugitive methane leak detection using mid-infrared hollow-core photonic crystal fiber containing ultrafast laser drilled side-holes

    Science.gov (United States)

    Karp, Jason; Challener, William; Kasten, Matthias; Choudhury, Niloy; Palit, Sabarni; Pickrell, Gary; Homa, Daniel; Floyd, Adam; Cheng, Yujie; Yu, Fei; Knight, Jonathan

    2016-05-01

    The increase in domestic natural gas production has brought attention to the environmental impacts of persistent gas leakages. The desire to identify fugitive gas emission, specifically for methane, presents new sensing challenges within the production and distribution supply chain. A spectroscopic gas sensing solution would ideally combine a long optical path length for high sensitivity and distributed detection over large areas. Specialty micro-structured fiber with a hollow core can exhibit a relatively low attenuation at mid-infrared wavelengths where methane has strong absorption lines. Methane diffusion into the hollow core is enabled by machining side-holes along the fiber length through ultrafast laser drilling methods. The complete system provides hundreds of meters of optical path for routing along well pads and pipelines while being interrogated by a single laser and detector. This work will present transmission and methane detection capabilities of mid-infrared photonic crystal fibers. Side-hole drilling techniques for methane diffusion will be highlighted as a means to convert hollow-core fibers into applicable gas sensors.

  11. A Gas Cell Based on Hollow-Core Photonic Crystal Fiber (PCF and Its Application for the Detection of Greenhouse Gas (GHG: Nitrous Oxide (N2O

    Directory of Open Access Journals (Sweden)

    Jonas K. Valiunas

    2016-01-01

    Full Text Available The authors report the detection of nitrous oxide gas using intracavity fiber laser absorption spectroscopy. A gas cell based on a hollow-core photonic crystal fiber was constructed and used inside a fiber ring laser cavity as an intracavity gas cell. The fiber laser in the 1.55 μm band was developed using a polarization-maintaining erbium-doped fiber as the gain medium. The wavelength of the laser was selected by a fiber Bragg grating (FBG, and it matches one of the absorption lines of the gas under investigation. The laser wavelength contained multilongitudinal modes, which increases the sensitivity of the detection system. N2O gas has overtones of the fundamental absorption bands and rovibrational transitions in the 1.55 μm band. The system was operated at room temperature and was capable of detecting nitrous oxide gas at sub-ppmv concentration level.

  12. An All-Fiber Gas Raman Light Source Based on a Hydrogen-Filled Hollow-Core Photonic Crystal Fiber Pumped with a Q-Switched Fiber Laser

    International Nuclear Information System (INIS)

    Chen Xiao-Dong; Mao Qing-He; Sun Qing; Zhao Jia-Sheng; Li Pan; Feng Su-Juan

    2011-01-01

    A gas Raman light source based on a H 2 -filled hollow-core photonic-crystal-fiber cell with a Q-switched fiber laser followed by a fiber amplifier as the Raman pump source is demonstrated. The Stokes frequency-shift lasing line is observed at 1135.7 nm with the Q-switched pump pulses at 1064.7 nm. Our experimental results show that the generated Stokes pulse is much narrower than the pump pulse, and the generated Stokes pulse duration is increased with the single pulse energy for the same duration pump pulses. For the 125 ns pump pulses with a repetition rate of 5 kHz, the Raman threshold pump energy and the conversion efficiency at the Raman threshold are 2.13 μJ and 9.82%. Moreover, by choosing narrower pump pulses, the Raman threshold pump energy may be reduced and the conversion efficiency may be improved. (fundamental areas of phenomenology(including applications))

  13. Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

    Science.gov (United States)

    Bromberger, H.; Ermolov, A.; Belli, F.; Liu, H.; Calegari, F.; Chávez-Cervantes, M.; Li, M. T.; Lin, C. T.; Abdolvand, A.; Russell, P. St. J.; Cavalleri, A.; Travers, J. C.; Gierz, I.

    2015-08-01

    A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi2Se3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials.

  14. Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

    International Nuclear Information System (INIS)

    Bromberger, H.; Liu, H.; Chávez-Cervantes, M.; Gierz, I.; Ermolov, A.; Belli, F.; Abdolvand, A.; Russell, P. St. J.; Travers, J. C.; Calegari, F.; Li, M. T.; Lin, C. T.; Cavalleri, A.

    2015-01-01

    A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi 2 Se 3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials

  15. Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

    Energy Technology Data Exchange (ETDEWEB)

    Bromberger, H., E-mail: Hubertus.Bromberger@mpsd.mpg.de; Liu, H.; Chávez-Cervantes, M.; Gierz, I. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Ermolov, A.; Belli, F.; Abdolvand, A.; Russell, P. St. J.; Travers, J. C. [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Calegari, F. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Institute for Photonics and Nanotechnologies, IFN-CNR, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Li, M. T.; Lin, C. T. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Cavalleri, A. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Clarendon Laboratory, Department of Physics, University of Oxford, Parks Rd. Oxford OX1 3PU (United Kingdom)

    2015-08-31

    A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi{sub 2}Se{sub 3} with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials.

  16. Realizing A Mid-Infrared Optically Pumped Molecular Gas Laser Inside Hollow-Core Photonic Crystal Fiber

    Science.gov (United States)

    2012-01-01

    structure resembling a star- of- David pattern can clearly be seen surrounding the hollow core region. The fiber’s hollow core is created by leaving out...O.R. Wood, An optically pumped CO2 laser. IEEE Journal of Quantum Electronics, 1972. 8(6): p. 598. 19. Schlossberg, H.R. and H.R. Fetterman

  17. Monolithic all-PM femtosecond Yb-fiber laser stabilized with a narrow-band fiber Bragg grating and pulse-compressed in a hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

    2008-01-01

    . The laser output is compressed in a spliced-on hollow-core PM photonic crystal fiber, thus providing direct end-of-the-fiber delivery of pulses of around 370 fs duration and 4 nJ energy with high mode quality. Tuning the pump power of the end amplifier of the laser allows for the control of output pulse......We report on an environmentally stable self-starting monolithic (i.e. without any free-space coupling) all-polarization-maintaining (PM) femtosecond Yb-fiber laser, stabilized against Q-switching by a narrow-band fiber Bragg grating and modelocked using a semiconductor saturable absorber mirror...

  18. Understanding the dynamics of photoionization-induced nonlinear effects and solitons in gas-filled hollow-core photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, Mohammed F.; Biancalana, Fabio [Max Planck Institute for the Science of Light, Guenther-Scharowsky Str. 1, DE-91058 Erlangen (Germany)

    2011-12-15

    We present the details of our previously formulated model [Saleh et al., Phys. Rev. Lett. 107, 203902 (2011)] that governs pulse propagation in hollow-core photonic crystal fibers filled by an ionizable gas. By using perturbative methods, we find that the photoionization process induces the opposite phenomenon of the well-known Raman self-frequency redshift of solitons in solid-core glass fibers, as was recently experimentally demonstrated [Hoelzer et al., Phys. Rev. Lett. 107, 203901 (2011)]. This process is only limited by ionization losses, and leads to a constant acceleration of solitons in the time domain with a continuous blueshift in the frequency domain. By applying the Gagnon-Belanger gauge transformation, multipeak ''inverted gravitylike'' solitary waves are predicted. We also demonstrate that the pulse dynamics shows the ejection of solitons during propagation in such fibers, analogous to what happens in conventional solid-core fibers. Moreover, unconventional long-range nonlocal interactions between temporally distant solitons, unique of gas plasma systems, are predicted and studied. Finally, the effects of higher-order dispersion coefficients and the shock operator on the pulse dynamics are investigated, showing that the conversion efficiency of resonant radiation into the deep UV can be improved via plasma formation.

  19. Widely tunable broadband deep-ultraviolet to visible wavelength generation by the cross phase modulation in a hollow-core photonic crystal fiber cladding

    International Nuclear Information System (INIS)

    Yuan, J H; Sang, X Z; Wu, Q; Yu, C X; Shen, X W; Wang, K R; Yan, B B; Teng, Y L; Farrell, G; Zhou, G Y; Xia, C M; Han, Y; Li, S G; Hou, L T

    2013-01-01

    The deep-ultraviolet (UV) to visible wavelengths are efficiently generated for the first time by the cross phase modulation (XPM) between the red-shifted solitons and the blue-shifted dispersive waves (DWs) in the fundamental guided mode of the multi-knots of a hollow-core photonic crystal fiber cladding (HC-PCFC). When the femtosecond pulses with a wavelength of 850 nm and average power of 300 mW are coupled into the knots 1–3, the conversion efficiency η uv−v of 11% and bandwidth B uv−v of 100 nm in the deep-UV region are experimentally obtained. The multi-milliwatt ultrashort pulses are tunable over the deep-UV (below 200 nm) to visible spectral region by adjusting the wavelengths of the pump pulses in different knots. It is expected that these widely tunable broadband ultrashort deep-UV–visible pulse sources could have important applications in ultrafast photonics, femtochemisty, photobiology, and UV–visible resonant Raman scattering. (letter)

  20. Hybrid photonic-crystal fiber

    DEFF Research Database (Denmark)

    Markos, Christos; Travers, John C.; Abdolvand, Amir

    2017-01-01

    This article offers an extensive survey of results obtained using hybrid photonic-crystal fibers (PCFs) which constitute one of the most active research fields in contemporary fiber optics. The ability to integrate novel and functional materials in solid- and hollow-core PCFs through various...... is reviewed from scientific and technological perspectives, focusing on how different fluids, solids, and gases can significantly extend the functionality of PCFs. The first part of this review discusses the efforts to develop tunable linear and nonlinear fiber-optic devices using PCFs infiltrated...... with various liquids, glasses, semiconductors, and metals. The second part concentrates on recent and state-of-the-art advances in the field of gas-filled hollow-core PCFs. Extreme ultrafast gas-based nonlinear optics toward light generation in the extreme wavelength regions of vacuum ultraviolet, pulse...

  1. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  2. Monolithic Yb-fiber femtosecond laser using photonic crystal fiber

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2008-01-01

    We demonstrate, both experimentally and theoretically, an environmentally stable monolithic all-PM modelocked femtosecond Yb-fiber laser, with laser output pulse compressed in a spliced-on low-loss hollow-core photonic crystal fiber. Our laser provides direct fiber-end delivery of 4 nJ pulses...

  3. Photonic Crystal Fibers

    National Research Council Canada - National Science Library

    Kristiansen, Rene E

    2005-01-01

    This report results from a contract tasking Crystal Fibre A/S as follows: Crystal Fibre will conduct research and development of large mode area, dual clad multi-core Yb-doped photonic crystal fiber...

  4. Hybrid photonic-crystal fiber

    Science.gov (United States)

    Markos, Christos; Travers, John C.; Abdolvand, Amir; Eggleton, Benjamin J.; Bang, Ole

    2017-10-01

    This article offers an extensive survey of results obtained using hybrid photonic-crystal fibers (PCFs) which constitute one of the most active research fields in contemporary fiber optics. The ability to integrate novel and functional materials in solid- and hollow-core PCFs through various postprocessing methods has enabled new directions toward understanding fundamental linear and nonlinear phenomena as well as novel application aspects, within the fields of optoelectronics, material and laser science, remote sensing, and spectroscopy. Here the recent progress in the field of hybrid PCFs is reviewed from scientific and technological perspectives, focusing on how different fluids, solids, and gases can significantly extend the functionality of PCFs. The first part of this review discusses the efforts to develop tunable linear and nonlinear fiber-optic devices using PCFs infiltrated with various liquids, glasses, semiconductors, and metals. The second part concentrates on recent and state-of-the-art advances in the field of gas-filled hollow-core PCFs. Extreme ultrafast gas-based nonlinear optics toward light generation in the extreme wavelength regions of vacuum ultraviolet, pulse propagation, and compression dynamics in both atomic and molecular gases, and novel soliton-plasma interactions are reviewed. A discussion of future prospects and directions is also included.

  5. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead....... The freedom to design the dispersion profile of the fibers is much larger and it is possible to create fibers, which support only a single spatial mode, regardless of wavelength. In comparison, the standard dispersion-shifted fibers are limited by a much lower index-contrast between the core and the cladding...... in 1996, and are today on their way to become the dominating technology within the specialty fiber field. Whether they will replace the standard fiber in the more traditional areas like telecommunication transmission, is not yet clear, but the nonlinear photonic crystal fibers are here to stay....

  6. Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre

    Science.gov (United States)

    Okaba, Shoichi; Takano, Tetsushi; Benabid, Fetah; Bradley, Tom; Vincetti, Luca; Maizelis, Zakhar; Yampol'skii, Valery; Nori, Franco; Katori, Hidetoshi

    2014-01-01

    Unlike photons, which are conveniently handled by mirrors and optical fibres without loss of coherence, atoms lose their coherence via atom–atom and atom–wall interactions. This decoherence of atoms deteriorates the performance of atomic clocks and magnetometers, and also hinders their miniaturization. Here we report a novel platform for precision spectroscopy. Ultracold strontium atoms inside a kagome-lattice hollow-core photonic crystal fibre are transversely confined by an optical lattice to prevent atoms from interacting with the fibre wall. By confining at most one atom in each lattice site, to avoid atom–atom interactions and Doppler effect, a 7.8-kHz-wide spectrum is observed for the 1S0−3P1(m=0) transition. Atoms singly trapped in a magic lattice in hollow-core photonic crystal fibres improve the optical depth while preserving atomic coherence time. PMID:24934478

  7. Hollow-core photonic band gap fibers for particle acceleration

    Directory of Open Access Journals (Sweden)

    Robert J. Noble

    2011-12-01

    Full Text Available Photonic band gap (PBG dielectric fibers with hollow cores are being studied both theoretically and experimentally for use as laser driven accelerator structures. The hollow core functions as both a longitudinal waveguide for the transverse-magnetic (TM accelerating fields and a channel for the charged particles. The dielectric surrounding the core is permeated by a periodic array of smaller holes to confine the mode, forming a photonic crystal fiber in which modes exist in frequency passbands, separated by band gaps. The hollow core acts as a defect which breaks the crystal symmetry, and so-called defect, or trapped modes having frequencies in the band gap will only propagate near the defect. We describe the design of 2D hollow-core PBG fibers to support TM defect modes with high longitudinal fields and high characteristic impedance. Using as-built dimensions of industrially made fibers, we perform a simulation analysis of prototype PBG fibers with dimensions appropriate for speed-of-light TM modes.

  8. Realization of 7-cell hollow-core photonic crystal fibers with low loss in the region between 1.4 μm and 2.3 μm

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, Brian Joseph; Jakobsen, C.

    2009-01-01

    Five 7-cell core hollow-core fibers with photonic bandgap spectral positions between 1.4 μm and 2.3 μm were fabricated. The loss follows the ≈ λ-3 dependency previously reported [1] with a minimum measured loss of 9.5 dB/km at 1992 nm.......Five 7-cell core hollow-core fibers with photonic bandgap spectral positions between 1.4 μm and 2.3 μm were fabricated. The loss follows the ≈ λ-3 dependency previously reported [1] with a minimum measured loss of 9.5 dB/km at 1992 nm....

  9. Monolithic femtosecond Yb-fiber laser with photonic crystal fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    We demonstrate a monolithic stable SESAM-modelocked self-starting Yb-fiber laser. A novel PM all-solid photonic bandgap fiber is used for intra-cavity of dispersion management. The ex-cavity final pulse compression is performed in a spliced-on PM hollow-core photonic crystal fiber. The laser...... directly delivers 9 nJ pulses of 275 fs duration with pulse repetition of 26.7MHz....

  10. Light and gas confinement in hollow-core photonic crystal fibre based photonic microcells

    DEFF Research Database (Denmark)

    Benabid, F.; Roberts, John; Couny, F.

    2009-01-01

    guides via a photonic bandgap and the other guides by virtue of an inhibited coupling between core and cladding mode constituents. For the former fibre type, we explore how the bandgap is formed using a photonic analogue of the tight-binding model and how it is related to the anti-resonant reflection...... on electromagnetically induced transparency in a rubidium filled hollow-core photonic crystal fibre, the CW-pumped hydrogen Raman laser and the generation of multi-octave spanning stimulated Raman scattering spectral combs....

  11. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  12. Sensing Features of Long Period Gratings in Hollow Core Fibers

    Directory of Open Access Journals (Sweden)

    Agostino Iadicicco

    2015-04-01

    Full Text Available We report on the investigation of the sensing features of the Long-Period fiber Gratings (LPGs fabricated in hollow core photonic crystal fibers (HC-PCFs by the pressure assisted Electric Arc Discharge (EAD technique. In particular, the characterization of the LPG in terms of shift in resonant wavelengths and changes in attenuation band depth to the environmental parameters: strain, temperature, curvature, refractive index and pressure is presented. The achieved results show that LPGs in HC-PCFs represent a novel high performance sensing platform for measurements of different physical parameters including strain, temperature and, especially, for measurements of environmental pressure. The pressure sensitivity enhancement is about four times greater if we compare LPGs in HC and standard fibers. Moreover, differently from LPGs in standard fibers, these LPGs realized in innovative fibers, i.e., the HC-PCFs, are not sensitive to surrounding refractive index.

  13. Transmission properties of hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.

    2010-01-01

    Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers.......Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers....

  14. Light propagation in gas-filled kagomé hollow core photonic crystal fibres

    Science.gov (United States)

    Rodrigues, Sílvia M. G.; Facão, Margarida; Ferreira, Mário F. S.

    2018-04-01

    We study the propagation of light in kagomé hollow core photonic crystal fibres (HC-PCFs) filled with three different noble gases, namely, helium, xenon and argon. Various properties, including the guided modes, the group-velocity dispersion, and the nonlinear parameter were determined. The zero dispersion wavelength and the nonlinear parameter vary with the gas pressure which may be used to tune the generation of new frequencies using the same pump laser and the same fibre. In the case of the kagomé HC-PCF filled with xenon, the zero dispersion wavelength shifts from 693 to 1973 nm when the pressure is increased from 1 to 150bar, while the effective Kerr nonlinearity becomes comparable to that of silica. We have simulated the propagation of femtosecond pulses launched at 790 nm in order to study the generation of supercontinuum and UV light in kagomé HC-PCFs filled with the noble gases.

  15. Chalcogenide glass hollow core microstructured optical fibers

    Directory of Open Access Journals (Sweden)

    Vladimir S. eShiryaev

    2015-03-01

    Full Text Available The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  16. Portable optical frequency standard based on sealed gas-filled hollow-core fiber using a novel encapsulation technique

    DEFF Research Database (Denmark)

    Triches, Marco; Brusch, Anders; Hald, Jan

    2015-01-01

    A portable stand-alone optical frequency standard based on a gas-filled hollow-core photonic crystal fiber is developed to stabilize a fiber laser to the 13C2H2 P(16) (ν1 + ν3) transition at 1542 nm using saturated absorption. A novel encapsulation technique is developed to permanently seal...

  17. High Power Spark Delivery System Using Hollow Core Kagome Lattice Fibers

    Directory of Open Access Journals (Sweden)

    Ciprian Dumitrache

    2014-08-01

    Full Text Available This study examines the use of the recently developed hollow core kagome lattice fibers for delivery of high power laser pulses. Compared to other photonic crystal fibers (PCFs, the hollow core kagome fibers have larger core diameter (~50 µm, which allows for higher energy coupling in the fiber while also maintaining high beam quality at the output (M2 = 1.25. We have conducted a study of the maximum deliverable energy versus laser pulse duration using a Nd:YAG laser at 1064 nm. Pulse energies as high as 30 mJ were transmitted for 30 ns pulse durations. This represents, to our knowledge; the highest laser pulse energy delivered using PCFs. Two fiber damage mechanisms were identified as damage at the fiber input and damage within the bulk of the fiber. Finally, we have demonstrated fiber delivered laser ignition on a single-cylinder gasoline direct injection engine.

  18. Photonic crystal fibers -

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou

    2002-01-01

    . Such micro-structured fibers are the ones most often trated in literature concerning micro-structured fibers. These micro-structured fibers offer a whole range of novel wave guiding characteristics, including the possibility of fibers that guide only one mode irrespective of the frequency of light...

  19. Ultrafast Raman scattering in gas-filled hollow-core fibers

    OpenAIRE

    Belli, Federico

    2017-01-01

    The experimental and numerical work reported here is rooted in ultrafast molecular phenomena and nonlinear fiber optics, which are brought together in a deceptively simple system: a homo-nuclear molecular gas (e.g. H2,D2) loaded in the hollow-core of a broad-band guiding photonic crystal fiber (PCF) and exposed to ultrashort pulses of moderate energies (∼ μJ). On one hand, the choice of a molecular gas as the nonlinear medium provides a rich playground for light-matter interactions. ...

  20. Hollow-core fibers for high power pulse delivery

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Lyngsø, Jens K.; Jakobsen, Christian

    2016-01-01

    We investigate hollow-core fibers for fiber delivery of high power ultrashort laser pulses. We use numerical techniques to design an anti-resonant hollow-core fiber having one layer of non-touching tubes to determine which structures offer the best optical properties for the delivery of high power...... picosecond pulses. A novel fiber with 7 tubes and a core of 30 mu m was fabricated and it is here described and characterized, showing remarkable low loss, low bend loss, and good mode quality. Its optical properties are compared to both a 10 mu m and a 18 mu m core diameter photonic band gap hollow......-core fiber. The three fibers are characterized experimentally for the delivery of 22 picosecond pulses at 1032nm. We demonstrate flexible, diffraction limited beam delivery with output average powers in excess of 70W. (C) 2016 Optical Society of America...

  1. Antiresonant hollow core fiber with seven nested capillaries

    DEFF Research Database (Denmark)

    Antonio-Lopez, Jose E.; Habib, Selim; Van Newkirk, Amy

    2016-01-01

    We report an antiresonant hollow core fiber formed of 7 non-touching capillaries with inner tubes. The fiber has a core diameter of ∼33μm and a core wall of ∼780nm of thickness. We demonstrate robust single mode operation at 1064nm and broad transmission bandwidth.......We report an antiresonant hollow core fiber formed of 7 non-touching capillaries with inner tubes. The fiber has a core diameter of ∼33μm and a core wall of ∼780nm of thickness. We demonstrate robust single mode operation at 1064nm and broad transmission bandwidth....

  2. Laser breakdown with millijoule trains of picosecond pulses transmitted through a hollow-core photonic-crystal fibre

    CERN Document Server

    Konorov, S O; Kolevatova, O A; Beloglasov, V I; Skibina, N B; Shcherbakov, A V; Wintner, E; Zheltikov, A M

    2003-01-01

    Sequences of picosecond pulses with a total energy in the pulse train of about 1 mJ are transmitted through a hollow-core photonic-crystal fibre with a core diameter of approximately 14 mu m. The fluence of laser radiation coupled into the core of the fibre under these conditions exceeds the breakdown threshold of fused silica by nearly an order of magnitude. The laser beam coming out of the fibre is then focused to produce a breakdown on a solid surface. Parameters of laser radiation were chosen in such a way as to avoid effects related to the excitation of higher order waveguide modes and ionization of the gas filling the fibre in order to provide the possibility to focus the output beam into a spot with a minimum diameter, thus ensuring the maximum spatial resolution and the maximum power density in the focal spot.

  3. Investigation on Guided-Mode Characteristics of Hollow-Core Photonic Crystal Fibre at Near-Infrared Wavelengths

    International Nuclear Information System (INIS)

    Jin-Hui, Yuan; Chong-Xiu, Yu; Xin-Zhu, Sang; Wen-Jing, Li; Gui-Yao, Zhou; Shu-Guang, Li; Lan-Tian, Hou

    2009-01-01

    Guided-mode characteristics of hollow-core photonic crystal fibre (HC-PCF) are experimentally and theoretically investigated. The transmission spectrum in the range from 755 to 845 nm is observed and the loss is measured to be 0.12 dB/m at 800 nm by cut-back method. Based on the full-vector beam propagation method and the full-vector plane-wave method, the characteristics of mode field over propagation distance 1 m are simulated, and the results show that the propagation efficiency can be above 80%. Compared with the fundamental guided mode well confined in air core within shorter propagation distance, the second-order guided mode leaks into the cladding region and gradually attenuates due to larger refractive index difference. The primary loss factors in HC-PCF and the corresponding solutions are elementarily discussed. (fundamental areas of phenomenology (including applications))

  4. Soliton formation in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2009-01-01

    of an approximate scaling relation is tested. It is concluded that compression of input pulses of several ps duration and sub-MW peak power can lead to a formation of solitons with ∼100 fs duration and multi-megawatt peak powers. The dispersion slope of realistic hollow-core fibers appears to be the main obstacle......The formation of solitons upon compression of linearly chirped pulses in hollow-core photonic bandgap fibers is investigated numerically. The dependence of soliton duration on the chirp and power of the input pulse and on the dispersion slope of the fiber is investigated, and the validity...

  5. High-birefringent photonic crystal fiber

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou; Broeng, Jes; Knudsen, Erik

    2001-01-01

    A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber.......A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber....

  6. Photonic crystal fiber based antibody detection

    DEFF Research Database (Denmark)

    Duval, A; Lhoutellier, M; Jensen, J B

    2004-01-01

    An original approach for detecting labeled antibodies based on strong penetration photonic crystal fibers is introduced. The target antibody is immobilized inside the air-holes of a photonic crystal fiber and the detection is realized by the means of evanescent-wave fluorescence spectroscopy...

  7. Photonic Crystal Fibers for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Ana M. R. Pinto

    2012-01-01

    Full Text Available Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications. A review of photonic crystal fiber sensors is presented. Two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter. Several sensors have been reported until the date, and more are expected to be developed due to the remarkable characteristics such fibers can offer.

  8. Confinement less spectral behavior in hollow-core Bragg fibers

    DEFF Research Database (Denmark)

    Foroni, M.; Passaro, D.; Poli, F.

    2007-01-01

    The influence of each cross-section geometric parameter on hollow-core Bragg fiber guiding properties has been numerically investigated. Fabricated fibers have been modeled, giving insight into the spectral behavior of the confinement loss. It has been verified that, by changing the amount...

  9. Photonic bandgap narrowing in conical hollow core Bragg fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Fahri Emre; Yildirim, Adem; Kanik, Mehmet [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Bayindir, Mehmet, E-mail: bayindir@nano.org.tr [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Department of Physics, Bilkent University, 06800 Ankara (Turkey)

    2014-08-18

    We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.

  10. Mode Division Multiplexing Exploring Hollow-Core Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Xu, Jing; Lyngso, Jens Kristian; Leick, Lasse

    2013-01-01

    We review our recent exploratory investigations on mode division multiplexing using hollow-core photonic bandgap fibers (HC-PBGFs). Compared with traditional multimode fibers, HC-PBGFs have several attractive features such as ultra-low nonlinearities, low-loss transmission window around 2 µm etc....... After having discussed the potential and challenges of using HC-PBGFs as transmission fibers for mode multiplexing applications, we will report a number of recent proof-of-concept results obtained in our group using direct detection receivers. The first one is the transmission of two 10.7 Gbit/s non...

  11. Loss mechanisms in hollow-core fibers

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, B.J.; Jakobsen, C.

    2009-01-01

    With the recent advances in digital signal processing (DSP), coherent detection is currently living its second life in the world of fiber-optics. First generation transponders using coherent detection are coming to the market, and a significant amount of research is being invested in this area....... With the rise of digital signal processing as an integral part of optical communication systems, most of the complexity is shifted from the optical/analogue to the electrical/digital domain. This will fundamentally change the way we should design our systems. At the same time, new generations of WDM systems...

  12. Supercontinuum noise in tapered photonic crystal fibers

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Moselund, Peter Morten

    Supercontinuum generation (SCG) in highly nonlinear photonic crystal fibers (PCF) has drawn a lot of attention for the last decade. Pumping such PCFs with high-power picosecond laser pulses enables the creation of broadband and intense light. Picosecond SCG is initiated by modulation instability ...

  13. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Johansen, Mette Marie; Lyngsø, Jens Kristian

    2015-01-01

    We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers......We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers...

  14. Interference Cancellation for Hollow-Core Fiber Reference Cells

    DEFF Research Database (Denmark)

    Seppä, Jeremias; Merimaa, Mikko; Merimaa, Mikko

    2015-01-01

    Doppler-free saturated absorption spectroscopy of gases in hollow-core fiber (HCF)-based cells can be used for realizing new compact, robust, and portable frequency standards. In this paper, methods for cancelling interferences resulting from the optical connections between standard fiber and HCF...... and other factors such as varying coupling to HCF modes are investigated. Laser power modulation with simultaneous detection of ac and dc signal is used to separate saturated absorption from interferences. In addition, a technique of two piezoelectric stack actuators stretching the fiber at different...... locations is described. The presented experimental results demonstrate that 99% interference attenuation is readily attainable with the techniques. Frequency comb-referenced measurement of saturated acetylene absorption features near 1.54 μm, with fiber length and power modulation, is presented...

  15. Photonic crystal fiber technology for compact fiber-delivered high-power ultrafast fiber lasers

    Science.gov (United States)

    Triches, Marco; Michieletto, Mattia; Johansen, Mette M.; Jakobsen, Christian; Olesen, Anders S.; Papior, Sidsel R.; Kristensen, Torben; Bondue, Magalie; Weirich, Johannes; Alkeskjold, Thomas T.

    2018-02-01

    Photonic crystal fiber (PCF) technology has radically impacted the scientific and industrial ultrafast laser market. Reducing platform dimensions are important to decrease cost and footprint while maintaining high optical efficiency. We present our recent work on short 85 μm core ROD-type fiber amplifiers that maintain single-mode performance and excellent beam quality. Robust long-term performance at 100 W average power and 250 kW peak power in 20 ps pulses at 1030 nm wavelength is presented, exceeding 500 h with stable performance in terms of both polarization and power. In addition, we present our recent results on hollow-core ultrafast fiber delivery maintaining high beam quality and polarization purity.

  16. Low-Loss Hollow-Core Anti-Resonant Fibers With Semi-Circular Nested Tubes

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    Hollow-core fibers with a single ring of circular antiresonant tubes as the cladding provide a simple way of getting a negative-curvature hollow core, resulting in broadband low-loss transmission with little power overlap in the glass. These fibers show a significant improvement in loss performan...

  17. Coupling to photonic crystal fibers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Bjarklev, Anders Overgaard; Knudsen, Erik

    2002-01-01

    In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained.......In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained....

  18. Spectroscopy of Rb atoms in hollow-core fibers

    International Nuclear Information System (INIS)

    Slepkov, Aaron D.; Bhagwat, Amar R.; Venkataraman, Vivek; Londero, Pablo; Gaeta, Alexander L.

    2010-01-01

    Recent demonstrations of light-matter interactions with atoms and molecules confined to hollow waveguides offer great promise for ultralow-light-level applications. The use of waveguides allows for tight optical confinement over interaction lengths much greater than what could be achieved in bulk geometries. However, the combination of strong atom-photon interactions and nonuniformity of guided light modes gives rise to spectroscopic features that must be understood in order to take full advantage of the properties of such systems. We use light-induced atomic desorption to generate an optically dense Rb vapor at room temperature inside a hollow-core photonic band-gap fiber. Saturable-absorption spectroscopy and passive slow-light experiments reveal large ac Stark shifts, power broadening, and transit-time broadening, that are present in this system even at nanowatt powers.

  19. Hollow Core Optical Fiber Gas Lasers: Toward Novel and Practical Systems in Fused Silica

    Science.gov (United States)

    2017-05-18

    Hollow core Optically pumped Fiber Gas LASer’s (HOFGLAS’s) based on population inversion combine advantages of fiber lasers such as long interaction...polarization dependent fiber properties. Preliminary experiments were performed toward simultaneous lasing in the visible and near infrared; lasing in...words) Hollow core Optically pumped Fiber Gas LASer’s (HOFGLAS’s) based on population inversion combine advantages of fiber lasers such as long

  20. All-Silica Hollow-Core Microstructured Bragg Fibers for Biosensor Application

    DEFF Research Database (Denmark)

    Passaro, Davide; Foroni, Matteo; Poli, Federica

    2008-01-01

    The possibility to exploit all-silica hollow-core-microstructured Bragg fibers to realize a biosensor useful to detect the DNA hybridization process has been investigated. A Bragg fiber recently fabricated has been considered for the analysis performed by means of a full-vector modal solver based...... layer on the inner surface of the fiber holes can modify the fundamental mode properties. The numerical analysis results have successfully demonstrated the DNA bio-sensor feasibility in hollow-core Bragg fibers....

  1. Hollow-core fiber sensing technique for pipeline leak detection

    Science.gov (United States)

    Challener, W. A.; Kasten, Matthias A.; Karp, Jason; Choudhury, Niloy

    2018-02-01

    Recently there has been increased interest on the part of federal and state regulators to detect and quantify emissions of methane, an important greenhouse gas, from various parts of the oil and gas infrastructure including well pads and pipelines. Pressure and/or flow anomalies are typically used to detect leaks along natural gas pipelines, but are generally very insensitive and subject to false alarms. We have developed a system to detect and localize methane leaks along gas pipelines that is an order of magnitude more sensitive by combining tunable diode laser spectroscopy (TDLAS) with conventional sensor tube technology. This technique can potentially localize leaks along pipelines up to 100 km lengths with an accuracy of +/-50 m or less. A sensor tube buried along the pipeline with a gas-permeable membrane collects leaking gas during a soak period. The leak plume within the tube is then carried to the nearest sensor node along the tube in a purge cycle. The time-to-detection is used to determine leak location. Multiple sensor nodes are situated along the pipeline to minimize the time to detection, and each node is composed of a short segment of hollow core fiber (HCF) into which leaking gas is transported quickly through a small pressure differential. The HCF sensing node is spliced to standard telecom solid core fiber which transports the laser light for spectroscopy to a remote interrogator. The interrogator is multiplexed across the sensor nodes to minimize equipment cost and complexity.

  2. Pulsed-induced electromagnetically induced transparency in the acetylene-filled hollow-core fibers

    Science.gov (United States)

    Rodríguez, Nayeli Casillas; Stepanov, Serguei; Miramontes, Manuel Ocegueda; Hernández, Eliseo Hernández

    2017-06-01

    Experimental results on pulsed excitation of electromagnetically induced transparency (EIT) in the acetylene-filled hollow-core photonic crystal fiber (HC-PCF) at pressures 0.1-0.4 Torr are reported. The EIT was observed both in Λ and V interaction configurations with the continuous probe wave tuned to R9 (1520.08 nm) acetylene absorption line and with the control pulses tuned to P11 (1531.58 nm) and P9 (1530.37 nm) lines, respectively. The utilized control pulses were of up to 40 ns duration with EIT was up to 40 and 15% for the co- and counter-propagation of the probe and control waves, respectively, and importance of the waves polarization matching was demonstrated. For a qualitative explanation of reduction in the counter-propagation EIT efficiency a simple model of the accelerated mismatch of the two-frequency EIT resonance with deviation of the molecule thermal velocity from the resonance value was utilized. It was shown experimentally that the EIT efficiencies in both configurations do not depend on the longitudinal velocity of the molecules. The characteristic relaxation time of the of the EIT response was found to be about 9 ns, i.e., is close to the relaxation times T 1,2 of the acetylene molecules under the utilized experimental conditions.

  3. Guiding Properties of Silica/Air Hollow-Core Bragg Fibers

    DEFF Research Database (Denmark)

    Foroni, Matteo; Passaro, Davide; Poli, Federica

    2008-01-01

    The guiding properties of realistic silica/air hollow-core Bragg fibers have been investigated by calculating the dispersion curves, the confinement loss spectrum and the field distribution of the guided modes through a full-vector modal solver based on the finite element method. In particular, t...... the different possible applications, the feasibility of a DNA bio-sensor based on a hollow-core Bragg fiber has been demonstrated....

  4. Photonic crystal fiber design for broadband directional coupling

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bang, Ole; Bjarklev, Anders Overgaard

    2004-01-01

    A novel design for a broadband directional coupler based on a photonic crystal fiber is investigated numerically. It is shown that suitable index-depressing doping of the core regions in an index-guiding twin-core photonic crystal fiber can stabilize the coupling coefficient between the cores over...

  5. Sol-gel processing to form doped sol-gel monoliths inside hollow core optical fiber and sol-gel core fiber devices made thereby

    Science.gov (United States)

    Shaw, Harry C. (Inventor); Ott, Melanie N. (Inventor); Manuel, Michele V. (Inventor)

    2002-01-01

    A process of fabricating a fiber device includes providing a hollow core fiber, and forming a sol-gel material inside the hollow core fiber. The hollow core fiber is preferably an optical fiber, and the sol-gel material is doped with a dopant. Devices made in this manner includes a wide variety of sensors.

  6. Hollow-core infrared fiber incorporating metal-wire metamaterial

    DEFF Research Database (Denmark)

    Yan, Min; Mortensen, Asger

    2009-01-01

    Infrared (IR) light is considered important for short-range wireless communication, thermal sensing, spectroscopy, material processing, medical surgery, astronomy etc. However, IR light is in general much harder to transport than optical light or microwave radiation. Existing hollow-core IR...

  7. A novel method for polarization squeezing with Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Milanovic, Josip; Lassen, Mikael Østergaard; Andersen, Ulrik Lund

    2010-01-01

    Photonic Crystal Fibers can be tailored to increase the effective Kerr nonlinearity, while producing smaller amounts of excess noise compared to standard silicon fibers. Using these features of Photonic Crystal Fibers we create polarization squeezed states with increased purity compared to standa...... Stokes parameter squeezing of −3.9 ±0.3dB and anti-squeezing of 16.2 ±0.3dB....

  8. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Johansen, Mette Marie; Lyngsø, Jens Kristian

    2016-01-01

    We demonstrated robust and bend insensitive fiber delivery of high power laser with diffraction limited beam quality for two different kinds of hollow core band gap fibers. The light source for this experiment consists of ytterbium-doped double clad fiber aeroGAIN-ROD-PM85 in a high power amplifier...

  9. Frequency stabilization of a 2.05 μm laser using hollow-core fiber CO2 frequency reference cell

    Science.gov (United States)

    Meras, Patrick; Poberezhskiy, Ilya Y.; Chang, Daniel H.; Spiers, Gary D.

    2010-04-01

    We have designed and built a hollow-core fiber frequency reference cell, filled it with CO2, and used it to demonstrate frequency stabilization of a 2.05 μm Tm:Ho:YLF laser using frequency modulation (FM) spectroscopy technique. The frequency reference cell is housed in a compact and robust hermetic package that contains a several meter long hollow-core photonic crystal fiber optically coupled to index-guiding fibers with a fusion splice on one end and a mechanical splice on the other end. The package has connectorized fiber pigtails and a valve used to evacuate, refill it, or adjust the gas pressure. We have demonstrated laser frequency standard deviation decreasing from >450MHz (free-running) to laser wavelength is of particular interest for spectroscopic instruments due to the presence of many CO2 and H20 absorption lines in its vicinity. To our knowledge, this is the first reported demonstration of laser frequency stabilization at this wavelength using a hollow-core fiber reference cell. This approach enables all-fiber implementation of the optical portion of laser frequency stabilization system, thus making it dramatically more lightweight, compact, and robust than the traditional free-space version that utilizes glass or metal gas cells. It can also provide much longer interaction length of light with gas and does not require any alignment. The demonstrated frequency reference cell is particularly attractive for use in aircraft and space coherent lidar instruments for measuring atmospheric CO2 profile.

  10. Tapered photonic crystal fibers for blue-enhanced supercontinuum generation

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper

    2012-01-01

    Tapering of photonic crystal fibers is an effective way of shifting the blue edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for enhancing the power in the blue edge....

  11. Nonlinear optics at the single-photon level inside a hollow core fiber

    DEFF Research Database (Denmark)

    Hofferberth, Sebastian; Peyronel, Thibault; Liang, Qiyu

    2011-01-01

    Cold atoms inside a hollow core fiber provide an unique system for studying optical nonlinearities at the few-photon level. Confinement of both atoms and photons inside the fiber core to a diameter of just a few wavelengths results in high electric field intensity per photon and large optical...

  12. Multiple soliton compression stages in mid-IR gas-filled hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Md Selim; Markos, Christos; Bang, Ole

    2017-01-01

    The light confinement inside hollow-core (HC) fibers filled with noble gases constitutes an efficient route to study interesting soliton-plasma dynamics [1]. More recently, plasma-induced soliton splitting at the self-compression point was observed in a gas-filled fiber in the near-IR [2]. However...

  13. Curvature and position of nested tubes in hollow-core anti-resonant fibers

    DEFF Research Database (Denmark)

    Habib, Md Selim; Markos, Christos; Bang, Ole

    2017-01-01

    Hollow-core anti-resonant (HC-AR) fibers where a symmetric distribution of cladding tubes compose a “negative-curvature” core boundary have extraordinary optical properties, such as low transmission loss, wide transmission bands and weak power overlap between the core modes and the silica parts [1...

  14. Transmission properties of hollow-core photonic bandgap fibers in relation to molecular spectroscopy

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.

    2010-01-01

    The transmission properties of five types of hollow-core photonic bandgap fibers (HC-PBFs) are characterized in the telecom wavelength range around 1:5 μm. The variations in optical transmission are measured as a function of laser frequency over a 2GHz scan range as well as a function of time over...

  15. Slow-light enhanced absorption in a hollow-core fiber

    DEFF Research Database (Denmark)

    Grgic, Jure; Xiao, Sanshui; Mørk, Jesper

    2010-01-01

    Light traversing a hollow-core photonic band-gap fiber may experience multiple reflections and thereby a slow-down and enhanced optical path length. This offers a technologically interesting way of increasing the optical absorption of an otherwise weakly absorbing material which can infiltrate...

  16. Silica Bridge Impact on Hollow-core Bragg Fiber Transmission Properties

    DEFF Research Database (Denmark)

    Poli, F.; Foroni, M.; Giovanelli, D.

    2007-01-01

    The silica bridges impact on the hollow-core Bragg fiber guiding properties is investigated. Results demonstrate that silica nanosupports are responsible for the surface mode presence, which causes the peaks experimentally measured in the transmission spectrum. © 2006 Optical Society of America....

  17. Low-loss single-mode hollow-core fiber with anisotropic anti-resonant elements

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    A hollow-core fiber using anisotropic anti-resonant tubes in thecladding is proposed for low loss and effectively single-mode guidance. We show that the loss performance and higher-order mode suppression is significantly improved by using symmetrically distributed anisotropic antiresonant tubes i...

  18. Low-loss hollow-core silica fibers with adjacent nested anti-resonant tubes

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2015-01-01

    We report on numerical design optimization of hollow-core antiresonant fibers with the aim of reducing transmission losses. We show that re-arranging the nested anti-resonant tubes in the cladding to be adjacent has the effect of significantly reducing leakage as well as bending losses, and for r...

  19. Impact of geometrical parameters on the optical properties of negative curvature hollow-core fibers

    International Nuclear Information System (INIS)

    Alagashev, G K; Pryamikov, A D; Kosolapov, A F; Kolyadin, A N; Lukovkin, A Yu; Biriukov, A S

    2015-01-01

    We analyze the impact of geometrical parameters on such important optical characteristics of negative curvature hollow-core fibers (NCHCFs) as waveguide dispersion, waveguide losses and the structure of transmission bands. We consider both theoretically and experimentally the resonance effects and formation of band edges under bending in NCHCFs. (paper)

  20. Soliton-plasma nonlinear dynamics in mid-IR gas-filled hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Markos, Christos; Bang, Ole

    2017-01-01

    We investigate numerically soliton-plasma interaction in a noble-gas-filled silica hollow-core anti-resonant fiber pumped in the mid-IR at 3.0 mu m. We observe multiple soliton self-compression stages due to distinct stages where either the self-focusing or the self-defocusing nonlinearity...

  1. Mode-coupling in photonic crystal fibers with multiple cores

    DEFF Research Database (Denmark)

    Kristensen, Martin

    2000-01-01

    Summary form only given. We have fabricated a photonic crystal fiber (PCF) with multiple cores by drawing a fiber preform from stacked glass tubes. Transmission is high through each core despite many unintentional defects in the cladding indicating that the guidance is determined by the holes near...

  2. Ultra-large bandwidth hollow-core guiding in all-silica bragg fibers with nano-supports

    DEFF Research Database (Denmark)

    Vienne, Guillaume; Xu, Yong; Jakobsen, Christian

    2004-01-01

    We demonstrate a new class of hollow-core Bragg fibers that are composed of concentric cylindrical silica rings separated by nanoscale support bridges. We theoretically predict and experimentally observe hollow-core confinement over an octave frequency range. The bandwidth of bandgap guiding in t...... in this new class of Bragg fibers exceeds that of other hollow-core fibers reported in the literature. With only three rings of silica cladding layers, these Bragg fibers achieve propagation loss of the order of 1 dB/m....

  3. Hollow-core optical fiber incorporating a metamaterial cladding

    DEFF Research Database (Denmark)

    2010-01-01

    An optical fiber (100, 200, 300) for guidance of electromagnetic radiation with an operational wavelength l, the fiber (100, 200, 300) having a longitudinal direction along a longitudinal axis and a transverse direction in a plane perpendicular to the longitudinal axis, the fiber (100, 200, 300...... further relates to a method relating to and the use of the inventive fiber....

  4. Silica hollow core microstructured fibers for beam delivery in industrial and medical applications

    Directory of Open Access Journals (Sweden)

    Jonathan Dale Shephard

    2015-04-01

    Full Text Available The focus of this review is our recent work to develop microstructured hollow core fibers for two applications where the flexible delivery of a single mode beam is desired. Also, a review of other fiber based solutions is included.High power, short-pulsed lasers are widely used for micro-machining, providing high precision and high quality. However, the lack of truly flexible beam delivery systems limits their application to the processing of relatively small planar components. To address this, we developed hollow-core optical fibers for the 1 μm and green wavelength ranges. The hollow core overcomes the power delivery limitations of conventional silica fibers arising from nonlinear effects and material damage in the solid core. We have characterized such fibers in terms of power handling capability, damage threshold, bend loss and dispersion, and practically demonstrated delivery of high peak power pulses from the nanosecond to the femtosecond regime. Such fibers are ideal candidates for industrial laser machining applications.In laser surgical applications, meanwhile, an Er:YAG laser (2.94 μm is frequently the laser of choice because the water contained in tissue strongly absorbs this wavelength. If this laser beam is precisely delivered damage to surrounding tissue can be minimized. A common delivery method of surgical lasers, for use in the operating theatre, is articulated arms that are bulky, cumbersome and unsuitable for endoscopic procedures. To address this need for flexible mid-IR delivery we developed silica based hollow core fibers. By minimizing the overlap of the light with glass it is possible to overcome the material absorption limits of silica and achieve low attenuation. Additionally, it is possible to deliver pulse energies suitable for the ablation of both hard and soft tissue even with very small bend radii. The flexibility and small physical size of systems based on these fibers will enable new minimally invasive surgical

  5. Theory of adiabatic pressure-gradient soliton compression in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, John

    2009-01-01

    Adiabatic soliton compression by means of a pressure gradient in a hollow-core photonic bandgap fiber is investigated theoretically and numerically. It is shown that the dureation of the compressed pulse is limited mainly by the interplay between third-order dispersion and the Raman-induced soliton...... frequency shift. Analytical expressions for this limit are derived and compared with results of detailed numerical simulations for a realistic fiber structure....

  6. Photonic Crystal Fiber Sensors for Strain and Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Jian Ju

    2009-01-01

    Full Text Available This paper discusses the applications of photonic crystal fibers (PCFs for strain and temperature measurement. Long-period grating sensors and in-fiber modal interferometric sensors are described and compared with their conventional single-mode counterparts. The strain sensitivities of the air-silica PCF sensors are comparable or higher than those implemented in conventional single-mode fibers but the temperature sensitivities of the PCF sensors are much lower.

  7. Supercontinuum Generation in Uniform and Tapered Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Møller, Uffe Visbech; Larsen, Casper

    Supercontinuum generation (SCG) is a striking phenomenon of extreme spectral broadening involving a wealth of beautiful nonlinear physics. The study of SCG and development of today’s commercial sources really took off with the invention of the photonic crystal fiber (PCF), in which light can be m...

  8. Initial steps of supercontinuum generation in photonic crystal fibers

    DEFF Research Database (Denmark)

    Hilligsøe, Karen Marie; Paulsen, H.N.; Thøgersen, J.

    2003-01-01

    The onset of supercontinuum generation in a photonic crystal fiber is investigated experimentally and numerically as a function of pump wavelength and intensity with 100-fs pulses. Soliton formation is found to be the determining factor in the initial step. The formation and behavior of a blueshi...

  9. Temporal nonlinear beam dynamics in infiltrated photonic crystal fibers

    DEFF Research Database (Denmark)

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

    Liquid-infiltrated photonic crystal fibers (PCFs) offer a new way of studying light propagation in periodic and discrete systems. A wide range of available fiber structures combined with the ease of infiltration opens up a range of novel experimental opportunities for optical detection and bio...... the evolution of the fiber output beam in the few micro or milliseconds after the beam is turned on. The characterization of the temporal behavior of the thermal nonlinear response provides important information about the nonlocality associated with heat diffusion inside the fiber, thus enabling studies of long...... and technological potential of liquid-infiltrated PCFs it is important to understand the temporal dynamics of nonlinear beam propagation in such structures. In this work we consider thermally induced spatial nonlinear effects in infiltrated photonic crystal fibers. We experimentally study the temporal dynamics...

  10. Anomalous transparency in photonic crystals and its application to point-by-point grating inscription in photonic crystal fibers.

    Science.gov (United States)

    Baghdasaryan, Tigran; Geernaert, Thomas; Chah, Karima; Caucheteur, Christophe; Schuster, Kay; Kobelke, Jens; Thienpont, Hugo; Berghmans, Francis

    2018-04-03

    It is common belief that photonic crystals behave similarly to isotropic and transparent media only when their feature sizes are much smaller than the wavelength of light. Here, we counter that belief and we report on photonic crystals that are transparent for anomalously high normalized frequencies up to 0.9, where the crystal's feature sizes are comparable with the free space wavelength. Using traditional photonic band theory, we demonstrate that the isofrequency curves can be circular in the region above the first stop band for triangular lattice photonic crystals. In addition, by simulating how efficiently a tightly focused Gaussian beam propagates through the photonic crystal slab, we judge on the photonic crystal's transparency rather than on isotropy only. Using this approach, we identified a wide range of photonic crystal parameters that provide anomalous transparency. Our findings indicate the possibility to scale up the features of photonic crystals and to extend their operational wavelength range for applications including optical cloaking and graded index guiding. We applied our result in the domain of femtosecond laser micromachining, by demonstrating what we believe to be the first point-by-point grating inscribed in a multi-ring photonic crystal fiber.

  11. Arc-Induced Long Period Gratings from Standard to Polarization-Maintaining and Photonic Crystal Fibers

    Directory of Open Access Journals (Sweden)

    Flavio Esposito

    2018-03-01

    Full Text Available In this work, we report about our recent results concerning the fabrication of Long Period Grating (LPG sensors in several optical fibers, through the Electric Arc Discharge (EAD technique. In particular, the following silica fibers with both different dopants and geometrical structures are considered: standard Ge-doped, photosensitive B/Ge codoped, P-doped, pure-silica core with F-doped cladding, Panda type Polarization-maintaining, and Hollow core Photonic crystal fiber. An adaptive platform was developed and the appropriate “recipe” was identified for each fiber, in terms of both arc discharge parameters and setup arrangement, for manufacturing LPGs with strong and narrow attenuation bands, low insertion losses, and short length. As the fabricated devices have appealing features from the application point of view, the sensitivity characteristics towards changes in different external perturbations (i.e., surrounding refractive index, temperature, and strain are investigated and compared, highlighting the effects of different fiber composition and structure.

  12. Thermal properties photonic crystal fiber transducers with ferromagnetic nanoparticles

    Science.gov (United States)

    Przybysz, N.; Marć, P.; Kisielewska, A.; Jaroszewicz, L. R.

    2015-12-01

    The main aim of the research is to design new types of fiber optic transducers based on filled photonic crystal fibers for sensor applications. In our research we propose to use as a filling material nanoparticles' ferrofluids (Fe3O4 NPs). Optical properties of such transducers are studied by measurements of spectral characteristics' changes when transducers are exposed to temperature and magnetic field changes. From synthesized ferrofluid several mixtures with different NPs' concentrations were prepared. Partially filled commercially available photonic crystal fiber LMA 10 (NKT Photonics) was used to design PCF transducers. Their thermo-optic properties were tested in a temperature chamber. Taking into account magnetic properties of synthetized NPs the patch cords based on a partially filled PM 1550 PCF were measured.

  13. Influence of air pressure on soliton formation in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, Peter John

    2009-01-01

    Abstract Soliton formation during dispersive compression of chirped few-picosecond pulses at the microjoule level in a hollow-core photonic bandgap (HC-PBG) fiber is studied by numerical simulations. Long-pass filtering of the emerging frequency-shifted solitons is investigated with the objective...... of obtaining pedestal-free output pulses. Particular emphasis is placed on the influence of the air pressure in the HC-PBG fiber. It is found that a reduction in air pressure enables an increase in the fraction of power going into the most redshifted soliton and also improves the quality of the filtered pulse...

  14. Mid-infrared 1  W hollow-core fiber gas laser source.

    Science.gov (United States)

    Xu, Mengrong; Yu, Fei; Knight, Jonathan

    2017-10-15

    We report the characteristics of a 1 W hollow-core fiber gas laser emitting CW in the mid-IR. Our system is based on an acetylene-filled hollow-core optical fiber guiding with low losses at both the pump and laser wavelengths and operating in the single-pass amplified spontaneous emission regime. Through systematic characterization of the pump absorption and output power dependence on gas pressure, fiber length, and pump intensity, we determine that the reduction of pump absorption at high pump flux and the degradation of gain performance at high gas pressure necessitate the use of increased gain fiber length for efficient lasing at higher powers. Low fiber attenuation is therefore key to efficient high-power laser operation. We demonstrate 1.1 W output power at a 3.1 μm wavelength by using a high-power erbium-doped fiber amplifier pump in a single-pass configuration, approximately 400 times higher CW output power than in the ring cavity previously reported.

  15. Characterization of Fabricated Photonic Crystal Fibers Using Effective Index Method

    OpenAIRE

    Faramarz E. Seraji

    2009-01-01

    In this paper, the characteristics of photonic crystal fibers (PCFs), which have been experimentally determined in the last few years in Iran's Telecom Research Center are analyzed and compared theoretically using an effective index method. The PCFs under investigation are fabricated with a high speed drawing process that has not yet been reported elsewhere. It was shown that at higher wavelengths in PCFs; the light field is confined in the core where in shorter wavelengths the field spread...

  16. Coatings influencing thermal stress in photonic crystal fiber laser

    Science.gov (United States)

    Pang, Dongqing; Li, Yan; Li, Yao; Hu, Minglie

    2018-06-01

    We studied how coating materials influence the thermal stress in the fiber core for three holding methods by simulating the temperature distribution and the thermal stress distribution in the photonic-crystal fiber laser. The results show that coating materials strongly influence both the thermal stress in the fiber core and the stress differences caused by holding methods. On the basis of the results, a two-coating PCF was designed. This design reduces the stress differences caused by variant holding conditions to zero, then the stability of laser operations can be improved.

  17. Antiresonant guiding in a poly(methyl-methacrylate) hollow-core optical fiber

    DEFF Research Database (Denmark)

    Markos, Christos; Nielsen, Kristian; Bang, Ole

    2015-01-01

    Strong antiresonant reflecting optical waveguiding is demonstrated in a novel poly (methyl-methacrylate) (PMMA) hollow-core fiber. The transmission spectrum of the fiber was characterized using a supercontinuum source and it revealed distinct resonances with resonant dips as strong as ~20 d......B in the wavelength range 480-900 nm, where PMMA has low absorption. The total propagation loss of the fiber was measured to have a minimum of ~45 dB m-1 at around 500 nm. The thermal sensitivity of the fiber is 256 ± 16 pm °C-1, defined as the red-shift of the resonances per °C, which is three times higher than...... the sensitivity of polymer fiber Bragg gratings....

  18. Antiresonant guiding in a poly(methyl-methacrylate) hollow-core optical fiber

    International Nuclear Information System (INIS)

    Markos, Christos; Nielsen, Kristian; Bang, Ole

    2015-01-01

    Strong antiresonant reflecting optical waveguiding is demonstrated in a novel poly (methyl-methacrylate) (PMMA) hollow-core fiber. The transmission spectrum of the fiber was characterized using a supercontinuum source and it revealed distinct resonances with resonant dips as strong as ∼20 dB in the wavelength range 480–900 nm, where PMMA has low absorption. The total propagation loss of the fiber was measured to have a minimum of ∼45 dB m −1 at around 500 nm. The thermal sensitivity of the fiber is 256 ± 16 pm °C −1 , defined as the red-shift of the resonances per °C, which is three times higher than the sensitivity of polymer fiber Bragg gratings. (paper)

  19. Anisotropic anti-resonant elements gives broadband single-mode low-loss hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    Hollow-core fibers with node-free anisotropic anti-resonant elements give broadband low-loss fibers that are also single-moded. At 1.06 μm silica-based fiber designs show higher-order-mode extinction-ratio >1000 and losses below 10 dB/km over a broad wavelength range....

  20. Chromatic Dispersion Compensation Using Photonic Crystal Fibers with Hexagonal Distribution

    Directory of Open Access Journals (Sweden)

    Erick E. Reyes-Vera

    2013-11-01

    Full Text Available In this paper we show various configurations of photonic crystal fiber with hexagonal holes distribution for compensation of chromatic dispersion in optical communications links. The vectorial finite element method with scattering boundary condition was used for the analysis of the fibers. From these results it was estimated variation of the dispersion and the dispersion slope with respect to change in the diameter of the holes in the microstructure. With the above was possible to obtain values of dispersion in the C and L bands of telecommunications close to -850 ps / nm * km, with confinement losses 10-3 dB / km

  1. Cladding defects in hollow core fibers for surface mode suppression and improved birefringence

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Lyngso, J. K.; Lægsgaard, Jesper

    2014-01-01

    We demonstrate a novel polarization maintaining hollow-core photonic bandgap fiber geometry that reduces the impact of surface modes on fiber transmission. The cladding structure is modified with a row of partially collapsed holes to strip away unwanted surface modes. A theoretical investigation...... of the surface mode stripping is presented and compared to the measured performance of four 7-cells core fibers that were drawn with different collapse ratio of the defects. The varying pressure along the defect row in the cladding during drawing introduces an ellipticity of the core. This, combined...... with the presence of antiresonant features on the core wall, makes the fibers birefringent, with excellent polarization maintaining properties. (C) 2014 Optical Society of America...

  2. Generation of multiple VUV dispersive waves using a tapered gas-filled hollow-core anti-resonant fiber

    DEFF Research Database (Denmark)

    Habib, Md Selim; Markos, Christos; Bang, Ole

    2017-01-01

    Hollow-core anti-resonant (HC-AR) fibers are perhaps the best platform for ultrafast nonlinear optics based on light-gas interactions because they offer broadband guidance and low-loss guidance. The main advantage of using gases inside HC fibers is that both the dispersion and nonlinearity can...... be tuned by simply changing the pressure of the gas [1]. The emission of efficient dispersive wave (DW) in the deep-UV has been already observed in a uniform Ar-filled hollow-core fiber with tunability from 200 to 320 nm by changing the gas pressure and pulse energy [2]. In the quest of optimizing...

  3. Low loss mid-IR transmission bands using silica hollow-core anisotropic anti-resonant fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    In this paper, a node-free anisotropic hollow-core anti-resonant fiber has been proposed to give low transmission loss in the near-IR to mid-IR spectral regime. The proposed silica-based fiber design shows transmission loss below 10 dB/km at 2.94 μm with multiple low loss transmission bands. Tran...

  4. Hydrostatic Pressure Sensing with High Birefringence Photonic Crystal Fibers

    Science.gov (United States)

    Fávero, Fernando C.; Quintero, Sully M. M.; Martelli, Cicero; Braga, Arthur M.B.; Silva, Vinícius V.; Carvalho, Isabel C. S.; Llerena, Roberth W. A.; Valente, Luiz C. G.

    2010-01-01

    The effect of hydrostatic pressure on the waveguiding properties of high birefringence photonic crystal fibers (HiBi PCF) is evaluated both numerically and experimentally. A fiber design presenting form birefringence induced by two enlarged holes in the innermost ring defining the fiber core is investigated. Numerical results show that modal sensitivity to the applied pressure depends on the diameters of the holes, and can be tailored by independently varying the sizes of the large or small holes. Numerical and experimental results are compared showing excellent agreement. A hydrostatic pressure sensor is proposed and demonstrated using an in-fiber modal interferometer where the two orthogonally polarized modes of a HiBi PCF generate fringes over the optical spectrum of a broad band source. From the analysis of experimental results, it is concluded that, in principle, an operating limit of 92 MPa in pressure could be achieved with 0.0003% of full scale resolution. PMID:22163435

  5. Widely tunable femtosecond solitonic radiation in photonic crystal fiber cladding

    DEFF Research Database (Denmark)

    Peng, J. H.; Sokolov, A. V.; Benabid, F.

    2010-01-01

    We report on a means to generate tunable ultrashort optical pulses. We demonstrate that dispersive waves generated by solitons within the small-core features of a photonic crystal fiber cladding can be used to obtain femtosecond pulses tunable over an octave-wide spectral range. The generation...... process is highly efficient and occurs at the relatively low laser powers available from a simple Ti:sapphire laser oscillator. The described phenomenon is general and will play an important role in other systems where solitons are known to exist....

  6. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    DEFF Research Database (Denmark)

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-01-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass...... nanofilms at the inner surface of the air-channels of a poly-methyl-methacrylate (PMMA) PCF. The integrated high refractive index glass films introduce distinct antiresonant transmission bands in the 480-900 nm wavelength region. We demonstrate that the ultra-high Kerr nonlinearity of the chalcogenide glass...

  7. Generation of 2.5 μm and 4.6 μm Dispersive Waves in Kagome Photonic Crystal Fiber with Plasma Production

    Institute of Scientific and Technical Information of China (English)

    Tian-Qi Zhao; Meng Li; Dong Wei; Xin Ding; Gui-Zhong Zhang; Jian-Quan Yao

    2017-01-01

    We report our numerical simulation on dispersive waves (DWs) generated in the Kr-filled Kagome hollow-core photonic crystal fiber,by deploying the unidirectional pulse propagation equation.Relatively strong dispersive waves are simultaneously generated at 2.5μm and 4.6μm.It is deciphered that the interplay between plasma currents due to Kr ionization and nonlinear effects plays a key role in DW generation.Remarkably,this kind of DW generation is corroborated by the plasma-corrected phase-matching condition.

  8. Broadband dynamic phase matching of high-order harmonic generation by a high-peak-power soliton pump field in a gas-filled hollow photonic-crystal fiber.

    Science.gov (United States)

    Serebryannikov, Evgenii E; von der Linde, Dietrich; Zheltikov, Aleksei M

    2008-05-01

    Hollow-core photonic-crystal fibers are shown to enable dynamically phase-matched high-order harmonic generation by a gigawatt soliton pump field. With a careful design of the waveguide structure and an appropriate choice of input-pulse and gas parameters, a remarkably broadband phase matching can be achieved for a soliton pump field and a large group of optical harmonics in the soft-x-ray-extreme-ultraviolet spectral range.

  9. Nanoengineering of photonic crystal fibers for supercontinuum spectral shaping

    DEFF Research Database (Denmark)

    Frosz, Michael Henoch; Sørensen, Thorkild; Bang, Ole

    2006-01-01

    ) on the location of the Stokes and anti-Stokes bands and gain bandwidth. An analysis shows that the Raman effect is responsible for reducing the four-wave mixing gain and a slight reduction in the corresponding frequency shift from the pump, when the frequency shift is much larger than the Raman shift. Using......Supercontinuum generation using picosecond pulses pumped into cobweb photonic crystal fibers is investigated. Dispersion profiles are calculated for several fiber designs and used to analytically investigate the influence of the fiber structural parameters (core size and wall thickness...... numerical simulations we find that four-wave mixing is the dominant physical mechanism for the pumping scheme considered, and that there is a trade-off between the spectral width and the spectral flatness of the supercontinuum. The balance of this trade-off is determined by nanometer-scale design...

  10. Compression of realistic laser pulses in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, John

    2009-01-01

    Dispersive compression of chirped few-picosecond pulses at the microjoule level in a hollow-core photonic bandgap fiber is studied numerically. The performance of ideal parabolic input pulses is compared to pulses from a narrowband picosecond oscillator broadened by self-phase modulation during...... amplification. It is shown that the parabolic pulses are superior for compression of high-quality femtosecond pulses up to the few-megawatts level. With peak powers of 5-10 MW or higher, there is no significant difference in power scaling and pulse quality between the two pulse types for comparable values...... of power, duration, and bandwidth. The same conclusion is found for the peak power and energy of solitons formed beyond the point of maximal compression. Long-pass filtering of these solitons is shown to be a promising route to clean solitonlike output pulses with peak powers of several MW....

  11. Semi-analytical model for hollow-core anti-resonant fibers

    Directory of Open Access Journals (Sweden)

    Wei eDing

    2015-03-01

    Full Text Available We detailedly describe a recently-developed semi-analytical method to quantitatively calculate light transmission properties of hollow-core anti-resonant fibers (HC-ARFs. Formation of equiphase interface at fiber’s outermost boundary and outward light emission ruled by Helmholtz equation in fiber’s transverse plane constitute the basis of this method. Our semi-analytical calculation results agree well with those of precise simulations and clarify the light leakage dependences on azimuthal angle, geometrical shape and polarization. Using this method, we show investigations on HC-ARFs having various core shapes (e.g. polygon, hypocycloid with single- and multi-layered core-surrounds. The polarization properties of ARFs are also studied. Our semi-analytical method provides clear physical insights into the light guidance in ARF and can play as a fast and useful design aid for better ARFs.

  12. Application of Negative Curvature Hollow-Core Fiber in an Optical Fiber Sensor Setup for Multiphoton Spectroscopy.

    Science.gov (United States)

    Popenda, Maciej Andrzej; Stawska, Hanna Izabela; Mazur, Leszek Mateusz; Jakubowski, Konrad; Kosolapov, Alexey; Kolyadin, Anton; Bereś-Pawlik, Elżbieta

    2017-10-06

    In this paper, an application of negative curvature hollow core fiber (NCHCF) in an all-fiber, multiphoton fluorescence sensor setup is presented. The dispersion parameter (D) of this fiber does not exceed the value of 5 ps/nm × km across the optical spectrum of (680-750) nm, making it well suited for the purpose of multiphoton excitation of biological fluorophores. Employing 1.5 m of this fiber in a simple, all-fiber sensor setup allows us to perform multiphoton experiments without any dispersion compensation methods. Multiphoton excitation of nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) with this fiber shows a 6- and 9-fold increase, respectively, in the total fluorescence signal collected when compared with the commercial solution in the form of a hollow-core photonic band gap fiber (HCPBF). To the author's best knowledge, this is the first time an NCHCF was used in an optical-fiber sensor setup for multiphoton fluorescence experiments.

  13. Orbital angular momentum modes by twisting of a hollow core antiresonant fiber

    DEFF Research Database (Denmark)

    Stefani, Alessio; Kuhlmey, Boris T.; Fleming, Simon

    2017-01-01

    Generation and use of orbital angular momentum (OAM) of light is finding more and more interest in a wide variety of fields of photonics: communications, optical trapping, quantum optics, and many more [1]. In the investigation of such behavior, twisting of photonic crystal fibers shows interesting......, allowing a simple and tunable way to generate OAM modes. We take advantage of THz time domain spectroscopy to obtain information on both intensity and field components, and to be able to investigate how they change both in time and with frequency....

  14. Terahertz detection of alcohol using a photonic crystal fiber sensor.

    Science.gov (United States)

    Sultana, Jakeya; Islam, Md Saiful; Ahmed, Kawsar; Dinovitser, Alex; Ng, Brian W-H; Abbott, Derek

    2018-04-01

    Ethanol is widely used in chemical industrial processes as well as in the food and beverage industry. Therefore, methods of detecting alcohol must be accurate, precise, and reliable. In this content, a novel Zeonex-based photonic crystal fiber (PCF) has been modeled and analyzed for ethanol detection in terahertz frequency range. A finite-element-method-based simulation of the PCF sensor shows a high relative sensitivity of 68.87% with negligible confinement loss of 7.79×10 -12    cm -1 at 1 THz frequency and x -polarization mode. Moreover, the core power fraction, birefringence, effective material loss, dispersion, and numerical aperture are also determined in the terahertz frequency range. Owing to the simple fiber structure, existing fabrication methods are feasible. With the outstanding waveguiding properties, the proposed sensor can potentially be used in ethanol detection, as well as polarization-preserving applications of terahertz waves.

  15. A modified hexagonal photonic crystal fiber for terahertz applications

    Science.gov (United States)

    Islam, Md. Saiful; Sultana, Jakeya; Faisal, Mohammad; Islam, Mohammad Rakibul; Dinovitser, Alex; Ng, Brian W.-H.; Abbott, Derek

    2018-05-01

    We present a Zeonex based highly birefringent and dispersion flattened porous core photonic crystal fiber (PC-PCF) for polarization preserving applications in the terahertz region. In order to facilitate birefringence, an array of elliptical shaped air holes surrounded by porous cladding is introduced. The porous cladding comprises circular air-holes in a modified hexagonal arrangement. The transmission characteristics of the proposed PCF are investigated using a full-vector finite element method with perfectly matched layer (PML) absorbing boundary conditions. Simulation results show a high birefringence of 0.086 and an ultra-flattened dispersion variation of ± 0.03 ps/THz/cm at optimal design parameters. Besides, a number of other important wave-guiding properties including frequency dependence of the effective material loss (EML), confinement loss, and effective area are also investigated to assess the fiber's effectiveness as a terahertz waveguide.

  16. Photonic crystal fiber sensing characteristics research based on alcohol asymmetry filling

    Science.gov (United States)

    Shi, Fu-quan; Luo, Yan; Li, Hai-tao; Peng, Bao-jin

    2018-02-01

    A new type of Sagnac fiber temperature sensor based on alcohol asymmetric filling photonic crystal fiber is proposed. First, the corrosion of photonic crystal fiber and the treatment of air hole collapse are carried out. Then, the asymmetric structure of photonic crystal fiber is filled with alcohol, and then the structure is connected to the Sagnac interference ring. When the temperature changes, the thermal expansion effect of filling alcohol will lead to the change of birefringence of photonic crystal fiber, so that the interference spectrum of the sensor will drift along with the change of temperature. The experimental results show that the interference red shift will occur with the increase of temperature, and the temperature sensitivity is 0.1864nm/ °C. The sensor has high sensitivity to temperature. At the same time, the structure has the advantages of high stability, anti electromagnetic interference and easy to build. It provides a new method for obtaining birefringence in ordinary photonic crystal fibers.

  17. Second-order polarization-mode dispersion in photonic crystal fibers

    DEFF Research Database (Denmark)

    Larsen, T; Bjarklev, Anders Overgaard; Peterson, A

    2003-01-01

    We report the first experimental measurements of second-order polarization-mode dispersion in two successive 900 meter pulls of a silica photonic crystal fiber.......We report the first experimental measurements of second-order polarization-mode dispersion in two successive 900 meter pulls of a silica photonic crystal fiber....

  18. Highly Nonlinear and Birefringent Spiral Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    S. Revathi

    2014-01-01

    Full Text Available We propose and design a spiral photonic crystal fiber with elliptical air holes for achieving high birefringence, large nonlinearity, and negative dispersion. The structure is designed using chalcogenide glass (As2S3 for different ellipticity ratios of air holes in the cladding and the effect on various properties is observed. The proposed structure has birefringence of the order 10−2, nonlinearity of 26739.42 W−1 m−1, and dispersion of −1136.69 at 0.85 μm. An accurate numerical approach based on finite element method is used for the design and simulation of the structure. Due to high birefringence and negative dispersion, the proposed structure can be used for polarization control and dispersion compensation, respectively.

  19. Novel multichannel surface plasmon resonance photonic crystal fiber biosensor

    Science.gov (United States)

    Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, A. A.; El Deeb, Walid S.; Obayya, S. S. A.

    2016-04-01

    In this paper, a novel design of highly sensitive biosensor based on photonic crystal fiber is presented and analyzed using full vectorial finite element method. The suggested design depends on using silver layer as a plasmonic active material coated by a gold layer to protect silver oxidation. The reported sensor is based on the detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes which offers the possibility of multi-channel/multi-analyte sensing. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained for the quasi TM and quasi TE modes, respectively.

  20. Efficient 1.5-μm Raman generation in ethane-filled hollow-core fiber

    Science.gov (United States)

    Chen, Yubin; Gu, Bo; Wang, Zefeng; Lu, Qisheng

    2016-11-01

    We demonstrated for the first time a novel and effective method for obtaining both high peak-power and narrow linewidth 1.5 μm fiber sources through gas Raman effect in hollow core fibers. An Ethane-filled ice-cream antiresonance hollow-core fiber is pumped with a high peak-power pulse 1064 nm microchip laser, generating 1552.7 nm Stokes wave by pure vibrational stimulated Raman scattering of ethane molecules. A maximum peak-power of about 400 kW is achieved with 6 meter fiber length at 2 bar pressure, and the linewidth is about 6.3 GHz. The maximum Raman conversion efficiency of 1064 nm to 1552.7 nm is about 38%, and the corresponding laser slope efficiency is about 61.5%.

  1. Frequency conversion through spontaneous degenerate four wave mixing in large mode area hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Olausson, Christina Bjarnal Thulin

    2014-01-01

    Frequency conversion through spontaneous degenerate four wave mixing (FWM) is investigated in large mode area hybrid photonic crystal fibers. Different FWM processes are observed, phasematching between fiber modes of orthogonal polarization, intermodal phasematching across bandgaps, and intramodal...

  2. Selective detection of labeled DNA using an air-clad photonic crystal fiber

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Hoiby, P.E.; Pedersen, L.H.

    2004-01-01

    Demonstration of selective detection of fluorophore labeled DNA by hybridization inside the air holes of a photonic crystal fiber A laser exposes the fiber from the side and the emitted fluorescence tunnels into the core.......Demonstration of selective detection of fluorophore labeled DNA by hybridization inside the air holes of a photonic crystal fiber A laser exposes the fiber from the side and the emitted fluorescence tunnels into the core....

  3. Guided mode gain competition in Yb-doped rod-type photonic crystal fibers

    DEFF Research Database (Denmark)

    Poli, Federica; Passaro, Davide; Cucinotta, Annamaria

    2009-01-01

    The gain competition among the guided modes in Yb-doped rod-type photonic crystal fibers with a low refractive index core is investigated with a spatial model to demonstrate the fiber effective single-mode behaviour.......The gain competition among the guided modes in Yb-doped rod-type photonic crystal fibers with a low refractive index core is investigated with a spatial model to demonstrate the fiber effective single-mode behaviour....

  4. Dispersion-tailored, low-loss photonic crystal fibers for the THz range

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Adam, Aurèle J.L.

    2009-01-01

    We have fabricated a new type of photonic crystal fibers based on a cyclic olefin copolymer, transparent in the THz range. We characterize the propagation loss, dispersion, and spatial beam profile in fibers designed for low and high dispersion.......We have fabricated a new type of photonic crystal fibers based on a cyclic olefin copolymer, transparent in the THz range. We characterize the propagation loss, dispersion, and spatial beam profile in fibers designed for low and high dispersion....

  5. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    Science.gov (United States)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

  6. UV Absorption Spectroscopy in Water-Filled Antiresonant Hollow Core Fibers for Pharmaceutical Detection.

    Science.gov (United States)

    Nissen, Mona; Doherty, Brenda; Hamperl, Jonas; Kobelke, Jens; Weber, Karina; Henkel, Thomas; Schmidt, Markus A

    2018-02-06

    Due to a worldwide increased use of pharmaceuticals and, in particular, antibiotics, a growing number of these substance residues now contaminate natural water resources and drinking supplies. This triggers a considerable demand for low-cost, high-sensitivity methods for monitoring water quality. Since many biological substances exhibit strong and characteristic absorption features at wavelengths shorter than 300 nm, UV spectroscopy presents a suitable approach for the quantitative identification of such water-contaminating species. However, current UV spectroscopic devices often show limited light-matter interaction lengths, demand sophisticated and bulky experimental infrastructure which is not compatible with microfluidics, and leave large fractions of the sample analyte unused. Here, we introduce the concept of UV spectroscopy in liquid-filled anti-resonant hollow core fibers, with large core diameters and lengths of approximately 1 m, as a means to overcome such limitations. This extended light-matter interaction length principally improves the concentration detection limit by two orders of magnitude while using almost the entire sample volume-that is three orders of magnitude smaller compared to cuvette based approaches. By integrating the fibers into an optofluidic chip environment and operating within the lowest experimentally feasible transmission band, concentrations of the application-relevant pharmaceutical substances, sulfamethoxazole (SMX) and sodium salicylate (SS), were detectable down to 0.1 µM (26 ppb) and 0.4 µM (64 ppb), respectively, with the potential to reach significantly lower detection limits for further device integration.

  7. UV Absorption Spectroscopy in Water-Filled Antiresonant Hollow Core Fibers for Pharmaceutical Detection

    Directory of Open Access Journals (Sweden)

    Mona Nissen

    2018-02-01

    Full Text Available Due to a worldwide increased use of pharmaceuticals and, in particular, antibiotics, a growing number of these substance residues now contaminate natural water resources and drinking supplies. This triggers a considerable demand for low-cost, high-sensitivity methods for monitoring water quality. Since many biological substances exhibit strong and characteristic absorption features at wavelengths shorter than 300 nm, UV spectroscopy presents a suitable approach for the quantitative identification of such water-contaminating species. However, current UV spectroscopic devices often show limited light-matter interaction lengths, demand sophisticated and bulky experimental infrastructure which is not compatible with microfluidics, and leave large fractions of the sample analyte unused. Here, we introduce the concept of UV spectroscopy in liquid-filled anti-resonant hollow core fibers, with large core diameters and lengths of approximately 1 m, as a means to overcome such limitations. This extended light-matter interaction length principally improves the concentration detection limit by two orders of magnitude while using almost the entire sample volume—that is three orders of magnitude smaller compared to cuvette based approaches. By integrating the fibers into an optofluidic chip environment and operating within the lowest experimentally feasible transmission band, concentrations of the application-relevant pharmaceutical substances, sulfamethoxazole (SMX and sodium salicylate (SS, were detectable down to 0.1 µM (26 ppb and 0.4 µM (64 ppb, respectively, with the potential to reach significantly lower detection limits for further device integration.

  8. High-resolution wavefront shaping with a photonic crystal fiber for multimode fiber imaging

    NARCIS (Netherlands)

    Amitonova, L. V.; Descloux, A.; Petschulat, J.; Frosz, M. H.; Ahmed, G.; Babic, F.; Jiang, X.; Mosk, A. P.; Russell, P. S. J.; Pinkse, P.W.H.

    2016-01-01

    We demonstrate that a high-numerical-aperture photonic crystal fiber allows lensless focusing at an unparalleled res- olution by complex wavefront shaping. This paves the way toward high-resolution imaging exceeding the capabilities of imaging with multi-core single-mode optical fibers. We analyze

  9. Photonic crystal fiber monitors for intracellular ice formation

    Science.gov (United States)

    Battinelli, Emily; Reimlinger, Mark; Wynne, Rosalind

    2012-04-01

    An all-silica steering wheel photonic crystal fiber (SW-PCF) device with real-time analysis for cellular temperature sensing is presented. Results are provided for water-filled SW-PCF fibers experiencing cooling down near -40°C. Cellular temperature sensors with fast response times are of interest particularly to the study of cryopreservation, which has been influential in applications such as tissue preservation, food quality control, genetic engineering, as well as drug discovery and in- vitro toxin testing. Results of this investigation are relevant to detection of intracellular ice formation (IIF) and better understanding cell freezing at very low temperatures. IIF detection is determined as a function of absorption occurring within the core of the SW-PCF. The SW-PCF has a 3.3μm core diameter, 125μm outer diameter and steering wheel-like air hole pattern with triangular symmetry, with a 20μm radius. One end of a 0.6m length of the SW-PCF is placed between two thermoelectric coolers, filled with ~0.1μL water. This end is butt coupled to a 0.5m length of single mode fiber (SMF), the distal end of the fiber is then inserted into an optical spectrum analyzer. A near-IR light source is guided through the fiber, such that the absorption of the material in the core can be measured. Spectral characteristics demonstrated by the optical absorption of the water sample were present near the 1300-1700nm window region with strongest peaks at 1350, 1410 and 1460nm, further shifting of the absorption peaks is possible at cryogenic temperatures making this device suitable for IIF monitoring applications.

  10. Dataset on photonic crystal fiber based chemical sensor.

    Science.gov (United States)

    Ahmed, Kawsar; Paul, Bikash Kumar; Chowdhury, Sawrab; Islam, Md Shadidul; Sen, Shuvo; Islam, Md Ibadul; Asaduzzaman, Sayed; Bahar, Ali Newaz; Miah, Mohammad Badrul Alam

    2017-06-01

    This article represents the data set of micro porous core photonic crystal fiber based chemical sensor. The suggested structure is folded cladding porous shaped with circular air hole. Here is investigated four distinctive parameters including relative sensitivity, confinement loss, numerical aperture (NA), and effective area ( A eff). The numerical outcomes are computed over the E+S+C+L+U communication band. The useable sensed chemicals are methanol, ethanol, propanol, butanol, and pentanol whose are lies in the alcohol series (Paul et al., 2017) [1]. Furthermore, V -parameter ( V ), Marcuse spot size (MSS), and beam divergence (BD) are also investigated rigorously. All examined results have been obtained using finite element method based simulation software COMSOL Multiphysics 4.2 versions with anisotropic circular perfectly matched layer (A-CPML). The proposed PCF shows the high NA from 0.35 to 0.36; the low CL from ~10 -11 to ~10 -7  dB/m; the high A eff from 5.50 to 5.66 µm 2 ; the MSS from 1.0 to 1.08 µm; the BD from 0.43 to 0.46 rad at the controlling wavelength λ = 1.55 µm for employing alcohol series respectively.

  11. Dataset on photonic crystal fiber based chemical sensor

    Directory of Open Access Journals (Sweden)

    Kawsar Ahmed

    2017-06-01

    Full Text Available This article represents the data set of micro porous core photonic crystal fiber based chemical sensor. The suggested structure is folded cladding porous shaped with circular air hole. Here is investigated four distinctive parameters including relative sensitivity, confinement loss, numerical aperture (NA, and effective area (Aeff. The numerical outcomes are computed over the E+S+C+L+U communication band. The useable sensed chemicals are methanol, ethanol, propanol, butanol, and pentanol whose are lies in the alcohol series (Paul et al., 2017 [1]. Furthermore, V-parameter (V, Marcuse spot size (MSS, and beam divergence (BD are also investigated rigorously. All examined results have been obtained using finite element method based simulation software COMSOL Multiphysics 4.2 versions with anisotropic circular perfectly matched layer (A-CPML. The proposed PCF shows the high NA from 0.35 to 0.36; the low CL from ~10–11 to ~10−7 dB/m; the high Aeff from 5.50 to 5.66 µm2; the MSS from 1.0 to 1.08 µm; the BD from 0.43 to 0.46 rad at the controlling wavelength λ = 1.55 µm for employing alcohol series respectively.

  12. Design of highly sensitive multichannel bimetallic photonic crystal fiber biosensor

    Science.gov (United States)

    Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, Abdelhamid A.; El Deeb, Walid S.; Obayya, Salah S. A.

    2016-10-01

    A design of a highly sensitive multichannel biosensor based on photonic crystal fiber is proposed and analyzed. The suggested design has a silver layer as a plasmonic material coated by a gold layer to protect silver oxidation. The reported sensor is based on detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, which offers the possibility of multichannel/multianalyte sensing. The numerical results are obtained using a finite element method with perfect matched layer boundary conditions. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High-refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained according to the quasi TM and quasi TE modes of the proposed sensor, respectively. Further, the reported design can be used as a self-calibration biosensor within an unknown analyte refractive index ranging from 1.33 to 1.35 with high linearity and high accuracy. Moreover, the suggested biosensor has advantages in terms of compactness and better integration of microfluidics setup, waveguide, and metallic layers into a single structure.

  13. Active Photonic crystal fibers for high power applications

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin

    The photonic crystal ber technology provides means to realize bers optimized for high power operation, due to the large single-mode cores and the unique design exibility of the microstructure. The work presented in this thesis focuses on improving the properties of active photonic crystal bers...... contributed to the compounding of new and improved material compositions. The second part is an investigation of pump absorption in photonic crystal bers, demonstrating that the microstructure in photonic crystal bers improves the pump absorption by up to a factor of two compared to step-index bers....... This plays an important role in high power lasers and ampliers with respect to efficiency, packaging, and thermal handling. The third part of the work has involved developing tools for characterizing the mode quality and stability of large core bers. Stable, single-mode bers with larger cores are essential...

  14. Optimization of Tapered Photonic Crystal Fibers for Blue-Enhanced Supercontinuum Generation

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper

    2012-01-01

    Tapering of photonic crystal fibers is an effective way of shifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for blue-enhanced supercontinuum generation....

  15. Extremely Low Loss THz Guidance Using Kagome Lattice Porous Core Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Hossain, Anwar; Hasanuzzaman, G.K.M.; Habib, Selim

    2015-01-01

    A novel porous core Kagome lattice photonic crystal fiber is proposed for extremely low loss THz waves guiding. It has been reported that 82.5% of bulk effective material loss of Topas can be reduced...

  16. Toward single-mode UV to near-IR guidance using hollow-core anti-resonant silica fiber

    DEFF Research Database (Denmark)

    Habib, Md Selim; Antonio-Lopez, Jose Enrique; Van Newkirk, Amy

    2017-01-01

    Hollow-core anti-resonant (HC-AR) fibers with a “negative-curvature” of the core-cladding boundary have been extensively studied over the past few years owing to their low loss and wide transmission bandwidths. The key unique feature of the HC-AR fiber is that the coupling between the core and cl...... a silica HC-AR fiber having a single ring of 7 non-touching capillaries, designed to have effectively single-mode operation and low loss from UV to near-IR....

  17. Tunable diffraction and self-defocusing in liquid-filled photonic crystal fibers

    DEFF Research Database (Denmark)

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

    2007-01-01

    We suggest and demonstrate a novel platform for the study of tunable nonlinear light propagation in two-dimensional discrete systems, based on photonic crystal fibers filled with high index nonlinear liquids. Using the infiltrated cladding region of a photonic crystal fiber as a nonlinear waveguide...... array, we experimentally demonstrate highly tunable beam diffraction and thermal self-defocusing, and realize a compact all-optical power limiter based on a tunable nonlinear response....

  18. Tunable bandpass filter based on photonic crystal fiber filled with multiple liquid crystals

    DEFF Research Database (Denmark)

    Scolari, Lara; Tartarini, G.; Borelli, E.

    2007-01-01

    A tunable bandpass filter based on a photonic crystal fiber filled with two different liquid crystals is demonstrated. 130 nm bandwidth tunability is achieved by tuning the temperature from 30degC to 90degC.......A tunable bandpass filter based on a photonic crystal fiber filled with two different liquid crystals is demonstrated. 130 nm bandwidth tunability is achieved by tuning the temperature from 30degC to 90degC....

  19. Yb-doped rod-type photonic crystal fibers for single-mode amplification

    DEFF Research Database (Denmark)

    Poli, Frederica; Passaro, Davide; Cucinotta, Annamaria

    2009-01-01

    The competition among the guided modes in rod-type photonic crystal fibers with a low refractive index ring in the Yb-doped core is investigated with an amplifier model to demonstrate the effective higher-order mode suppression.......The competition among the guided modes in rod-type photonic crystal fibers with a low refractive index ring in the Yb-doped core is investigated with an amplifier model to demonstrate the effective higher-order mode suppression....

  20. Intermodal parametric gain of degenerate four wave mixing in large mode area hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard

    2013-01-01

    Intermodal degenerate four wave mixing (FWM) is investigated numerically in large mode area hybrid photonic crystal fibers. The dispersion is controlled independently of core size, and thus allows for power scaling of the FWM process.......Intermodal degenerate four wave mixing (FWM) is investigated numerically in large mode area hybrid photonic crystal fibers. The dispersion is controlled independently of core size, and thus allows for power scaling of the FWM process....

  1. Photonic crystal fiber modal interferometer based on thin-core-fiber mode exciter.

    Science.gov (United States)

    Miao, Yinping; Ma, Xixi; Wu, Jixuan; Song, Binbin; Zhang, Hao; Liu, Bo; Yao, Jianquan

    2015-11-10

    A thin-core-fiber excited photonic crystal fiber modal interferometer has been proposed and experimentally demonstrated. By employing a thin-core fiber as the mode exciter, both of the core and cladding modes propagate in the photonic crystal fiber and interfere with each other. The experimental results show that the transmission dips corresponding to different-order modes have various strain responses with opposite shift directions. The strain sensitivity could be improved to 58.57  pm/με for the applied strain from 0 to 491 με by utilizing the wavelength interval between the dips with opposite shift directions. Moreover, due to the pure silica property of the employed photonic crystal fiber, the proposed fiber modal interferometer exhibits a low-temperature sensitivity of about 0.56  pm/°C within a temperature range from 26.4°C (room temperature) to 70°C. Additionally, the proposed fiber modal interferometer has several advantages, such as good stability, compact structure, and simple fabrication. Therefore, it is more applicable for strain measurement with reducing temperature cross-sensitivity.

  2. Agile Photonic Crystals

    Science.gov (United States)

    2011-01-03

    75, pp. 3253-3256, Oct. 1995. [24] F. Benabid, J. C. Knight, and P. S. J. Russell, “Particle levitation and guidance in hollow-core photonic crystal...B. Mizaikoff, “Midinfrared sensors meet nanotechnology: Trace gas sensing with quantum cascade lasers inside photonic band-gap hollow waveguides

  3. Photonic crystal fibers for supercontinuum generation pumped by a gain-switched CW fiber laser

    DEFF Research Database (Denmark)

    Larsen, Casper; Noordegraaf, Danny; Hansen, Kim P.

    2012-01-01

    Supercontinuum generation in photonics crystal fibers (PCFs) pumped by CW lasers yields high spectral power density and average power. However, such systems require very high pump power and long nonlinear fibers. By on/off modulating the pump diodes of the fiber laser, the relaxation oscillations...... of the laser can be exploited to enhance the broadening process. The physics behind the supercontinuum generation is investigated by sweeping the fiber length, the zero dispersion wavelength, and the fiber nonlinearity. We show that by applying gain-switching a high average output power of up to 30 W can...

  4. Rapid growth of amorphous carbon films on the inner surface of micron-thick and hollow-core fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Longfei [Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Electric Science, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022 (China); Liu, Dongping, E-mail: Dongping.liu@dlnu.edu.cn [Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Electric Science, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022 (China); Zhou, Xinwei [Department of Mechanical Engineering, Zhejiang University, Zhejiang 310007 (China); Song, Ying [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Ni, Weiyuan [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022 (China); Niu, Jinhai; Fan, Hongyu [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China)

    2013-10-01

    Ultrathick (> 25 μm) carbon films were obtained on the inner surface of hollow and micron-thick quartz fibers by confining CH{sub 4}/He or C{sub 2}H{sub 2}/He microplasmas in their hollow cores. The resulting carbon films were studied by using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The microplasma-enhanced chemical vapor deposition (CVD) technique resulted in the uniform growth of amorphous carbon films on the inner surface of very long (> 1 m) hollow-core fibers. Film deposition is performed by using microplasmas at atmospheric pressure and at 50 Pa. The carbon films obtained with the latter show the smooth inner surfaces and the well continuity across the film/optical fiber. Low-pressure CH{sub 4}/He and C{sub 2}H{sub 2}/He microplasmas can lead to a rapid growth (∼ 2.00 μm/min) of carbon films with their thickness of > 25 μm. The optical emission measurements show that various hydrocarbon species were formed in these depositing microplasmas due to the collisions between CH{sub 4}/C{sub 2}H{sub 2} molecules and energetic species. The microplasma-enhanced CVD technique running without the complicated fabrication processes shows its potentials for rapidly depositing the overlong carbon tubes with their inner diameters of tens of microns. - Highlights: • The microplasma device is applied for coating deposition inside hollow-core fibers. • The microplasma device results in > 25 μm-thick carbon films. • The microplasma device is simple for deposition of ultralong carbon tubes.

  5. On-fiber 3D printing of photonic crystal fiber tapers for mode field diameter conversion

    KAUST Repository

    Bertoncini, Andrea; Rajamanickam, Vijayakumar Palanisamy; Liberale, Carlo

    2017-01-01

    The large mismatch between the Mode Field Diameter (MFD) of conventional single-mode fibers (SMFs) and the MFD of highly nonlinear Photonic Crystal Fibers (PCFs), that can be down to 1.5 μm, or Large Mode Area PCF, that can be up to 25 μm, would require a substantial fiber mode size rescaling in order to allow an efficient direct coupling between PCFs and SMFs. Over the years different solutions have been proposed, as fiber splicing of SMF to PCF. However these procedures are not straightforward, as they involve developing special splicing recipes, and can affect PCF optical properties at the splice interface [1].

  6. On-fiber 3D printing of photonic crystal fiber tapers for mode field diameter conversion

    KAUST Repository

    Bertoncini, Andrea

    2017-11-02

    The large mismatch between the Mode Field Diameter (MFD) of conventional single-mode fibers (SMFs) and the MFD of highly nonlinear Photonic Crystal Fibers (PCFs), that can be down to 1.5 μm, or Large Mode Area PCF, that can be up to 25 μm, would require a substantial fiber mode size rescaling in order to allow an efficient direct coupling between PCFs and SMFs. Over the years different solutions have been proposed, as fiber splicing of SMF to PCF. However these procedures are not straightforward, as they involve developing special splicing recipes, and can affect PCF optical properties at the splice interface [1].

  7. Guiding and amplification properties of rod-type photonic crystal fibers with sectioned core doping

    DEFF Research Database (Denmark)

    Selleri, Stefano; Poli, Federica; Passaro, Davide

    2009-01-01

    Rod-type photonic crystal fibers are large mode area double-cladding fibers with an outer diameter of few millimeters which can provide important advantages for high-power lasers and amplifiers. Numerical studies have recently demonstrated the guidance of higher-order modes in these fibers, which...... can worsen the output beam quality of lasers and amplifiers. In the present analysis a sectioned core doping has been proposed for Yb-doped rod-type photonic crystal fibers, with the aim to improve the higher-order mode suppression. A full-vector modal solver based on the finite element method has...

  8. Coherent anti-Stokes Raman scattering microscopy with a photonic crystal fiber based light source

    DEFF Research Database (Denmark)

    Paulsen, H.N.; Hilligsøe, Karen Marie; Thøgersen, J.

    2003-01-01

    A coherent anti-Stokes Raman scattering microscope based on a Ti:sapphire femtosecond oscillator and a photonic crystal fiber is demonstrated. The nonlinear response of the fiber is used to generate the additional wavelength needed in the Raman process. The applicability of the setup is demonstra......A coherent anti-Stokes Raman scattering microscope based on a Ti:sapphire femtosecond oscillator and a photonic crystal fiber is demonstrated. The nonlinear response of the fiber is used to generate the additional wavelength needed in the Raman process. The applicability of the setup...

  9. Fabrication of Shatter-Proof Metal Hollow-Core Optical Fibers for Endoscopic Mid-Infrared Laser Applications

    Directory of Open Access Journals (Sweden)

    Katsumasa Iwai

    2018-04-01

    Full Text Available A method for fabricating robust and thin hollow-core optical fibers that carry mid-infrared light is proposed for use in endoscopic laser applications. The fiber is made of stainless steel tubing, eliminating the risk of scattering small glass fragments inside the body if the fiber breaks. To reduce the inner surface roughness of the tubing, a polymer base layer is formed prior to depositing silver and optical-polymer layers that confine light inside the hollow core. The surface roughness is greatly decreased by re-coating thin polymer base layers. Because of this smooth base layer surface, a uniform optical-polymer film can be formed around the core. As a result, clear interference peaks are observed in both the visible and mid-infrared regions. Transmission losses were also low for the carbon dioxide laser used for medical treatments as well as the visible laser diode used for an aiming beam. Measurements of bending losses for these lasers demonstrate the feasibility of the designed fiber for endoscopic applications.

  10. Tailoring nonlinearity and dispersion of photonic crystal fibers using hybrid cladding

    International Nuclear Information System (INIS)

    Zhao-lun, Liu; Lan-tian, Hou; Wei, Wang

    2009-01-01

    We present a hybrid cladding photonic crystal fiber for shaping high nonlinear and flattened dispersion in a wide range of wavelengths. The new structure adopts hybrid cladding with different pitches, air-holes diameters and air-holes arrayed fashions. The full-vector finite element method with perfectly matched layer is used to investigate the characteristics of the hybrid cladding photonic crystal fiber such as nonlinearity and dispersion properties. The influence of the cladding structure parameters on the nonlinear coefficient and geometric dispersion is analyzed. High nonlinear coefficient and the dispersion properties of fibers are tailored by adjusting the cladding structure parameters. A novel hybrid cladding photonic crystal fiber with high nonlinear coefficient and dispersion flattened which is suited for super continuum generation is designed. (author)

  11. Broadband photonic crystal fiber coupler with polarization selection of coupling ratio

    Science.gov (United States)

    Jaroszewicz, Leszek R.; Stasiewicz, Karol A.; Marć, Paweł; Szymański, Michał

    2010-09-01

    In the paper a new broadband photonic crystal fiber coupler is presented. The proper application of the biconical taper technology has been used for manufacturing the coupler without air holes collapse in LMA10 fiber (NKT Photonics Crystal). This coupler, operates in the weakly coupling condition, protects coupling operation in range from 900 nm to 1700 nm. The coupling ratio between output arms is depending on wavelength and can be tuning by selection the proper input state of polarization. It gives opportunity to use the broadband crystal fiber coupler in many applications in which it is necessary to tune a coupling between output arms during the measurement.

  12. Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope.

    Science.gov (United States)

    Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

    2017-10-26

    A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10 -5 deg/√h.

  13. Exploring the effect of nested capillaries on core-cladding mode resonances in hollow-core antiresonant fibers

    Science.gov (United States)

    Provino, Laurent; Taunay, Thierry

    2018-02-01

    Optimal suppression of higher-order modes (HOMs) in hollow-core antiresonant fibers comprising a single ring of thin-walled capillaries was previously studied, and can be achieved when the condition on the capillary-tocore diameter ratio is satisfied (d/D ≍ 0.68). Here we report on the conditions for maximizing the leakage losses of HOMs in hollow-core nested antiresonant node-less fibers, while preserving low confinement loss for the fundamental mode. Using an analytical model based on coupled capillary waveguides, as well as full-vector finite element modeling, we show that optimal d/D value leading to high leakage losses of HOMs, is strongly correlated to the size of nested capillaries. We also show that extremely high value of degree of HOM suppression (˜1200) at the resonant coupling is almost unchanged on a wide range of nested capillary diameter dN ested values. These results thus suggest the possibility of designing antiresonant fibers with nested elements, which show optimal guiding performances in terms of the HOM loss compared to that of the fundamental mode, for clearly defined paired values of the ratios dN ested/d and d/D. These can also tend towards a single-mode behavior only when the dimensionless parameter dN ested/d is less than 0.30, with identical wall thicknesses for all of the capillaries.

  14. Nonlinear spatial mode imaging of hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Laurila, Marko

    2013-01-01

    Degenerate spontaneous four wave mixing is studied for the rst time in a large mode area hybrid photonic crystal ber, where light con nement is achieved by combined index- and bandgap guiding. Four wave mixing products are generated on the edges of the bandgaps, which is veri ed by numerical and ...... and experimental results. Since the core mode is in resonance with cladding modes near the bandedges an unconventional measurement technique is used, in this work named nonlinear spatial mode imaging....

  15. Hybrid Ytterbium-doped large-mode-area photonic crystal fiber amplifier for long wavelengths

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas T.; Poli, Federica

    2012-01-01

    A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with build-in gain shaping is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes define the large-mode-area core. ...

  16. Sensitivity of photonic crystal fiber grating sensors: biosensing, refractive index, strain, and temperature sensing

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Bang, Ole

    2008-01-01

    We study the sensitivity of fiber grating sensors in the applications of strain, temperature, internal label-free biosensing, and internal refractive index sensing. New analytical expressions for the sensitivities, valid for photonic crystal fibers are rigorously derived. These are generally vali...

  17. Applications of photonic crystal fibers in optical communications - What is in the future?

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Lin, Chinlon

    2005-01-01

    Superior control of guiding properties in photonic-crystal fibers led to several interesting applications in optical communications ranging from nonlinear optical signal processing to high-power fiber amplifiers. This paper will review recent developments and discuss the future possibilities....

  18. Structure fits the purpose: photonic crystal fibers for evanescent-field surface-enhanced Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Oo, M. K .K.; Han, Y.; Kaňka, Jiří; Sukhishvili, S.; Du, H.

    2010-01-01

    Roč. 35, č. 4 (2010), s. 466-468 ISSN 0146-9592 R&D Projects: GA ČR GA102/08/1719 Institutional research plan: CEZ:AV0Z20670512 Keywords : Photonic crystal fiber * Raman spectroscopy * Fiber-optic evanescent sensor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.316, year: 2010

  19. A Novel Low Loss, Highly Birefringent Photonic Crystal Fiber in THz Regime

    DEFF Research Database (Denmark)

    Hasanuzzaman, G. K. M.; Rana, Sohel; Habib, Selim

    2016-01-01

    We present a new kind of dual-hole unit-based porous-core hexagonal photonic crystal fiber (H-PCF) with low loss and high birefringence in terahertz regime. The proposed fiber offers simultaneously high birefringence and low effective material loss (EML) in the frequency range of 0.5-0.85 THz wit...

  20. Strong Light Localization and a Peculiar Feature of Light Leakage in the Negative Curvature Hollow Core Fibers

    Directory of Open Access Journals (Sweden)

    Andrey D. Pryamikov

    2017-11-01

    Full Text Available In this paper we would like to continue a discussion started in our previous work and devoted to the mechanism of light localization in hollow core microstructured fibers with a noncircular core-cladding boundary. It has been shown in many works that, for waveguide microstructures with different types of core-cladding boundary shape, the positions of the transmission bands’ edges can be predicted by applying the well-known anti–resonant reflecting optical waveguide (ARROW model. At the same time, the ARROW model cannot explain the strong light localization and guiding at high material loss inside the transmission bands which are observed in negative curvature hollow core fibers, for example. In this paper we want to clarify our previous findings and consider the light localization process from another point of view, namely, by comparing the light leakage process in waveguide microstructures with different shapes of the core-cladding boundary. The results are discussed based on the ARROW model and a new approach associated with the consideration of spatial dispersion occurring under the interaction of the air core mode with the core-cladding boundary.

  1. Photonic crystal fibers used in a multi-wavelength source and as transmission fiber in a WDM system

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Zsigri, Beata; Peucheret, Christophe

    2004-01-01

    We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF.......We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF....

  2. Low-loss Kagome hollow-core fibers operating from the near- to the mid-IR.

    Science.gov (United States)

    Wheeler, N V; Bradley, T D; Hayes, J R; Gouveia, M A; Liang, S; Chen, Y; Sandoghchi, S R; Abokhamis Mousavi, S M; Poletti, F; Petrovich, M N; Richardson, D J

    2017-07-01

    We report the fabrication and characterization of Kagome hollow-core antiresonant fibers, which combine low attenuation (as measured at ∼30  cm bend diameter) with a wide operating bandwidth and high modal purity. Record low attenuation values are reported: 12.3 dB/km, 13.9 dB/km, and 9.6 dB/km in three different fibers optimized for operation at 1 μm, 1.55 μm, and 2.5 μm, respectively. These fibers are excellent candidates for ultra-high power delivery at key laser wavelengths including 1.064 μm and 2.94 μm, as well as for applications in gas-based sensing and nonlinear optics.

  3. Efficient Mid-Infrared Supercontinuum Generation in Tapered Large Mode Area Chalcogenide Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Petersen, Christian Rosenberg; Engelsholm, Rasmus Dybbro; Markos, Christos

    2017-01-01

    Mid-infrared supercontinuum spanning from 1.8-9  μm with an output power of 41.5 mW is demonstrated by pumping tapered large mode area chalcogenide photonic crystal fibers using a 4 μm optical parametric source.......Mid-infrared supercontinuum spanning from 1.8-9  μm with an output power of 41.5 mW is demonstrated by pumping tapered large mode area chalcogenide photonic crystal fibers using a 4 μm optical parametric source....

  4. Direct writing of fiber optic components in photonic crystal fibers and other specialty fibers

    Science.gov (United States)

    Fernandes, Luis Andre; Sezerman, Omur; Best, Garland; Ng, Mi Li; Kane, Saidou

    2016-04-01

    Femtosecond direct laser writing has recently shown great potential for the fabrication of complex integrated devices in the cladding of optical fibers. Such devices have the advantage of requiring no bulk optical components and no breaks in the fiber path, thus reducing the need for complicated alignment, eliminating contamination, and increasing stability. This technology has already found applications using combinations of Bragg gratings, interferometers, and couplers for the fabrication of optical filters, sensors, and power monitors. The femtosecond laser writing method produces a local modification of refractive index through non-linear absorption of the ultrafast laser pulses inside the dielectric material of both the core and cladding of the fiber. However, fiber geometries that incorporate air or hollow structures, such as photonic crystal fibers (PCFs), still present a challenge since the index modification regions created by the writing process cannot be generated in the hollow regions of the fiber. In this work, the femtosecond laser method is used together with a pre-modification method that consists of partially collapsing the hollow holes using an electrical arc discharge. The partial collapse of the photonic band gap structure provides a path for femtosecond laser written waveguides to couple light from the core to the edge of the fiber for in-line power monitoring. This novel approach is expected to have applications in other specialty fibers such as suspended core fibers and can open the way for the integration of complex devices and facilitate miniaturization of optical circuits to take advantage of the particular characteristics of the PCFs.

  5. Modeling thermo-optic effect in large mode area double cladding photonic crystal fibers

    Science.gov (United States)

    Coscelli, Enrico; Cucinotta, Annamaria

    2014-02-01

    The impact of thermally-induced refractive index changes on the single-mode (SM) properties of large mode area (LMA) photonic crystal fibers are thoroughly investigated by means of a full-vector modal solver with integrated thermal model. Three photonic crystal fiber designs are taken into account, namely the 19-cell core fiber, the large-pitch fiber (LPF) and the distributed modal filtering (DMF) fiber, to assess the effects of the interplay between thermal effects and the high-order mode (HOM) suppression mechanisms exploited in order to obtain effectively SM guiding. The results have shown significant differences in the way the SM regime is changed by the increase of heat load, providing useful hints for the design of LMA fibers for high power lasers.

  6. Supercontinuum generation for coherent anti- Stokes Raman scattering microscopy with photonic crystal fibers

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Isomäki, Antti; Hansen, Kim P.

    2011-01-01

    Photonic crystal fiber (PCF) designs with two zero-dispersion wavelengths (ZDWs) are experimentally investigated in order to suggest a novel PCF for coherent anti-Stokes Raman scattering (CARS) microscopy. From our investigation, we select the optimum PCF design and demonstrate a tailored spectru...

  7. Extremely High-Birefringent Asymmetric Slotted-Core Photonic Crystal Fiber in THz Regime

    DEFF Research Database (Denmark)

    Islam, Raonaqul; Habib, Selim; Hasanuzzaman, G.K.M.

    2015-01-01

    We present a thorough numerical analysis of a highly birefringent slotted porous-core circular photonic crystal fiber (PCF) for terahertz (THz) wave guidance. The slot shaped air-holes break the symmetry of the porous-core which offers a very high birefringence whereas the compact geometry of the...

  8. THz waveguides, devices and hybrid polymer-chalcogenide photonic crystal fibers

    DEFF Research Database (Denmark)

    Bao, Hualong; Markos, Christos; Nielsen, Kristian

    2014-01-01

    In this contribution, we review our recent activities in the design, fabrication and characterization of polymer THz waveguides. Besides the THz waveguides, we finally will also briefly show some of our initial results on a novel hybrid polymer photonic crystal fiber with integrated chalcogenide...

  9. Perturbative modeling of Bragg-grating-based biosensors in photonic-crystal fibers

    DEFF Research Database (Denmark)

    Burani, Nicola; Lægsgaard, Jesper

    2005-01-01

    We present a modeling study carried out to support the design of a novel, to our knowledge, kind of photonic-crystal fiber (PCF)-based sensor. This device, based on a PCF Bragg grating, detects the presence of selected single-stranded DNA molecules, hybridized to a biofilm in the air holes of the...

  10. Broadband multiplex coherent anti-Stokes Raman scattering microscopy employing photonic-crystal fibers

    DEFF Research Database (Denmark)

    Andresen, Esben Ravn; Paulsen, Henrik Nørgaard; Birkedal, Victoria

    2006-01-01

    We demonstrate spectral multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopy and microscopy based on a single Ti:sapphire oscillator and a nonlinear photonic-crystal fiber (PCF). The Stokes pulse is generated by spectral conversion of the laser pulse in a PCF. The pump pulse is eit...

  11. Zero-velocity solitons in high-index photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2011-01-01

    Nonlinear propagation in slow-light states of high-index photonic crystal fibers (PCFs) is studied numerically. To avoid divergencies in dispersion and nonlinear parameters around the zero-velocity mode, a time-propagating generalized nonlinear Schrödinger equation is formulated. Calculated slow-...

  12. Chromatic dispersion of liquid crystal infiltrated capillary tubes and photonic crystal fibers

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Lægsgaard, Jesper; Bang, Ole

    2006-01-01

    We consider chromatic dispersion of capillary tubes and photonic crystal fibers infiltrated with liquid crystals. A perturbative scheme for inclusion of material dispersion of both liquid crystal and the surrounding waveguide material is derived. The method is used to calculate the chromatic...

  13. Polymeric THz 2D Photonic Crystal Filters Fabricated by Fiber Drawing

    DEFF Research Database (Denmark)

    Stecher, Matthias; Jansen, Christian; Ahmadi-Boroujeni, Mehdi

    2012-01-01

    In this paper, we report on a new form of polymeric 2D photonic crystal filters for THz frequencies fabricated using a standard fiber drawing technique. The band stop filters were modeled and designed using the generalized multipole technique. The frequency and angle-dependent transmission...

  14. Long period gratings written in large-mode area photonic crystal fiber

    DEFF Research Database (Denmark)

    Nodop, D.; Linke, S.; Jansen, F.

    2008-01-01

    We report for the first time, to the best of our knowledge, on the fabrication and characterization of CO2-laser written long-period gratings in a large-mode area photonic crystal fiber with a core diameter of 25 mu m. The gratings have low insertion losses ( 10 d...

  15. Picosecond anti-Stokes generation in a photonic-crystal fiber for interferometric CARS microscopy

    DEFF Research Database (Denmark)

    Keiding, Søren Rud

    2006-01-01

    We generate tunable picosecond anti-Stokes pulses by four-wave mixing of two picosecond pump and Stokes pulse trains in a photonic-crystal fiber. The visible, spectrally narrow anti-Stokes pulses with shifts over 150 nm are generated without generating other spectral features. As a demonstration,...

  16. Photonic crystal fiber for layer-by-layer assembly and measurements of polyelectrolyte thin films

    Czech Academy of Sciences Publication Activity Database

    Tian, F.; Kaňka, Jiří; Sukhishvili, S.; Du, H.

    2012-01-01

    Roč. 37, č. 20 (2012), s. 4299-4301 ISSN 0146-9592 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Photonic crystal fiber * Long-period grating * Optical sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.385, year: 2012

  17. Extremely low-loss single-mode photonic crystal fiber in the terahertz regime

    DEFF Research Database (Denmark)

    Islam, Raonaqul; Hasanuzzaman, G. K M; Sadath, Md Anwar

    2015-01-01

    This paper presents an updated design and numerical characterization of a rotated porous-core hexagonal photonic crystal fiber (PCF) for single-mode terahertz (THz) wave guidance. The simulation results are found using an efficient finite element method (FEM) which show a better and ultra-low eff...

  18. Low Loss Single-Mode Porous-Core Kagome Photonic Crystal Fiber for THz Wave Guidance

    DEFF Research Database (Denmark)

    Hasanuzzaman, G. K. M.; Habib, Selim; Abdur Razzak, S. M.

    2015-01-01

    A novel porous-core kagome lattice photonic crystal fiber (PCF) is designed and analyzed in this paper for terahertz (THz) wave guidance. Using finite element method (FEM), properties of the proposed kagome lattice PCF are simulated in details including the effective material loss (EML), confinem...

  19. Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Pedersen, Lars H.; Hoiby, Poul E.

    2004-01-01

    We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding c...

  20. Nanotag-enabled photonic crystal fiber as quantitative surface-enhanced Raman scattering optofluidic platform

    Czech Academy of Sciences Publication Activity Database

    Pinkhasova, P.; Chen, H.; Kaňka, Jiří; Mergo, P.; Du, H.

    2015-01-01

    Roč. 106, č. 7 (2015), 0711061-0711064 ISSN 0003-6951 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Photonic crystal fibers * Raman scattering * Crystal whiskers Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.142, year: 2015

  1. Highly-stable monolithic femtosecond Yb-fiber laser system based on photonic crystal fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2010-01-01

    in the oscillator cavity for dispersion balancing and nonlinear optical limiting, and another one is used for low nonlinearity final pulse recompression. The chirped-pulse amplification and recompression of the 232-fs, 45-pJ/pulse oscillator output yields a final direct fiber-end delivery of 7.3-nJ energy pulses......A self-starting, passively stabilized, monolithic all polarizationmaintaining femtosecond Yb-fiber master oscillator / power amplifier with very high operational and environmental stability is demonstrated. The system is based on the use of two different photonic crystal fibers. One is used...... of around 297 fs duration. Our laser shows exceptional stability. No Q-switched modelocking events were detected during 4-days long observation. An average fluctuation of only 7.85 · 10−4 over the mean output power was determined as a result of more than 6-hours long measurement. The laser is stable towards...

  2. Mid-infrared fiber-coupled supercontinuum spectroscopic imaging using a tapered chalcogenide photonic crystal fiber

    Science.gov (United States)

    Rosenberg Petersen, Christian; Prtljaga, Nikola; Farries, Mark; Ward, Jon; Napier, Bruce; Lloyd, Gavin Rhys; Nallala, Jayakrupakar; Stone, Nick; Bang, Ole

    2018-02-01

    We present the first demonstration of mid-infrared spectroscopic imaging of human tissue using a fiber-coupled supercontinuum source spanning from 2-7.5 μm. The supercontinuum was generated in a tapered large mode area chalcogenide photonic crystal fiber in order to obtain broad bandwidth, high average power, and single-mode output for good imaging properties. Tissue imaging was demonstrated in transmission by raster scanning over a sub-mm region of paraffinized colon tissue on CaF2 substrate, and the signal was measured using a fiber-coupled grating spectrometer. This demonstration has shown that we can distinguish between epithelial and surrounding connective tissues within a paraffinized section of colon tissue by imaging at discrete wavelengths related to distinct chemical absorption features.

  3. Characteristics of 1.9-μm laser emission from hydrogen-filled hollow-core fiber by vibrational stimulated Raman scattering

    Science.gov (United States)

    Gu, Bo; Chen, Yubin; Wang, Zefeng

    2016-12-01

    We report here the characteristics of 1.9-μm laser emission from a gas-filled hollow-core fiber by stimulated Raman scattering (SRS). A 6.5-m hydrogen-filled ice-cream negative curvature hollow-core fiber is pumped with a high peak-power, narrow linewidth, linearly polarized subnanosecond pulsed 1064-nm microchip laser, generating a pulsed vibrational Stokes wave at 1908.5 nm. The maximum quantum efficiency of about 48% is obtained, which is mainly limited by the mode mismatch between the pump laser beam and the Stokes wave in the hollow-core fiber. The linewidths of the pump laser and the first-order vibrational Stokes wave are measured to be about 1 and 2 GHz, respectively, by a scanning Fabry-Perot interferometer. The pressure selection phenomenon of the vibrational anti-Stokes waves is also investigated. The pulse duration of the vibrational Stokes wave is recorded to be narrower than that of the pump laser. The polarization properties of the hollow-core fiber and the polarization dependence of the vibrational and the rotational SRS are also studied. The beam profile of the vibrational Stokes wave shows good quality.

  4. Toward power scaling in an acetylene mid-infrared hollow-core optical fiber gas laser: effects of pressure, fiber length, and pump power

    Science.gov (United States)

    Weerasinghe, H. W. Kushan; Dadashzadeh, Neda; Thirugnanasambandam, Manasadevi P.; Debord, Benoît.; Chafer, Matthieu; Gérôme, Frédéric; Benabid, Fetah; Corwin, Kristan L.; Washburn, Brian R.

    2018-02-01

    The effect of gas pressure, fiber length, and optical pump power on an acetylene mid-infrared hollow-core optical fiber gas laser (HOFGLAS) is experimentally determined in order to scale the laser to higher powers. The absorbed optical power and threshold power are measured for different pressures providing an optimum pressure for a given fiber length. We observe a linear dependence of both absorbed pump energy and lasing threshold for the acetylene HOFGLAS, while maintaining a good mode quality with an M-squared of 1.15. The threshold and mode behavior are encouraging for scaling to higher pressures and pump powers.

  5. Guiding and amplification properties of rod-type photonic crystal fibers with sectioned core doping

    Science.gov (United States)

    Selleri, S.; Poli, F.; Passaro, D.; Cucinotta, A.; Lægsgaard, J.; Broeng, J.

    2009-05-01

    Rod-type photonic crystal fibers are large mode area double-cladding fibers with an outer diameter of few millimeters which can provide important advantages for high-power lasers and amplifiers. Numerical studies have recently demonstrated the guidance of higher-order modes in these fibers, which can worsen the output beam quality of lasers and amplifiers. In the present analysis a sectioned core doping has been proposed for Ybdoped rod-type photonic crystal fibers, with the aim to improve the higher-order mode suppression. A full-vector modal solver based on the finite element method has been applied to properly design the low refractive index ring in the fiber core, which can provide an increase of the differential overlap between the fundamental and the higher-order mode. Then, the gain competition among the guided modes along the Yb-doped rod-type fibers has been investigated with a spatial and spectral amplifier model. Simulation results have shown the effectiveness of the sectioned core doping in worsening the higher-order mode overlap on the doped area, thus providing an effective single-mode behavior of the Yb-doped rod-type photonic crystal fibers.

  6. Frequency tunability of solid-core photonic crystal fibers filled with nanoparticle-doped liquid crystals

    OpenAIRE

    Scolari, Lara; Gauza, Sebastian; Xianyu, Haiqing; Zhai, Lei; Eskildsen, Lars; Alkeskjold, Thomas Tanggaard; Wu, Shin-Tson; Bjarklev, Anders Overgaard

    2009-01-01

    We infiltrate liquid crystals doped with BaTiO3 nanoparticles in a photonic crystal fiber and compare the measured transmission spectrum with the one achieved without dopant. New interesting features, such as frequency modulation response of the device and a transmission spectrum with tunable attenuation on the short wavelength side of the widest bandgap, suggest a potential application of this device as a tunable all-in-fiber gain equalization filter with an adjustable slope. The tunability ...

  7. Simulating human photoreceptor optics using a liquid-filled photonic crystal fiber.

    Science.gov (United States)

    Rativa, Diego; Vohnsen, Brian

    2011-02-11

    We introduce a liquid-filled photonic crystal fiber to simulate a retinal cone photoreceptor mosaic and the directionality selective mechanism broadly known as the Stiles-Crawford effect. Experimental measurements are realized across the visible spectrum to study waveguide coupling and directionality at different managed waveguide parameters. The crystal fiber method is a hybrid tool between theory and a real biological sample and a valuable addition as a retina model for real eye simulations.

  8. New Trends in Amplifiers and Sources via Chalcogenide Photonic Crystal Fibers

    Directory of Open Access Journals (Sweden)

    L. Mescia

    2012-01-01

    Full Text Available Rare-earth-doped chalcogenide glass fiber lasers and amplifiers have great applicative potential in many fields since they are key elements in the near and medium-infrared (mid-IR wavelength range. In this paper, a review, even if not exhaustive, on amplification and lasing obtained by employing rare-earth-doped chalcogenide photonic crystal fibers is reported. Materials, devices, and feasible applications in the mid-IR are briefly mentioned.

  9. Multiple soliton self-frequency shift cancellations in a temporally tailored photonic crystal fiber

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lai; Kang, Zhe; Li, Qing; Gao, Xuejian; Qin, Guanshi, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn; Qin, Weiping, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Liao, Meisong; Hu, Lili [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Ohishi, Yasutake [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2014-11-03

    We report the generation of multiple soliton self-frequency shift cancellations in a temporally tailored tellurite photonic crystal fiber (PCF). The temporally regulated group velocity dispersion (GVD) is generated in the fiber by soliton induced optical Kerr effect. Two red-shifted dispersive waves spring up when two Raman solitons meet their own second zero-dispersion-wavelengths in the PCF. These results show how, through temporally tailored GVD, nonlinearities can be harnessed to generate unexpected effects.

  10. Investigation on the Effect of Underwater Acoustic Pressure on the Fundamental Mode of Hollow-Core Photonic Bandgap Fibers

    Directory of Open Access Journals (Sweden)

    Adel Abdallah

    2015-01-01

    Full Text Available Recently, microstructured optical fibers have become the subject of extensive research as they can be employed in many civilian and military applications. One of the recent areas of research is to enhance the normalized responsivity (NR to acoustic pressure of the optical fiber hydrophones by replacing the conventional single mode fibers (SMFs with hollow-core photonic bandgap fibers (HC-PBFs. However, this needs further investigation. In order to fully understand the feasibility of using HC-PBFs as acoustic pressure sensors and in underwater communication systems, it is important to study their modal properties in this environment. In this paper, the finite element solver (FES COMSOL Multiphysics is used to study the effect of underwater acoustic pressure on the effective refractive index neff of the fundamental mode and discuss its contribution to NR. Besides, we investigate, for the first time to our knowledge, the effect of underwater acoustic pressure on the effective area Aeff and the numerical aperture (NA of the HC-PBF.

  11. Harmonic Mode-Locked Fiber Laser based on Photonic Crystal Fiber Filled with Topological Insulator Solution

    Directory of Open Access Journals (Sweden)

    Yu-Shan Chen

    2015-04-01

    Full Text Available We reported that the photonic crystal fiber (PCF filled with TI:Bi2Te3 nanosheets solution could act as an effective saturable absorber (SA. Employing this TI-PCF SA device; we constructed an ytterbium-doped all-fiber laser oscillator and achieved the evanescent wave mode-locking operation. Due to the large cavity dispersion; the fundamental mode-locking pulse had the large full width at half maximum (FWHM of 2.33 ns with the repetition rate of ~1.11 MHz; and the radio frequency (RF spectrum with signal-to-noise ratio (SNR of 61 dB. In addition; the transition dynamics from a bunched state of pulses to harmonic mode-locking (HML was also observed; which was up to 26th order.

  12. Design of a novel multi channel photonic crystal fiber polarization beam splitter

    Science.gov (United States)

    Zhao, Yunyan; Li, Shuguang; Wang, Xinyu; Wang, Guangyao; Shi, Min; Wu, Junjun

    2017-10-01

    A kind of multi channel dual-core photonic crystal fiber polarization beam splitter is designed. We analyze the effects of the lattice parameters and the thickness of gold layer on the beam splitting by the finite element method. Numerical results show that the thickness of metal layer and the size of the air holes near the fiber cores are closely linked with the nature of the polarization beam splitter. We also obtain that extinction ratio can reach -73.87 dB at 1 . 55 μm wavelength and at 1 . 41 μm, 1 . 65 μm extinction ratio can reach 30.8978 dB and 31.1741 dB, respectively. The comparison of the effect on the characteristic of the photonic crystal fiber with coating no gold is also taken into account.

  13. Soliton self-frequency shift controlled by a weak seed laser in tellurite photonic crystal fibers.

    Science.gov (United States)

    Liu, Lai; Meng, Xiangwei; Yin, Feixiang; Liao, Meisong; Zhao, Dan; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

    2013-08-01

    We report the first demonstration of soliton self-frequency shift (SSFS) controlled by a weak continuous-wave (CW) laser, from a tellurite photonic crystal fiber pumped by a 1560 nm femtosecond fiber laser. The control of SSFS is performed by the cross-gain modulation of the 1560 nm femtosecond laser. By varying the input power of the weak CW laser (1560 nm) from 0 to 1.17 mW, the soliton generated in the tellurite photonic crystal fiber blue shifts from 1935 to 1591 nm. The dependence of the soliton wavelength on the operation wavelength of the weak CW laser is also measured. The results show the CW laser with a wavelength tunable range of 1530-1592 nm can be used to control the SSFS generation.

  14. FIBER LASER CONSTRUCTION AND THEORY INCLUDING FIBER BRAGG GRATINGS Photonic Crystal Fibers (PCFs) and applications of gas filled PCFs

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Jacob O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-08

    The principles used in fiber lasers have been around for a while but it is only within the past few years that fiber lasers have become commercially available and used in high power laser applications. This paper will focus on the basic design principles of fiber lasers, including fiber Bragg gratings, principles of operation, and forms of non-linear effects. It will describe the type and associated doping of the fiber used and difficult designs used to guide energy from the pump to the active medium. Topics covered include fiber laser design, fiber Bragg gratings, materials used, differences in quantum energy loss, thermo-optical effects, stimulated Raman scattering, Brillouin scattering, photonic crystal fibers and applications of gas filled Photonic Crystal Fibers (PCFs). Thanks to fiber lasers, the energy required to produce high power lasers has greatly dropped and as such we can now produce kW power using a standard 120V 15A circuit. High power laser applications are always requiring more power. The fiber laser can now deliver the greater power that these applications demand. Future applications requiring more power than can be combined using standard materials or configurations will need to be developed to overcome the high energy density and high non-linear optical scattering effects present during high power operations.

  15. Band gap of two-dimensional fiber-air photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shu, E-mail: yangshu5678@163.com; Li, Masha

    2016-04-15

    A two-dimensional photonic crystal (PC) composed of textile fiber and air is initially discussed in this paper. Textile materials are so called soft materials, which are different from the previous PCs composed of rigid materials. The plain wave expansion method is used to calculate band structure of different PCs by altering component properties or structural parameters. Results show that the dielectric constant of textile fibers, fiber filling ratio and lattice arrangement are effective factors which influence PCs' band gap. Yet lattice constant and fiber diameter make inconspicuous influence on the band gap feature.

  16. Cross-correlated imaging of single-mode photonic crystal rod fiber with distributed mode filtering

    DEFF Research Database (Denmark)

    Laurila, Marko; Barankov, Roman; Jørgensen, Mette Marie

    2013-01-01

    Photonic crystal bandgap fibers employing distributed mode filtering design provide near diffraction-limited light outputs, a critical property of fiber-based high-power lasers. Microstructure of the fibers is tailored to achieve single-mode operation at specific wavelength by resonant mode...... identify regimes of resonant coupling between higher-order core modes and cladding band. We demonstrate a passive fiber design in which the higher-order modal content inside the single-mode guiding regime is suppressed by at least 20 dB even for significantly misaligned input-coupling configurations....

  17. Theoretical proposal of a low-loss wide-bandwidth silicon photonic crystal fiber for supporting 30 orbital angular momentum modes.

    Directory of Open Access Journals (Sweden)

    Xun Xu

    Full Text Available We propose a novel four-ring hollow-core silicon photonic crystal fiber (PCF, and we systematically and theoretically investigate the properties of their vector modes. Our PCF can stably support 30 OAM states from the wavelength of 1.5 μm to 2.4 μm, with a large effective refractive index separation of above 1×10-4. The confinement loss is less than 1×10-9 dB/m at the wavelength of 1.55 μm, and the average confinement loss is less than 1×10-8 dB/m from the wavelength of 1.2 μm to 2.4 μm. Moreover, the curve of the dispersion tends to flatten as the wavelength increases. In addition, we comparably investigate PCFs with different hole spacing. This kind of fiber structure will be a potential candidate for high-capacity optical fiber communications and OAM sensing applications using fibers.

  18. Midinfrared optical rogue waves in soft glass photonic crystal fiber

    DEFF Research Database (Denmark)

    Buccoliero, Daniel; Steffensen, Henrik; Ebendorff-Heidepriem, Heike

    2011-01-01

    We investigate numerically the formation of extreme events or rogue waves in soft glass tellurite fibers and demonstrate that optical loss drastically diminishes shot-to-shot fluctuations characteristic of picosecond pumped supercontinuum (SC). When loss is neglected these fluctuations include...... distributions. Our results thus implicitly show that rogue waves will not occur in any SC spectrum that is limited by loss, such as commercial silica fiber based SC sources. © 2011 Optical Society of America....

  19. Comment on "Design of a broadband highly dispersive pure silica photonic crystal fiber"

    DEFF Research Database (Denmark)

    Mortensen, Niels Asger

    2008-01-01

    In a recent paper, Subbaraman et al. [Appl. Opt. 46, 3263–3268 (2007)] reported a theoretical and numerical study of highly dispersive pure silica photonic crystal fiber supporting group-velocity dispersion exceeding −2 × 104 ps=nm=km. This Comment argues that the authors consider only one of two...... sides of the same coin by not taking the corresponding beating length into account....

  20. The Orbital Angular Momentum Modes Supporting Fibers Based on the Photonic Crystal Fiber Structure

    Directory of Open Access Journals (Sweden)

    Hu Zhang

    2017-10-01

    Full Text Available The orbital angular momentum (OAM of light can be another physical dimension that we exploit to make multiplexing in the spatial domain. The design of the OAM mode supporting fiber attracts many attentions in the field of the space division multiplexing (SDM system. This paper reviews the recent progresses in photonic crystal fiber (PCF supporting OAM modes, and summarizes why a PCF structure can be used to support stable OAM transmission modes. The emphasis is on the circular PCFs, which possess many excellent features of transmission performance, such as good-quality OAM modes, enough separation of the effective indices, low confinement loss, flat dispersion, a large effective area, and a low nonlinear coefficient. We also compare the transmission properties between the circular PCF and the ring core fiber, as well as the properties between the OAM EDFA based on circular PCF and the OAM EDFA based on the ring core fiber. At last, the challenges and prospects of OAM fibers based on the PCF structure are also discussed.

  1. Analysis of Leaky Modes in Photonic Crystal Fibers Using the Surface Integral Equation Method

    Directory of Open Access Journals (Sweden)

    Jung-Sheng Chiang

    2018-04-01

    Full Text Available A fully vectorial algorithm based on the surface integral equation method for the modelling of leaky modes in photonic crystal fibers (PCFs by solely solving the complex propagation constants of characteristic equations is presented. It can be used for calculations of the complex effective index and confinement losses of photonic crystal fibers. As complex root examination is the key technique in the solution, the new algorithm which possesses this technique can be used to solve the leaky modes of photonic crystal fibers. The leaky modes of solid-core PCFs with a hexagonal lattice of circular air-holes are reported and discussed. The simulation results indicate how the confinement loss by the imaginary part of the effective index changes with air-hole size, the number of rings of air-holes, and wavelength. Confinement loss reductions can be realized by increasing the air-hole size and the number of air-holes. The results show that the confinement loss rises with wavelength, implying that the light leaks more easily for longer wavelengths; meanwhile, the losses are decreased significantly as the air-hole size d/Λ is increased.

  2. Optical tuning of photonic bandgaps in dye-doped nematic liquid crystal photonic crystal fibers

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard; Hermann, David Sparre

    2005-01-01

    An all-optical modulator is demonstrated, which utilizes a pulsed 532 nm laser to modulate the spectral position of the bandgaps in a photonic crystal fiber infiltrated with a dye-doped nematic liquid crystal. In order to investigate the time response of the LCPBG fiber device, a low-power CW probe...... laser was coupled into the fiber together with the pulsed pump laser of 2.3 mW and we have demonstrated a modulation frequency of up to 2 kHz....

  3. Reduction of coupling loss to photonic crystal fibers by controlled hole collapse: A numerical study

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bjarklev, Anders Overgaard

    2004-01-01

    The mode profile evolution of small-core photonic crystal fibers (PCFs) during a gradual collapse of the cladding airholes is investigated. The mode overlap with standard step-index fibers having a small index contrast is calculated, and it is found that overlaps around 90% can be achieved in all...... cases studied, with the proper degree of hole collapse. Thus, hole collapse induced by, e.g. laser irradiation could prove an efficient and practical way of reducing splice losses when coupling small-core PCFs to other fiber types....

  4. Estimation of the Maximum Output Power of Double-Clad Photonic Crystal Fiber Laser

    International Nuclear Information System (INIS)

    Chen Yue-E; Wang Yong; Qu Xi-Long

    2012-01-01

    Compared with traditional optical fiber lasers, double-clad photonic crystal fiber (PCF) lasers have larger surface-area-to-volume ratios. With an increase of output power, thermal effects may severely restrict output power and deteriorate beam quality of fiber lasers. We utilize the heat-conduction equations to estimate the maximum output power of a double-clad PCF laser under natural-convection, air-cooling, and water-cooling conditions in terms of a certain surface-volume heat ratio of the PCF. The thermal effects hence define an upper power limit of double-clad PCF lasers when scaling output power. (fundamental areas of phenomenology(including applications))

  5. All-optical control of group velocity dispersion in tellurite photonic crystal fibers.

    Science.gov (United States)

    Liu, Lai; Tian, Qijun; Liao, Meisong; Zhao, Dan; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

    2012-12-15

    We demonstrate all-optical control of group velocity dispersion (GVD) via optical Kerr effect in highly nonlinear tellurite photonic crystal fibers. The redshift of the zero-dispersion wavelength is over 307 nm, measured by soliton self-frequency shift cancellation, when the pump peak power of a 1.56 μm femtosecond fiber laser is increased to 11.6 kW. The all-optical control of GVD not only offers a new platform for constructing all-optical-control photonic devices but also promises a new class of experiments in nonlinear fiber optics and light-matter interactions.

  6. Photonic crystal fibers: fundamental properties and applications within sensors

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Riishede, Jesper; Broeng, Jes

    2003-01-01

    a large variety of novel optical properties and improvements compared to standard optical fibers. The stack-and-pull procedure used to manufacture PCFs is a highly flexible method offering a large degree of freedom in the fabrication of PCFs with specific characteristics. A few of the remarkable optical...

  7. High power supercontinuum generation in tapered photonic crystal fibers

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper

    2012-01-01

    the concept of a group-acceleration mismatch, that for a given taper length, the downtapering section should be as long as possible to enhance the amount of blueshifted light. We also discuss the noise properties of supercontinuum in uniform and tapered fibers and we demonstrate that the amplitude noise...

  8. Leakage-free, guidance of light in hollow core optical fibers

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou; Broeng, Jes; Bjarklev, Anders Overgaard

    2000-01-01

    Summary form only given. Despite their tremendous success optical fibers of today are limited by the laws of total internal reflection. During the past five years, however, it has become increasingly evident, that a new operational principle of optical fibers is possible, namely guidance due to p...... design of the analyzed fiber is depicted. The central air hole corresponds to the core of the fiber, while the surrounding periodic air/silica region is the cladding structure. The fiber is assumed invariant in the longitudinal direction....

  9. Thermally Optimized Polarization-Maintaining Photonic Crystal Fiber and Its FOG Application.

    Science.gov (United States)

    Zhang, Chunxi; Zhang, Zhihao; Xu, Xiaobin; Cai, Wei

    2018-02-13

    In this paper, we propose a small-diameter polarization-maintaining solid-core photonic crystal fiber. The coating diameter, cladding diameter and other key parameters relating to the thermal properties were studied. Based on the optimized parameters, a fiber with a Shupe constant 15% lower than commercial photonic crystal fibers (PCFs) was fabricated, and the transmission loss was lower than 2 dB/km. The superior thermal stability of our fiber design was proven through both simulation and measurement. Using the small-diameter fiber, a split high precision fiber optic gyro (FOG) prototype was fabricated. The bias stability of the FOG was 0.0023 °/h, the random walk was 0.0003 °/ h , and the scale factor error was less than 1 ppm. Throughout a temperature variation ranging from -40 to 60 °C, the bias stability was less than 0.02 °/h without temperature compensation which is notably better than FOG with panda fiber. As a result, the PCF FOG is a promising choice for high precision FOG applications.

  10. Characteristics of 1.9 μm laser emission from hydrogen-filled hollow-core fiber by stimulated Raman scattering

    Science.gov (United States)

    Gu, Bo; Chen, Yubin; Wang, Zefeng

    2016-11-01

    We report here the detailed characteristics of 1.9 μm laser emission from hydrogen-filled hollow-core fiber by stimulated Raman scattering. A 6.5 m hydrogen-filled Ice-cream negative curvature hollow-core fiber is pumped with a high peak power, narrow linewidth, liner polarized subnanosecond pulsed 1064 nm microchip laser, generating pulsed 1908.5 nm vibrational Stokes wave. The linewidth of the pump laser and the vibrational Stokes wave is about 1 GHz and 2 GHz respectively. And the maximum Raman conversion quantum efficiency is about 48%. We also studied the pulse shapes of the pump laser and the vibrational Stokes wave. The polarization dependence of the vibrational and the rotational stimulated Raman scattering is also investigated. In addition, the beam profile of vibrational Stokes wave shows good quality, which may be taken advantage of in many applications.

  11. Photonic crystal fiber coil sensor for water-depth sensing

    Science.gov (United States)

    Fan, Chen-Feng; Yu, Chin-Ping

    2013-05-01

    We fabricate a PCF coil sensor for water-depth sensing by winding a PCF on a plastic straw. Due to the bending-induced birefringence along the PCF, we can observe clear interference pattern in the output spectrum by placing the PCF coil into a Sagnac fiber loop. As we horizontally immerse the fabricated PCF coil into water, a nonlinear relationship between the water depth and the wavelength shift can be obtained. We have also measured the interference spectrum by vertically immersing the PCF coil into water. We can observe a linear relationship between the water depth and the wavelength shift, and the measured water-depth sensitivity for vertical immersion is -1.17 nm/mm.

  12. Ultra-short pulse delivery at high average power with low-loss hollow core fibers coupled to TRUMPF's TruMicro laser platforms for industrial applications

    Science.gov (United States)

    Baumbach, S.; Pricking, S.; Overbuschmann, J.; Nutsch, S.; Kleinbauer, J.; Gebs, R.; Tan, C.; Scelle, R.; Kahmann, M.; Budnicki, A.; Sutter, D. H.; Killi, A.

    2017-02-01

    Multi-megawatt ultrafast laser systems at micrometer wavelength are commonly used for material processing applications, including ablation, cutting and drilling of various materials or cleaving of display glass with excellent quality. There is a need for flexible and efficient beam guidance, avoiding free space propagation of light between the laser head and the processing unit. Solid core step index fibers are only feasible for delivering laser pulses with peak powers in the kW-regime due to the optical damage threshold in bulk silica. In contrast, hollow core fibers are capable of guiding ultra-short laser pulses with orders of magnitude higher peak powers. This is possible since a micro-structured cladding confines the light within the hollow core and therefore minimizes the spatial overlap between silica and the electro-magnetic field. We report on recent results of single-mode ultra-short pulse delivery over several meters in a lowloss hollow core fiber packaged with industrial connectors. TRUMPF's ultrafast TruMicro laser platforms equipped with advanced temperature control and precisely engineered opto-mechanical components provide excellent position and pointing stability. They are thus perfectly suited for passive coupling of ultra-short laser pulses into hollow core fibers. Neither active beam launching components nor beam trackers are necessary for a reliable beam delivery in a space and cost saving packaging. Long term tests with weeks of stable operation, excellent beam quality and an overall transmission efficiency of above 85 percent even at high average power confirm the reliability for industrial applications.

  13. Silica-air photonic crystal fiber design that permits waveguiding by a true photonic bandgap effect

    DEFF Research Database (Denmark)

    Barkou, Stig Eigil; Broeng, Jes; Bjarklev, Anders Overgaard

    1999-01-01

    A theoretical investigation of a novel type of optical fiber is presented. The operation of the fiber relies entirely on wave guidance through the photonic bandgap effect and not on total internal reflection, thereby distinguishing that fiber from all other known fibers, including recently studied...... photonic crystal fibers. The novel fiber has a central low-index core region and a cladding consisting of a silica background material with air holes situated within a honeycomb lattice structure. We show the existence of photonic bandgaps for the silica–air cladding structure and demonstrate how light can...... be guided at the central low-index core region for a well-defined frequency that falls inside the photonic bandgap region of the cladding structure....

  14. Monolithic all-PM femtosecond Yb-doped fiber laser using photonic bandgap fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2009-01-01

    We present a monolithic Yb fiber laser, dispersion managed by an all-solid photonic bandgap fiber, and pulse compressed in a hollow-core photonic crystal fiber. The laser delivers 9 nJ, 275-fs long pulses at 1035 nm.......We present a monolithic Yb fiber laser, dispersion managed by an all-solid photonic bandgap fiber, and pulse compressed in a hollow-core photonic crystal fiber. The laser delivers 9 nJ, 275-fs long pulses at 1035 nm....

  15. Design of turn-around-point long-period gratings in a photonic crystal fiber for refractometry of gases

    Czech Academy of Sciences Publication Activity Database

    Kaňka, Jiří

    2013-01-01

    Roč. 182, č. 6 (2013), s. 16-24 ISSN 0925-4005 R&D Projects: GA MŠk(CZ) LD11030; GA MŠk(CZ) LF11001 Institutional support: RVO:67985882 Keywords : Fiber design * Photonic crystal fiber * Microstructured optical fiber Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.840, year: 2013

  16. Low loss and flat dispersion Kagome photonic crystal fiber in the terahertz regime

    Science.gov (United States)

    Rana, Sohel; Rakin, Adnan Siraj; Hasan, Md. Rabiul; Reza, Md. Salim; Leonhardt, Rainer; Abbott, Derek; Subbaraman, Harish

    2018-03-01

    A novel fiber design based on hexagonal shaped holes incorporated within the core of a Kagome lattice photonic crystal fiber (PCF) is presented. The modal properties of the proposed fiber are evaluated by using a finite element method (FEM) with a perfectly matched layer as boundary condition. Simulation results exhibit an ultra-low effective material loss (EML) of 0.029 cm-1 at an operating frequency of 1.3 THz with an optimized core diameter of 300 μm. A positive, low, and flat dispersion of 0.49 ± 0.06 ps/THz/cm is obtained within a broad frequency range from 1.00 to 1.76 THz. Other essential guiding features of the designed fiber such as power fraction and confinement loss are studied. The fabrication possibilities are also investigated to demonstrate feasibility for a wide range of terahertz applications.

  17. Mach-Zehnder interferometric photonic crystal fiber for low acoustic frequency detections

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Dnyandeo; Rao, Ch. N.; Kale, S. N., E-mail: sangeetakale2004@gmail.com [Department of Applied Physics, Defence Institute of Advanced Technology (DU), Girinagar, Pune 411 025, Maharashtra (India); Choubey, Ravi Kant [Department of Applied Physics, Amity Institute of Applied Sciences, Amity University, Noida 201 313 (India)

    2016-01-25

    Low frequency under-water acoustic signal detections are challenging, especially for marine applications. A Mach-Zehnder interferometric hydrophone is demonstrated using polarization-maintaining photonic-crystal-fiber (PM-PCF), spliced between two single-mode-fibers, operated at 1550 nm source. These data are compared with standard hydrophone, single-mode and multimode fiber. The PM-PCF sensor shows the highest response with a power shift (2.32 dBm) and a wavelength shift (392.8 pm) at 200 Hz. High birefringence values and the effect of the imparted acoustic pressure on this fiber, introducing the difference between the fast and slow axis changes, owing to the phase change in the propagation waves, demonstrate the strain-optic properties of the sensor.

  18. Flat Supercontinuum Generation within the Telecommunication Wave Bands in a Photonic Crystal Fiber with Central Holes

    International Nuclear Information System (INIS)

    Han Ying; Hou Lan-Tian; Zhou Gui-Yao; Xia Chang-Ming; Wang Wei; Wang Chao; Hou Zhi-Yun; Yuan Jin-Hui

    2012-01-01

    Flat supercontinuum in the telecommunication wave bands of E+S+C is generated by coupling a train of femtosecond pulses generated by a mode-locked Ti:sapphire laser into the fundamental mode of a photonic crystal fiber with central holes fabricated in our lab. The pulse experiences the anomalous dispersion regime, and the soliton dynamic effect plays an important role in supercontinuum generation. The output spectrum in the wavelength range of 1360–1565 nm does not include significant ripples due to higher pump peak power, and the normalized intensity shows less fluctuation. (fundamental areas of phenomenology(including applications))

  19. Low-loss photonic crystal fibers for data transmission and their dispersion properties

    DEFF Research Database (Denmark)

    Nielsen, Martin Dybendal; Jacobsen, Christian; Mortensen, Niels Asger

    2004-01-01

    We report on a single-mode photonic crystal fiber with attenuation and effective area at 1550 nm of 0.48 dB/km and 130 µm2, respectively. This is, to our knowledge, the lowest loss reported for a PCF not made from VAD prepared silica and at the same time the largest effective area for a low......-loss (data transmission and show for the first time, both numerically and experimentally, how the group velocity dispersion is related to the mode field diameter....

  20. In-line microfluidic refractometer based on C-shaped fiber assisted photonic crystal fiber Sagnac interferometer.

    Science.gov (United States)

    Wu, Chuang; Tse, Ming-Leung Vincent; Liu, Zhengyong; Guan, Bai-Ou; Lu, Chao; Tam, Hwa-Yaw

    2013-09-01

    We propose and demonstrate a highly sensitive in-line photonic crystal fiber (PCF) microfluidic refractometer. Ultrathin C-shaped fibers are spliced in-between the PCF and standard single-mode fibers. The C-shaped fibers provide openings for liquid to flow in and out of the PCF. Based on a Sagnac interferometer, the refractive index (RI) response of the device is investigated theoretically and experimentally. A high sensitivity of 6621 nm/RIU for liquid RI from 1.330 to 1.333 is achieved in the experiment, which agrees well with the theoretical analysis.

  1. Electrically tunable zero dispersion wavelengths in photonic crystal fibers filled with a dual frequency addressable liquid crystal

    International Nuclear Information System (INIS)

    Wahle, Markus; Kitzerow, Heinz-Siegfried

    2015-01-01

    We present a liquid crystal (LC) infiltrated photonic crystal fiber, which enables the electrical tuning of the position of zero dispersion wavelengths (ZDWs). A dual frequency addressable liquid crystal is aligned perpendicular on the inclusion walls of a photonic crystal fiber, which results in an escaped radial director field. The orientation of the LC is controlled by applying an external electric field. Due to the high index of the liquid crystal the fiber guides light by the photonic band gap effect. Multiple ZDWs exist in the visible and near infrared. The positions of the ZDWs can be either blue or red shifted depending on the frequency of the applied voltage

  2. Degenerate four wave mixing in large mode area hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Lægsgaard, Jesper

    2013-01-01

    Spontaneous degenerate four wave mixing (FWM) is investigated in large mode area hybrid photonic crystal fibers, in which photonic bandgap guidance and index guidance is combined. Calculations show the parametric gain is maximum on the edge of a photonic bandgap, for a large range of pump...... wavelengths. The FWM products are observed on the edges of a transmission band experimentally, in good agreement with the numerical results. Thereby the bandedges can be used to control the spectral positions of FWM products through a proper fiber design. The parametric gain control combined with a large mode...... area fiber design potentially allows for power scaling of light at wavelengths not easily accessible with e.g. rare earth ions....

  3. Ytterbium-doped large-mode-area photonic crystal fiber amplifier with gain shaping for use at long wavelengths

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas T.; Poli, Federica

    2012-01-01

    A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with efficient suppression of amplified spontaneous emission is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes...

  4. Efficient fiber-coupled single-photon source based on quantum dots in a photonic-crystal waveguide

    DEFF Research Database (Denmark)

    Daveau, Raphaël S.; Balram, Krishna C.; Pregnolato, Tommaso

    2017-01-01

    Many photonic quantum information processing applications would benefit from a high brightness, fiber-coupled source of triggered single photons. Here, we present a fiber-coupled photonic-crystal waveguide (PCWG) singlephoton source relying on evanescent coupling of the light field from a tapered...

  5. Fiber up-tapering and down-tapering for low-loss coupling between anti-resonant hollow-core fiber and solid-core fiber

    Science.gov (United States)

    Zhang, Naiqian; Wang, Zefeng; Xi, Xiaoming

    2017-10-01

    In this paper, we demonstrate a novel method for the low-loss coupling between solid-core multi-mode fibers (MMFs) and anti-resonant hollow-core fibers (AR-HCFs). The core/cladding diameter of the MMF is 50/125μm and the mode field diameter of the AR-HCFs are 33.3μm and 71.2μm of the ice-cream type AR-HCFs and the non-node type ARHCFs, respectively. In order to match the mode field diameters of these two specific AR-HCFs, the mode field diameter of the MMFs is increased or decreased by up-tapering or down-tapering the MMFs. Then, according to the principle of coupled fiber mode matching, the optimal diameter of tapered fiber for low-loss coupling is calculated. Based on beam propagation method, the calculated coupling losses without tapering process are 0.31dB and 0.89dB, respectively for a MMF-HCF-MMF structure of the ice-cream type AR-HCFs and the non-node type AR-HCFs. These values can be reduced to 0.096dB and 0.047dB when the outer diameters of the MMF are down-tapered to 116μm and up-tapered to 269μm, respectively. What's more, these results can also be verified by existing experiments.

  6. Photonic crystal fiber as lab-in-fiber optofluidic platform for sensing and process monitoring

    Science.gov (United States)

    Tian, Fei

    The ability to design and fabricate photonic crystal fiber (PCF) of vastly different microstructural and optical characteristics is arguably one of the most significant recent advances in the field of fiber optics. This dissertation aims to advance the PCF research frontier by exploring long-period fiber gratings (LPG) inscribed in PCF for sensing and process monitoring via combined numerical and experimental investigation. Specifically, a mode solver based on the Finite Element Method (FEM) has been employed to calculate the mode field distribution, the phase matching condition, and the dispersive characteristics associated with LPG-induced coupling of the fundamental core mode (LP01) to various cladding modes (LPmn, m=0,1; n=2,3, ...) in an endlessly single mode PCF. The numerical results have been used to guide the design and fabrication of LPG in PCF by CO2 laser inscription to maximize index sensitivity in gas or liquid medium. Cascaded PCF-LPG has been fabricated and shown to exhibit record sensitivity in excess of 1700 nm/RIU with high resolution for index measurements of gas phase. The inherent interference fringes in the transmission spectrum of cascaded PCF-LPG have been utilized to analyze mode coupling behaviour. In addition, we have developed and implemented a reflective mirror-aided method to allow symmetrical CO2 laser irradiation of PCF during LPG inscription. Both numerical analysis and experimental measurements have shown significantly improved mode coupling behaviour, mode field distribution, as well as reproducibility in LPG fabrication, critical for practical exploitation of the PCF-LPG platform. We have further exploited the high index sensitivity of PCF-LPG to monitor layer-by-layer (LbL) self-assembly of poly(vinyl pyrrolidone) (PVPON) and poly(methacrylic acid) (PMAA) polyelectrolyte layers as well as the pH responsiveness of the cross-linked PMAA hydrogel films. A shift of ˜1.625 nm in the resonance wavelength per polyelectrolyte layer

  7. Photonic crystal fiber injected with Fe{sub 3}O{sub 4} nanofluid for magnetic field detection

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Harneet V.; Nalawade, Sandipan M.; Gupta, Swati [Photonics Group, Department of Applied Physics, Defence Institute of Advanced Technology, Girinagar, Pune 411 025 (India); Kitture, Rohini [Department of Electronic-Science, Fergusson College, Pune 411 004 (India); Kale, S. N. [Nanotechnology Group, Department of Applied Physics, Defence Institute of Advanced Technology, Girinagar, Pune 411 025 (India)

    2011-10-17

    We report a magnetic field sensor having advantages of both photonic crystal fiber and optofluidics, combining them on a single platform by infiltrating small amount of Fe{sub 3}O{sub 4} magnetic optofluid/nanofluid in cladding holes of polarization-maintaining photonic crystal fiber. We demonstrated that magnetic field of few mT can be easily and very well detected with higher sensitivity of 242 pm/mT. The change in the birefringence values has been correlated to the response of nanofluid to applied field.

  8. Thermal optical nonlinearity in photonic crystal fibers filled with nematic liquid crystals doped with gold nanoparticles

    Science.gov (United States)

    Lesiak, Piotr; Budaszewski, Daniel; Bednarska, Karolina; Wójcik, Michał; Sobotka, Piotr; Chychłowski, Miłosz; Woliński, Tomasz R.

    2017-05-01

    In this work we studied a newly reported class of nonlinear effects observed in 5CB liquid crystals doped with gold nanoparticles (GNPs). The size of the GNP was determined by direct TEM imaging and by X-ray scattering of the diluted NP solution. GNPs was coated by thiols with the ratio of mesogenic to n-alkyl thiols varying from 1:2 to 1:1. The research involved comparing properties of both undoped and doped 5CB (nematic LC) by infiltrating LC cell and microholes of the photonic crystal fiber (PCF) separately. In our experiment the PCF fiber type LMA-10 made by NKT Photonics as host material has been used.

  9. Ultrabroadband, Midinfrared Supercontinuum Generation in Dispersion Engineered As2Se3-Based Chalcogenide Photonic Crystal Fibers

    Directory of Open Access Journals (Sweden)

    Rim Cherif

    2013-01-01

    Full Text Available Small core As2Se3-based photonic crystal fibers (PCFs are accurately characterized for compact, high power, ultrabroadband, and coherent supercontinuum generation within few millimeters fiber length. Bandwidths of ~5.3 μm, 5 μm, and 3.2 μm were calculated for hole-to-hole spacings Λ= 3.5 μm, 4.5 μm, and 5.5 μm, respectively. The spectral broadening in the chalcogenide PCF is mainly caused by self-phase modulation and Raman-induced soliton self-frequency shift. The results show that small core As2Se3 PCFs are a promising candidate for mid-IR SCG up to ~8 μm.

  10. Ultrabroadband polarization splitter based on three-core photonic crystal fiber with a modulation core.

    Science.gov (United States)

    Zhao, Tongtong; Lou, Shuqin; Wang, Xin; Zhou, Min; Lian, Zhenggang

    2016-08-10

    We design an ultrabroadband polarization splitter based on three-core photonic crystal fiber (PCF). A modulation core and two fluorine-doped cores are introduced to achieve an ultrawide bandwidth. The properties of three-core PCF are modeled by using the full-vector finite element method along with the full-vector beam propagation method. Numerical results demonstrate that an ultrabroadband splitter with 320 nm bandwidth with an extinction ratio as low as -20  dB can be achieved by using 52.8 mm long three-core PCF. This splitter also has high compatibility with standard single-mode fibers as the input and output ports due to low splicing loss of 0.02 dB. All the air holes in the proposed structure are circular holes and arranged in a triangular lattice that makes it easy to fabricate.

  11. Design of single-polarization wavelength splitter based on photonic crystal fiber.

    Science.gov (United States)

    Zhang, Shanshan; Zhang, Weigang; Geng, Pengcheng; Li, Xiaolan; Ruan, Juan

    2011-12-20

    A new single-polarization wavelength splitter based on the photonic crystal fiber (PCF) has been proposed. The full-vector finite-element method (FEM) is applied to analyze the single-polarization single-mode guiding properties. Splitting of two different wavelengths is realized by adjusting the structural parameters. The semi-vector three-dimensional beam propagation method is employed to confirm the wavelength splitting characteristics of the PCF. Numerical simulations show that the wavelengths of 1.3 μm and 1.55 μm are split for a fiber length of 10.7 mm with single-polarization guiding in each core. The crosstalk between the two cores is low over appreciable optical bandwidths.

  12. Stress induced birefringence in hybrid TIR/PBG guiding solid photonic crystal fibers

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, Brian Joseph; Olausson, Christina Bjarnal Thulin

    2010-01-01

    We report on two types of polarization maintaining solid photonic crystal fibers that guide light by a combination of a photonic bandgap and total internal reflection. Group and phase birefringence are studied experimentally and numerically for stress-applying parts made from B-doped and F......-doped silica. The stress field originating from Ge-doped cladding rods is shown to interfere with the stress field from the B-doped and F-doped rods. Since the differential expansion coefficients of B-doped and F-doped silica have opposite signs this interference is either destructive or constructive....... Consequently, we found that the fiber with F-doped stress applying parts has the highest modal phase birefringence, and polarization cross talk is characterized by an h-parameter below 3⋅10−5 m−1....

  13. Field analysis of TE and TM modes in photonic crystal Bragg fibers by transmission matrix method

    Directory of Open Access Journals (Sweden)

    M Hosseini Farzad

    2010-03-01

    Full Text Available In this article, we considered the field analysis in photonic crystal Bragg fibers. We apply the method of transmission matrix to calculater the dispersion curves, the longitudinal wave number over wave number versus incident wavelength, and the field distributions of TE and TM modes in the Bragg fiber. Our analysis shows that the field of guided modes is confined in the core and can exist only in particular wavelength bands corresponding to the band-gap of the periodic structure of the clad. From another point of view, light confinement is due to Bragg reflection from high-and low-refractive index layers of the clad. Also, the diagram of average angular frequency with respect to average longitudinal wave number is plotted so that the band gap regions of the clad are clearly observed.

  14. Two Octaves Supercontinuum Generation in Lead-Bismuth Glass Based Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    Ryszard Buczynski

    2014-06-01

    Full Text Available In this paper we report a two octave spanning supercontinuum generation in a bandwidth of 700–3000 nm in a single-mode photonic crystal fiber made of lead-bismuth-gallate glass. To our knowledge this is the broadest supercontinuum reported in heavy metal oxide glass based fibers. The fiber was fabricated using an in-house synthesized glass with optimized nonlinear, rheological and transmission properties in the range of 500–4800 nm. The photonic cladding consists of 8 rings of air holes. The fiber has a zero dispersion wavelength (ZDW at 1460 nm. Its dispersion is determined mainly by the first ring of holes in the cladding with a relative hole size of 0.73. Relative hole size of the remaining seven rings is 0.54, which allows single mode performance of the fiber in the infrared range and reduces attenuation of the fundamental mode. The fiber is pumped into anomalous dispersion with 150 fs pulses at 1540 nm. Observed spectrum of 700–3000 nm was generated in 2 cm of fiber with pulse energy below 4 nJ. A flatness of 5 dB was observed in 950–2500 nm range.

  15. Photonic crystal pioneer

    Science.gov (United States)

    Anscombe, Nadya

    2011-08-01

    Over the past ten years, Crystal Fiber, now part of NKT Photonics, has been busy commercializing photonic crystal fibre. Nadya Anscombe finds out about the evolution of the technology and its applications.

  16. Thermal Stress-Induced Depolarization Loss in Conventional and Panda-Shaped Photonic Crystal Fiber Lasers

    Science.gov (United States)

    Mousavi, Seyedeh Laleh; Sabaeian, Mohammad

    2016-10-01

    We report on the modeling of the depolarization loss in the conventional and panda-shaped photonic crystal fiber lasers (PCFLs) due to the self-heating of the fiber, which we call it thermal stress-induced depolarization loss (TSIDL). We first calculated the temperature distribution over the fiber cross sections and then calculated the thermal stresses/strains as a function of heat load per meter. Thermal stress-induced birefringence (TSIB), which is defined as | n x - n y |, in the core and cladding regions was calculated. Finally, TSIDL was calculated for the conventional and panda-shaped PCFLs as a function of fiber length and, respectively, saturated values of 22 and 25 % were obtained which were independent of heat load per meter. For panda-shaped PCFLs, prior to being saturated, an oscillating and damping behavior against the fiber length was seen where in some lengths reached 35 %. The results are close to an experimental value of 30 % reported for a pulsed PCFL (Limpert et al., Opt Express 12:1313-1319, 2004) where the authors reported a degree of polarization of 70 % (i.e., a depolarization of 30 %). The most important result of this work is a saturation behavior of TSIDL at long-enough lengths of the fiber laser which is independent of heat load per meter. To our knowledge, this the first report of TSIBL for PCFLs.

  17. Efficient 1.9 μm emission in H2-filled hollow core fiber by pure stimulated vibrational Raman scattering

    International Nuclear Information System (INIS)

    Wang, Zefeng; Yu, Fei; Wadsworth, William J; Knight, Jonathan C

    2014-01-01

    We report here efficient 1.9 μm emission by pure stimulated vibrational Raman scattering in a hydrogen-filled anti-resonant hollow-core fiber pumped with a 1064 nm microchip laser. A maximum quantum conversion efficiency ∼48% was achieved by using a 6.5 m length of fiber filled with 23 bar hydrogen, with a maximum peak output power >2 kW. By properly designing the transmission bands of the fiber, selecting alternative pump sources and active gases, the emission wavelength could be extended into the mid-infrared. This provides a potential route for generating efficient, compact, broadly tunable, high power, and narrow linewidth mid-infrared fiber gas lasers with broad application in defense, environmental, and medical monitoring. (letter)

  18. Bend-insensitive single-mode photonic crystal fiber with ultralarge effective area for dual applications

    Science.gov (United States)

    Islam, Md. Asiful; Alam, M. Shah

    2013-05-01

    A novel photonic crystal fiber (PCF) having circular arrangement of cladding air holes has been designed and numerically optimized to obtain a bend insensitive single mode fiber with large mode area for both wavelength division multiplexing (WDM) communication and fiber-to-the-home (FTTH) application. The bending loss of the proposed bent PCF lies in the range of 10-3 to 10-4 dB/turn or lower over 1300 to 1700 nm, and 2 × 10-4 dB/turn at the wavelength of 1550 nm for a 30-mm bend radius with a higher order mode (HOM) cut-off frequency below 1200 nm for WDM application. When the whole structure of the PCF is scaled down, a bending loss of 6.78×10-4 dB/turn at 1550 nm for a 4-mm bend radius is obtained, and the loss remains in the order of 10-4 dB/turn over the same range of wavelength with an HOM cut-off frequency below 700 nm, and makes the fiber useful for FTTH applications. Furthermore, this structure is also optimized to show a splice loss near zero for fusion-splicing to a conventional single-mode fiber (SMF).

  19. Extension of supercontinuum spectrum, generated in polarization-maintaining photonic crystal fiber, using chirped femtosecond pulses

    Science.gov (United States)

    Vengelis, Julius; Jarutis, Vygandas; Sirutkaitis, Valdas

    2018-01-01

    We present results of experimental and numerical investigation of supercontinuum (SC) generation in polarization-maintaining photonic crystal fiber (PCF) using chirped femtosecond pulses. The initial unchirped pump pulse source was a mode-locked Yb:KGW laser generating 52-nJ energy, 110-fs duration pulses at 1030 nm with a 76-MHz repetition rate. The nonlinear medium was a 32-cm-long polarization-maintaining PCF manufactured by NKT Photonics A/S. We demonstrated the influence of pump pulse chirp on spectral characteristics of a SC. We showed that by chirping pump pulses positively or negatively one can obtain a broader SC spectrum than in the case of unchirped pump pulses at the same peak power. Moreover, the extension can be controlled by changing the amount of pump pulse chirp. Numerical simulation results also indicated that pump pulse chirp yields an extension of SC spectrum.

  20. Polarization splitter based on interference effects in all-solid photonic crystal fibers.

    Science.gov (United States)

    Mao, Dong; Guan, Chunying; Yuan, Libo

    2010-07-01

    We propose a novel kind of polarization splitter in all-solid photonic crystal fibers based on the mode interference effects. Both the full-vector finite-element method and the semi-vector three-dimensional beam propagation method are employed to design and analyze the characteristics of the splitter. Numerical simulations show that x-polarized and y-polarized modes are split entirely along with 6.8 mm long propagation. An extinction ratio of more than 20 dB and a crosstalk of less than -20 dB are obtained within the wavelength range of 1.541-1.556 microm. The extinction ratio and the crosstalk at 1.55 microm are 28.9 and -29.0 dB for x polarization, while the extinction ratio and the crosstalk at 1.55 microm are 29.9 and -29.8 dB for y polarization, respectively.

  1. Dynamics of Dispersive Wave Generation in Gas-Filled Photonic Crystal Fiber with the Normal Dispersion

    Directory of Open Access Journals (Sweden)

    Zhixiang Deng

    2017-01-01

    Full Text Available The absence of Raman and unique pressure-tunable dispersion is the characteristic feature of gas-filled photonic crystal fiber (PCF, and its zero dispersion points can be extended to the near-infrared by increasing gas pressure. The generation of dispersive wave (DW in the normal group velocity dispersion (GVD region of PCF is investigated. It is demonstrated that considering the self-steepening (SS and introducing the chirp of the initial input pulse are two suitable means to control the DW generation. The SS enhances the relative average intensity of blue-shift DW while weakening that of red-shift DW. The required propagation distance of DW emission is markedly varied by introducing the frequency chirp. Manipulating DW generation in gas-filled PCF by the combined effects of either SS or chirp and three-order dispersion (TOD provides a method for a concentrated transfer of energy into the targeted wavelengths.

  2. Temperature Compensated Strain Sensor Based on Cascaded Sagnac Interferometers and All-Solid Birefringent Hybrid Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Gu, Bobo; Yuan, Wu; He, Sailing

    2012-01-01

    We demonstrate a temperature compensated strain sensor with two cascaded Sagnac interferometers, that provide strain sensing and temperature compensation, respectively. The Sagnac interferometers use an all-solid hybrid photonic crystal fiber with stress-induced birefringence. The stress-induced ...

  3. Highly birefringent photonic crystal fiber with ultra-flattened negative dispersion over S + C + L + U bands

    DEFF Research Database (Denmark)

    Habib, Selim; Khandker, Emran

    2015-01-01

    We present a new cladding design for photonic crystal fiber (PCF) on a decagonal structure to simultaneously achieve ultra-flattened large negative dispersion and ultrahigh birefringence. Numerical results confirm that the proposed PCFexhibits ultra-flattened large negative dispersion over the S ...

  4. A novel Zeonex based oligoporous-core photonic crystal fiber for polarization preserving terahertz applications

    Science.gov (United States)

    Islam, Md. Saiful; Sultana, Jakeya; Dinovitser, Alex; Ng, Brian W.-H.; Abbott, Derek

    2018-04-01

    A novel waveguide consisting of oligo-porous core photonic crystal fiber (PCF) with a kagome lattice cladding has been designed for highly birefringent and near zero dispersion flattened applications of terahertz waves. The wave guiding properties of the designed PCF including birefringence, dispersion, effective material loss (EML), core power fraction, confinement loss, and modal effective area are investigated using a full vector Finite Element Method (FEM) with Perfectly Matched Layer (PML) absorbing boundary condition. Simulation results demonstrate that an ultra-high birefringence of 0.079, low EML of 0.05 cm-1, higher core power fraction of 44% and negligible confinement loss of 7 . 24 × 10-7 cm-1 can be achieved at 1 THz. Furthermore, for the y-polarization mode a near zero flattened dispersion of 0 . 49 ± 0 . 05 ps/THz/cm is achieved within a broad frequency range of 0.8-1.7 THz. The fabrication of the proposed fiber is feasible using the existing fabrication technology. Due to favorable wave-guiding properties, the proposed fiber has potential for terahertz imaging, sensing and polarization maintaining applications in the terahertz frequency range.

  5. 2-µm wavelength-range low-loss inhibited-coupling hollow-core PCF

    Science.gov (United States)

    Maurel, M.; Chafer, M.; Delahaye, F.; Amrani, F.; Debord, B.; Gerome, F.; Benabid, F.

    2018-02-01

    We report on the design and fabrication of inhibited-coupling guiding hollow-core photonic crystal fiber with a transmission band optimized for low loss guidance around 2 μm. Two fibers design based on a Kagome-lattice cladding have been studied to demonstrate a minimum loss figure of 25 dB/km at 2 μm associated to an ultra-broad transmission band spanning from the visible to our detection limit of 3.4 μm. Such fibers could be an excellent tool to deliver and compress ultra-short pulse laser systems, especially for the emerging 2-3 μm spectral region.

  6. Tunable microwave signal generation based on an Opto-DMD processor and a photonic crystal fiber

    International Nuclear Information System (INIS)

    Wang Tao; Sang Xin-Zhu; Yan Bin-Bin; Li Yan; Song Fei-Jun; Zhang Xia; Wang Kui-Ru; Yuan Jin-Hui; Yu Chong-Xiu; Ai Qi; Chen Xiao; Zhang Ying; Chen Gen-Xiang; Xiao Feng; Kamal Alameh

    2014-01-01

    Frequency-tunable microwave signal generation is proposed and experimentally demonstrated with a dual-wavelength single-longitudinal-mode (SLM) erbium-doped fiber ring laser based on a digital Opto-DMD processor and four-wave mixing (FWM) in a high-nonlinear photonic crystal fiber (PCF). The high-nonlinear PCF is employed for the generation of the FWM to obtain stable and uniform dual-wavelength oscillation. Two different short passive sub-ring cavities in the main ring cavity serve as mode filters to make SLM lasing. The two lasing wavelengths are electronically selected by loading different gratings on the Opto-DMD processor controlled with a computer. The wavelength spacing can be smartly adjusted from 0.165 nm to 1.08 nm within a tuning accuracy of 0.055 nm. Two microwave signals at 17.23 GHz and 27.47 GHz are achieved. The stability of the microwave signal is discussed. The system has the ability to generate a 137.36-GHz photonic millimeter signal at room temperature

  7. Monolithic stabilized Yb-fiber All-PM laser directly delivering nJ-level femtosecond pulses

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

    2008-01-01

    We present a monolithic, self-starting, all-PM, stabilized Yb-fiber laser, pulse-compressed in a hollow-core PM photonic crystal fiber, providing the 370 fs pulses of 4 nJ energy with high mode quality.......We present a monolithic, self-starting, all-PM, stabilized Yb-fiber laser, pulse-compressed in a hollow-core PM photonic crystal fiber, providing the 370 fs pulses of 4 nJ energy with high mode quality....

  8. Plasmonic excitations on metallic nanowires embedded in silica photonic crystal fibers

    International Nuclear Information System (INIS)

    Prill Sempere, Luis

    2010-01-01

    This thesis describes the theoretical and experimental investigation of metal-filled photonic crystal fibers (PCFs) and their fabrication. The thesis explains how to overcome the obstacles when infiltrating molten metals into sub-micron holes in fused silica (SiO 2 ) PCF. The optical properties of such filled fibers are theoretically and experimentally investigated, focusing on the coupling between the core mode of the fibers and the surface plasmon polaritons (SPPs) on the metal wires. The thesis introduces the ideas, physical challenges and results of two new filling techniques: the pressure cell technique and the splicing technique. These techniques make it possible for the first time to fill different fiber structures with sub-micron sized holes, such as PCFs and single-hole capillaries, with different metals like gold (Au) and silver (Ag). Samples with hole diameters between 120 nm and 20 μm and aspect ratios as high as 75000 have been realized. Theoretical simulations and models have been developed in order to understand the optical behavior of these novel structures. The light guided in the core of the filled PCF structure will couple to SPP modes on the wires. Several measurements have been performed to determine the resonance wavelengths and losses of such filled PCF structures. Also, different phenomena such as the shift of the resonance position with the wire diameter or pitch and the polarization dependence of SPP in polarization maintaining (PM)-PCF have been investigated. The fabrication of free standing metal arrays was another focus of this work. The critical question was how to remove the surrounding SiO 2 from the metal wires. Two different approaches have been tried: etching of the SiO 2 and cleaving the PCF. (orig.)

  9. Plasmonic excitations on metallic nanowires embedded in silica photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Prill Sempere, Luis

    2010-06-17

    This thesis describes the theoretical and experimental investigation of metal-filled photonic crystal fibers (PCFs) and their fabrication. The thesis explains how to overcome the obstacles when infiltrating molten metals into sub-micron holes in fused silica (SiO{sub 2}) PCF. The optical properties of such filled fibers are theoretically and experimentally investigated, focusing on the coupling between the core mode of the fibers and the surface plasmon polaritons (SPPs) on the metal wires. The thesis introduces the ideas, physical challenges and results of two new filling techniques: the pressure cell technique and the splicing technique. These techniques make it possible for the first time to fill different fiber structures with sub-micron sized holes, such as PCFs and single-hole capillaries, with different metals like gold (Au) and silver (Ag). Samples with hole diameters between 120 nm and 20 {mu}m and aspect ratios as high as 75000 have been realized. Theoretical simulations and models have been developed in order to understand the optical behavior of these novel structures. The light guided in the core of the filled PCF structure will couple to SPP modes on the wires. Several measurements have been performed to determine the resonance wavelengths and losses of such filled PCF structures. Also, different phenomena such as the shift of the resonance position with the wire diameter or pitch and the polarization dependence of SPP in polarization maintaining (PM)-PCF have been investigated. The fabrication of free standing metal arrays was another focus of this work. The critical question was how to remove the surrounding SiO{sub 2} from the metal wires. Two different approaches have been tried: etching of the SiO{sub 2} and cleaving the PCF. (orig.)

  10. Monolithic Ytterbium All-single-mode Fiber Laser with Direct Fiber-end Delivery of nJ-level Femtosecond Pulses

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry

    2008-01-01

    We demonstrate a monolithic, i.e. without any free-space coupling, all-single-mode passively modelocked Yb-fiber laser, with direct fiber-end delivery of 364−405 fs pulses of 4 nJ pulse energy using a low-loss hollow-core photonic crystal fiber compression....

  11. Extension of supercontinuum spectrum generated in photonic crystal fiber by using chirped femtosecond pulses

    Science.gov (United States)

    Vengelis, Julius; Jarutis, Vygandas; Sirutkaitis, Valdas

    2017-08-01

    We present results of experimental and numerical investigation of supercontinuum generation in polarization maintaining photonic crystal fiber (PCF) using chirped femtosecond pulses. The initial unchirped pump pulse source was a mode-locked Yb:KGW laser generating 52 nJ energy 110 fs duration pulses at 1030 nm with 76 MHz repetition rate. The nonlinear medium was a 32 cm long polarization maintaining PCF manufactured by NKT Photonics A/S. We demonstrated the influence of pump pulse chirp on spectral characteristics of supercontinuum. We showed that by chirping pump pulses positively or negatively one can obtain broader supercontinuum spectrum than in case of unchirped pump pulses at the same peak power. Moreover, the extension can be controlled by changing the amount of pump pulse chirp. In our case the supercontinuum spectrum width was extended by up to 115 nm (at maximum chirp value of +10500 fs2 that we could achieve in our setup) compared to the case of unchirped pump at the same peak power.

  12. Characteristics of Highly Birefringent Photonic Crystal Fiber with Defected Core and Equilateral Pentagon Architecture

    Directory of Open Access Journals (Sweden)

    Fei Yu

    2016-01-01

    Full Text Available A novel high birefringence and nearly zero dispersion-flattened photonic crystal fiber (PCF with elliptical defected core (E-DC and equilateral pentagonal architecture is designed. By applying the full-vector finite element method (FEM, the characteristics of electric field distribution, birefringence, and chromatic dispersion of the proposed E-DC PCF are numerically investigated in detail. The simulation results reveal that the proposed PCF can realize high birefringence, ranging from 10-3 to 10-2 orders of magnitude, owing to the embedded elliptical air hole in the core center. However, the existence of the elliptical air hole gives rise to an extraordinary electric field distribution, where a V-shaped notch appears and the size of the V-shaped notch varies at different operating wavelengths. Also, the mode field diameter is estimated to be about 2 μm, which implies the small effective mode area and highly nonlinear coefficient. Furthermore, the investigation of the chromatic dispersion characteristic shows that the introduction of the elliptical air hole is helpful to control the chromatic dispersion to be negative or nearly zero flattened over a wide wavelength bandwidth.

  13. Ultra-high tunable liquid crystal-plasmonic photonic crystal fiber polarization filter.

    Science.gov (United States)

    Hameed, Mohamed Farhat O; Heikal, A M; Younis, B M; Abdelrazzak, Maher; Obayya, S S A

    2015-03-23

    A novel ultra-high tunable photonic crystal fiber (PCF) polarization filter is proposed and analyzed using finite element method. The suggested design has a central hole infiltrated with a nematic liquid crystal (NLC) that offers high tunability with temperature and external electric field. Moreover, the PCF is selectively filled with metal wires into cladding air holes. Results show that the resonance losses and wavelengths are different in x and y polarized directions depending on the rotation angle φ of the NLC. The reported filter of compact device length 0.5 mm can achieve 600 dB / cm resonance losses at φ = 90° for x-polarized mode at communication wavelength of 1300 mm with low losses of 0.00751 dB / cm for y-polarized mode. However, resonance losses of 157.71 dB / cm at φ = 0° can be achieved for y-polarized mode at the same wavelength with low losses of 0.092 dB / cm for x-polarized mode.

  14. Supercontinuum generation in silicon nanowire embedded photonic crystal fibers with different core geometries

    Science.gov (United States)

    Abdosllam, M. Abobaker; Gunasundari, E.; Senthilnathan, K.; Sivabalan, S.; Nakkeeran, K.; Ramesh Babu, P.

    2014-07-01

    We design various silicon nanowire embedded photonic crystal fibers (SN-PCFs) with different core geometries, namely, circular, rectangular and elliptical using finite element method. Further, we study the optical properties such as group velocity dispersion (GVD), third order dispersion (TOD) of x and y-polarized modes and effective nonlinearity for a wavelength range from 0.8 to 1.6 μm. The proposed structure exhibits almost flat GVD (0.8 to 1.2 μm wavelength), zero GVD (≍ 1.31 μm) and small TOD (0.00069 ps3/m) at 1.1 μm wavelength and high nonlinearity (2916 W-1m-1) at 0.8 μm wavelength for a 300 nm core diameter of circular core SN-PCF. Besides, we have been able to demonstrate the supercontinuum for the different core geometries at 1.3 μm wavelength with a less input power of 25 W for the input pulse of 20 fs. The numerical simulation results reveal that the proposed circular core SN-PCF could generate the supercontinuum of wider bandwidth (900 nm) compared to that from rest of the geometries. This enhanced bandwidth turns out to be a boon for optical coherence tomography (OCT) system.

  15. Broadband Enhancement of Optical Frequency Comb Using Cascaded Four-Wave Mixing in Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    Tawfig Eltaif

    2017-01-01

    Full Text Available A cascaded intensity modulator (IM and phase modulator (PM are used to modulate a continuous-wave (CW laser and generate an optical frequency comb (OFC. Thus, the generated comb is utilized as an initial seed and combined with another CW-laser to generate four-wave mixing (FWM in photonic crystal fiber (PCF. Results show that an initial flat 30 GHz OFC of 29, 55 lines within power fluctuation of 0.8 dB and 2 dB, respectively, can be achieved by setting the ratio of the DC bias to amplitude of sinusoidal signal at 0.1 and setting the modulation indices of both IM and PM at 10. Moreover, the 1st order of FWM created through 14 m of PCF has over 68 and 94 lines with fluctuation of 0.8 dB and 2 dB, respectively. Hence, the generated wavelengths of 1st left and right order of FWM can be tuned in a range from ~1500 nm to ~1525 nm and ~1590 nm to ~1604 nm, respectively.

  16. Fourier analysis for hydrostatic pressure sensing in a polarization-maintaining photonic crystal fiber

    International Nuclear Information System (INIS)

    Childs, Paul; Wong, Allan C. L.; Fu, H. Y.; Liao, Yanbiao; Tam, Hwayaw; Lu Chao; Wai, P. K. A.

    2010-01-01

    .We measured the hydrostatic pressure dependence of the birefringence and birefringent dispersion of a Sagnac interferometric sensor incorporating a length of highly birefringent photonic crystal fiber using Fourier analysis. Sensitivity of both the phase and chirp spectra to hydrostatic pressure is demonstrated. Using this analysis, phase-based measurements showed a good linearity with an effective sensitivity of 9.45nm/MPa and an accuracy of ±7.8kPa using wavelength-encoded data and an effective sensitivity of -55.7cm -1 /MPa and an accuracy of ±4.4kPa using wavenumber-encoded data. Chirp-based measurements, though nonlinear in response, showed an improvement in accuracy at certain pressure ranges with an accuracy of ±5.5kPa for the full range of measured pressures using wavelength-encoded data and dropping to within ±2.5kPa in the range of 0.17 to 0.4MPa using wavenumber-encoded data. Improvements of the accuracy demonstrated the usefulness of implementing chirp-based analysis for sensing purposes.

  17. Nonlinear polarization dynamics in a weakly birefringent all-normal dispersion photonic crystal fiber : toward a practical coherent fiber supercontinuum laser

    DEFF Research Database (Denmark)

    Tu, Haohua; Liu, Yuan; Liu, Xiaomin

    2012-01-01

    Dispersion-flattened dispersion-decreased all-normal dispersion (DFDD-ANDi) photonic crystal fibers have been identified as promising candidates for high-spectral-power coherent supercontinuum (SC) generation. However, the effects of the unintentional birefringence of the fibers on the SC generat...... of polarization-maintaining DFDD-ANDi fibers to avoid these adverse effects in pursuing a practical coherent fiber SC laser.......Dispersion-flattened dispersion-decreased all-normal dispersion (DFDD-ANDi) photonic crystal fibers have been identified as promising candidates for high-spectral-power coherent supercontinuum (SC) generation. However, the effects of the unintentional birefringence of the fibers on the SC...... generation have been ignored. This birefringence is widely present in nonlinear non-polarization maintaining fibers with a typical core size of 2 µm, presumably due to the structural symmetry breaks introduced in the fiber drawing process. We find that an intrinsic form-birefringence on the order of 10...

  18. Porous shaped photonic crystal fiber with strong confinement field in sensing applications: Design and analysis

    Directory of Open Access Journals (Sweden)

    Sawrab Chowdhury

    2017-04-01

    Full Text Available In this article, porous core porous cladding photonic crystal fiber (P-PCF has been proposed for aqueous analytes sensing applications. Guiding properties of the proposed P-PCF has been numerically investigated by utilizing the full vectorial finite element method (FEM. The relative sensitivity and confinement loss are obtained by varying distinct geometrical parameters like the diameter of air holes, a pitch of the core and cladding region over a wider range of wavelength. The proposed P-PCF is organized with five rings air hole in the cladding and two rings air hole in a core territory which maximizes the relative sensitivity expressively and minimizes confinement loss depressively compare with the prior-PCF structures. After completing all investigations, it is also visualized that the relative sensitivity is increasing with the increment of the wavelength of communication band (O + E + S + C + L + U. Higher sensitivity is gained by using higher band for all applied liquids. Finally the investigating effects of different structural parameters of the proposed P-PCF are optimized which shows the sensitivity of 60.57%, 61.45% and 61.82%; the confinement loss of 8.71 × 10−08 dB/m, 1.41 × 10−10 dB/m and 6.51 × 10−10 dB/m for Water (n = 1.33, Ethanol (n = 1.354 and Benzene (n = 1.366 respectively at 1.33 μm wavelength. The optimized P-PCF with higher sensitivity and lower confinement loss has high impact in the area of the chemical as well as gas sensing purposes. Keywords: Porous shaped PCF, Sensitivity, Optical sensing, Liquid sensor, Confinement loss

  19. Cross two photon absorption in a silicon photonic crystal waveguide fiber taper coupler with a physical junction

    Energy Technology Data Exchange (ETDEWEB)

    Sarkissian, Raymond, E-mail: RaymondSark@gmail.com; O' Brien, John [Electrophysics department, University of Southern California, Los Angeles, California 90089 (United States)

    2015-01-21

    Cross two photon absorption in silicon is characterized using a tapered fiber photonic crystal silicon waveguide coupler. There is a physical junction between the tapered fiber and the waveguide constituting a stand-alone device. This device is used to obtain the spectrum for cross two photon absorption coefficient per unit volume of interaction between photons of nondegenerate energy. The corresponding Kerr coefficient per unit volume of interaction is also experimentally extracted. The thermal resistance of the device is also experimentally determined and the response time of the device is estimated for on-chip all-optical signal processing and data transfer between optical signals of different photon energies.

  20. Mode-selective mapping and control of vectorial nonlinear-optical processes in multimode photonic-crystal fibers.

    Science.gov (United States)

    Hu, Ming-Lie; Wang, Ching-Yue; Song, You-Jian; Li, Yan-Feng; Chai, Lu; Serebryannikov, Evgenii; Zheltikov, Aleksei

    2006-02-06

    We demonstrate an experimental technique that allows a mapping of vectorial nonlinear-optical processes in multimode photonic-crystal fibers (PCFs). Spatial and polarization modes of PCFs are selectively excited in this technique by varying the tilt angle of the input beam and rotating the polarization of the input field. Intensity spectra of the PCF output plotted as a function of the input field power and polarization then yield mode-resolved maps of nonlinear-optical interactions in multimode PCFs, facilitating the analysis and control of nonlinear-optical transformations of ultrashort laser pulses in such fibers.

  1. Laser guiding of cold atoms in photonic crystals

    International Nuclear Information System (INIS)

    Tarasishin, A V; Magnitskiy, Sergey A; Shuvaev, V A; Zheltikov, Aleksei M

    2000-01-01

    The possibility of using photonic crystals with a lattice defect for the laser guiding of cold atoms is analysed. We have found a configuration of a photonic-crystal lattice and a defect ensuring the distribution of a potential in the defect mode of the photonic crystal allowing the guiding of cold atoms along the defect due to the dipole force acting on atoms. Based on quantitative estimates, we have demonstrated that photonic crystals with a lattice defect permit the guiding of atoms with much higher transverse temperatures and a much higher transverse localisation degree than in the case of hollow-core fibres. (laser applications and other topics in quantum electronics)

  2. Switching of light with light using cold atoms inside a hollow optical fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Peyronel, Thibault

    2010-01-01

    We demonstrate a fiber-optical switch that operates with a few hundred photons per switching pulse. The light-light interaction is mediated by laser-cooled atoms. The required strong interaction between atoms and light is achieved by simultaneously confining photons and atoms inside the microscopic...... hollow core of a single-mode photonic-crystal fiber....

  3. Enhanced performance of an S-band fiber laser using a thulium-doped photonic crystal fiber

    Science.gov (United States)

    Muhammad, A. R.; Emami, S. D.; Hmood, J. K.; Sayar, K.; Penny, R.; Abdul-Rashid, H. A.; Ahmad, H.; Harun, S. W.

    2014-11-01

    This work proposes a new method to enhance the performance of an S-band fiber laser by using a thulium-doped photonic crystal fiber (PCF). The proposed method is based on amplified spontaneous emission (ASE) suppression provided by the thulium-doped PCF unique geometric structure. The enhanced performance of this filter based PCF is dependent on the short and long cut-off wavelength characteristics that define the fiber transmission window. Realizing the short wavelength cut-off location requires the PCF cladding to be doped with a high index material, which provides a refractive index difference between the core and cladding region. Achieving the long cut-off wavelength necessitates enlarging the size of the air holes surrounding the rare-earth doped core region. The PCF structure is optimized so as to achieve the desired ASE suppression regions of below 0.8 μm and above 1.8 μm. The laser performance is simulated for different host media, namely pure silica, alumino-silicate, and fluoride-based fiber ZBLAN based on this thulium-doped PCF design. The host media spectroscopic details, including lifetime variations and quantum efficiency effect on the lasing emission are also discussed. Information on the filter based PCF design is gathered via a full-vectorial finite element method analysis and specifically a numerical modelling solution for the energy level rate equation using the Runge-Kutta method. Results are analyzed for gain improvement, lasing cavity, laser efficiency and effect of core size diameter variation. Results are compared with conventional thulium-doped fiber and thulium-doped PCF for every single host media. We observe that the ZBLAN host media is the most promising candidate due to its greater quantum efficiency.

  4. Enhanced performance of an S-band fiber laser using a thulium-doped photonic crystal fiber

    International Nuclear Information System (INIS)

    Muhammad, A R; Emami, S D; Penny, R; Ahmad, H; Harun, S W; Hmood, J K; Sayar, K; Abdul-Rashid, H A

    2014-01-01

    This work proposes a new method to enhance the performance of an S-band fiber laser by using a thulium-doped photonic crystal fiber (PCF). The proposed method is based on amplified spontaneous emission (ASE) suppression provided by the thulium-doped PCF unique geometric structure. The enhanced performance of this filter based PCF is dependent on the short and long cut-off wavelength characteristics that define the fiber transmission window. Realizing the short wavelength cut-off location requires the PCF cladding to be doped with a high index material, which provides a refractive index difference between the core and cladding region. Achieving the long cut-off wavelength necessitates enlarging the size of the air holes surrounding the rare-earth doped core region. The PCF structure is optimized so as to achieve the desired ASE suppression regions of below 0.8 μm and above 1.8 μm. The laser performance is simulated for different host media, namely pure silica, alumino-silicate, and fluoride-based fiber ZBLAN based on this thulium-doped PCF design. The host media spectroscopic details, including lifetime variations and quantum efficiency effect on the lasing emission are also discussed. Information on the filter based PCF design is gathered via a full-vectorial finite element method analysis and specifically a numerical modelling solution for the energy level rate equation using the Runge–Kutta method. Results are analyzed for gain improvement, lasing cavity, laser efficiency and effect of core size diameter variation. Results are compared with conventional thulium-doped fiber and thulium-doped PCF for every single host media. We observe that the ZBLAN host media is the most promising candidate due to its greater quantum efficiency. (paper)

  5. Cascaded interactions between Raman induced solitons and dispersive waves in photonic crystal fibers at the advanced stage of supercontinuum generation.

    Science.gov (United States)

    Driben, Rodislav; Mitschke, Fedor; Zhavoronkov, Nickolai

    2010-12-06

    The complex mechanism of multiple interactions between solitary and dispersive waves at the advanced stage of supercontinuum generation in photonic crystal fiber is studied in experiment and numerical simulations. Injection of high power negatively chirped pulses near zero dispersion frequency results in an effective soliton fission process with multiple interactions between red shifted Raman solitons and dispersive waves. These interactions may result in relative acceleration of solitons with further collisions between them of quasi-elastic or quasi-plastic kinds. In the spectral domain these processes result in enhancement of certain wavelength regions within the spectrum or development of a new significant band at the long wavelength side of the spectrum.

  6. Transverse Micro-structuring of Photonic Crystal Fibers for Industrial Sensors and Side Viewing Probes for Optical Coherence Tomography Applications

    Directory of Open Access Journals (Sweden)

    Sanjay KHER

    2010-05-01

    Full Text Available In this work, we report a simple and easily adaptable technique of lateral micro-machining of Photonic Crystal fibers (PCFs using modulated CO2-laser in conjunction with electrical arc system. The technique is controlled, convenient and precise over wide dimensions (50-250 mm. Lateral access to the holes of PCF provides additional flexibility for sensitive real time detection of gases such as green-house gases. Long period gratings are made in PCF through inscription of micro-grooves for sensitive detection of longitudinal strain. A unique and versatile PCF based probe for possible endoscopic Optical Coherence Tomography (OCT applications is reported.

  7. Analysis of the dependence of the guided mode field distribution on the silica bridges in hollow-core Bragg fibers

    DEFF Research Database (Denmark)

    Selleri, S.; Poli, F.; Foroni, M.

    2007-01-01

    The guiding properties of fabricated air-silica Bragg fibers with different geometric characteristics have been numerically investigated through a modal solver based on the finite element method. The method has been used to compute the dispersion curves, the loss spectra and the field distribution...... of the modes sustained by the Bragg fibers under investigation. In particular, the silica bridge influence on the fundamental mode has been analyzed, by considering structures with different cross sections, that is an ideal Bragg fiber, without the silica nonosupports, a squared air-hole one and, finally......, a rounded air-hole one, which better describes the real fiber transverse section. Results have shown.the presence of anti-crossing points in the effective index curves associated with the transition of the guided mode to a surface mode. Moreover, it has been verified that these surface modes are responsible...

  8. Random photonic crystal optical memory

    International Nuclear Information System (INIS)

    Wirth Lima Jr, A; Sombra, A S B

    2012-01-01

    Currently, optical cross-connects working on wavelength division multiplexing systems are based on optical fiber delay lines buffering. We designed and analyzed a novel photonic crystal optical memory, which replaces the fiber delay lines of the current optical cross-connect buffer. Optical buffering systems based on random photonic crystal optical memory have similar behavior to the electronic buffering systems based on electronic RAM memory. In this paper, we show that OXCs working with optical buffering based on random photonic crystal optical memories provides better performance than the current optical cross-connects. (paper)

  9. Single-mode pumped high air-fill fraction photonic crystal fiber taper for high-power deep-blue supercontinuum sources

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Larsen, Casper; Jakobsen, Christian

    2014-01-01

    Dispersion control with axially nonuniform photonic crystal fibers (PCFs) permits supercontinuum (SC) generation into the deep-blue from an ytterbium pump laser. In this Letter, we exploit the full degrees of freedom afforded by PCFs to fabricate a fiber with longitudinally increasing air-fill fr...

  10. Core-cladding mode coupling and recoupling in photonic crystal fiber for enhanced overlap of evanescent field using long-period gratings

    Czech Academy of Sciences Publication Activity Database

    He, Z.; Zhu, Y.; Kaňka, Jiří; Du, H.

    2010-01-01

    Roč. 18, č. 2 (2010), s. 507-512 ISSN 1094-4087 R&D Projects: GA ČR GA102/08/1719 Institutional research plan: CEZ:AV0Z20670512 Keywords : Photonic crystal fiber * Long-period grating * Fiber-optic evanescent sensor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.749, year: 2010

  11. Design of a Polymer-Based Hollow-Core Bandgap Fiber for Low-Loss Terahertz Transmission

    DEFF Research Database (Denmark)

    Barh, Ajanta; Varshney, Ravi K.; Pal, Bishnu P.

    2016-01-01

    wavelength-scale circular air holes in a hexagonal pattern, embedded in a uniform Teflon matrix. The THz guidance in this fiber is achieved by exploiting the photonic bandgap (PBG) effect. In our low index contrast Teflon-air (1.44:1) hexagonal periodic lattice, the PBG appears only for a certain range...

  12. Accelerated rogue waves generated by soliton fusion at the advanced stage of supercontinuum formation in photonic-crystal fibers.

    Science.gov (United States)

    Driben, Rodislav; Babushkin, Ihar

    2012-12-15

    Soliton fusion is a fascinating and delicate phenomenon that manifests itself in optical fibers in case of interaction between copropagating solitons with small temporal and wavelength separation. We show that the mechanism of acceleration of a trailing soliton by dispersive waves radiated from the preceding one provides necessary conditions for soliton fusion at the advanced stage of supercontinuum generation in photonic-crystal fibers. As a result of fusion, large-intensity robust light structures arise and propagate over significant distances. In the presence of small random noise the delicate condition for the effective fusion between solitons can easily be broken, making the fusion-induced giant waves a rare statistical event. Thus oblong-shaped giant accelerated waves become excellent candidates for optical rogue waves.

  13. Photonic crystal fiber interferometric pH sensor based on polyvinyl alcohol/polyacrylic acid hydrogel coating.

    Science.gov (United States)

    Hu, Pengbing; Dong, Xinyong; Wong, Wei Chang; Chen, Li Han; Ni, Kai; Chan, Chi Chiu

    2015-04-01

    We present a simple photonic crystal fiber interferometer (PCFI) that operates in reflection mode for pH measurement. The sensor is made by coating polyvinyl alcohol/polyacrylic acid (PVA/PAA) hydrogel onto the surface of the PCFI, constructed by splicing a stub of PCF at the distal end of a single-mode fiber with its free end airhole collapsed. The experimental results demonstrate a high average sensitivity of 0.9 nm/pH unit for the 11 wt.% PVA/PAA coated sensor in the pH range from 2.5 to 6.5. The sensor also displays high repeatability and stability and low cross-sensitivity to temperature. Fast, reversible rise and fall times of 12 s and 18 s, respectively, are achieved for the sensor time response.

  14. Development of photonic-crystal-fiber-based optical coupler with a broad operating wavelength range of 800 nm

    International Nuclear Information System (INIS)

    Yoon, Min-Seok; Kwon, Oh-Jang; Kim, Hyun-Joo; Chu, Su-Ho; Kim, Gil-Hwan; Lee, Sang-Bae; Han, Young-Geun

    2010-01-01

    We developed a broadband optical coupler based on a photonic crystal fiber (PCF), which is very useful for applications to optical coherence tomography (OCT). The PCF-based coupler is fabricated by using a fused biconical tapering (FBT) method. The PCF has six hexagonally-stacked layers of air holes. The PCF-based coupler has a nearly-flat 50/50 coupling ratio in a broad bandwidth range of 800 nm, which is much wider than that previously reported for a PCF-based coupler and a singlemode-fiber-based coupler. The bandwidth and the bandedge wavelength of the broadband coupler are controlled by changing the elongation length. The fabricated broadband optical coupler has great potential for realizing a broadband interferogram with a high resolution in an OCT system.

  15. Latest developments on fibered MOPA in mJ range with hollow-core fiber beam delivery and fiber beam shaping used as seeder for large scale laser facilities (Conference Presentation)

    Science.gov (United States)

    Gleyze, Jean-François; Scol, Florent; Perrin, Arnaud; Gouriou, Pierre; Valentin, Constance; Bouwmans, Géraud; Hugonnot, Emmanuel

    2017-05-01

    The Laser Megajoule (LMJ) is a French large scale laser facility dedicated to inertial fusion and plasma physics research. LMJ front-ends are based on fiber laser technology at nanojoule range [1]. Scaling the energy of those fiber seeders to the millijoule range is a way to upgrade LMJ's front ends architecture and could also be used as seeder for lasers for ELI project for example. However, required performances are so restrictive (optical-signal-to-noise ratio higher than 50 dB, temporally-shaped nanosecond pulses and spatial single-mode top-hat beam output) that such fiber systems are very tricky to build. High-energy fiber amplifiers In 2015, we have demonstrated, an all-fiber MOPA prototype able to produce a millijoule seeder, but unfortunately not 100% conform for all LMJ's performances. A major difficulty was to manage the frequency modulation used to avoid stimulated Brillouin scattering, to amplitude modulation (FM-AM) conversion, this limits the energy at 170µJ. For upgrading the energy to the millijoule range, it's necessary to use an amplifier with a larger core fiber. However, this fiber must still be flexible; polarization maintaining and exhibit a strictly single-mode behaviour. We are thus developing a new amplifier architecture based on an Yb-doped tapered fiber: its core diameter is from a narrow input to a wide output (MFD 8 to 26 µm). A S² measurement on a 2,5m long tapered fiber rolled-up on 22 cm diameter confirmed that this original geometry allows obtaining strictly single-mode behaviour. In a 1 kHz repetition rate regime, we already obtain 750 µJ pulses, and we are on the way to mJ, respecting LMJ performances. Beam delivery In LMJ architecture the distance between the nanojoule fiber seeder and the amplifier stages is about 16 m. Beam delivery is achieved with a standard PM fiber, such a solution is no longer achievable with hundreds of kilowatt peak powers. An efficient way to minimize nonlinear effects is to use hollow-core (HC

  16. Photonic Crystal Fibres for Dispersion and Sensor Applications

    DEFF Research Database (Denmark)

    Sørensen, Thorkild

    2005-01-01

    of the involved nonlinear processes. A hollow-core photonic crystal fibre (HC-PCF) is used as a sensor for gas. It is filled with two gasses, 12C2H2 acetylene, and H13CN hydrogen cyanide, and the transmission spectra are subject for a discussion. A model for infusion speed of fluids to a capillary presented...

  17. Ultra-flattened nearly-zero dispersion and ultrahigh nonlinear slot silicon photonic crystal fibers with ultrahigh birefringence

    Science.gov (United States)

    Liao, Jianfei; Xie, Yingmao; Wang, Xinghua; Li, Dongbo; Huang, Tianye

    2017-07-01

    A slot silicon photonic crystal fiber (PCF) is proposed to simultaneously achieve ultrahigh birefringence, large nonlinearity and ultra-flattened nearly-zero dispersion over a wide wavelength range. By taking advantage on the slot effect, ultrahigh birefringence up to 0.0736 and ultrahigh nonlinear coefficient up to 211.48 W-1 m-1 for quasi-TE mode can be obtained at the wavelength of 1.55 μm. Moreover, ultra-flattened dispersion of 0.49 ps/(nm km) for quasi-TE mode can be achieved over a 180 nm wavelength range with low dispersion slope of 1.85 × 10-3 ps/(nm2 km) at 1.55 μm. Leveraging on these advantages, the proposed slot PCF has great potential for efficient all-optical signal processing applications.

  18. Simultaneous generation of tunable giant dispersive waves in the visible and mid-infrared regions based on photonic crystal fibers

    International Nuclear Information System (INIS)

    Zhang, Lei; Yang, Si-Gang; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong; Han, Ying

    2013-01-01

    Cherenkov radiation (CR) in both the visible and mid-infrared regions is simultaneously generated experimentally based on a photonic crystal fiber with two zero-dispersion wavelengths. The generation of CR in the visible region originates from solitons located in the anomalous group velocity dispersion (GVD) regime which are perturbed by positive third order dispersion. Conversely, the generation of CR in the mid-infrared region requires that the solitons in the anomalous GVD regime are perturbed by negative third order dispersion. The peak wavelength of the CR in the visible region can be tuned from 498 to 425 nm by increasing the average input pump power from 70 to 400 mW, while the peak wavelength of the CR in the mid-infrared region can be tuned from 1986 to 2279 nm by increasing the average input pump power from 70 to 320 mW. (paper)

  19. Long-period gratings in photonic crystal fibers operating near the phase-matching turning point for evanescent chemical and biochemical sensing

    Czech Academy of Sciences Publication Activity Database

    Tian, F.; Kaňka, Jiří; Du, H.

    2012-01-01

    Roč. 20, č. 19 (2012), s. 20952-20961 ISSN 1094-4087 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Photonic crystal fiber * Long-period grating * Optical sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.546, year: 2012

  20. A new photonic crystal fiber design on the high negative ultra-flattened dispersion for both X and Y polarization modes

    DEFF Research Database (Denmark)

    Mahmud, Russel Reza; Razzak, S. M Abdur; Hasan, Md Imran

    2016-01-01

    Analysis of numerical design and properties of a new silica based photonic crystal fiber (PCF) are proposed in this manuscript. The design performs ultra-flattened negative chromatic dispersion (UNCD) in the optical windows 2nd and 3rd involving O to U bands in the infrared (IF) portion. The guid...

  1. Wavelength conversion of a 40 Gb/s RZ-DPSK signal using four-wave mixing in a dispersion-flattened highly nonlinear photonic crystal fiber

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Tokle, Torger; Geng, Yan

    2005-01-01

    Wavelength conversion of a 40-Gb/s return-to-zero differential phase-shift keying signal is demonstrated in a highly nonlinear photonic crystal fiber (HNL-PCF) for the first time. A conversion efficiency of -20 dB for a pump power of 23 dBm and a conversion bandwidth of 31 nm, essentially limited...

  2. Phase modulation and structural effects in a D-shaped all-solid photonic crystal fiber surface plasmon resonance sensor.

    Science.gov (United States)

    Tan, Zhixin; Hao, Xin; Shao, Yonghong; Chen, Yuzhi; Li, Xuejin; Fan, Ping

    2014-06-16

    We numerically investigate a D-shaped fiber surface plasmon resonance sensor based on all-solid photonic crystal fiber (PCF) with finite element method. In the side-polished PCF sensor, field leakage is guided to penetrate through the gap between the rods, causing a pronounced phase modulation in the deep polishing case. Taking advantage of these amplified phase shifts, a high-performance fiber sensor design is proposed. The significant enhancements arising from this new sensor design should lift the performance of the fiber SPR sensor into the range capable of detecting a wide range of biochemical interactions, which makes it especially attractive for many in vivo and in situ bioanalysis applications. Several parameters which influence the field leakage, such as the polishing position, the pitch of the PCF, and the rod diameter, are inspected to evaluate their impacts. Furthermore, we develop a mathematical model to describe the effects of varying the structural parameters of a D-shaped PCF sensor on the evanescent field and the sensor performance.

  3. Stable narrow spacing dual-wavelength Q-switched graphene oxide embedded in a photonic crystal fiber

    International Nuclear Information System (INIS)

    Ahmad, H; Soltanian, M R K; Alimadad, M; Harun, S W

    2014-01-01

    An ultra-stable dual-wavelength saturable absorber based on a cladding-embedded commercial graphene oxide (GO) solution by capillary action in a solid core photonic crystal fiber (PCF) is demonstrated for the first time. The saturation absorption property is achieved through evanescent coupling between the guided light and the cladding-filled graphene layers. Stable spacing dual-wavelength fiber lasing is attained by controlling the polarization state of a simple 0.9 m long ring of highly doped Leikki Er80-8/125 erbium-doped fiber as the primary gain medium with PCF, polarization controller and tunable bandpass filter. Embedded GO is used to generate the desired pulsed output, and the laser is capable of generating pulses having a repetition rate of 24 kHz with an average output power and pulse energy of 0.167 mW and 8.98 nJ, respectively, at the maximum pump power of 220 mW. (paper)

  4. Generation of a mid-infrared broadband polarized supercontinuum in As2Se3 photonic crystal fibers

    International Nuclear Information System (INIS)

    Wang Xiao-Yan; Li Shu-Guang; Liu Shuo; Yin Guo-Bing; Li Jian-She

    2012-01-01

    A simplified structure of birefringent chalcogenide As 2 Se 3 photonic crystal fiber (PCF) is designed. Properties of birefringence, polarization extinction ratio, chromatic dispersion, nonlinear coefficient, and transmission are studied by using the multipole method, the finite-difference beam propagation method, and the adaptive split-step Fourier method. Considering that the zero dispersion wavelength of our proposed fiber is about 4 μm, we have analysed the mechanism of spectral broadening in PCFs with different pitches in detail, with femtosecond pulses at a wavelength of 4 μm as the pump pulses. Especially, mid-infrared broadband polarized supercontinuums are obtained in a 3-cm PCF with an optimal pitch of 2 μm. Their spectral width at −20 dB reaches up to 12 μm. In the birefringent PCF, we find that the supercontinuum generation changes with the pump alignment angle. Research results show that no coupling between eigenpolarization modes are observed at the maximum average power (i.e., 37 mW), which indicates that the polarization state is well maintained. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  5. Experimental generation of discrete ultraviolet wavelength by cascaded intermodal four-wave mixing in a multimode photonic crystal fiber.

    Science.gov (United States)

    Yuan, Jinhui; Kang, Zhe; Li, Feng; Zhang, Xianting; Mei, Chao; Zhou, Guiyao; Sang, Xinzhu; Wu, Qiang; Yan, Binbin; Zhou, Xian; Zhong, Kangping; Wang, Kuiru; Yu, Chongxiu; Farrell, Gerald; Lu, Chao; Tam, Hwa Yaw; Wai, P K A

    2017-09-15

    In this Letter, we demonstrate experimentally for the first time, to the best of our knowledge, discrete ultraviolet (UV) wavelength generation by cascaded intermodal FWM when femtosecond pump pulses at 800 nm are launched into the deeply normal dispersion region of the fundamental guided mode of a multimode photonic crystal fiber (MPCF). For pump pulses at average input powers of P av =450, 550, and 650 mW, the first anti-Stokes waves are generated at the visible wavelength of 538.1 nm through intermodal phase matching between the fundamental and second-order guided mode of the MPCF. The first anti-Stokes waves generated then serve as the secondary pump for the next intermodal FWM process. The second anti-Stokes waves in the form of the third-order guided mode are generated at the UV wavelength of 375.8 nm. The maximum output power is above 10 mW for P av =650  mW. We also confirm that the influences of fiber bending and intermodal walk-offs on the cascaded intermodal FWM-based frequency conversion process are negligible.

  6. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers

    DEFF Research Database (Denmark)

    Markos, Christos

    2016-01-01

    the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from similar to 500 nm up to similar to 1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed....../degrees C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements....

  7. Low-NA single-mode LMA photonic crystal fiber amplifier

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Scolari, Lara

    2011-01-01

    a spatially Distributed Mode Filter (DMF). This approach achieves SM performance in a short and straight rod fiber and allows preform tolerances to be compensated during draw. A low-NA SM rod fiber amplifier having a mode field diameter of ~60μm at 1064nm and a pump absorption of 27dB/m at 976nm...

  8. Photonic crystal rod fibers: Understanding a new class of active optical waveguides

    DEFF Research Database (Denmark)

    Laurila, Marko

    core modes and the cladding band as the underlying mechanics to ensure SM operation of the new rod fiber design (85 μm core diameter), which was developed during this thesis work. The second focus of this work is the study of the new ytterbiumdoped rod fiber design under active operation. Performance...... of the rod fiber is evaluated in high power laser and laser amplifier configurations. The high power rod amplifier setup including the seed source is developed and characterized. Results obtained from the rod fiber showed simultaneously SM, near diffraction limited output beam quality with high average power...... and pulse energy generation using both laser and laser amplifier configurations. Modal instabilities (MIs) in high power fiber amplifiers are discussed, and a memory effect of the MI threshold level together with a recovery method and evidence of improved performance while suppressing MIs are reported...

  9. Ytterbium‐doped distributed spectral filtering photonic crystal fibers for use at wavelengths above 1100 nm

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Lægsgaard, Jesper

    to avoid parasitic lasing due to Amplified Spontaneous Emission (ASE) build‐up. Nonlinear effects, such as stimulated Raman scattering, stimulated Brillouin scattering and four‐wave mixing, set the upper limit for achievable powers in fiber amplifiers. To increase the nonlinear threshold, Large......Rare‐earth doped high‐power fiber lasers and amplifiers have attracted a lot of attention, due to the advantages of the fiber amplification scheme. Compared to conventional optically pumped bulk lasers, heat is dissipated much more effectively in fiber lasers, having a large surface......‐to‐active volume ratio. Thereby, a stable beam with nearly diffraction‐limited quality can be achieved. The fibers are often cladding‐pumped with a number of low‐brightness semiconductor laser diodes, in which way a low‐cost pump of several kilowatts can be achieved [1]. However, the frequencies, which can...

  10. Coupling Characteristics of Fused Optical Fiber Coupler Formed with Single-Mode Fiber and Photonic Crystal Fiber Having Air Hole Collapsed Taper

    Directory of Open Access Journals (Sweden)

    Hirohisa Yokota

    2016-01-01

    Full Text Available Fused coupler forming with a single-mode fiber (SMF and a photonic crystal fiber (PCF is one of the solutions for optical coupling from a light source to a PCF. In this paper, we presented coupling characteristics of a fused fiber coupler formed with an ordinary SMF and a PCF having air hole collapsed taper. A prototype of SMF-PCF coupler with air hole collapsed taper was fabricated using CO2 laser irradiation. The coupling efficiency from SMF to PCF was −6.2 dB at 1554 nm wavelength in the fabricated coupler. The structure of the SMF-PCF coupler to obtain high coupling efficiency was theoretically clarified by beam propagation analysis using an equivalent model of the coupler with simplification. It was clarified that appropriately choosing the prestretched or etched SMF diameter and the length of air hole collapsed region was effective to obtain high coupling efficiency that was a result of high extinction ratio at cross port and low excess loss. We also demonstrated that the diameter of prestretched SMF to obtain high coupling efficiency was insensitive to the air hole diameter ratio to pitch of the PCF in the air hole collapsed SMF-PCF coupler.

  11. All-optically tunable waveform synthesis by a silicon nanowaveguide ring resonator coupled with a photonic-crystal fiber frequency shifter

    KAUST Repository

    Savvin, Aleksandr D.

    2011-03-01

    A silicon nanowaveguide ring resonator is combined with a photonic-crystal fiber (PCF) frequency shifter to demonstrate an all-optically tunable synthesis of ultrashort pulse trains, modulated by ultrafast photoinduced free-carrier generation in the silicon resonator. Pump-probe measurements performed with a 50-fs, 625-nm second-harmonic output of a Cr:forsterite laser, used as a carrier-injecting pump, and a 1.50-1.56-μm frequency-tunable 100-fs soliton output of a photonic-crystal fiber, serving as a probe, resolve tunable ultrafast oscillatory features in the silicon nanowaveguide resonator response. © 2010 Elsevier B.V. All rights reserved.

  12. All-optically tunable waveform synthesis by a silicon nanowaveguide ring resonator coupled with a photonic-crystal fiber frequency shifter

    KAUST Repository

    Savvin, Aleksandr D.; Melnikov, Vasily; Fedotov, Il'ya V.; Fedotov, Andrei B.; Perova, Tatiana S.; Zheltikov, Aleksei M.

    2011-01-01

    A silicon nanowaveguide ring resonator is combined with a photonic-crystal fiber (PCF) frequency shifter to demonstrate an all-optically tunable synthesis of ultrashort pulse trains, modulated by ultrafast photoinduced free-carrier generation in the silicon resonator. Pump-probe measurements performed with a 50-fs, 625-nm second-harmonic output of a Cr:forsterite laser, used as a carrier-injecting pump, and a 1.50-1.56-μm frequency-tunable 100-fs soliton output of a photonic-crystal fiber, serving as a probe, resolve tunable ultrafast oscillatory features in the silicon nanowaveguide resonator response. © 2010 Elsevier B.V. All rights reserved.

  13. Folded cladding porous shaped photonic crystal fiber with high sensitivity in optical sensing applications: Design and analysis

    Directory of Open Access Journals (Sweden)

    Bikash Kumar Paul

    2017-02-01

    Full Text Available A micro structure folded cladding porous shaped with circular air hole photonic crystal fiber (FP-PCF is proposed and numerically investigated in a broader wavelength range from 1.4 µm to 1.64 µm (E+S+C+L+U for chemical sensing purposes. Employing finite element method (FEM with anisotropic perfectly matched layer (PML various properties of the proposed FP-PCF are numerically inquired. Filling the hole of core with aqueous analyte ethanol (n = 1.354 and tuning different geometric parameters of the fiber, the sensitivity order of 64.19% and the confinement loss of 2.07 × 10-5 dB/m are attained at 1.48 µm wavelength in S band. The investigated numerical simulation result strongly focuses on sensing purposes; because this fiber attained higher sensitivity with lower confinement loss over the operating wavelength. Measuring time of sensitivity, simultaneously confinement loss also inquired. It reflects that confinement loss is highly dependable on PML depth but not for sensitivity. Beside above properties numerical aperture (NA, nonlinearity, and effective area are also computed. This FP-PCF also performed as sensor for other alcohol series (methanol, propanol, butanol, pentanol. Optimized FP-PCF shows higher sensitivity and low confinement loss carrying high impact in the area of chemical as well as gas sensing purposes. Surely it is clear that install such type of sensor will flourish technology massively.         Keywords: Confinement loss, Effective area, Index guiding FP-PCF, Numerical aperture, Nonlinear coefficient, Sensitivity

  14. A new design of photonic crystal fiber with ultra-flattened dispersion to simultaneously minimize the dispersion and confinement loss

    Science.gov (United States)

    Olyaee, Saeed; Taghipour, Fahimeh

    2011-02-01

    Photonic crystal fibers (PCFs) are highly suitable transmission media for wavelength-division-multiplexing (WDM) systems, in which low and ultra-flattened dispersion of PCFs is extremely desirable. It is also required to concurrently achieve both a low confinement loss as well as a large effective area in a wide range of wavelengths. Relatively low dispersion with negligible variation has become feasible in the wavelength range of 1.1 to 1.8μm through the proposed design in this paper. According to a new structure of PCF presented in this study, the dispersion slope is 6.8×10-4ps/km.nm2 and the confinement loss reaches below 10-6 dB/km in this range, while at the same time an effective area of more than 50μm2 has been attained. For the analysis of this PCF, finite-difference time-domain (FDTD) method with the perfectly matched layers (PML) boundary conditions has been used.

  15. Supercontinuum generation in optimized photonic crystal fiber at 1.3 μm for optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Ferhat M. L.

    2016-01-01

    Full Text Available In this paper, we have designed a high nonlinear photonic crystal fiber (HN-PCF based on square-lattice geometry with the zero dispersion wavelength (ZDW around 1300 nm. The exploitation of different nonlinear mechanisms in the pulse propagation allows supercontinuum generation, which is used to enhance the axial resolution of the optical coherence tomography (OCT systems. First mechanism demonstrated is the soliton self-compression, we came up to realize pulse compression of 28.4 fs around 1300 nm by the generation of solitons of different orders to obtain ultrashort pulses of about 4 fs pulses in a PCF length of 66cm, then, we improved the pulse compression until 1.2 fs in a PCF length of 26 cm.The exploitation of the interplay between many nonlinear effects as self-phase modulation, intrapulse Raman scattering and self-steepening as second mechanism allows a generation of supercontinuum with a spectral bandwith of SBW=260 nm. The obtained spectral bandwidth could contribute to enhance the OCwith OCT imaging axial resolution which can be evaluated to 2.8 μm in air, working at 1.3 μm center wavelength which is widely used in several fields.

  16. [Study on spectral gain characterization of FWM processes with multi-frequency pumps in photonic crystal fiber].

    Science.gov (United States)

    Hui, Zhan-Qiang

    2011-10-01

    Spectral gain induced by four-wave-mixing with multi-frequency pump was investigated by exploiting the data signal and continue lights co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of pump lights, polarization state of orthogonal or parallel of pump lights, polarization mismatch of signal light versus orthogonal pump lights, total power of signal and probe light on the spectrum gain were analyzed. The results show that good FWM gain effects with multi-frequency pump can be obtained in 36.4 nm wavelength range when power ratio of pump to probe light is appropriate and with identical polarization. Furthermore, the gain of FWM with multi-frequency pump is very sensitive to polarization fluctuation and the different idle waves obtain different gain with the variation in signal polarization state. Moreover, the impact of pump numbers was investigated. The obtained results would be helpful for further research on ultrahigh-speed all optical signal processing devices exploiting the FWM with multi-frequency pump in PCF for future photonics network.

  17. Spectrally-isolated violet to blue wavelength generation by cascaded degenerate four-wave mixing in a photonic crystal fiber.

    Science.gov (United States)

    Yuan, Jinhui; Kang, Zhe; Li, Feng; Zhang, Xianting; Zhou, Guiyao; Sang, Xinzhu; Wu, Qiang; Yan, Binbin; Zhou, Xian; Wang, Liang; Zhong, Kangping; Wang, Kuiru; Yu, Chongxiu; Tam, Hwa Yaw; Wai, P K A

    2016-06-01

    Generation of spectrally-isolated wavelengths in the violet to blue region based on cascaded degenerate four-wave mixing (FWM) is experimentally demonstrated for the first time in a tailor-made photonic crystal fiber, which has two adjacent zero dispersion wavelengths (ZDWs) at 696 and 852 nm in the fundamental mode. The influences of the wavelength λp and the input average power Pav of the femtosecond pump pulses on the phase-matched frequency conversion process are studied. When femtosecond pump pulses at λp of 880, 870, and 860 nm and Pav of 500 mW are coupled into the normal dispersion region close to the second ZDW, the first anti-Stokes waves generated near the first ZDW act as a secondary pump for the next FWM process. The conversion efficiency ηas2 of the second anti-Stokes waves, which are generated at the violet to blue wavelengths of 430, 456, and 472 nm, are 4.8, 6.48, and 9.66%, for λp equalling 880, 870, and 860 nm, respectively.

  18. Efficient terahertz wave generation from GaP crystals pumped by chirp-controlled pulses from femtosecond photonic crystal fiber amplifier

    International Nuclear Information System (INIS)

    Li, Jiang; Shi, Junkai; Xu, Baozhong; Xing, Qirong; Wang, Chingyue; Chai, Lu; Liu, Bowen; Hu, Minglie; Li, Yanfeng; Fedotov, Andrey B.; Zheltikov, Aleksei M.

    2014-01-01

    A chirp-tunable femtosecond 10 W, 42 MHz photonic-crystal-fiber oscillator-amplifier system that is capable of delivering sub-60 fs light pulses at 1040 nm is used to demonstrate high-efficiency terahertz radiation generation via optical rectification in GaP crystals only a few millimeters in length. The optimization of the chirp of the fiber-laser pulses is shown to radically enhance the terahertz output, indicating one possible way to more efficiently use these extended nonlinear crystals in compact fiber-pumped terahertz radiation sources

  19. Super continuum generation at 800 nm in highly nonlinear photonic crystal fibers with normal dispersion

    DEFF Research Database (Denmark)

    Hansen, Kim Per; Larsen, Jacob Juul; Jensen, Jacob Riis

    2001-01-01

    More than 90 nm broad self-phase modulation (SPM) induced pulses have been created from both 25 and 50 fs pulses in just 12.5 cm of fiber. The broadening is more than 2.5 times that observed in standard SMF. SPM broadening in PCFs has several advantages over more complex super continuum generatio...

  20. Characterization of external refractive index sensitivity of a photonic crystal fiber long-period grating

    Czech Academy of Sciences Publication Activity Database

    Tian, F.; Kaňka, Jiří; Du, H.

    2015-01-01

    Roč. 13, č. 7 (2015), s. 0705011-0705013 ISSN 1671-7694 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Carbon dioxide lasers * Crystal whiskers * Optical fiber fabrication Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.899, year: 2015

  1. A fusion-spliced near-field optical fiber probe using photonic crystal fiber for nanoscale thermometry based on fluorescence-lifetime measurement of quantum dots.

    Science.gov (United States)

    Fujii, Takuro; Taguchi, Yoshihiro; Saiki, Toshiharu; Nagasaka, Yuji

    2011-01-01

    We have developed a novel nanoscale temperature-measurement method using fluorescence in the near-field called fluorescence near-field optics thermal nanoscopy (Fluor-NOTN). Fluor-NOTN enables the temperature distributions of nanoscale materials to be measured in vivo/in situ. The proposed method measures temperature by detecting the temperature dependent fluorescence lifetimes of Cd/Se quantum dots (QDs). For a high-sensitivity temperature measurement, the auto-fluorescence generated from a fiber probe should be reduced. In order to decrease the noise, we have fabricated a novel near-field optical-fiber probe by fusion-splicing a photonic crystal fiber (PCF) and a conventional single-mode fiber (SMF). The validity of the novel fiber probe was assessed experimentally by evaluating the auto-fluorescence spectra of the PCF. Due to the decrease of auto-fluorescence, a six- to ten-fold increase of S/N in the near-field fluorescence lifetime detection was achieved with the newly fabricated fusion-spliced near-field optical fiber probe. Additionally, the near-field fluorescence lifetime of the quantum dots was successfully measured by the fabricated fusion-spliced near-field optical fiber probe at room temperature, and was estimated to be 10.0 ns.

  2. Extended parametric gain range in photonic crystal fibers with strongly frequency-dependent field distributions.

    Science.gov (United States)

    Petersen, Sidsel R; Alkeskjold, Thomas T; Olausson, Christina B; Lægsgaard, Jesper

    2014-08-15

    The parametric gain range of a degenerate four-wave mixing process is determined in the undepleted pump regime. The gain range is considered with and without taking the mode field distributions of the four-wave mixing components into account. It is found that the mode field distributions have to be included to evaluate the parametric gain correctly in dispersion-tailored speciality fibers and that mode profile engineering can provide a way to increase the parametric gain range.

  3. High energy supercontinuum sources using tapered photonic crystal fibers for multispectral photoacoustic microscopy

    DEFF Research Database (Denmark)

    Bondu, Magalie; Brooks, Christopher; Jakobsen, Christian

    2016-01-01

    We demonstrate a record bandwidth high energy supercontinuum source suitable for multispectral photoacoustic microscopy. The source has more than 150  nJ/10  nm150  nJ/10  nm bandwidth over a spectral range of 500 to 1600 nm. This performance is achieved using a carefully designed fiber taper...... with large-core input for improved power handling and small-core output that provides the desired spectral range of the supercontinuum source....

  4. Numerical Analysis of Index-Guiding Photonic Crystal Fibers with Low Confinement Loss and Ultra-Flattened Dispersion by FDFD Method

    Directory of Open Access Journals (Sweden)

    M. Pourmahyabadi

    2009-09-01

    Full Text Available In this article, perfectly matched layer (PML for the boundary treatment and an efficient compact two dimensional finite-difference frequency-domain (2-D FDFD method were combined to model photonic crystal fibers (PCF. For photonic crystal fibers, if we assume that the propagation constant along the propagation direction is fixed, three-dimensional hybrid guided modes can be calculated by using only a two-dimensional mesh. An index-guiding PCF with an array of air-holes surrounding the silica core region has special characteristics compared with conventional single-mode fibers (SMFs. Using this model, the fundamental characteristics of single mode photonic crystal fibers (SMPCFs such as confinement loss, bending loss, effective mode area and chromatic dispersion are numerically investigated. The results revealed that low confinement loss and zero-flattened chromatic dispersion can be obtained by varying the air-holes diameter of each ring along the PCF radius. In this work, an especial PCF with nearly zero-flattened dispersion (1.3 ps/nm/km over a wide wavelength range which covers O, E, S, C, L and U telecommunication wavelength bands and low confinement loss (0.06 dB/km at 1.55μm is designed. Macro-bending loss performance of the designed PCF is also studied and it is found that the fiber shows low bending losses for the smallest feasible bending radius of 5 mm. Also, it is revealed that the temperature sensitivity of PCFs is very low in compared with the conventional fibers.

  5. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  6. Alcohol sensing over O+E+S+C+L+U transmission band based on porous cored octagonal photonic crystal fiber

    Science.gov (United States)

    Paul, Bikash Kumar; Islam, Md. Shadidul; Ahmed, Kawsar; Asaduzzaman, Sayed

    2017-06-01

    A micro structure porous cored octagonal photonic crystal fiber (P-OPCF) has been proposed to sense aqueous analysts (alcohol series) over a wavelength range of 0.80 μm to 2.0 μm. By implementing a full vectorial finite element method (FEM), the numerical simulation on the proposed O-PCF has been analyzed. Numerical investigation shows that high sensitivity can be gained by changing the structural parameters. The obtained result shows the sensitivities of 66.78%, 67.66%, 68.34%, 68.72%, and 69.09%, and the confinement losses of 2.42×10-10 dB/m, 3.28×10-11 dB/m, 1.21×10-6 dB/m, 4.79×10-10 dB/m, and 4.99×10-9 dB/m at the 1.33 μm wavelength for methanol, ethanol, propanol, butanol, and pentanol, respectively can satisfy the condition of much legibility to install an optical system. The effects of the varying core and cladding diameters, pitch distance, operating wavelength, and effective refractive index are also reported here. It reflects that a significant sensitivity and low confinement loss can be achieved by the proposed P-OPCF. The proposed P-OPCF also covers the wavelength band (O+E+S+C+L+U). The investigation also exhibits that the sensitivity increases when the wavelength increases like S O-bandsensor.

  7. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic...

  8. Tunable and switchable multi-wavelength erbium-doped fiber laser with highly nonlinear photonic crystal fiber and polarization controllers

    International Nuclear Information System (INIS)

    Liu, X M; Lin, A; Zhao, W; Lu, K Q; Wang, Y S; Zhang, T Y; Chung, Y

    2008-01-01

    We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature

  9. All-fiber intensity bend sensor based on photonic crystal fiber with asymmetric air-hole structure

    Science.gov (United States)

    Budnicki, Dawid; Szostkiewicz, Lukasz; Szymanski, Michal O.; Ostrowski, Lukasz; Holdynski, Zbigniew; Lipinski, Stanislaw; Murawski, Michal; Wojcik, Grzegorz; Makara, Mariusz; Poturaj, Krzysztof; Mergo, Pawel; Napierala, Marek; Nasilowski, Tomasz

    2017-10-01

    Monitoring the geometry of an moving element is a crucial task for example in robotics. The robots equipped with fiber bend sensor integrated in their arms can be a promising solution for medicine, physiotherapy and also for application in computer games. We report an all-fiber intensity bend sensor, which is based on microstructured multicore optical fiber. It allows to perform a measurement of the bending radius as well as the bending orientation. The reported solution has a special airhole structure which makes the sensor only bend-sensitive. Our solution is an intensity based sensor, which measures power transmitted along the fiber, influenced by bend. The sensor is based on a multicore fiber with the special air-hole structure that allows detection of bending orientation in range of 360°. Each core in the multicore fiber is sensitive to bend in specified direction. The principle behind sensor operation is to differentiate the confinement loss of fundamental mode propagating in each core. Thanks to received power differences one can distinguish not only bend direction but also its amplitude. Multicore fiber is designed to utilize most common light sources that operate at 1.55 μm thus ensuring high stability of operation. The sensitivity of the proposed solution is equal 29,4 dB/cm and the accuracy of bend direction for the fiber end point is up to 5 degrees for 15 cm fiber length. Such sensitivity allows to perform end point detection with millimeter precision.

  10. Clinical coherent anti-Stokes Raman scattering and multiphoton tomography of human skin with a femtosecond laser and photonic crystal fiber

    International Nuclear Information System (INIS)

    Breunig, Hans Georg; Weinigel, Martin; Bückle, Rainer; Kellner-Höfer, Marcel; König, Karsten; Lademann, Jürgen; Darvin, Maxim E; Sterry, Wolfram

    2013-01-01

    We report on in vivo coherent anti-Stokes Raman scattering spectroscopy (CARS), two-photon fluorescence and second-harmonic-generation imaging on human skin with a novel multimodal clinical CARS/multiphoton tomograph. CARS imaging is realized by a combination of femtosecond pulses with broadband continuum pulses generated by a photonic crystal fiber. The images reveal the microscopic distribution of (i) non-fluorescent lipids, (ii) endogenous fluorophores and (iii) the collagen network inside the human skin in vivo with subcellular resolution. Examples of healthy as well as cancer-affected skin are presented. (letter)

  11. Clinical coherent anti-Stokes Raman scattering and multiphoton tomography of human skin with a femtosecond laser and photonic crystal fiber

    Science.gov (United States)

    Breunig, Hans Georg; Weinigel, Martin; Bückle, Rainer; Kellner-Höfer, Marcel; Lademann, Jürgen; Darvin, Maxim E.; Sterry, Wolfram; König, Karsten

    2013-02-01

    We report on in vivo coherent anti-Stokes Raman scattering spectroscopy (CARS), two-photon fluorescence and second-harmonic-generation imaging on human skin with a novel multimodal clinical CARS/multiphoton tomograph. CARS imaging is realized by a combination of femtosecond pulses with broadband continuum pulses generated by a photonic crystal fiber. The images reveal the microscopic distribution of (i) non-fluorescent lipids, (ii) endogenous fluorophores and (iii) the collagen network inside the human skin in vivo with subcellular resolution. Examples of healthy as well as cancer-affected skin are presented.

  12. Photonic Crystal Laser-Driven Accelerator Structures

    International Nuclear Information System (INIS)

    Cowan, B

    2004-01-01

    The authors discuss simulated photonic crystal structure designs for laser-driven particle acceleration. They focus on three-dimensional planar structures based on the so-called ''woodpile'' lattice, demonstrating guiding of a speed-of-light accelerating mode by a defect in the photonic crystal lattice. They introduce a candidate geometry and discuss the properties of the accelerating mode. They also discuss the linear beam dynamics in the structure present a novelmethod for focusing the beam. In addition they describe ongoing investigations of photonic crystal fiber-based structures

  13. Numerical analysis and experimental investigation of highly sensitive photonic crystal fiber long-period grating refractive index sensor

    Czech Academy of Sciences Publication Activity Database

    Zhu, Y.; He, Z.; Kaňka, Jiří; Du, H.

    2008-01-01

    Roč. 129, č. 1 (2008), s. 99-105 ISSN 0925-4005 R&D Projects: GA MŠk 1P05OC002 Grant - others:National Science Foundation(US) ECS-0404002 Institutional research plan: CEZ:AV0Z20670512 Source of funding: V - iné verejné zdroje Keywords : photonic crystals * Bragg gratings * optical fibres * fibre optic sensors * refractometers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.122, year: 2008

  14. Measurement of temperature and concentration influence on the dispersion of fused silica glass photonic crystal fiber infiltrated with water-ethanol mixture

    Science.gov (United States)

    Van, Hieu Le; Buczynski, Ryszard; Long, Van Cao; Trippenbach, Marek; Borzycki, Krzysztof; Manh, An Nguyen; Kasztelanic, Rafal

    2018-01-01

    We present experimental and simulation results of the zero-dispersion shift in photonics crystal fibers infiltrated with water-ethanol mixture. The fiber based on the fused silica glass with a hexagonal lattice consists of seven rings of air-holes filled by liquid. We show that it is possible to shift the zero-dispersion wavelength by 35 ps/nm/km when changing the temperature by 60 °C, and by 42 ps/nm/km when changing the concentration of ethanol from 0 to 100%. The results also show that for the optical fiber filed with pure ethanol the flattened part of the dispersion shifts from anomalous to the normal regime at temperatures below -70 °C.

  15. A stable dual-wavelength Q-switch using a compact passive device containing photonics crystal fiber embedded with carbon platinum

    Science.gov (United States)

    Safaei, R.; Amiri, I. S.; Rezayi, M.; Ahmad, H.

    2018-01-01

    A compact fiber laser utilizing platinum nanoparticles doped on carbon (Pt/C) embedded in photonic crystal fiber capable of generating a stable Q-switch dual-wavelength is designed and verified. Stable Q-switch pulses, with a repetition rate of 73.6 kHz, pulse width of 1.45 µs and power of 3.8 nJ in two separated wavelengths of 1557.39 nm and 1558.86 nm at a pump power of 350 mW, have been obtained. This is a novel method for generating Q-switch dual-wavelength pulses using a well-protected component that introduces both a saturable absorber and Mach-Zehnder interferometer effects simultaneously in the laser cavity. Furthermore, to best of our knowledge, this is the first time that Pt/C nanoparticles have been used in a saturable absorber for optical pulse generation.

  16. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    Science.gov (United States)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  17. Single-mode amplification in Yb-doped rod-type photonic crystal fibers for high brilliance lasers

    DEFF Research Database (Denmark)

    Poli, F.; Lægsgaard, Jesper; Passaro, D.

    2009-01-01

    This paper presents the effect of a low refractive index ring in the Yb-doped rod-type photonic crystal fibre core on the guided mode propagation and analyzed through a spatial and spectral amplifier model. The ring provides a higher differential overlap between the fundamental mode (FM...... to identify a proper ring characteristic that is width, position and refractive index. Then rod-type PCF designs have been optimized with a full-vector modal solver based on the finite-element method. Then, the amplification properties of the Yb-doped rod-type PCFs have been investigated by assuming a forward...

  18. Photonic Crystal Nanocavity Arrays

    National Research Council Canada - National Science Library

    Altug, Hatice; Vuckovic, Jelena

    2006-01-01

    We recently proposed two-dimensional coupled photonic crystal nanocavity arrays as a route to achieve a slow-group velocity of light in all crystal directions, thereby enabling numerous applications...

  19. Broad bandwidth and 600 μm length photonic crystal fiber polarization filter at the communication window of 1.55 μm

    Science.gov (United States)

    Zhang, Zhen; Li, Shuguang; Liu, Qiang; Zhang, Shuhuan; Wang, Yujun; Wu, Junjun

    2018-02-01

    A broad bandwidth and 600-μm length photonic crystal fiber polarization filter at the communication window of 1.55 μm is proposed. The physical parameters are analyzed by the finite element method. In the structure, the loss is 705.81 dB/cm for y-polarized mode and 24.06 dB/cm for x-polarized mode at the wavelength of 1.55 μm; the y-polarized mode will be filtered out because of this property. The bandwidth of an extinction ratio (ER) better than -20 dB is 65 nm when the filter length is 600 μm, and the ER is -41 dB at the communication wavelength of 1.55 μm. The filter structure is simple and easy to produce, and it can be used to produce a single-polarization filter.

  20. Stabilized soliton self-frequency shift and 0.1- PHz sideband generation in a photonic-crystal fiber with an air-hole-modified core.

    Science.gov (United States)

    Liu, Bo-Wen; Hu, Ming-Lie; Fang, Xiao-Hui; Li, Yan-Feng; Chai, Lu; Wang, Ching-Yue; Tong, Weijun; Luo, Jie; Voronin, Aleksandr A; Zheltikov, Aleksei M

    2008-09-15

    Fiber dispersion and nonlinearity management strategy based on a modification of a photonic-crystal fiber (PCF) core with an air hole is shown to facilitate optimization of PCF components for a stable soliton frequency shift and subpetahertz sideband generation through four-wave mixing. Spectral recoil of an optical soliton by a red-shifted dispersive wave, generated through a soliton instability induced by high-order fiber dispersion, is shown to stabilize the soliton self-frequency shift in a highly nonlinear PCF with an air-hole-modified core relative to pump power variations. A fiber with a 2.3-microm-diameter core modified with a 0.9-microm-diameter air hole is used to demonstrate a robust soliton self-frequency shift of unamplified 50-fs Ti: sapphire laser pulses to a central wavelength of about 960 nm, which remains insensitive to variations in the pump pulse energy within the range from 60 to at least 100 pJ. In this regime of frequency shifting, intense high- and low-frequency branches of dispersive wave radiation are simultaneously observed in the spectrum of PCF output. An air-hole-modified-core PCF with appropriate dispersion and nonlinearity parameters is shown to provide efficient four-wave mixing, giving rise to Stokes and anti-Stokes sidebands whose frequency shift relative to the pump wavelength falls within the subpetahertz range, thus offering an attractive source for nonlinear Raman microspectroscopy.

  1. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...

  2. Nonlinear performance of asymmetric coupler based on dual-core photonic crystal fiber: Towards sub-nanojoule solitonic ultrafast all-optical switching

    Science.gov (United States)

    Curilla, L.; Astrauskas, I.; Pugzlys, A.; Stajanca, P.; Pysz, D.; Uherek, F.; Baltuska, A.; Bugar, I.

    2018-05-01

    We demonstrate ultrafast soliton-based nonlinear balancing of dual-core asymmetry in highly nonlinear photonic crystal fiber at sub-nanojoule pulse energy level. The effect of fiber asymmetry was studied experimentally by selective excitation and monitoring of individual fiber cores at different wavelengths between 1500 nm and 1800 nm. Higher energy transfer rate to non-excited core was observed in the case of fast core excitation due to nonlinear asymmetry balancing of temporal solitons, which was confirmed by the dedicated numerical simulations based on the coupled generalized nonlinear Schrödinger equations. Moreover, the simulation results correspond qualitatively with the experimentally acquired dependences of the output dual-core extinction ratio on excitation energy and wavelength. In the case of 1800 nm fast core excitation, narrow band spectral intensity switching between the output channels was registered with contrast of 23 dB. The switching was achieved by the change of the excitation pulse energy in sub-nanojoule region. The performed detailed analysis of the nonlinear balancing of dual-core asymmetry in solitonic propagation regime opens new perspectives for the development of ultrafast nonlinear all-optical switching devices.

  3. Wavelength conversion, time demultiplexing and multicasting based on cross-phase modulation and four-wave mixing in dispersion-flattened highly nonlinear photonic crystal fiber

    International Nuclear Information System (INIS)

    Hui, Zhan-Qiang; Zhang, Jian-Guo

    2012-01-01

    We propose the use of cross-phase modulation (XPM) and four-wave mixing (FWM) in dispersion-flattened highly nonlinear photonic crystal fibers (HNL-PCFs) to implement the functionalities of wavelength conversion, simultaneous time demultiplexing and wavelength multicasting in optical time-division multiplexing (OTDM) systems. The experiments on wavelength conversion at 80 Gbit s −1 and OTDM demultiplexing from 80 to 10 Gbit s −1 with wavelength multicasting of two channels are successfully demonstrated to validate the proposed scheme, which are carried out by using two segments of dispersion-flattened HNL-PCFs with lengths of 100 and 50 m, respectively. Moreover, the bit error rate (BER) performance is also measured. The results show that our designed system can achieve a power penalty of less than 4.6 dB for two multicasting channels with a 24 nm wavelength span at the BER of 10 −9 when compared with the 10 Gbit/s back-to-back measurement. The proposed system is transparent to bit rate since only an ultrafast third-order nonlinear effect is used. The resulting configuration is compact, robust and reliable, benefiting from the use of dispersion-flattened HNL-PCFs with short lengths. This also makes the proposed system more flexible in the operational wavelengths than those based on dispersion-shifted fibers and traditional highly nonlinear fibers. (paper)

  4. Nearly fully compressed 1053 nm pulses directly obtained from 800 nm laser-seeded photonic crystal fiber below zero dispersion point

    Science.gov (United States)

    Refaeli, Zaharit; Shamir, Yariv; Ofir, Atara; Marcus, Gilad

    2018-02-01

    We report a simple robust and broadly spectral-adjustable source generating near fully compressed 1053 nm 62 fs pulses directly out of a highly-nonlinear photonic crystal fiber. A dispersion-nonlinearity balance of 800 nm Ti:Sa 20 fs pulses was obtained initially by negative pre-chirping and then launching the pulses into the fibers' normal dispersion regime. Following a self-phase modulation spectral broadening, some energy that leaked below the zero dispersion point formed a soliton whose central wavelength could be tuned by Self-Frequency-Raman-Shift effect. Contrary to a common approach of power, or, fiber-length control over the shift, here we continuously varied the state of polarization, exploiting the Raman and Kerr nonlinearities responsivity for state of polarization. We obtained soliton pulses with central wavelength tuned over 150 nm, spanning from well below 1000 to over 1150 nm, of which we could select stable pulses around the 1 μm vicinity. With linewidth of > 20 nm FWHM Gaussian-like temporal-shape pulses with 62 fs duration and near flat phase structure we confirmed high quality pulse source. We believe such scheme can be used for high energy or high power glass lasers systems, such as Nd or Yb ion-doped amplifiers and systems.

  5. Designing analysis of the polarization beam splitter in two communication bands based on a gold-filled dual-core photonic crystal fiber

    International Nuclear Information System (INIS)

    Fan Zhen-Kai; Li Shu-Guang; Fan Yu-Qiu; Zhang Wan; An Guo-Wen; Bao Ya-Jie

    2014-01-01

    We design a novel kind of polarization beam splitter based on a gold-filled dual-core photonic crystal fiber (DC-PCF). Owing to filling with two gold wires in this DC-PCF, its coupling characteristics can be changed greatly by the second-order surface plasmon polariton (SPP) and the resonant coupling between the surface plasmon modes and the fiber-core guided modes can enhance the directional power transfer in the two fiber-cores. Numerical results by using the finite element method show the extinction ratio at the wavethlengths of 1.327 μm and 1.55 μm can reach −58 dB and −60 dB and the bandwidths as the extinction ratio better than −12 dB are about 54 nm and 47 nm, respectively. Compared with the gold-unfilled DC-PCF, a 1.746-mm-long gold-filled DC-PCF is better applied to the polarization beam splitter in the two communication bands of λ = 1.327 μm and 1.55 μm. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  6. Optimization of photonic crystal cavities

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole

    2017-01-01

    We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....

  7. Photonic crystal fiber modal interferometer with Pd/WO3 coating for real-time monitoring of dissolved hydrogen concentration in transformer oil.

    Science.gov (United States)

    Zhang, Ya-Nan; Wu, Qilu; Peng, Huijie; Zhao, Yong

    2016-12-01

    A highly-sensitive and temperature-robust photonic crystal fiber (PCF) modal interferometer coated with Pd/WO 3 film was fabricated and studied, aiming for real-time monitoring of dissolved hydrogen concentration in transformer oil. The sensor probe was fabricated by splicing two segments of a single mode fiber (SMF) with both ends of the PCF. Since the collapse of air holes in the PCF in the interfaces between SMF and PCF, a SMF-PCF-SMF interferometer structure was formed. The Pd/WO 3 film was fabricated by sol-gel method and coated on the surface of the PCF by dip-coating method. When the Pd/WO 3 film is exposed to hydrogen, both the length and cladding refractive index of the PCF would be changed, resulting in the resonant wavelength shift of the interferometer. Experimental results showed that the hydrogen measurement sensitivity of the proposed sensor can reach 0.109 pm/(μl/l) in the transformer oil, with the measurement range of 0-10 000 μl/l and response time less than 33 min. Besides, the proposed sensor was temperature-insensitive without any compensation process, easy to fabricate without any tapering, polishing, or etching process, low cost and quickly response without any oil-gas separation device. All these performances satisfy the actual need of real-time monitoring of dissolved hydrogen concentration in the transformer oil.

  8. Thermal effect-resilient design of large mode area double-cladding Yb-doped photonic crystal fibers

    DEFF Research Database (Denmark)

    Coscelli, Enrico; Poli, Federica; Johansen, Mette Marie

    2013-01-01

    The effects of thermally-induced refractive index change on the guiding properties of different large mode area fibers have been numerically analyzed. A simple but accurate model has been applied to obtain the refractive index change in the fiber cross-section, and a full-vector modal solver base...

  9. Graphene-based photonic crystal

    International Nuclear Information System (INIS)

    Berman, Oleg L.; Boyko, Vladimir S.; Kezerashvili, Roman Ya.; Kolesnikov, Anton A.; Lozovik, Yurii E.

    2010-01-01

    A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters and waveguides for the far infrared region of electromagnetic spectrum. Due to substantial suppression of absorption of low-frequency radiation in doped graphene the damping and skin effect in the photonic crystal are also suppressed. The advantages of the graphene-based photonic crystal are discussed.

  10. Photonic Crystals: Physics and Technology

    CERN Document Server

    Sibilia, Concita; Marciniak, Marian; Szoplik, Tomasz

    2008-01-01

    The aim of the work is give an overview of the activity in the field of Photonic Crystal developed in the frame of COST P11 action . The main objective of the COST P11 action was to unify and coordinate national efforts aimed at studying linear and nonlinear optical interactions with Photonic Crystals (PCs), without neglecting an important aspect related to the material research as idea and methods of realizations of 3D PC, together with the development and implementation of measurement techniques for the experimental evaluation of their potential applications in different area, as for example telecommunication with novel optical fibers, lasers, nonlinear multi-functionality, display devices , opto-electronics, sensors. The book contain contributions from authors who gave their lecture at the Cost P11 Training School. Training School was held at the Warsaw University (2007) and National Institute of Telecommunications (May 23), Warsaw. It was attended by 23 students. The focus of the School was on the work of...

  11. Fiber-based portable optical frequency standard for telecommunication

    DEFF Research Database (Denmark)

    Triches, Marco; Brusch, Anders; Hald, Jan

    2015-01-01

    Gas-filled hollow-core photonic crystal fibers are used to stabilize a fiber laser to the 13C2H2 P(16) (ν1 + ν3) transition at 1542 nm using saturated absorption. The fiber is encapsulated in glass cells for gas handling and compact free-space coupling, and packaged in a easy-to-use configuration....... The system is showing a locking-point repeatability within 60 kHz with respect to a conventional acetylene vapor cell reference and an Allan deviation below 8×10−11 (τ/s)−1/2 for 1

  12. Hollow Core Photonic Crystal Fibre Comprising a Fibre Grating in the Cladding and its Applications

    DEFF Research Database (Denmark)

    2010-01-01

    An optical fibre is provided having a fibre cladding around a longitudinally extending optical propagation core. The cladding has a reflection region of a varying refractive index in the longitudinal direction....

  13. Slotted Photonic Crystal Sensors

    Science.gov (United States)

    Scullion, Mark G.; Krauss, Thomas F.; Di Falco, Andrea

    2013-01-01

    Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them results in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This review article presents a new platform for optical biosensors, namely slotted photonic crystals, which provide higher sensitivities due to their ability to confine, spatially and temporally, the optical mode peak within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. Higher sensitivities were observed in smaller structures than possible with most competing devices reported in the literature. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study. PMID:23503295

  14. Slotted Photonic Crystal Sensors

    Directory of Open Access Journals (Sweden)

    Andrea Di Falco

    2013-03-01

    Full Text Available Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them results in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This review article presents a new platform for optical biosensors, namely slotted photonic crystals, which provide higher sensitivities due to their ability to confine, spatially and temporally, the optical mode peak within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. Higher sensitivities were observed in smaller structures than possible with most competing devices reported in the literature. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study.

  15. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    is therefore going on in the Netherlands about the fire resistance of hollow-core slabs. In 2014 the producers of hollow-core slabs have published a report of a project called Holcofire containing a collection of 162 fire tests on hollow-core slabs giving for the first time an overview of the fire tests made....... The present paper analyses the evidence now available for assessment of the fire resistance of extruded hollow-core slabs. The 162 fire tests from the Holcofire report are compared against the requirements for testing from the product standard for hollow-core slabs EN1168 and knowledge about the possible......Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...

  16. Elliptical As2Se3 filled core ultra-high-nonlinearity and polarization-maintaining photonic crystal fiber with double hexagonal lattice cladding

    Science.gov (United States)

    Li, Feng; He, Menghui; Zhang, Xuedian; Chang, Min; Wu, Zhizheng; Liu, Zheng; Chen, Hua

    2018-05-01

    A high birefringence and ultra-high nonlinearity photonic crystal fiber (PCF) is proposed, which is composed of an elliptical As2Se3-doped core and an inner cladding with hexagonal lattice. Optical properties of the PCF are simulated by the full-vector finite element method. The simulation results show that the high birefringence of ∼0.33, ultra-high-nonlinearity coefficient of 300757 W-1km-1 and the low confinement loss can be achieved in the proposed PCF simultaneously at the wavelength of 1.55 μm. Furthermore, by comparison with the other two materials (80PbO•20Ga2O3, As2S3) filled in the core, the As2Se3-doped PCF is found to have the highest birefringence and nonlinearity due to its higher refractive index and nonlinear refractive index. The flattened dispersion feature, as well as the low confinement loss of the proposed PCF structure make it suitable as a wide range of applications, such as the coherent optical communications, polarization-maintaining and nonlinear optics, etc.

  17. Efficient and broadband Stokes wave generation by degenerate four-wave mixing at the mid-infrared wavelength in a silica photonic crystal fiber.

    Science.gov (United States)

    Yuan, Jinhui; Sang, Xinzhu; Wu, Qiang; Zhou, Guiyao; Yu, Chongxiu; Wang, Kuiru; Yan, Binbin; Han, Ying; Farrell, Gerald; Hou, Lantian

    2013-12-15

    Based on degenerate four-wave mixing (FWM), the broadband Stokes waves are efficiently generated at the mid-infrared wavelength above 2 μm, for the first time to our knowledge, by coupling the femtosecond pulses into the fundamental mode of a silica photonic crystal fiber designed and fabricated in our laboratory. Influences of the power and wavelength of pump pulses on the phase-matched frequency conversion process are discussed. When pump pulses with central wavelength of 815 nm and average power of 300 mW are used, the output power ratio of the Stokes wave generated at 2226 nm and the residual pump wave P(s)/P(res) is estimated to be 10.8:1, and the corresponding conversion efficiency η(s) and bandwidth B(s) of the Stokes wave can be up to 26% and 33 nm, respectively. The efficient and broadband Stokes waves can be used as the ultrashort pulse sources for mid-infrared photonics and spectroscopy.

  18. Tunable ultra-broadband polarization filter based on three-core resonance of the fluid-infiltrated and gold-coated photonic crystal fiber

    Science.gov (United States)

    Liu, Yingchao; Chen, Hailiang; Ma, Mingjian; Zhang, Wenxun; Wang, Yujun; Li, Shuguang

    2018-03-01

    We propose a tunable ultra-broadband polarization filter based on three-core resonance of the fluid-infiltrated and gold-coated high birefringent photonic crystal fiber (HB-PCF). Gold film was applied to the inner walls of two cladding air holes and surface plasmon polaritons were generated on its surface. The two gold-coated cladding air holes acted as two defective cores. As the phase matching condition was satisfied, light transmitted in the fiber core and coupled to the two defective cores. The three-core PCF supported three super modes in two orthogonal polarization directions. The coupling characteristics among these modes were investigated using the finite-element method. We found that the coupling wavelengths and strength between these guided modes can be tuned by altering the structural parameters of the designed HB-PCF, such as the size of the voids, thickness of the gold-films and liquid infilling pattern. Under the optimized structural parameters, a tunable broadband polarization filter was realized. For one liquid infilling pattern, we obtained a broadband polarization filter which filtered out the light in y-polarization direction at the wavelength of 1550 nm. For another liquid infilling pattern, we filtered out light in the x-polarization direction at the wavelength of 1310 nm. Our studies on the designed HB-PCF made contributions to the further devising of tunable broadband polarization filters, which are extensively used in telecommunication and sensor systems. Project supported by the National Natural Science Foundation of China (Grant Nos. 61505175 and 61475134) and the Natural Science Foundation of Hebei Province (Grant Nos. F2017203110 and F2017203193).

  19. Optical microfiber-based photonic crystal cavity

    International Nuclear Information System (INIS)

    Yu, Yang; Sun, Yi-zhi; Li, Zhi-yuan; Ding, Wei; Andrews, Steve

    2016-01-01

    Using a focused ion beam milling technique, we fabricate broad stop band (∼10% wide) photonic crystal (PhC) cavities in adiabatically-tapered silica fibers. Abrupt structural design of PhC mirrors efficiently reduces radiation loss, increasing the cavity finesse to ∼7.5. Further experiments and simulations verify that the remaining loss is mainly due to Ga ion implantation. Such a microfiber PhC cavity probably has potentials in many light-matter interaction applications. (paper)

  20. Progress on photonic crystals

    CERN Document Server

    Lecoq, P; Gundacker, S; Hillemanns, H; Jarron, P; Knapitsch, A; Leclercq, J L; Letartre, X; Meyer, T; Pauwels, K; Powolny, F; Seassal, C

    2010-01-01

    The renewal of interest for Time of Flight Positron Emission Tomography (TOF PET) has highlighted the need for increasing the light output of scintillating crystals and in particular for improving the light extraction from materials with a high index of refraction. One possible solution to overcome the problem of total internal reflection and light losses resulting from multiple bouncing within the crystal is to improve the light extraction efficiency at the crystal/photodetector interface by means of photonic crystals, i.e. media with a periodic modulation of the dielectric constant at the wavelength scale. After a short reminder of the underlying principles this contribution proposes to present the very encouraging results we have recently obtained on LYSO pixels and the perspectives on other crystals such as BGO, LuYAP and LuAG. These results confirm the impressive predictions from our previously published Monte Carlo simulations. A detailed description of the sample preparation procedure is given as well ...

  1. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  2. Natural photonic crystals

    International Nuclear Information System (INIS)

    Vigneron, Jean Pol; Simonis, Priscilla

    2012-01-01

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  3. Hollow core waveguide as mid-infrared laser modal beam filter

    Energy Technology Data Exchange (ETDEWEB)

    Patimisco, P.; Giglio, M.; Spagnolo, V. [Dipartimento Interateneo di Fisica, Università e Politecnico di Bari, CNR-IFN UOS BARI, Via Amendola 173, 70126 Bari (Italy); Sampaolo, A. [Dipartimento Interateneo di Fisica, Università e Politecnico di Bari, CNR-IFN UOS BARI, Via Amendola 173, 70126 Bari (Italy); Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005 (United States); Kriesel, J. M. [Opto-Knowledge Systems, Inc. (OKSI), 19805 Hamilton Ave., Torrance, California 90502-1341 (United States); Tittel, F. K. [Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005 (United States)

    2015-09-21

    A novel method for mid-IR laser beam mode cleaning employing hollow core waveguide as a modal filter element is reported. The influence of the input laser beam quality on fiber optical losses and output beam profile using a hollow core waveguide with 200 μm-bore size was investigated. Our results demonstrate that even when using a laser with a poor spatial profile, there will exist a minimum fiber length that allows transmission of only the Gaussian-like fundamental waveguide mode from the fiber, filtering out all the higher order modes. This essentially single mode output is preserved also when the waveguide is bent to a radius of curvature of 7.5 cm, which demonstrates that laser mode filtering can be realized even if a curved light path is required.

  4. Optics of globular photonic crystals

    International Nuclear Information System (INIS)

    Gorelik, V S

    2007-01-01

    The results of experimental and theoretical studies of the optical properties of globular photonic crystals - new physical objects having a crystal structure with the lattice period exceeding considerably the atomic size, are presented. As globular photonic crystals, artificial opal matrices consisting of close-packed silica globules of diameter ∼200 nm were used. The reflection spectra of these objects characterising the parameters of photonic bands existing in these crystals in the visible spectral region are presented. The idealised models of the energy band structure of photonic crystals investigated in the review give analytic dispersion dependences for the group velocity and the effective photon mass in a globular photonic crystal. The characteristics of secondary emission excited in globular photonic crystals by monochromatic and broadband radiation are presented. The results of investigations of single-photon-excited delayed scattering of light observed in globular photonic crystals exposed to cw UV radiation and radiation from a repetitively pulsed copper vapour laser are presented. The possibilities of using globular photonic crystals as active media for lasing in different spectral regions are considered. It is proposed to use globular photonic crystals as sensitive sensors in optoelectronic devices for molecular analysis of organic and inorganic materials by the modern methods of laser spectroscopy. The results of experimental studies of spontaneous and stimulated globular scattering of light are discussed. The conditions for observing resonance and two-photon-excited delayed scattering of light are found. The possibility of accumulation and localisation of the laser radiation energy inside a globular photonic crystal is reported. (review)

  5. Controlling spontaneous emission of light by photonic crystals

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2005-01-01

    Photonic bandgap crystals were proposed almost two decades ago as a unique tool for controlling propagation and emission of light. Since then the research field of photonic crystals has exploded and many beautiful demonstrations of the use of photonic crystals and fibers for molding light...... propagation have appeared that hold great promises for integrated optics. These major achievements solidly demonstrate the ability to control propagation of light. In contrast, an experimental demonstration of the use of photonic crystals for timing the emission of light has so far lacked. In a recent...... publication in Nature, we have demonstrated experimentally that both the direction and time of spontaneous emission can be controlled, thereby confirming the original proposal by Eli Yablonovich that founded the field of photonic crystals. We believe that this work opens new opportunities for solid...

  6. Spectrofluorimetry with attomole sensitivity in photonic crystal fibres

    International Nuclear Information System (INIS)

    Williams, Gareth O S; Jones, Anita C; Euser, Tijmen G; Russell, Philip St J

    2013-01-01

    We report the use of photonic crystal fibres (PCF) as spectrofluorimetric systems in which sample solutions are excited within the microstructure of the fibre. The use of intra-fibre excitation has several advantages that combine to enable highly sensitive measurements of fluorescence spectra and lifetimes: long path-lengths are achieved by the efficient guidance of the fundamental mode; sample volumes contained within the micron-scale structure are very small, only a few nanolitres per cm of path; collection and guidance of the emitted fluorescence is efficient and the fluorescence lifetime is unperturbed. Fluorophores in bulk solution can be studied in hollow core PCF, whereas the use of PCF with a suspended, solid core enables selective excitation of molecules in close proximity to the silica surface, through interaction with the evanescent field. We demonstrate the measurement of fluorescence spectra and fluorescence lifetimes in each of these excitation regimes and report the detection of attomole quantities of fluorescein. (paper)

  7. Patterned Colloidal Photonic Crystals.

    Science.gov (United States)

    Hou, Jue; Li, Mingzhu; Song, Yanlin

    2018-03-01

    Colloidal photonic crystals (PCs) have been well developed because they are easy to prepare, cost-effective, and versatile with regards to modification and functionalization. Patterned colloidal PCs contribute a novel approach to constructing high-performance PC devices with unique structures and specific functions. In this review, an overview of the strategies for fabricating patterned colloidal PCs, including patterned substrate-induced assembly, inkjet printing, and selective immobilization and modification, is presented. The advantages of patterned PC devices are also discussed in detail, for example, improved detection sensitivity and response speed of the sensors, control over the flow direction and wicking rate of microfluidic channels, recognition of cross-reactive molecules through an array-patterned microchip, fabrication of display devices with tunable patterns, well-arranged RGB units, and wide viewing-angles, and the ability to construct anti-counterfeiting devices with different security strategies. Finally, the perspective of future developments and challenges is presented. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Reconfigurable topological photonic crystal

    Science.gov (United States)

    Shalaev, Mikhail I.; Desnavi, Sameerah; Walasik, Wiktor; Litchinitser, Natalia M.

    2018-02-01

    Topological insulators are materials that conduct on the surface and insulate in their interior due to non-trivial topology of the band structure. The edge states on the interface between topological (non-trivial) and conventional (trivial) insulators are topologically protected from scattering due to structural defects and disorders. Recently, it was shown that photonic crystals (PCs) can serve as a platform for realizing a scatter-free propagation of light waves. In conventional PCs, imperfections, structural disorders, and surface roughness lead to significant losses. The breakthrough in overcoming these problems is likely to come from the synergy of the topological PCs and silicon-based photonics technology that enables high integration density, lossless propagation, and immunity to fabrication imperfections. For many applications, reconfigurability and capability to control the propagation of these non-trivial photonic edge states is essential. One way to facilitate such dynamic control is to use liquid crystals (LCs), which allow to modify the refractive index with external electric field. Here, we demonstrate dynamic control of topological edge states by modifying the refractive index of a LC background medium. Background index is changed depending on the orientation of a LC, while preserving the topology of the system. This results in a change of the spectral position of the photonic bandgap and the topological edge states. The proposed concept might be implemented using conventional semiconductor technology, and can be used for robust energy transport in integrated photonic devices, all-optical circuity, and optical communication systems.

  9. Modeling of photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Barkou, Stig Eigil

    1999-01-01

    Diferent theoretical models for analysis of photonic crystal fibres are reviewed and compaired. The methods span from simple scalar approaches to full-vectorial models using different mode-field decompositions. The specific advantages of the methods are evaluated.......Diferent theoretical models for analysis of photonic crystal fibres are reviewed and compaired. The methods span from simple scalar approaches to full-vectorial models using different mode-field decompositions. The specific advantages of the methods are evaluated....

  10. Quasimetallic silicon micromachined photonic crystals

    International Nuclear Information System (INIS)

    Temelkuran, B.; Bayindir, Mehmet; Ozbay, E.; Kavanaugh, J. P.; Sigalas, M. M.; Tuttle, G.

    2001-01-01

    We report on fabrication of a layer-by-layer photonic crystal using highly doped silicon wafers processed by semiconductor micromachining techniques. The crystals, built using (100) silicon wafers, resulted in an upper stop band edge at 100 GHz. The transmission and defect characteristics of these structures were found to be analogous to metallic photonic crystals. We also investigated the effect of doping concentration on the defect characteristics. The experimental results agree well with predictions of the transfer matrix method simulations

  11. Fabrication and characterization of solid-core photonic crystal fiber with steering-wheel air-cladding for strong evanescent field overlap

    Czech Academy of Sciences Publication Activity Database

    Zhu, Y.; Bise, R. T.; Kaňka, Jiří; Peterka, Pavel; Du, H.

    Vol. 281, No. 1 (2008), s. 55-60 ISSN 0030-4018 R&D Projects: GA ČR GA102/05/0995 Grant - others:US National Science Foundation(US) ECS-0404002 Institutional research plan: CEZ:AV0Z20670512 Keywords : photonic crystals * fibre optic sensors * optic al fibres Subject RIV: BH - Optic s, Masers, Lasers Impact factor: 1.552, year: 2008

  12. Few photon switching with slow light in hollow fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Balic, Vlatko

    2009-01-01

    Cold atoms confined inside a hollow-core photonic-crystal fiber with core diameters of a few photon wavelengths are a promising medium for studying nonlinear optical interactions at extremely low light levels. The high electric field intensity per photon and interaction lengths not limited...... by diffraction are some of the unique features of this system. Here, we present the results of our first nonlinear optics experiments in this system including a demonstration of an all-optical switch that is activated at energies corresponding to few hundred optical photons per pulse....

  13. The analogy between photonic crystal fibres and step index fibres

    DEFF Research Database (Denmark)

    Birks, T.A.; Mogilevtsev, D.; Knight, J.C.

    1999-01-01

    The propagation constant of a photonic crystal fiber (PCF) can be approximated by substituting the effective V-value and NA into a formula valid for step index fibers (SIF), provided the V-value is defined with a core radius of 0.625 $Lambda@. V$PRM and NA must still be computed. Care must be taken...

  14. Low loss hollow-core waveguide on a silicon substrate

    Science.gov (United States)

    Yang, Weijian; Ferrara, James; Grutter, Karen; Yeh, Anthony; Chase, Chris; Yue, Yang; Willner, Alan E.; Wu, Ming C.; Chang-Hasnain, Connie J.

    2012-07-01

    Optical-fiber-based, hollow-core waveguides (HCWs) have opened up many new applications in laser surgery, gas sensors, and non-linear optics. Chip-scale HCWs are desirable because they are compact, light-weight and can be integrated with other devices into systems-on-a-chip. However, their progress has been hindered by the lack of a low loss waveguide architecture. Here, a completely new waveguiding concept is demonstrated using two planar, parallel, silicon-on-insulator wafers with high-contrast subwavelength gratings to reflect light in-between. We report a record low optical loss of 0.37 dB/cm for a 9-μm waveguide, mode-matched to a single mode fiber. Two-dimensional light confinement is experimentally realized without sidewalls in the HCWs, which is promising for ultrafast sensing response with nearly instantaneous flow of gases or fluids. This unique waveguide geometry establishes an entirely new scheme for low-cost chip-scale sensor arrays and lab-on-a-chip applications.

  15. Spatial filtering with photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Maigyte, Lina [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Rambla Sant Nebridi 22, Terrassa 08222 (Spain); Staliunas, Kestutis [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Rambla Sant Nebridi 22, Terrassa 08222 (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, Barcelona 08010 (Spain)

    2015-03-15

    Photonic crystals are well known for their celebrated photonic band-gaps—the forbidden frequency ranges, for which the light waves cannot propagate through the structure. The frequency (or chromatic) band-gaps of photonic crystals can be utilized for frequency filtering. In analogy to the chromatic band-gaps and the frequency filtering, the angular band-gaps and the angular (spatial) filtering are also possible in photonic crystals. In this article, we review the recent advances of the spatial filtering using the photonic crystals in different propagation regimes and for different geometries. We review the most evident configuration of filtering in Bragg regime (with the back-reflection—i.e., in the configuration with band-gaps) as well as in Laue regime (with forward deflection—i.e., in the configuration without band-gaps). We explore the spatial filtering in crystals with different symmetries, including axisymmetric crystals; we discuss the role of chirping, i.e., the dependence of the longitudinal period along the structure. We also review the experimental techniques to fabricate the photonic crystals and numerical techniques to explore the spatial filtering. Finally, we discuss several implementations of such filters for intracavity spatial filtering.

  16. Influence of ionization on ultrafast gas-based nonlinear fiber optics.

    Science.gov (United States)

    Chang, W; Nazarkin, A; Travers, J C; Nold, J; Hölzer, P; Joly, N Y; Russell, P St J

    2011-10-10

    We numerically investigate the effect of ionization on ultrashort high-energy pulses propagating in gas-filled kagomé-lattice hollow-core photonic crystal fibers by solving an established uni-directional field equation. We consider the dynamics of two distinct regimes: ionization induced blue-shift and resonant dispersive wave emission in the deep-UV. We illustrate how the system evolves between these regimes and the changing influence of ionization. Finally, we consider the effect of higher ionization stages.

  17. Molecular Gas-Filled Hollow Optical Fiber Lasers in the Near Infrared

    Science.gov (United States)

    2012-01-12

    Benabid, F., Roberts , P. J., Light, P. S., and Raymer , M. G., “Generation and photonic guidance of multi-octave optical-frequency combs,” Science, 318...scattering in molecular hydrogen," Phys. Rev. Lett. 93, 123903 (2004). 16. F. Couny, F. Benabid, P. J. Roberts , P. S. Light, and M. G. Raymer ...Couny, F., Wang, Y. Y., Wheeler, N. V., Roberts , P. J., and Benabid, F., “Double photonic bandgap hollow-core photonic crystal fiber,” Opt

  18. Photonic-crystal waveguide biosensor

    DEFF Research Database (Denmark)

    Skivesen, Nina; Têtu, Amélie; Kristensen, Martin

    2007-01-01

    A photonic-crystal waveguide sensor is presented for biosensing. The sensor is applied for refractive index measurements and detection of protein-concentrations. Concentrations around 10 μg/ml (0.15μMolar) are measured with excellent signal to noise ratio, and a broad, dynamic refractive index se...

  19. Slow Light by Two-Dimensional Photonic Crystal Waveguides

    International Nuclear Information System (INIS)

    Chao, Zhang; Yan, Huang; Xiao-Yu, Mao; Kai-Yu, Cui; Yi-Dong, Huang; Wei, Zhang; Jiang-De, Peng

    2009-01-01

    A simple and effective way to measure the group velocity of photonic crystal waveguides (PCWGs) is developed by using a fiber Mach–Zehnder interferometer. A PCWG with perfect air-bridge structure is fabricated and slow light with group velocity slower than c/80 is demonstrated. (fundamental areas of phenomenology (including applications))

  20. Analysis of Indexed-Guided Highly Birefringent Photonic Crystal ...

    African Journals Online (AJOL)

    In this paper, a comparative study of three geometries of highly birefringent photonic crystal fibers (HB PCF) is presented. The proposed geometries are: V type PCF, Pseudo-Panda PCF and selectively liquid-filled PCF. Based on the famous Finite Difference Time Domain (FDTD) method with the perfectly matched layer ...

  1. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    2017-01-01

    to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Findings – Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. Originality......Purpose – Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found...... in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of loadbearing capacity of hollow-core slabs when exposed to fire. Design/methodology/approach – Furthermore, it compares theoretica calculation and assessment according...

  2. Modelling of photonic crystal fibres

    DEFF Research Database (Denmark)

    Knudsen, Erik

    2003-01-01

    , as well as a honeycomb bandgap fibre and the first analysis of semi-periodic layered air-hole fibres. Using the modelling framework established as a basis, we provide an analysis of microbend loss, by regarding displacement of a fibre core as a stationary stochastic process, inducing mismatch between......In the presenta ph.d. work a theoretical study of aspects of modelling photonic crystal fibres was carried out. Photonic crystal fibres form a class of optical waveguides where guidance is no longer provided by a difference in refractive index between core and cladding. Instead, guidance...... is provided by an arrangement of air-holes running along the length of the fibre. Depending on the geometry of the fibre, the guiding mechanism may be either arising from the formation of a photonic bandgap in the cladding structure (photonic bandgap fibre), or by an effect resembling total internal...

  3. Optical Magnetometer Incorporating Photonic Crystals

    Science.gov (United States)

    Kulikov, Igor; Florescu, Lucia

    2007-01-01

    According to a proposal, photonic crystals would be used to greatly increase the sensitivities of optical magnetometers that are already regarded as ultrasensitive. The proposal applies, more specifically, to a state-of-the-art type of quantum coherent magnetometer that exploits the electromagnetically-induced-transparency (EIT) method for determining a small change in a magnetic field indirectly via measurement of the shift, induced by that change, in the hyperfine levels of resonant atoms exposed to the field.

  4. Quartz substrate infrared photonic crystal

    Science.gov (United States)

    Ghadiri, Khosrow; Rejeb, Jalel; Vitchev, Vladimir N.

    2003-01-01

    This paper presents the fabrication of a planar photonic crystal (p2c) made of a square array of dielectric rods embedded in air, operating in the infrared spectrum. A quartz substrate is employed instead of the commonly used silicon or column III-V substrate. Our square structure has a normalized cylinder radius-to-pitch ratio of r/a = 0.248 and dielectric material contrast ɛr of 4.5. We choose a Z-cut synthetic quartz for its cut (geometry), and etching properties. Then a particular Z-axis etching process is employed in order to ensure the sharp-edged verticality of the rods and fast etching speed. We also present the computer simulations that allowed the establishment of the photonic band gaps (PBG) of our photonic crystal, as well as the actual measurements. An experimental measurement have been carried out and compared with different simulations. It was found that experimental results are in good agreement with different simulation results. Finally, a frequency selective device for optical communication based on the introduction of impurity sites in the photonic crystal is presented. With our proposed structure Optical System on a Chip (OsoC) with micro-cavity based active devices such as lasers, diodes, modulators, couplers, frequency selective emitters, add-drop filters, detectors, mux/demuxes and polarizers connected by passive waveguide links can be realized.

  5. Hollow-core revolver fibre with a double-capillary reflective cladding

    Energy Technology Data Exchange (ETDEWEB)

    Kosolapov, A F; Alagashev, G K; Kolyadin, A N; Pryamikov, A D; Dianov, E M [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Biryukov, A S; Bufetov, I A [Moscow Institute of Physics and Technology (State University), Dolgoprudnyi, Moscow Region (Russian Federation)

    2016-03-31

    We report the fabrication of the first hollow-core revolver fibre with a core diameter as small as 25 μm and an optical loss no higher than 75 dB km{sup -1} at a wavelength of 1850 nm. The decrease in core diameter, with no significant increase in optical loss, is due to the use of double nested capillaries in the reflective cladding design. A number of technical problems pertaining to the fabrication of such fibres are resolved. (fiber optics)

  6. Hybrid colloidal plasmonic-photonic crystals.

    Science.gov (United States)

    Romanov, Sergei G; Korovin, Alexander V; Regensburger, Alois; Peschel, Ulf

    2011-06-17

    We review the recently emerged class of hybrid metal-dielectric colloidal photonic crystals. The hybrid approach is understood as the combination of a dielectric photonic crystal with a continuous metal film. It allows to achieve a strong modification of the optical properties of photonic crystals by involving the light scattering at electronic excitations in the metal component into moulding of the light flow in series to the diffraction resonances occurring in the body of the photonic crystal. We consider different realizations of hybrid plasmonic-photonic crystals based on two- and three-dimensional colloidal photonic crystals in association with flat and corrugated metal films. In agreement with model calculations, different resonance phenomena determine the optical response of hybrid crystals leading to a broadly tuneable functionality of these crystals. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. FDTD simulation for plasma photonic crystals

    International Nuclear Information System (INIS)

    Liu Shaobin; Zhu Chuanxi; Yuan Naichang

    2005-01-01

    Plasma photonic crystals are artificially periodic structures, which are composed of plasmas and dielectric structures (or vacuum). In this paper, the piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method is applied to study the plasma photonic crystals and those containing defects. In time-domain, the electromagnetic (EM) propagation process and reflection/transmission electric field of Gauss pulses passing through the plasma photonic crystals are investigated. In frequency-domain, the reflection and transmission coefficients of the pulses through the two kinds of crystals are computed. The results illustrate that the plasma photonic crystals mostly reflect for the EM wave of frequencies less than the plasma frequency, and mostly transmit for EM wave of frequencies higher than the plasma frequency. In high frequency domain, the plasma photonic crystals have photonic band gaps, which is analogous to the conventional photonic crystals. (authors)

  8. REVIEW: Optics of globular photonic crystals

    Science.gov (United States)

    Gorelik, V. S.

    2007-05-01

    The results of experimental and theoretical studies of the optical properties of globular photonic crystals - new physical objects having a crystal structure with the lattice period exceeding considerably the atomic size, are presented. As globular photonic crystals, artificial opal matrices consisting of close-packed silica globules of diameter ~200 nm were used. The reflection spectra of these objects characterising the parameters of photonic bands existing in these crystals in the visible spectral region are presented. The idealised models of the energy band structure of photonic crystals investigated in the review give analytic dispersion dependences for the group velocity and the effective photon mass in a globular photonic crystal. The characteristics of secondary emission excited in globular photonic crystals by monochromatic and broadband radiation are presented. The results of investigations of single-photon-excited delayed scattering of light observed in globular photonic crystals exposed to cw UV radiation and radiation from a repetitively pulsed copper vapour laser are presented. The possibilities of using globular photonic crystals as active media for lasing in different spectral regions are considered. It is proposed to use globular photonic crystals as sensitive sensors in optoelectronic devices for molecular analysis of organic and inorganic materials by the modern methods of laser spectroscopy. The results of experimental studies of spontaneous and stimulated globular scattering of light are discussed. The conditions for observing resonance and two-photon-excited delayed scattering of light are found. The possibility of accumulation and localisation of the laser radiation energy inside a globular photonic crystal is reported.

  9. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Giuliani, Luisa; Sørensen, Lars Schiøtt

    2016-01-01

    Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60- and 120 minutes found in most...... a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. For the first time the mechanisms responsible for loss of load......-bearing capacity are identified and test results and calculation approach are for the first time Applied in accordance with each other for assessment of fire resistance of the structure....

  10. Development of an optical fiber SERS microprobe for minimally invasive sensing applications

    Science.gov (United States)

    Mamun, Md Abdullah Al; Juodkazis, Saulius; Mahadevan-Jansen, Anita; Stoddart, Paul R.

    2018-02-01

    Numerous potential biomedical sensing applications of surface-enhanced Raman scattering (SERS) have been reported, but its practical use has been limited by the lack of a robust sensing platform. Optical fiber SERS probes show great promise, but are limited by the prominent silica Raman background, which requires the use of bulky optics for filtering the signal collection and excitation delivery paths. In the present study, a SERS microprobe has been designed and developed to eliminate the bottlenecks outlined above. For efficient excitation and delivery of the SERS signal, both hollow core photonic crystal fiber and double clad fiber have been investigated. While the hollow core fiber was still found to have excessive silica background, the double clad fiber allows efficient signal collection via the multi-mode inner cladding. A micro filtering mechanism has been designed, which can be integrated into the tip of the optical fiber SERS probe, providing filtering to suppress silica Raman background and thus avoiding the need for bulky optics. The design also assists in the efficient collection of SERS signal from the sample by rejecting Rayleigh scattered light from the sample. Optical fiber cleaving using ultra-short laser pulses was tested for improved control of the fiber tip geometry. With this miniaturized and integrated filtering mechanism, it is expected that the developed probe will promote the use of SERS for minimally invasive biomedical monitoring and sensing applications in future. The probe could potentially be placed inside a small gauge hypodermic needle and would be compatible with handheld portable spectrometers.

  11. Dispersion properties of photonic crystal fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Dridi, Kim

    1998-01-01

    Approximate dispersion and bending properties of all-silica two-dimensional photonic crystal fibres are characterised by the combination of an effective-index model and classical analysis tools for optical fibres. We believe for the first time to have predicted the dispersion properties of photonic...... crystal fibres. The results strongly indicate that these fibres have potential applications as dispersion managing components...

  12. Precursors in photonic crystals - art. no. 618218

    NARCIS (Netherlands)

    Uitham, R.; Hoenders, B. J.; DeLaRue, RM; Viktorovitch, P; Lopez, C; Midrio, M

    2006-01-01

    We derive the Sommerfeld precursor and present the first calculations for the Brillouin precursor that result from the transmission of a pulse through a photonic crystal. The photonic crystal is modelled by a one-dimensional N-layer medium and the pulse is a generic electromagnetic plane wave packet

  13. Nanoimprinted polymer photonic crystal dye lasers

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Smith, Cameron; Buss, Thomas

    2010-01-01

    Optically pumped polymer photonic crystal band-edge dye lasers are presented. The photonic crystal is a rectangular lattice providing laser feedback as well as an optical resonance for the pump light. The lasers are defined in a thin film of photodefinable Ormocore hybrid polymer, doped...

  14. Selective filling of Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild

    2005-01-01

    A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre...

  15. Photonic crystal scintillators and methods of manufacture

    Science.gov (United States)

    Torres, Ricardo D.; Sexton, Lindsay T.; Fuentes, Roderick E.; Cortes-Concepcion, Jose

    2015-08-11

    Photonic crystal scintillators and their methods of manufacture are provided. Exemplary methods of manufacture include using a highly-ordered porous anodic alumina membrane as a pattern transfer mask for either the etching of underlying material or for the deposition of additional material onto the surface of a scintillator. Exemplary detectors utilizing such photonic crystal scintillators are also provided.

  16. Coupled Photonic Crystal Cavity Array Laser

    DEFF Research Database (Denmark)

    Schubert, Martin

    in the quadratic lattice. Processing techniques are developed and optimized in order fabricate photonic crystals membranes in gallium arsenide with quantum dots as gain medium and in indium gallium arsenide phosphide with quantum wells as gain medium. Several key issues in process to ensure good quality....... The results are in good agreement with standard coupled mode theory. Also a novel type of photonic crystal structure is proposed called lambda shifted cavity which is a twodimensional photonic crystal laser analog of a VCSEL laser. Detailed measurements of the coupled modes in the photonic crystals...... with quantum dots are carried out. In agreement with a simple gain model the structures do not show stimulated emission. The spectral splitting due to the coupling between single cavities as well as arrays of cavities is studied theoretically and experimentally. Lasing is observed for photonic crystal cavity...

  17. Photonic crystals physics, fabrication and applications

    CERN Document Server

    Ohtaka, Kazuo

    2004-01-01

    "Photonic Crystals" details recent progress in the study of photonic crystals, ranging from fundamental aspects to up-to-date applications, in one unified treatment It covers most of the worldwide frontier fields in photonic crystals, including up-to-date fabrication techniques, recent and future technological applications, and our basic understanding of the various optical properties of photonic crystals Brand-new theoretical and experimental data are also presented The book is intended for graduate course students and specialists actively working in this field, but it will also be useful for newcomers, especially the extensive chapter dealing with fundamental aspects of photonic crystals, which paves the way to a full appreciation of the other topics addressed

  18. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  19. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  20. Surface states in photonic crystals

    Directory of Open Access Journals (Sweden)

    Vojtíšek P.

    2013-05-01

    Full Text Available Among many unusual and interesting physical properties of photonic crystals (PhC, in recent years, the propagation of surface electromagnetic waves along dielectric PhC boundaries have attracted considerable attention, also in connection to their possible applications. Such surfaces states, produced with the help of specialized defects on PhC boundaries, similarly to surfaces plasmons, are localized surfaces waves and, as such, can be used in various sensing applications. In this contribution, we present our recent studies on numerical modelling of surface states (SS for all three cases of PhC dimensionality. Simulations of these states were carried out by the use of plane wave expansion (PWE method via the MIT MPB package.

  1. Long-period gratings in photonic crystal fibers operating near the phase-matching turning point for evanescent chemical and biochemical sensing

    Science.gov (United States)

    Kanka, Jiri

    2012-06-01

    Fiber-optic long-period grating (LPG) operating near the dispersion turning point in its phase matching curve (PMC), referred to as a Turn Around Point (TAP) LPG, is known to be extremely sensitive to external parameters. Moreover, in a TAP LPG the phase matching condition can be almost satisfied over large spectral range, yielding a broadband LPG operation. TAP LPGs have been investigated, namely for use as broadband mode convertors and biosensors. So far TAP LPGs have been realized in specially designed or post-processed conventional fibers, not yet in PCFs, which allow a great degree of freedom in engineering the fiber's dispersion properties through the control of the PCF structural parameters. We have developed the design optimization technique for TAP PCF LPGs employing the finite element method for PCF modal analysis in a combination with the Nelder-Mead simplex method for minimizing the objective function based on target-specific PCF properties. Using this tool we have designed TAP PCF LPGs for specified wavelength ranges and refractive indices of medium in the air holes. Possible TAP PCF-LPG operational regimes - dual-resonance, broadband mode conversion and transmitted intensity-based operation - will be demonstrated numerically. Potential and limitations of TAP PCF-LPGs for evanescent chemical and biochemical sensing will be assessed.

  2. Structural Behavior of Fibrous Reinforced Concrete Hollow Core One-Way Slabs Strengthening by C.F.R.P

    Directory of Open Access Journals (Sweden)

    وصيف مجيد

    2016-02-01

    Full Text Available A reinforced concrete hollow core one-way slab is one of the types of slabs used widely around the world in residential and industrial buildings to take advantage of them Economic and thermal insulation as well as to reduce the self-weight of the construction. The aim of the present study is to examine the structural behavior of the reinforced concrete hollow core one-way slabs reduce failure using the normal concrete and fibrous concrete and then strengthened using carbon fiber(CFRPThis study include molding of ( 6 specimens differ in terms of the voids volume (Vv , volumetric percentage of steel fibers (ا, and then strengthened by using fibers of carbon , with the aim of rehabilitation by fibers, carbon polymer (CFRP is to find out how efficient element structural when treated after the occurrence of the failure and the validity of its use in the event of a failure has occurred entirely or partly in the roof, and re- examined using the same method and conditions that were examined ceilings is affected through it, knowing that these ceilings have been addressed and strengthened in the same way , the results of the tests of the models that have been rehabilitated using carbon fiber (CFRP, compared with the same models before strengthening and examined reduce failure, increased very high susceptibility endurance extreme , with the increase ranging from (51.6% to (96.2%, as has been observed decrease in deflection value of models after strengthening by (CFRP.It is concluded through this study the possibility of using its concrete hollow core one-way slab as a roofing system for buildings also proved the highly efficient for this slab after rehabilitation using carbon fiber (CFRP.

  3. Large-area photonic crystals

    Science.gov (United States)

    Ruhl, Tilmann; Spahn, Peter; Hellmann, Gotz P.; Winkler, Holger

    2004-09-01

    Materials with a periodically modulated refractive index, with periods on the scale of light wavelengths, are currently attracting much attention because of their unique optical properties which are caused by Bragg scattering of the visible light. In nature, 3d structures of this kind are found in the form of opals in which monodisperse silica spheres with submicron diameters form a face-centered-cubic (fcc) lattice. Artificial opals, with the same colloidal-crystalline fcc structure, have meanwhile been prepared by crystallizing spherical colloidal particles via sedimentation or drying of dispersions. In this report, colloidal crystalline films are introduced that were produced by a novel technique based on shear flow in the melts of specially designed submicroscopic silica-polymer core-shell hybrid spheres: when the melt of these spheres flows between the plates of a press, the spheres crystallize along the plates, layer by layer, and the silica cores assume the hexagonal order corresponding to the (111) plane of the fcc lattice. This process is fast and yields large-area films, thin or thick. To enhance the refractive index contrast in these films, the colloidal crystalline structure was inverted by etching out the silica cores with hydrofluoric acid. This type of an inverse opal, in which the fcc lattice is formed by mesopores, is referred to as a polymer-air photonic crystal.

  4. Nonlinear modes in the hollow-cores of liquid vortices

    KAUST Repository

    Amaouche, Mustapha; Ait Abderrahmane, Hamid; Vatistas, Georgios H.

    2013-01-01

    In this paper we show that the wave patterns observed on the interfacial contours of hollow-core vortices, produced within a shallow layer of fluid contained in stationary cylinder and driven by a rotating disk at the bottom [G.H. Vatistas, H.A. Abderrahmane, M.H. Kamran Siddiqui, Experimental confirmation of Kelvin's equilibria, Phys. Rev. Lett. 100 (2008) 174503-174504], can be described as travelling cnoidal waves. These rotating stationary waves are obtained as solutions of a Korteweg-de Vries type equation, in accordance with the geometrical and kinematic characteristics of the observed polygonal patterns. © 2013 Elsevier Masson SAS. All rights reserved.

  5. Nonlinear modes in the hollow-cores of liquid vortices

    KAUST Repository

    Amaouche, Mustapha

    2013-09-01

    In this paper we show that the wave patterns observed on the interfacial contours of hollow-core vortices, produced within a shallow layer of fluid contained in stationary cylinder and driven by a rotating disk at the bottom [G.H. Vatistas, H.A. Abderrahmane, M.H. Kamran Siddiqui, Experimental confirmation of Kelvin\\'s equilibria, Phys. Rev. Lett. 100 (2008) 174503-174504], can be described as travelling cnoidal waves. These rotating stationary waves are obtained as solutions of a Korteweg-de Vries type equation, in accordance with the geometrical and kinematic characteristics of the observed polygonal patterns. © 2013 Elsevier Masson SAS. All rights reserved.

  6. Large-bandwidth planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Lavrinenko, Andrei

    2002-01-01

    A general design principle is presented for making finite-height photonic crystal waveguides that support leakage-free guidance of light over large frequency intervals. The large bandwidth waveguides are designed by introducing line defects in photonic crystal slabs, where the material in the line...... defect has appropriate dispersion properties relative to the photonic crystal slab material surrounding the line defect. A three-dimensional theoretical analysis is given for large-bandwidth waveguide designs based on a silicon-air photonic crystal slab suspended in air. In one example, the leakage......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap....

  7. Photonic crystal fibres and effective index approaches

    DEFF Research Database (Denmark)

    Riishede, Jesper; Libori, Stig E. Barkou; Bjarklev, Anders Overgaard

    2001-01-01

    Photonic crystal fibres are investigated with an effective index approach. The effective index of both core and cladding is found to be wavelength dependent. Accurate modelling must respect the rich topology of these fibres.......Photonic crystal fibres are investigated with an effective index approach. The effective index of both core and cladding is found to be wavelength dependent. Accurate modelling must respect the rich topology of these fibres....

  8. Spatial solitons in nonlinear photonic crystals

    DEFF Research Database (Denmark)

    Corney, Joel Frederick; Bang, Ole

    2000-01-01

    We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero.......We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero....

  9. Quarter-lambda-shifted photonic crystal lasers

    DEFF Research Database (Denmark)

    Schubert, Martin; Skovgård, Troels Suhr; Ek, Sara

    A new design for photonic crystal lasers is proposed and realised. It allows an intuitive design for ultralow mode volume and high Q cavities which can be realized in a connected membrane structure.......A new design for photonic crystal lasers is proposed and realised. It allows an intuitive design for ultralow mode volume and high Q cavities which can be realized in a connected membrane structure....

  10. Selective gas sensing for photonic crystal lasers

    DEFF Research Database (Denmark)

    Smith, Cameron; Christiansen, Mads Brøkner; Buss, Thomas

    2011-01-01

    We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk.......We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk....

  11. Fully-etched apodized fiber-to-chip grating coupler on the SOI platform with -0.78 dB coupling efficiency using photonic crystals and bonded Al mirror

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Peucheret, Christophe

    2014-01-01

    We design and fabricate an ultra-high coupling efficiency fully-etched apodized grating coupler on the SOI platform using photonic crystals and bonded aluminum mirror. Ultra-high coupling efficiency of -0.78 dB with a 3 dB bandwidth of 74 nm are demonstrated.......We design and fabricate an ultra-high coupling efficiency fully-etched apodized grating coupler on the SOI platform using photonic crystals and bonded aluminum mirror. Ultra-high coupling efficiency of -0.78 dB with a 3 dB bandwidth of 74 nm are demonstrated....

  12. Monitoring the Wobbe Index of Natural Gas Using Fiber-Enhanced Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Vincenz Sandfort

    2017-11-01

    Full Text Available The fast and reliable analysis of the natural gas composition requires the simultaneous quantification of numerous gaseous components. To this end, fiber-enhanced Raman spectroscopy is a powerful tool to detect most components in a single measurement using a single laser source. However, practical issues such as detection limit, gas exchange time and background Raman signals from the fiber material still pose obstacles to utilizing the scheme in real-world settings. This paper compares the performance of two types of hollow-core photonic crystal fiber (PCF, namely photonic bandgap PCF and kagomé-style PCF, and assesses their potential for online determination of the Wobbe index. In contrast to bandgap PCF, kagomé-PCF allows for reliable detection of Raman-scattered photons even below 1200 cm−1, which in turn enables fast and comprehensive assessment of the natural gas quality of arbitrary mixtures.

  13. Monitoring the Wobbe Index of Natural Gas Using Fiber-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Sandfort, Vincenz; Trabold, Barbara M; Abdolvand, Amir; Bolwien, Carsten; Russell, Philip St. J; Wöllenstein, Jürgen; Palzer, Stefan

    2017-11-24

    The fast and reliable analysis of the natural gas composition requires the simultaneous quantification of numerous gaseous components. To this end, fiber-enhanced Raman spectroscopy is a powerful tool to detect most components in a single measurement using a single laser source. However, practical issues such as detection limit, gas exchange time and background Raman signals from the fiber material still pose obstacles to utilizing the scheme in real-world settings. This paper compares the performance of two types of hollow-core photonic crystal fiber (PCF), namely photonic bandgap PCF and kagomé-style PCF, and assesses their potential for online determination of the Wobbe index. In contrast to bandgap PCF, kagomé-PCF allows for reliable detection of Raman-scattered photons even below 1200 cm -1 , which in turn enables fast and comprehensive assessment of the natural gas quality of arbitrary mixtures.

  14. Mesoscale cavities in hollow-core waveguides for quantum optics with atomic ensembles

    Directory of Open Access Journals (Sweden)

    Haapamaki C.M.

    2016-08-01

    Full Text Available Single-mode hollow-core waveguides loaded with atomic ensembles offer an excellent platform for light–matter interactions and nonlinear optics at low photon levels. We review and discuss possible approaches for incorporating mirrors, cavities, and Bragg gratings into these waveguides without obstructing their hollow cores. With these additional features controlling the light propagation in the hollow-core waveguides, one could potentially achieve optical nonlinearities controllable by single photons in systems with small footprints that can be integrated on a chip. We propose possible applications such as single-photon transistors and superradiant lasers that could be implemented in these enhanced hollow-core waveguides.

  15. A novel method of rapidly modeling optical properties of actual photonic crystal fibres

    International Nuclear Information System (INIS)

    Li-Wen, Wang; Shu-Qin, Lou; Wei-Guo, Chen; Hong-Lei, Li

    2010-01-01

    The flexible structure of photonic crystal fibre not only offers novel optical properties but also brings some difficulties in keeping the fibre structure in the fabrication process which inevitably cause the optical properties of the resulting fibre to deviate from the designed properties. Therefore, a method of evaluating the optical properties of the actual fibre is necessary for the purpose of application. Up to now, the methods employed to measure the properties of the actual photonic crystal fibre often require long fibre samples or complex expensive equipments. To our knowledge, there are few studies of modeling an actual photonic crystal fibre and evaluating its properties rapidly. In this paper, a novel method, based on the combination model of digital image processing and the finite element method, is proposed to rapidly model the optical properties of the actual photonic crystal fibre. Two kinds of photonic crystal fibres made by Crystal Fiber A/S are modeled. It is confirmed from numerical results that the proposed method is simple, rapid and accurate for evaluating the optical properties of the actual photonic crystal fibre without requiring complex equipment. (rapid communication)

  16. Ultra-High-Efficiency Apodized Grating Coupler Using a Fully Etched Photonic Crystal

    DEFF Research Database (Denmark)

    Ding, Yunhong; Peucheret, Christophe; Ou, Haiyan

    2013-01-01

    We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated.......We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated....

  17. Sub-mm Scale Fiber Guided Deep/Vacuum Ultra-Violet Optical Source for Trapped Mercury Ion Clocks

    Science.gov (United States)

    Yi, Lin; Burt, Eric A.; Huang, Shouhua; Tjoelker, Robert L.

    2013-01-01

    We demonstrate the functionality of a mercury capillary lamp with a diameter in the sub-mm range and deep ultraviolet (DUV)/ vacuum ultraviolet (VUV) radiation delivery via an optical fiber integrated with the capillary. DUV spectrum control is observed by varying the fabrication parameters such as buffer gas type and pressure, capillary diameter, electrical resonator design, and temperature. We also show spectroscopic data of the 199Hg+ hyper-fine transition at 40.5GHz when applying the above fiber optical design. We present efforts toward micro-plasma generation in hollow-core photonic crystal fiber with related optical design and theoretical estimations. This new approach towards a more practical DUV optical interface could benefit trapped ion clock developments for future ultra-stable frequency reference and time-keeping applications.

  18. Manipulating light with strongly modulated photonic crystals

    International Nuclear Information System (INIS)

    Notomi, Masaya

    2010-01-01

    Recently, strongly modulated photonic crystals, fabricated by the state-of-the-art semiconductor nanofabrication process, have realized various novel optical properties. This paper describes the way in which they differ from other optical media, and clarifies what they can do. In particular, three important issues are considered: light confinement, frequency dispersion and spatial dispersion. First, I describe the latest status and impact of ultra-strong light confinement in a wavelength-cubic volume achieved in photonic crystals. Second, the extreme reduction in the speed of light is reported, which was achieved as a result of frequency dispersion management. Third, strange negative refraction in photonic crystals is introduced, which results from their unique spatial dispersion, and it is clarified how this leads to perfect imaging. The last two sections are devoted to applications of these novel properties. First, I report the fact that strong light confinement and huge light-matter interaction enhancement make strongly modulated photonic crystals promising for on-chip all-optical processing, and present several examples including all-optical switches/memories and optical logics. As a second application, it is shown that the strong light confinement and slow light in strongly modulated photonic crystals enable the adiabatic tuning of light, which leads to various novel ways of controlling light, such as adiabatic frequency conversion, efficient optomechanics systems, photon memories and photons pinning.

  19. Calculation of shear strength of prestressed hollow core slabs by use of plastic theory

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Jørgensen, H.G.; Nielsen, Mogens Peter

    2014-01-01

    Th is paper deals with calculations of the shear capacity of precast, prestressed hollow core slabs. Such slabs are often used as floor systems in building structures. A common way to produce hollow core slabs is to use the extrusion technique where long strips of slabs are extruded and thereafter...

  20. Measurement of Thermal Dependencies of PBG Fiber Properties

    International Nuclear Information System (INIS)

    Laouar, Rachik

    2011-01-01

    Photonic crystal fibers (PCFs) represent a class of optical fibers which have a wide spectrum of applications in the telecom and sensing industries. Currently, the Advanced Accelerator Research Department at SLAC is developing photonic bandgap particle accelerators, which are photonic crystal structures with a central defect used to accelerate electrons and achieve high longitudinal electric fields. Extremely compact and less costly than the traditional accelerators, these structures can support higher accelerating gradients and will open a new era in high energy physics as well as other fields of science. Based on direct laser acceleration in dielectric materials, the so called photonic band gap accelerators will benefit from mature laser and semiconductor industries. One of the key elements to direct laser acceleration in hollow core PCFs, is maintaining thermal and structural stability. Previous simulations demonstrate that accelerating modes are sensitive to the geometry of the defect region and the variations in the effective index. Unlike the telecom modes (for which over 95% of the energy propagates in the hollow core) most of the power of these modes is located in the glass at the periphery of the central hole which has a higher thermal constant than air (γ SiO# sub 2# = 1.19 x 10 -6 1/K, γ air = -9 x 10 -7 1/K with γ = dn/dT). To fully control laser driven acceleration, we need to evaluate the thermal and structural consequences of such modes on the PCFs. We are conducting series of interferometric tests to quantify the dependencies of the HC-633-02 (NKT Photonics) propagation constant (k z ) on temperature, vibration amplitude, stress and electric field strength. In this paper we will present the theoretical principles characterizing the thermal behavior of a PCF, the measurements realized for the fundamental telecom mode (TE 00 ), and the experimental demonstration of TM-like mode propagation in the HC-633-02 fiber.

  1. Theory of fluorescence in photonic crystals

    International Nuclear Information System (INIS)

    Vats, Nipun; John, Sajeev; Busch, Kurt

    2002-01-01

    We present a formalism for the description of fluorescence from optically active materials embedded in a photonic crystal structure possessing a photonic band gap or pseudogap. An electromagnetic field expansion in terms of Bloch modes of the crystal is used to develop the equations for fluorescence in terms of the local density of photon modes available to the emitting atoms in either the high or low dielectric regions of the crystal. We then obtain expressions for fluorescence spectra and emission dynamics for luminescent materials in photonic crystals. The validity of our formalism is demonstrated through the calculation of relevant quantities for model photon densities of states. The connection of our calculations to the description of realistic systems is discussed. We also describe the consequences of these analyses on the accurate description of the interaction between radiative systems and the electromagnetic reservoir within photonic crystals

  2. One-Dimensional Photonic Crystal Superprisms

    Science.gov (United States)

    Ting, David

    2005-01-01

    Theoretical calculations indicate that it should be possible for one-dimensional (1D) photonic crystals (see figure) to exhibit giant dispersions known as the superprism effect. Previously, three-dimensional (3D) photonic crystal superprisms have demonstrated strong wavelength dispersion - about 500 times that of conventional prisms and diffraction gratings. Unlike diffraction gratings, superprisms do not exhibit zero-order transmission or higher-order diffraction, thereby eliminating cross-talk problems. However, the fabrication of these 3D photonic crystals requires complex electron-beam substrate patterning and multilayer thin-film sputtering processes. The proposed 1D superprism is much simpler in structural complexity and, therefore, easier to design and fabricate. Like their 3D counterparts, the 1D superprisms can exhibit giant dispersions over small spectral bands that can be tailored by judicious structure design and tuned by varying incident beam direction. Potential applications include miniature gas-sensing devices.

  3. Ultra compact spectrometer apparatus and method using photonic crystals

    Science.gov (United States)

    Ting, David Z. (Inventor); Hill, Cory J. (Inventor); Bandara, Sumith V. (Inventor); Gunapala, Sarath D. (Inventor)

    2009-01-01

    The present invention is directed to methods of photonic crystal formation, and to methods and apparatus for using such photonic crystals, particularly in conjunction with detector arrays. Photonic crystal parameters and detector array parameters are compared to optimize the selection and orientation of a photonic crystal shape. A photonic crystal is operatively positioned relative to a plurality of light sensors. The light sensors can be separated by a pitch distance and positioned within one half of the pitch distance of an exit surface of the photonic crystals.

  4. Two-dimensional photonic crystal accelerator structures

    Directory of Open Access Journals (Sweden)

    Benjamin M. Cowan

    2003-10-01

    Full Text Available Photonic crystals provide a method of confining a synchronous speed-of-light mode in an all-dielectric structure, likely a necessary feature in any optical accelerator. We explore computationally a class of photonic crystal structures with translational symmetry in a direction transverse to the electron beam. We demonstrate synchronous waveguide modes and discuss relevant parameters of such modes. We then explore how accelerator parameters vary as the geometry of the structure is changed and consider trade-offs inherent in the design of an accelerator of this type.

  5. Giant Lamb shift in photonic crystals

    International Nuclear Information System (INIS)

    Wang Xuehua; Kivshar, Yuri S.; Gu Benyuan

    2004-01-01

    We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases

  6. Photonic crystals, amorphous materials, and quasicrystals.

    Science.gov (United States)

    Edagawa, Keiichi

    2014-06-01

    Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states.

  7. Graded photonic crystals by optical interference holography

    International Nuclear Information System (INIS)

    Han, Chunrui; Tam, Wing Yim

    2012-01-01

    We report on the fabrication of graded photonic crystals in dye doped dichromate gelatin emulsions using an optical interference holographic technique. The gradedness is achieved by imposing a gradient form factor in the interference intensity resulting from the absorption of the dye in the dichromate gelatin. Wider and deeper photonic bandgaps are observed for the dyed samples as compared to the un-dyed samples. Our method could open up a new direction in fabricating graded photonic crystals which cannot be achieved easily using other techniques. (paper)

  8. Experimental and numerical investigations of Si-based photonic crystals with ordered Ge quantum dots emitters

    International Nuclear Information System (INIS)

    Jannesari, R.

    2014-01-01

    In recent years quasi-two-dimensional (2D) photonic crystals, also known as photonic crystal slabs, have been the subject of extensive research. The present work is based on photonic crystals where a hexagonal 2D lattice of air holes is etched through a silicon-on-insulator (SOI) slab. Light is guided in the horizontal plane using photonic band-gap properties, and index guiding provides the optical confinement in the third dimension. This work discusses photonic crystal slabs with Ge quantum dots (QDs) as internal sources. Ge quantum dots have luminescence around 1500nm, which is well suited for optical fiber communication in a way that is fully compatible with standard silicon technology. QD emission can be controlled by epitaxial growth on a pre-patterned SOI substrate. In this way the position of the QDs is controlled, as well as their homogeneity and spectral emission range. During this thesis, photonic crystal fabrication techniques together with techniques for the alignment of the photonic crystal holes with the QDs positions were developed. The employed techniques involve electron beam lithography (EBL) and inductively-coupled-plasma reactive ion etching (ICP-RIE). Perfect ordering of the QDs position was achieved by employing these techniques for pit patterning and the subsequent growth of Ge dots using molecular beam epitaxy (MBE). A second EBL step was then used for photonic crystal writing, which needed to be aligned with respect to the pit pattern with a precision of about ± 30nm. Micro-photoluminescence spectroscopy was used for the optical characterization of the photonic crystal. The emission from ordered quantum dots in different symmetry positions within a unit cell of photonic crystal was theoretically and experimentally investigated and compared with randomly distributed ones. Besides, different geometrical parameters of photonic crystals were studied. The theoretical investigations were mainly based on the rigorous coupled wave analysis (RCWA

  9. Polarization-insensitive all-optical dual pump-phase transmultiplexing from 2 x 10-GBd OOKs to 10-GBd RZ-QPSK using cross-phase modulation in a passive nonlinear birefringent photonic crystal fiber

    Science.gov (United States)

    Mahmood, Tanvir

    Considering the network size, bit rate, spectral and channel capacity limitations, different modulation formats may be selectively used in future optical networks. Although the traditional metropolitan area networks (MANs) still uses the non-return-to-zero on-off keying (NRZ-OOK) modulation format due to its technical simplicity and therefore low cost, QPSK format is more advantageous in spectrally efficient long-haul fiber optic transmission systems because of its constant power envelope, and robustness to various transmission impairments. Consequently, an important problem may arise, in particular how to route the OOK-data streams from MANs to long-haul backbone networks when the state of polarization (SOP) of the remotely generated OOK is unpredictable. Hence, the focus of this dissertation was to investigate a polarization insensitive (PI) all-optical nonlinear optical signal processing (NOSP) method that can be implemented at the network cross-connect (X-connect) to transfer data from a remotely and a locally generated OOK data simultaneously to more effectual QPSK format for long-haul transmission. By utilizing cross-phase modulation (XPM) and inherent birefringence of the device, the work demonstrated, for the first time, PI all-optical data transfer utilizing dual pump-phase transmultiplexing (DPTM) from 2 x 10-GBd OOKs to 10-GBd RZ-QPSK in a passive nonlinear birefringent photonic crystal fiber (PCF). Polarization insensitivity was achieved by scrambling the SOP of the remotely generated OOK pump and launching the locally generated OOK pump and the probe off-axis. To mitigate polarization induced power fluctuations and detrimental effects due to nearby partially degenerate and non-degenerate four wave mixings, an optimum pump-probe detuning was also utilized. The PI DPTM RZ-QPSK demonstrated a pre-amplified receiver sensitivity penalty < 5.5 dB at 10--9 bit-error-rate (BER), relative to relative to the FPGA-precoded RZ-DQPSK baseline in ASE

  10. Fiber transport of spatially entangled photons

    Science.gov (United States)

    Löffler, W.; Eliel, E. R.; Woerdman, J. P.; Euser, T. G.; Scharrer, M.; Russell, P.

    2012-03-01

    High-dimensional entangled photons pairs are interesting for quantum information and cryptography: Compared to the well-known 2D polarization case, the stronger non-local quantum correlations could improve noise resistance or security, and the larger amount of information per photon increases the available bandwidth. One implementation is to use entanglement in the spatial degree of freedom of twin photons created by spontaneous parametric down-conversion, which is equivalent to orbital angular momentum entanglement, this has been proven to be an excellent model system. The use of optical fiber technology for distribution of such photons has only very recently been practically demonstrated and is of fundamental and applied interest. It poses a big challenge compared to the established time and frequency domain methods: For spatially entangled photons, fiber transport requires the use of multimode fibers, and mode coupling and intermodal dispersion therein must be minimized not to destroy the spatial quantum correlations. We demonstrate that these shortcomings of conventional multimode fibers can be overcome by using a hollow-core photonic crystal fiber, which follows the paradigm to mimic free-space transport as good as possible, and are able to confirm entanglement of the fiber-transported photons. Fiber transport of spatially entangled photons is largely unexplored yet, therefore we discuss the main complications, the interplay of intermodal dispersion and mode mixing, the influence of external stress and core deformations, and consider the pros and cons of various fiber types.

  11. Chaotic behaviour of photonic crystals resonators

    KAUST Repository

    Di Falco, A.; Liu, C.; Krauss, T. F.; Fratalocchi, Andrea

    2015-01-01

    We show here theoretically and experimentally how chaotic Photonic Crystal resonators can be used for en- ergy harvesting applications and the demonstration of fundamental theories, like the onset of superradiance in quantum systems. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  12. All-optical tunable photonic crystal cavity

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan

    2010-01-01

    We demonstrate an ultra-small photonic crystal cavity with two resonant modes. An all-optical tuning operation based on the free-carrier plasma effect is, for the first time, realized utilizing a continuous wave light source. The termo-optical effect is minimized by isoproponal infiltration...

  13. Chaotic behaviour of photonic crystals resonators

    KAUST Repository

    Di Falco, A.

    2015-02-08

    We show here theoretically and experimentally how chaotic Photonic Crystal resonators can be used for en- ergy harvesting applications and the demonstration of fundamental theories, like the onset of superradiance in quantum systems. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  14. All-polymer photonic crystal slab sensor

    DEFF Research Database (Denmark)

    Hermannsson, Pétur Gordon; Sørensen, Kristian Tølbøl; Vannahme, Christoph

    2015-01-01

    An all-polymer photonic crystal slab sensor is presented, and shown to exhibit narrow resonant reflection with a FWHM of less than 1 nm and a sensitivity of 31 nm/RIU when sensing media with refractive indices around that of water. This results in a detection limit of 4.5x10-6 RIU when measured...

  15. Fabrication and Analysis of Photonic Crystals

    Science.gov (United States)

    Campbell, Dean J.; Korte, Kylee E.; Xia, Younan

    2007-01-01

    These laboratory experiments are designed to explore aspects of nanoscale chemistry by constructing and spectroscopically analyzing thin films of photonic crystals. Films comprised of colloidal spheres and polydimethylsiloxane exhibit diffraction-based stop bands that shift reversibly upon exposure to some common solvents. Topics covered in these…

  16. Photonic crystals: towards nanoscale photonic devices

    National Research Council Canada - National Science Library

    Lourtioz, J.-M

    2005-01-01

    .... From this point of view, the emergence of photonic bandgap materials and photonic crystals at the end of the 1980s can be seen as a revenge to the benefit this time of optics and electromagnetism. In the same way as the periodicity of solid state crystals determines the energy bands and the conduction properties of electrons, the periodical structur...

  17. Geometric properties of optimal photonic crystals

    DEFF Research Database (Denmark)

    Sigmund, Ole; Hougaard, Kristian G.

    2008-01-01

    Photonic crystals can be designed to control and confine light. Since the introduction of the concept by Yablonovitch and John two decades ago, there has been a quest for the optimal structure, i.e., the periodic arrangement of dielectric and air that maximizes the photonic band gap. Based...

  18. Photonic Crystal Sensors Based on Porous Silicon

    Directory of Open Access Journals (Sweden)

    Claudia Pacholski

    2013-04-01

    Full Text Available Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  19. Transverse angular momentum in topological photonic crystals

    Science.gov (United States)

    Deng, Wei-Min; Chen, Xiao-Dong; Zhao, Fu-Li; Dong, Jian-Wen

    2018-01-01

    Engineering local angular momentum of structured light fields in real space enables applications in many fields, in particular, the realization of unidirectional robust transport in topological photonic crystals with a non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin angular momentum or transverse phase vortex, robust light flow propagating along opposite directions is observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating phase vortex exists at the boundary of two such photonic crystals. In addition, unidirectional transport is robust to the working frequency even when the ring size or location of the pseudo-spin source varies in a certain range, leading to the superiority of the broadband photonic device. These findings enable one to make use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in the telecom region and other potential applications in integrated photonic circuits, such as on-chip robust delay lines.

  20. Photonic crystal Fano lasers and Fano switches

    DEFF Research Database (Denmark)

    Mørk, Jesper; Yu, Yi; Bekele, Dagmawi Alemayehu

    2017-01-01

    We show that Fano resonances can be realized in photonic crystal membrane structures by coupling line-defect waveguides and point-defect nanocavities. The Fano resonance can be exploited to realize optical switches with very small switching energy, as well as Fano lasers, that can generate short...

  1. Fabrication of Nanoimprint stamps for photonic crystals

    International Nuclear Information System (INIS)

    Kouba, J; Kubenz, M; Mai, A; Ropers, G; Eberhardt, W; Loechel, B

    2006-01-01

    We report on fabrication of nanoimprint stamps for fabrication of two dimensional photonic crystals in visible range of spectra. Nanoimprint stamps made of silicon and/or nickel were successfully fabricated using electron beam lithography and advanced dry etching techniques. The quality of the stamps was evaluated using scanning electron microscopy. The fabricated stamps were also evaluated by imprinting them into suitable polymer materials

  2. The Sommerfeld precursor in photonic crystals

    NARCIS (Netherlands)

    Uitham, R; Hoenders, BJ

    2006-01-01

    We calculate the Sommerfeld precursor that results after transmission of a generic electromagnetic plane wave pulse with transverse electric polarization, through a one-dimensional rectangular N-layer photonic crystal with two slabs per layer. The shape of this precursor equals the shape of the

  3. Vectorial analysis of dielectric photonic crystal VCSEL

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2009-01-01

    A new vertical-cavity surface-emitting laser structure employing a dielectric photonic crystal mirror has been suggested and been numerically investigated. The new structure has a smaller threshold gain, a moderate strength of single-transverse-mode operation, a high quality of emission beam free...

  4. Lambda shifted photonic crystal cavity laser

    DEFF Research Database (Denmark)

    Schubert, Martin; Skovgård, Troels Suhr; Ek, Sara

    2010-01-01

    We propose and demonstrate an alternative type of photonic crystal laser design that shifts all the holes in the lattice by a fixed fraction of the targeted emission wavelength. The structures are realized in InGaAsP =1.15 with InGaAsP quantum wells =1.52 as gain material. Cavities with shifts of...

  5. Photonic crystal nanostructures for optical biosensing applications

    DEFF Research Database (Denmark)

    Dorfner, D.; Zabel, T.; Hürlimann, T.

    2009-01-01

    We present the design, fabrication and optical investigation of photonic crystal (PhC) nanocavity drop filters for use as optical biosensors. The resonant cavity mode wavelength and Q-factor are studied as a function of the ambient refractive index and as a function of adsorbed proteins (bovine...

  6. Photonic Crystal Sensors Based on Porous Silicon

    Science.gov (United States)

    Pacholski, Claudia

    2013-01-01

    Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential. PMID:23571671

  7. Refractive index sensor based on a 1D photonic crystal in a microfluidic channel

    DEFF Research Database (Denmark)

    Rodrigues de Sousa Nunes, Pedro André; Mortensen, Asger; Kutter, Jörg Peter

    2010-01-01

    A refractive index sensor has been fabricated in silicon oxynitride by standard UV lithography and dry etching processes. The refractive index sensor consists of a 1D photonic crystal (PhC) embedded in a microfluidic channel addressed by fiber-terminated planar waveguides. Experimental...

  8. Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, Gary [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States); Scott, Brian [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2014-06-30

    This report covers the technical progress on the program “Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems”, funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Materials Science & Engineering and Electrical & Computer Engineering Departments at Virginia Tech, and summarizes technical progress from July 1st, 2005 –June 30th, 2014. The objective of this program was to develop novel fiber materials for high temperature gas sensors based on evanescent wave absorption in optical fibers. This project focused on two primary areas: the study of a sapphire photonic crystal fiber (SPCF) for operation at high temperature and long wavelengths, and a porous glass based fiber optic sensor for gas detection. The sapphire component of the project focused on the development of a sapphire photonic crystal fiber, modeling of the new structures, fabrication of the optimal structure, development of a long wavelength interrogation system, testing of the optical properties, and gas and temperature testing of the final sensor. The fabrication of the 6 rod SPCF gap bundle (diameter of 70μm) with a hollow core was successfully constructed with lead-in and lead-out 50μm diameter fiber along with transmission and gas detection testing. Testing of the sapphire photonic crystal fiber sensor capabilities with the developed long wavelength optical system showed the ability to detect CO2 at or below 1000ppm at temperatures up to 1000°C. Work on the porous glass sensor focused on the development of a porous clad solid core optical fiber, a hollow core waveguide, gas detection capabilities at room and high temperature, simultaneous gas species detection, suitable joining technologies for the lead-in and lead-out fibers and the porous sensor, sensor system sensitivity improvement, signal processing improvement, relationship between pore structure and fiber

  9. Liquid filling of photonic crystal fibres for grating writing

    DEFF Research Database (Denmark)

    Sørensen, Henrik Rokkjær; Canning, John; Lægsgaard, Jesper

    2007-01-01

    liquid filling of photonic crystal fibres reduces the scattering from air–glass interfaces during Bragg grating writing in many layered photonic crystal fibres. Within experimental uncertainty, the grating index modulation of a grating written in germanium-doped photonic crystal fibre with 10 rings...

  10. Hollow-Core FRP–Concrete–Steel Bridge Columns under Torsional Loading

    Directory of Open Access Journals (Sweden)

    Sujith Anumolu

    2017-11-01

    Full Text Available This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm and applied load height of 96 in. (2438 mm with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube. A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not.

  11. Realization of a complementary medium using dielectric photonic crystals.

    Science.gov (United States)

    Xu, Tao; Fang, Anan; Jia, Ziyuan; Ji, Liyu; Hang, Zhi Hong

    2017-12-01

    By exploiting the scaling invariance of photonic band diagrams, a complementary photonic crystal slab structure is realized by stacking two uniformly scaled double-zero-index dielectric photonic crystal slabs together. The space cancellation effect in complementary photonic crystals is demonstrated in both numerical simulations and microwave experiments. The refractive index dispersion of double-zero-index dielectric photonic crystal is experimentally measured. Using pure dielectrics, our photonic crystal structure will be an ideal platform to explore various intriguing properties related to a complementary medium.

  12. Limits of slow light in photonic crystals

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Xiao, Sanshui; Mortensen, N. Asger

    2008-01-01

    in the group velocity acquiring a finite value above zero at the band-gap edges while attaining uperluminal values within the band gap. Simple scalings of the minimum and maximum group velocities with the imaginary part of the dielectric function or, equivalently, the linewidth of the broadened states......While ideal photonic crystals would support modes with a vanishing group velocity, state-of-the-art structures have still only provided a slow down by roughly two orders of magnitude. We find that the induced density of states caused by lifetime broadening of the electromagnetic modes results...... are presented. The results obtained are entirely general and may be applied to any effect which results in a broadening of the electromagnetic states, such as loss, disorder, and finite-size effects. This significantly limits the reduction in group velocity attainable via photonic crystals....

  13. Quantum Dots in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Sollner, Immo Nathanael

    This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission...... into the mode exceeding 98% for emitters spectrally close to the band-edge of the waveguide mode. In addition we illustrate the broadband nature of the underlying eects, by obtaining coupling eciencies above 90% for quantum dots detuned from the band edge by as far as 20nm. These values are in good agreement...... with numerical simulations. Such a high coupling eciency implies that the system can be considered an articial 1D-atom, and we theoretically show that this system can generate strong photon-photon interaction, which is an essential functionality for deterministic optical quantum information processing. We...

  14. Energy flow in photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Dridi, Kim

    2000-01-01

    Theoretical and numerical investigations of energy flow in photonic crystal waveguides made of line defects and branching points are presented. It is shown that vortices of energy flow may occur, and the net energy flow along: the line defect is described via the effective propagation velocity....... Single-mode and multimode operations are studied, and dispersion relations are computed for different waveguide widths. Both strong positive, strong negative, and zero dispersion an possible. It is shown that geometric parameters such as the nature of the lattice, the line defect orientation, the defect...... width, and the branching-point geometry have a significant influence on the electrodynamics. These are important issues for the fabrication of photonic crystal structures....

  15. Topological photonic crystals with zero Berry curvature

    Science.gov (United States)

    Liu, Feng; Deng, Hai-Yao; Wakabayashi, Katsunori

    2018-02-01

    Topological photonic crystals are designed based on the concept of Zak's phase rather than the topological invariants such as the Chern number and spin Chern number, which rely on the existence of a nonvanishing Berry curvature. Our photonic crystals (PCs) are made of pure dielectrics and sit on a square lattice obeying the C4 v point-group symmetry. Two varieties of PCs are considered: one closely resembles the electronic two-dimensional Su-Schrieffer-Heeger model, and the other continues as an extension of this analogy. In both cases, the topological transitions are induced by adjusting the lattice constants. Topological edge modes (TEMs) are shown to exist within the nontrivial photonic band gaps on the termination of those PCs. The high efficiency of these TEMs transferring electromagnetic energy against several types of disorders has been demonstrated using the finite-element method.

  16. Two-Dimentional Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Dridi, Kim

    1999-01-01

    possible a novel class of optical microcavities, whereas line defects make possible a novel class of waveguides. In this paper we will analyze two-dimensional photonic crystal waveguides based on photonic crystals with rods arranged on a triangular and a square lattice using a plane-wave expansion method......In the recent years a new class of periodic high-index contrast dielectric structures, known as photonic bandgap structures, has been discovered. In these structures frequency intervals, known as photonic bandgaps, where propagation of electromagnetic waves is not allowed, exist due to the periodic...... dielectric function. This is analogous to semiconductors, where electronic bandgaps exist due to the periodic arrangement of atoms. As is also the case for semiconductor structures, photonic bandgap structures may become of even greater value when defects are introduced. In particular, point defects make...

  17. Photonic crystal geometry for organic solar cells.

    Science.gov (United States)

    Ko, Doo-Hyun; Tumbleston, John R; Zhang, Lei; Williams, Stuart; DeSimone, Joseph M; Lopez, Rene; Samulski, Edward T

    2009-07-01

    We report organic solar cells with a photonic crystal nanostructure embossed in the photoactive bulk heterojunction layer, a topography that exhibits a 3-fold enhancement of the absorption in specific regions of the solar spectrum in part through multiple excitation resonances. The photonic crystal geometry is fabricated using a materials-agnostic process called PRINT wherein highly ordered arrays of nanoscale features are readily made in a single processing step over wide areas (approximately 4 cm(2)) that is scalable. We show efficiency improvements of approximately 70% that result not only from greater absorption, but also from electrical enhancements. The methodology is generally applicable to organic solar cells and the experimental findings reported in our manuscript corroborate theoretical expectations.

  18. Photon-phonon interaction in photonic crystals

    International Nuclear Information System (INIS)

    Ueta, T

    2010-01-01

    Photon-phonon interaction on the analogy of electron-phonon interaction is considered in one-dimensional photonic crystal. When lattice vibration is artificially introduced to the photonic crystal, a governing equation of electromagnetic field is derived. A simple model is numerically analysed and the following novel phenomena are found out. The lattice vibration generates the light of frequency which added the integral multiple of the vibration frequency to that of the incident wave and also amplifies the incident wave resonantly. On a resonance, the amplification factor increases very rapidly with the number of layers increases. Resonance frequencies change with the phases of lattice vibration. The amplification phenomenon is analytically discussed for low frequency of the lattice vibration.

  19. Density of states functions for photonic crystals

    International Nuclear Information System (INIS)

    McPhedran, R.C.; McOrist, J.; Sterke, C.M. de; Nicorovici, N.A.; Botten, L.C.; Asatryan, A.A.

    2004-01-01

    We discuss density of states functions for photonic crystals, in the context of the two-dimensional problem for arrays of cylinders of arbitrary cross section. We introduce the mutual density of states (MDOS), and show that this function can be used to calculate both the local density of states (LDOS), which gives position information for emission of radiation from photonic crystals, and the spectral density of states (SDOS), which gives angular information. We establish the connection between MDOS, LDOS, SDOS and the conventional density of states, which depends only on frequency. We relate all four functions to the band structure and propagating states within the crystal, and give numerical examples of the relation between band structure and density of states functions

  20. Transmission character of general function photonic crystals

    Science.gov (United States)

    Wu, Xiang-Yao; Zhang, Bo-Jun; Yang, Jing-Hai; Zhang, Si-Qi; Liu, Xiao-Jing; Wang, Jing; Ba, Nuo; Hua, Zhong; Yin, Xin-Guo

    2012-08-01

    In the paper, we present a new general function photonic crystals (GFPCs), whose refractive index of medium is a arbitrary function of space position. Unlike conventional photonic crystals (PCs), whose structure grows from two mediums A and B, with different constant refractive indexes na and nb. Based on the Fermat principle, we give the motion equations of light in one-dimensional GFPCs, and calculate its transfer matrix, which is different from the conventional PCs. We choose the linearity refractive index function for two mediums A and B, and find the transmissivity of one-dimensional GFPCs can be much larger or smaller than 1 for different slope linearity refractive index functions, which are different from the transmissivity of conventional PCs (its transmissivity is in the range of 0 and 1). Otherwise, we study the effect of different incident angles, the number of periods and optical thickness on the transmissivity, and obtain some new results different from the conventional PCs.

  1. One-dimensional photonic crystal design

    International Nuclear Information System (INIS)

    Mee, Cornelis van der; Contu, Pietro; Pintus, Paolo

    2010-01-01

    In this article we present a method to determine the band spectrum, band gaps, and discrete energy levels, of a one-dimensional photonic crystal with localized impurities. For one-dimensional crystals with piecewise constant refractive indices we develop an algorithm to recover the refractive index distribution from the period map. Finally, we derive the relationship between the period map and the scattering matrix containing the information on the localized modes.

  2. Electrically Driven Photonic Crystal Nanocavity Devices

    Science.gov (United States)

    2012-01-01

    material, here gallium arsenide and indium arsenide self- assembled quantum dots (QDs). QDs are preferred for the gain medium because they can have...blue points ) and 150 K (green points ). The black lines are linear fits to the above threshold output power of the lasers, which are used to find the...SHAMBAT et al.: ELECTRICALLY DRIVEN PHOTONIC CRYSTAL NANOCAVITY DEVICES 1707 Fig. 13. (a) Tilted SEM picture of a fabricated triple cavity device. The in

  3. Photonic crystal waveguides in artificial opals

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Kiyan, Roman; Neumeister, Andrei

    2008-01-01

    3D photonic crystals based on Si inverted-opals are numerically explored as hosts for effective air-channel waveguides, which can serve as parts of photonic circuits. Two basic shapes of straight waveguides are considered: cylindrical and a chain of spheres. Modelling shows that transmission...... is heavily dependent on the lattice position of the waveguide and its direction. Our experiments of defect inscription by 2-photon polymerization for the production of straight and bent waveguides in opal templates are reported....

  4. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

    2012-01-01

    We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission....... These results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

  5. Rabi oscillations in bidimensional photonic crystals

    International Nuclear Information System (INIS)

    Centeno, E.; Felbacq, D.

    2000-01-01

    We theoretically and numerically investigate transient phenomena in finite two-dimensional photonic crystals doped by single-mode microcavities. We show that for antisymmetric defect modes, there are Rabi oscillations between the microcavities. We develop a spectral analysis which permits us to compute the Rabi frequencies of these oscillations as well as the Q factor of the microcavities. We present a method allowing the computation of the coupling factor between localized modes

  6. Butterfly wing color: A photonic crystal demonstration

    Science.gov (United States)

    Proietti Zaccaria, Remo

    2016-01-01

    We have theoretically modeled the optical behavior of a natural occurring photonic crystal, as defined by the geometrical characteristics of the Teinopalpus Imperialis butterfly. In particular, following a genetic algorithm approach, we demonstrate how its wings follow a triclinic crystal geometry with a tetrahedron unit base. By performing both photonic band analysis and transmission/reflection simulations, we are able to explain the characteristic colors emerging by the butterfly wings, thus confirming their crystal form.

  7. Butterflies: Photonic Crystals on the Wing

    Science.gov (United States)

    2007-03-22

    green hairstreak , Callophrys rubi, suggested that the scales have a 3D cubic network organization (Fig. 9). An extensive analysis of the scales of a...Fig. 9. a Ventral side of the wings of the green hairstreak , Callophrys rubi. b Transmission electron micrograph of a small area of a single...Report 3. DATES COVERED (From – To) 15 March 2006 - 08-Jun-07 4. TITLE AND SUBTITLE Butterflies : Photonic Crystals on the Wing 5a. CONTRACT

  8. Photonic crystal fibres in the market

    DEFF Research Database (Denmark)

    Broeng, Jes; Laurila, Marko; Noordegraaf, Danny

    2011-01-01

    Photonic crystal fibres (PCFs) emerged as a research topic in the mid 1990'ies [1]. Today, 15 years later, these fibres are increasing deployed in various commercial markets. Here, we will address three of these markets; medical imaging, materials processing and sensors. We will describe how...... the PCFs provide radical improvements and illustrate the strong diversity in the evolution of PCFs to serve these different markets....

  9. Solitons in quadratic nonlinear photonic crystals

    DEFF Research Database (Denmark)

    Corney, Joel Frederick; Bang, Ole

    2001-01-01

    We study solitons in one-dimensional quadratic nonlinear photonic crystals with modulation of both the linear and nonlinear susceptibilities. We derive averaged equations that include induced cubic nonlinearities, which can be defocusing, and we numerically find previously unknown soliton families....... Because of these induced cubic terms, solitons still exist even when the effective quadratic nonlinearity vanishes and conventional theory predicts that there can be no soliton. We demonstrate that both bright and dark forms of these solitons can propagate stably....

  10. Capsize of polarization in dilute photonic crystals.

    Science.gov (United States)

    Gevorkian, Zhyrair; Hakhoumian, Arsen; Gasparian, Vladimir; Cuevas, Emilio

    2017-11-29

    We investigate, experimentally and theoretically, polarization rotation effects in dilute photonic crystals with transverse permittivity inhomogeneity perpendicular to the traveling direction of waves. A capsize, namely a drastic change of polarization to the perpendicular direction is observed in a one-dimensional photonic crystal in the frequency range 10 ÷ 140 GHz. To gain more insights into the rotational mechanism, we have developed a theoretical model of dilute photonic crystal, based on Maxwell's equations with a spatially dependent two dimensional inhomogeneous dielectric permittivity. We show that the polarization's rotation can be explained by an optical splitting parameter appearing naturally in Maxwell's equations for magnetic or electric fields components. This parameter is an optical analogous of Rashba like spin-orbit interaction parameter present in quantum waves, introduces a correction to the band structure of the two-dimensional Bloch states, creates the dynamical phase shift between the waves propagating in the orthogonal directions and finally leads to capsizing of the initial polarization. Excellent agreement between theory and experiment is found.

  11. Intravitreal properties of porous silicon photonic crystals

    Science.gov (United States)

    Cheng, L; Anglin, E; Cunin, F; Kim, D; Sailor, M J; Falkenstein, I; Tammewar, A; Freeman, W R

    2009-01-01

    Aim To determine the suitability of porous silicon photonic crystals for intraocular drug-delivery. Methods A rugate structure was electrochemically etched into a highly doped p-type silicon substrate to create a porous silicon film that was subsequently removed and ultrasonically fractured into particles. To stabilise the particles in aqueous media, the silicon particles were modified by surface alkylation (using thermal hydrosilylation) or by thermal oxidation. Unmodified particles, hydrosilylated particles and oxidised particles were injected into rabbit vitreous. The stability and toxicity of each type of particle were studied by indirect ophthalmoscopy, biomicroscopy, tonometry, electroretinography (ERG) and histology. Results No toxicity was observed with any type of the particles during a period of >4 months. Surface alkylation led to dramatically increased intravitreal stability and slow degradation. The estimated vitreous half-life increased from 1 week (fresh particles) to 5 weeks (oxidised particles) and to 16 weeks (hydrosilylated particles). Conclusion The porous silicon photonic crystals showed good biocompatibility and may be used as an intraocular drug-delivery system. The intravitreal injectable porous silicon photonic crystals may be engineered to host a variety of therapeutics and achieve controlled drug release over long periods of time to treat chronic vitreoretinal diseases. PMID:18441177

  12. Fiber optic refractive index sensor using optofluidic anti-resonant reflecting guidance

    Science.gov (United States)

    Gao, Ran; Lu, Danfeng; Cheng, Jin; Qi, Zhi-mei

    2017-10-01

    An optofluidic anti-resonant reflecting guidance has been proposed and experimental demonstrated for the measurement of liquid refractive index. Two micro-channels were fabricated for the delivery of the liquid sample in the hollow core photonic crystal fiber by using femtosecond laser micromachining, serving as an inlet and outlet. The refractive index can be detected by using the resonant condition of the Fabry-Perot resonator, which is interrogated through the wavelength shift and of the lossy dip in the transmission spectrum. The experimental results show that the sensitivity of up to 1328 nm/RIU is achieved for the refractive index in the range from 1.345 to 1.363 RIU, respectively. The proposed sensor appears to have potential applications of precise measurement in chemistry, medicine, and biology.

  13. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren

    2010-01-01

    Quantum optics and quantum information technologies require enhancement of light-matter interaction by, for example, confining light in a small volume. A very recently demonstrated route towards light confinement makes use of multiple scattering of light and wave interference in disordered photonic...... structures [1,2]. Originally proposed for electrons by P. W. Anderson [3], only completely random systems without any long-range correlation between the scattering sites have been used so far, meaning that the Anderson-localized modes cannot be controlled. In disordered photonic crystals, these modes...... denoted by ng. By coupling light into a PCW with a tapered fiber (Fig. 1a), we have measured the ensemble-averaged exponential decay of the light distribution in the range 885 nm

  14. Two-dimensional plasma photonic crystals in dielectric barrier discharge

    International Nuclear Information System (INIS)

    Fan Weili; Dong Lifang; Zhang Xinchun

    2010-01-01

    A series of two-dimensional plasma photonic crystals have been obtained by filaments' self-organization in atmospheric dielectric barrier discharge with two water electrodes, which undergo the transition from square to square superlattice and finally to the hexagon. The spatio-temporal behaviors of the plasma photonic crystals in nanosecond scale have been studied by optical method, which show that the plasma photonic crystal is actually an integration of different transient sublattices. The photonic band diagrams of the transverse electric (TE) mode and transverse magnetic mode for each sublattice of these plasma photonic crystals have been investigated theoretically. A wide complete band gap is formed in the hexagonal plasma photonic crystal with the TE mode. The changes of the band edge frequencies and the band gap widths in the evolvement of different structures are studied. A kind of tunable plasma photonic crystal which can be controlled both in space and time is suggested.

  15. Dirac directional emission in anisotropic zero refractive index photonic crystals.

    Science.gov (United States)

    He, Xin-Tao; Zhong, Yao-Nan; Zhou, You; Zhong, Zhi-Chao; Dong, Jian-Wen

    2015-08-14

    A certain class of photonic crystals with conical dispersion is known to behave as isotropic zero-refractive-index medium. However, the discrete building blocks in such photonic crystals are limited to construct multidirectional devices, even for high-symmetric photonic crystals. Here, we show multidirectional emission from low-symmetric photonic crystals with semi-Dirac dispersion at the zone center. We demonstrate that such low-symmetric photonic crystal can be considered as an effective anisotropic zero-refractive-index medium, as long as there is only one propagation mode near Dirac frequency. Four kinds of Dirac multidirectional emitters are achieved with the channel numbers of five, seven, eleven, and thirteen, respectively. Spatial power combination for such kind of Dirac directional emitter is also verified even when multiple sources are randomly placed in the anisotropic zero-refractive-index photonic crystal.

  16. Plasmonic-photonic crystal coupled nanolaser

    International Nuclear Information System (INIS)

    Zhang, Taiping; Callard, Ségolène; Jamois, Cécile; Chevalier, Céline; Feng, Di; Belarouci, Ali

    2014-01-01

    We propose and demonstrate a hybrid photonic-plasmonic nanolaser that combines the light harvesting features of a dielectric photonic crystal cavity with the extraordinary confining properties of an optical nano-antenna. For this purpose, we developed a novel fabrication method based on multi-step electron-beam lithography. We show that it enables the robust and reproducible production of hybrid structures, using a fully top-down approach to accurately position the antenna. Coherent coupling of the photonic and plasmonic modes is highlighted and opens up a broad range of new hybrid nanophotonic devices. (paper)

  17. Photonic crystal waveguides in PECVD glass

    DEFF Research Database (Denmark)

    Liu, Haoling; Frandsen, Lars Hagedorn; Têtu, Amélie

    Silicon oxynitride (SiON) on silicon has found wide use as a robust and versatileplatform for integrated, optical devices. With plasma-enhanced chemical vapourdeposition (PECVD) the refractive index can be varied all the way from 1.5 (pure silica,SiO2) to 2.0 (pure silicon nitride, Si3N4). We have...... fabricated glasses with refractive indexup to approximately 1.75, with which value it is possible to fabricate photonic crystalwaveguides. These structures have the advantage of being transparent in the whole of thevisible region, which makes them different from photonic crystals made...

  18. Supercontinuum Generation in a Photonic Crystal Fibre

    Institute of Scientific and Technical Information of China (English)

    YAN Pei-Guang; RUAN Shuang-Chen; LIN Hao-Jia; DU Chen-Lin; YU Yong-Qin; LU Ke-Cheng; YAO Jian-Quan

    2004-01-01

    @@ Nearly 1000-nm broad continuum from 390nm to 1370nm is generated in a 2-m long photonic crystal fibre. The maximum total power of supercontinuum is measured to be 60mW with the pumping power of 800mW output from a 200-fs Ti:sapphire laser. The evolution of the pumping light into supercontinuum is experimentally studied in detail. It is found that the mechanism for supercontinuum generation has direct relations with Raman effect and soliton effect, and the four-wave mixing plays an important role in the last phase of the supercontinuum generation.

  19. Amorphous photonic crystals with only short-range order.

    Science.gov (United States)

    Shi, Lei; Zhang, Yafeng; Dong, Biqin; Zhan, Tianrong; Liu, Xiaohan; Zi, Jian

    2013-10-04

    Distinct from conventional photonic crystals with both short- and long-range order, amorphous photonic crystals that possess only short-range order show interesting optical responses owing to their unique structural features. Amorphous photonic crystals exhibit unique light scattering and transport, which lead to a variety of interesting phenomena such as isotropic photonic bandgaps or pseudogaps, noniridescent structural colors, and light localization. Recent experimental and theoretical advances in the study of amorphous photonic crystals are summarized, focusing on their unique optical properties, artificial fabrication, bionspiration, and potential applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Photonic crystals: role of architecture and disorder on spectral properties.

    Science.gov (United States)

    Verma, Rupesh; Audhkhasi, Romil; Thyagarajan, Krishna; Banerjee, Varsha

    2018-03-01

    Many of the present-day optical devices use photonic crystals. These are multilayers of dielectric media that control the reflection and transmission of light falling on them. In this paper, we study the optical properties of periodic, fractal, and aperiodic photonic crystals and compare them based on their attributes. Our calculations of the band reflectivity and degree of robustness reveal novel features, e.g., fractal photonic crystals are found to reflect the maximum amount of incident light. On the other hand, aperiodic photonic crystals have the largest immunity to disorder. We believe that such properties will be useful in a variety of applications in the field of optical communication.

  1. Structural coloration of chitosan-cationized cotton fabric using photonic crystals

    Science.gov (United States)

    Yavuz, G.; Zille, A.; Seventekin, N.; Souto, A. P.

    2017-10-01

    In this work, poly (styrene-methyl methacrylate-acrylic acid) P(St-MMA-AA) composite nanospheres were deposited onto chitosan-cationized woven cotton fabrics followed by a second layer of chitosan. The deposited photonic crystals (PCs) on the fabrics were evaluated for coating efficiency and resistance, chemical analysis and color variation by optical and SEM microscopy, ATR-FTIR, diffuse reflectance spectroscopy and washing fastness. Chitosan deposition on cotton fabric provided cationic groups on the fiber surface promoting electrostatic interaction with photonic crystals. SEM images of the washed samples indicate that the PCs are firmly coated on the cotton surface only in the chitosan treated sample. The photonic nanospheres show an average diameter of 280 nm and display a face-centered cubic closepacking structure with an average thickness of 10 μm. A further chitosan post-treatment enhances color yield of the samples due to the chitosan transparent covering layer that induce bright reflections where the angles of incidence and reflection are the same. After washing, no photonic crystal can be detected on control fabric surface. However, the sample that received a chitosan post-treatment showed a good washing fastness maintaining a reasonable degree of iridescence. Chitosan fills the spaces between the polymer spheres in the matrix stabilizing the photonic structure. Sizeable variations in lattice spacing will allow color variations using more flexible non-close-packed photonic crystal arrays in chitosan hydrogels matrices.

  2. Porous photonic crystal external cavity laser biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qinglan [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Peh, Jessie; Hergenrother, Paul J. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Cunningham, Brian T. [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2016-08-15

    We report the design, fabrication, and testing of a photonic crystal (PC) biosensor structure that incorporates a porous high refractive index TiO{sub 2} dielectric film that enables immobilization of capture proteins within an enhanced surface-area volume that spatially overlaps with the regions of resonant electromagnetic fields where biomolecular binding can produce the greatest shifts in photonic crystal resonant wavelength. Despite the nanoscale porosity of the sensor structure, the PC slab exhibits narrowband and high efficiency resonant reflection, enabling the structure to serve as a wavelength-tunable element of an external cavity laser. In the context of sensing small molecule interactions with much larger immobilized proteins, we demonstrate that the porous structure provides 3.7× larger biosensor signals than an equivalent nonporous structure, while the external cavity laser (ECL) detection method provides capability for sensing picometer-scale shifts in the PC resonant wavelength caused by small molecule binding. The porous ECL achieves a record high figure of merit for label-free optical biosensors.

  3. Mode conversion in magneto photonic crystal fibre

    International Nuclear Information System (INIS)

    Otmani, Hamza; Bouchemat, Mohamed; Hocini, Abdesselam; Boumaza, Touraya; Benmerkhi, Ahlem

    2017-01-01

    The first concept of an integrated isolator was based on nonreciprocal TE–TM mode conversion, the nonreciprocal coupling between these modes is caused by the Faraday rotation if the magnetization is aligned along the z–axis, parallel to mode propagation. We propose to study this magneto-optical phenomenon, by the simulation of magneto photonic crystal fibre (MPCF), it consists of a periodic triangular lattice of air-holes filled with magnetic fluid which consists of magnetic nanoparticles into a BIG (Bismuth Iron Garnet) fibre. We simulated the influence of gyrotropy and the wavelength, and calculated Faraday rotation and modal birefringence. In this fibre the light is guided by internal total reflection, like classical fibres. However it was shown that they could function on a mode conversion much stronger than conventional fibres. - Highlights: • We propose to study mode conversion TE–TM, by the simulation of magneto photonic crystal fibre (MPCF). • We simulated the influence of gyrotropy. • We simulated the wavelength. • We calculated Faraday rotation. • We calculated modal birefringence.

  4. Photonic Crystal Laser-Driven Accelerator Structures

    International Nuclear Information System (INIS)

    Cowan, Benjamin M.

    2007-01-01

    Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques

  5. Novel fluorescence adjustable photonic crystal materials

    Science.gov (United States)

    Zhu, Cheng; Liu, Xiaoxia; Ni, Yaru; Fang, Jiaojiao; Fang, Liang; Lu, Chunhua; Xu, Zhongzi

    2017-11-01

    Novel photonic crystal materials (PCMs) with adjustable fluorescence were fabricated by distributing organic fluorescent powders of Yb0.2Er0.4Tm0.4(TTA)3Phen into the opal structures of self-assembled silica photonic crystals (PCs). Via removing the silica solution in a constant speed, PCs with controllable thicknesses and different periodic sizes were obtained on glass slides. Yb0.2Er0.4Tm0.4(TTA)3Phen powders were subsequently distributed into the opal structures. The structures and optical properties of the prepared PCMs were investigated. Finite-difference-time-domain (FDTD) calculation was used to further analyze the electric field distributions in PCs with different periodic sizes while the relation between periodic sizes and fluorescent spectra of PCMs was discussed. The results showed that the emission color of the PCMs under irradiation of 980 nm laser can be easily adjusted from green to blue by increasing the periodic size from 250 to 450 nm.

  6. Microstructured optical fibers for gas sensing systems

    Science.gov (United States)

    Challener, William Albert; Choudhury, Niloy; Palit, Sabarni

    2017-10-17

    Microstructured optical fiber (MOF) includes a cladding extending a length between first and second ends. The cladding includes an inner porous microstructure that at least partially surrounds a hollow core. A perimeter contour of the hollow core has a non-uniform radial distance from a center axis of the cladding such that first segments of the cladding along the perimeter contour have a shorter radial distance from the center axis relative to second segments of the cladding along the perimeter contour. The cladding receives and propagates light energy through the hollow core, and the inner porous microstructure substantially confines the light energy within the hollow core. The cladding defines at least one port hole that extends radially from an exterior surface of the cladding to the hollow core. Each port hole penetrates the perimeter contour of the hollow core through one of the second segments of the cladding.

  7. Numerical Analysis of Heat Storage and Heat Conductivity in the Concrete Hollow Core Deck Element

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2011-01-01

    extent these simplified models estimate the heat storage potential of precast hollow-core concrete decks correctly. This study investigates various approaches on how to model the heat transfer within the air void in the deck. Furthermore, it is analysed how different heat transfer models influence...... the overall heat transfer and heat storage in the hollow-core decks. The presented results allow comparison between detailed results from 2D-COMSOL simulations and simple 1D calculations from the whole building simulation tool such as BSim program and moreover, it is possible to validate the calculation...... method in BSim for the concrete deck element with air voids. Finally, this paper presents a comparison of the calculated heat conductivity of the hollow-core concrete deck and the measured heat conductivity for the same deck by using hot box apparatus....

  8. 3D-printed PMMA Preform for Hollow-core POF Drawing

    DEFF Research Database (Denmark)

    Zubel, M. G.; Fasano, Andrea; Woyessa, Getinet

    2016-01-01

    In this paper we report the first, to our knowledge, 3D-printed hollow-core poly(methyl methacrylate) (PMMA) preform for polymer optical fibre drawing. It was printed of commercial PMMA by means of fused deposition modelling technique. The preform was drawn to cane, proving good enough quality...... of drawing process and the PMMA molecular weight to be appropriate for drawing. This ascertains that the manufacturing process provides preforms suitable for hollow-core fibre drawing. The paper focuses on maximisation of transparency of PMMA 3D printouts by optimising printing process parameters: nozzle...... temperature, printing speed and infill...

  9. A new approach to low loss photonic crystal waveguides

    DEFF Research Database (Denmark)

    Krüger, Asger Christian; Zhang, Min; Groothoff, Nathaniel

    Photonic crystal waveguides allow ultra-compact realization of integrated optical components because they have high group index. However, they also induce significant losses in effect reducing the scope of their applications. We find that by increasing the photonic crystal hole to pitch ratio r...

  10. Passive integrated circuits utilizing slow light in photonic crystal waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Têtu, Amélie; Yang, Lirong

    2006-01-01

    We report thorough investigations of photonic crystal waveguide properties in the slow light regime. The transmission and the group index near the cutoff wavelengths oscillate in phase in close analogy with the ID photonic crystal behavior. The influence of having a finite number of periods...

  11. Fractional decay of quantum dots in real photonic crystals

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Koenderink, A. Femius; Lodahl, Peter

    2008-01-01

    We show that fractional decay may be observable in experiments using quantum dots and photonic crystals with parameters that are currently achievable. We focus on the case of inverse opal photonic crystals and locate the position in the crystal where the effect is most pronounced. Furthermore, we...

  12. Fractional decay of quantum dots in photonic crystals

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Koenderink, Femius; Lodahl, Peter

    2008-01-01

    We define a practical measure for the degree of fractional decay and establish conditions for the effect to be observable for quantum dots in photonic crystals exhibiting absorptive losses.......We define a practical measure for the degree of fractional decay and establish conditions for the effect to be observable for quantum dots in photonic crystals exhibiting absorptive losses....

  13. Investigations on the parity of Fano resonances in photonic crystals

    DEFF Research Database (Denmark)

    Østerkryger, Andreas Dyhl; de Lasson, Jakob Rosenkrantz; Yu, Yi

    We investigate the relation between the parity of Fano resonances and field distribution in a photonic crystal structure using Fourier modal method, establishing a correlation between Fano parity and field profile.......We investigate the relation between the parity of Fano resonances and field distribution in a photonic crystal structure using Fourier modal method, establishing a correlation between Fano parity and field profile....

  14. Control of exceptional points in photonic crystal slabs

    DEFF Research Database (Denmark)

    Kaminski, Piotr Marek; Taghizadeh, Alireza; Breinbjerg, Olav

    2017-01-01

    Various ways of controlling the extent of the ring of exceptional points in photonic crystal slabs are investigated. The extent of the ring in photonic crystal slabs is found to vary with the thickness of the slab. This enables recovery of Dirac cones in open, non-Hermitian systems, such as a pho...

  15. Numerical characterization of nanopillar photonic crystal waveguides and directional couplers

    DEFF Research Database (Denmark)

    Chigrin, Dmitry N.; Lavrinenko, Andrei; Sotomayor Torres, Clivia M.

    2005-01-01

    We numerically characterize a novel type of a photonic crystal waveguide, which consists of several rows of periodically arranged dielectric cylinders. In such a nanopillar photonic crystal waveguide, light confinement is due to the total internal reflection. A nanopillar waveguide is a multimode...

  16. Rare-Earth Doped Photonic Crystal Fibre Lasers and Amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.

    2005-01-01

    In this thesis, a theoretical and numerical study of the use of rare-earthdoped photonic crystal fibres as optical amplifiers and lasers, has been performed. Photonic crystal fibres or microstructured optical fibres is a new kind of optical fibre in which the cladding region typically consist....... Their novel properties allow for design of optical fibre amplifiers and fibre lasers with superior performance, compared to solutions based on conventional fibres. The primary applications considered are high efficiency fibre amplifiers based on index guiding photonic crystal fibres, and cladding pumped....... The thesis also presents the basic properties of optical amplification, and describes the numerical model developed to model the behaviour of lasers and amplifiers based on photonic crystal fibres. The developed numerical tools are then used to investigate specific applications of photonic crystal fibres...

  17. Quantum Electrodynamics in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Nielsen, Henri Thyrrestrup

    In this thesis we have performed quantum electrodynamics (QED) experiments in photonic crystal (PhC) waveguides and cavity QED in the Anderson localized regime in disordered PhC waveguides. Decay rate measurements of quantum dots embedded in PhC waveguides has been used to map out the variations...... in the local density of states (LDOS) in PhC waveguides. From decay rate measurements on quantum dot lines temperature tuned in the vicinity of the waveguide band edge, a β-factor for a single quantum dot of more then 85% has been extracted. Finite difference time domain simulations (FDTD) for disordered Ph...... is shown to increase from 3 − 7 um for no intentional disorder to 25 um for 6% disorder. A distribution of losses is seen to be necessary to explain the measured Q-factor distributions. Finally we have performed a cavity QED experiment between single quantum dots and an Anderson localized mode, where a β...

  18. Liquid Photonic Crystals for Mesopore Detection.

    Science.gov (United States)

    Zhu, Biting; Fu, Qianqian; Chen, Ke; Ge, Jianping

    2018-01-02

    Nitrogen adsorption-desorption for mesopore characterization requires the using of expensive instrumentation, time-consuming processes, and the consumption of liquid nitrogen. Herein, a new method is developed to measure the pore parameters through mixing a mesoporous substance with a supersaturated SiO 2 colloidal solution at different temperatures, and subsequent rapid measurement of reflection changes of the precipitated liquid photonic crystals. The pore volumes and diameters of mesoporous silica were measured according to the positive correlation between unit mass reflection change (Δλ/m) and pore volume (V), and the negative correlation between average absorption temperature (T) and pore diameter (D). This new approach may provide an alternative method for fast, convenient and economical characterization of mesoporous materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Three-dimensional function photonic crystals

    Science.gov (United States)

    Zhang, Hai-Feng

    2017-11-01

    In this paper, the properties of the photonic band gaps (PBGs) of three-dimensional (3D) function photonic crystals (PCs) are theoretically investigated by a modified plane wave expansion (PWE) method, whose equations for computations are deduced. The configuration of 3D function PCs is the dielectric spheres inserted in the air background with simple-cubic (SC) lattices whose dielectric constants are the functions of space coordinates, which can be realized by the electro-optical or optical Kerr effect in the practice. The influences of the parameter for 3D function PCs on the PBGs also are discussed. The calculated results show that the bandwidths and number of PBGs can be tuned with different distributions of function dielectrics. Compared with the conventional 3D dielectric PCs with SC lattices, the larger and more PBGs can be obtained in the 3D function PCs. Those results provide a new way to design the novel practical devices.

  20. Photonic Crystal Emitters for Thermophotovoltaic Energy Conversion

    International Nuclear Information System (INIS)

    Stelmakh, Veronika; Chan, Walker R; Joannopoulos, John D; Celanovic, Ivan; Ghebrebrhan, Michael; Soljacic, Marin

    2015-01-01

    This paper reports the design, fabrication, and characterization of 2D photonic crystal (PhC) thermal emitters for a millimeter-scale hydrocarbon TPV microgenerator as a possible replacement for batteries in portable microelectronics, robotics, etc. In our TPV system, combustion heats a PhC emitter to incandescence and the resulting radiation is converted by a low-bandgap TPV cell. The PhC tailors the photonic density of states to produce spectrally confined thermal emission that matches the bandgap of the TPV cell, enabling high heat-to-electricity conversion efficiency. The work builds on a previously developed fabrication process to produce a square array of cylindrical cavities in a metal substrate. We will present ongoing incremental improvements in the optical and thermo-mechanical properties, the fabrication process, and the system integration, as recently combined with fabrication using novel materials, such as sputtered coatings, to enable a monolithic system. (paper)