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Sample records for kyoto3dii fabry-perot mode

  1. High-finesse fiber Fabry-Perot cavities: stabilization and mode matching analysis

    NASA Astrophysics Data System (ADS)

    Gallego, J.; Ghosh, S.; Alavi, S. K.; Alt, W.; Martinez-Dorantes, M.; Meschede, D.; Ratschbacher, L.

    2016-03-01

    Fiber Fabry-Perot cavities, formed by micro-machined mirrors on the end-facets of optical fibers, are used in an increasing number of technical and scientific applications, where they typically require precise stabilization of their optical resonances. Here, we study two different approaches to construct fiber Fabry-Perot resonators and stabilize their length for experiments in cavity quantum electrodynamics with neutral atoms. A piezo-mechanically actuated cavity with feedback based on the Pound-Drever-Hall locking technique is compared to a novel rigid cavity design that makes use of the high passive stability of a monolithic cavity spacer and employs thermal self-locking and external temperature tuning. Furthermore, we present a general analysis of the mode matching problem in fiber Fabry-Perot cavities, which explains the asymmetry in their reflective line shapes and has important implications for the optimal alignment of the fiber resonators. Finally, we discuss the issue of fiber-generated background photons. We expect that our results contribute toward the integration of high-finesse fiber Fabry-Perot cavities into compact and robust quantum-enabled devices in the future.

  2. Mode-resolved Fabry-Perot experiment in low-loss Bragg-reflection waveguides.

    PubMed

    Pressl, B; Günthner, T; Laiho, K; Geßler, J; Kamp, M; Höfling, S; Schneider, C; Weihs, G

    2015-12-28

    Based on the interaction between different spatial modes, semiconductor Bragg-reflection waveguides (BRWs) provide a highly functional platform for non-linear optics. For achieving any desired quantum optical functionality, we must control and engineer the properties of each spatial mode. To reach this purpose we extend the Fabry-Perot technique and achieve a detailed linear optical characterization of dispersive multimode semiconductor waveguides. With this efficient broadband spectral method we gain direct experimental access to the relevant modes of our BRWs and determine their group velocities. Furthermore, we show that our waveguides have lower than expected loss coefficients. This renders them suitable for integrated quantum optics applications.

  3. Meta-Optics with Nanowire Grid Arrays: Hyperbolic Fabry-Perot Modes and Hyperbolic Tamm Plasmons

    NASA Astrophysics Data System (ADS)

    Durach, Maxim; Keene, David; Lepain, Matthew

    2015-03-01

    In this talk we introduce a new class of structures - cavities formed by metal-dielectric metasurfaces. These cavities support a zoo of various resonances, including hyperbolic Tamm plasmons and hyperbolic Fabry-Perot modes, which feature anisotropic clover-leaf dispersion parallel to the metasurface and strong coupling between TM and TE polarizations in the modes. The properties and spectrum of the modes are highly tunable by the dimensional and material parameters of the structure and can be used for directional emission, modification of radiation produced by electric dipole emitters into magnetic dipole radiation as well as 90 degree polarization rotators and polarization rotation mirrors.

  4. Analysis of quenching conditions of Fabry-Perot mode lasing in semiconductor stripe-contact lasers

    SciTech Connect

    Slipchenko, S. O. Podoskin, A. A.; Vinokurov, D. A.; Stankevich, A. L.; Leshko, A. Y.; Pikhtin, N. A.; Zabrodskiy, V. V.; Tarasov, I. S.

    2011-10-15

    Radiative characteristics of semiconductor stripe-contact lasers operating under quenching conditions of Fabry-Perot-mode lasing are studied. It is found that reversible turning off of Fabry-Perot-mode lasing is caused by switching to closed-mode lasing. Radiative characteristics of the closed mode are controlled by the mode structure with the close-to-zero loss for radiation output, which covers the entire crystal. The main threshold conditions of closed-mode lasing are a decrease in interband absorption in the passive region and an increase in the modal gain of the closed-mode lasing line. It is shown that a decrease in interband absorption in the passive region can be provided by both spontaneous emission from the injection region and lasing-mode photons. An increase in the modal gain of the closed-mode lasing line is provided by shifting the energy minima of the conduction band and maxima of the valence band of the injection region with respect to the energy bands of the passive region.

  5. Self-starting, passively mode-locked Fabry-Perot fiber soliton laser using nonlinear polarization evolution

    SciTech Connect

    Matsas, V.J.; Loh, W.H.; Richardson, D.J. )

    1993-05-01

    During the last three years the potential of mode-locked rare-earth-doped fiber lasers for ultrashort pulse generation has been explored and both passive and active mode-locking schemes have been demonstrated. Three cavity configurations are most commonly used: Fabry-Perot, ring, and those which exploit the nonlinear properties of the fiber Sagnac loop mirror. Systems which use nonlinear polarization evolution (NLPE) in conjunction with an intracavity polarizer to provide the passive mode-locking mechanism have so far been demonstrated in ring and Fabry-Perot configurations, the latter of which employed an intracavity bulk polarizer and modulator. Here, the authors demonstrate pure self-starting mode-locked operation in a fiber Fabry-Perot cavity. The laser produces 1.6 ps transform-limited soliton pulses by means of nonlinear polarization evolution in conjunction with an intracavity fiber polarizer.

  6. Gain-guided index-antiguided fiber with a Fabry-Perot layer for large mode area laser amplifiers.

    PubMed

    Lai, Chih-Hsien; Chen, Hsuan-Yu; Du, Cheng-Han; Chiou, Yih-Peng

    2015-02-23

    We propose a modified gain-guided index-antiguided (GGIAG) fiber structure for large mode area laser amplifiers, in which a thin dielectric layer is placed between the low-index core and the high-index cladding. The introduced dielectric layer functions as a Fabry-Perot etalon. By letting the resonant wavelength of the Fabry-Perot layer coincide with the signal wavelength, the signal is gain-guided in the fiber core. Moreover, the pump is confined in the low-index core owing to the antiresonant reflection originated from the Fabry-Perot layer. Numerical results indicate that the leakage loss of the pump can be minified over two orders of magnitude in the proposed structure, and thus the end-pumping efficiency could be enhanced significantly.

  7. Gain-guided index-antiguided fiber with a Fabry-Perot layer for large mode area laser amplifiers.

    PubMed

    Lai, Chih-Hsien; Chen, Hsuan-Yu; Du, Cheng-Han; Chiou, Yih-Peng

    2015-02-23

    We propose a modified gain-guided index-antiguided (GGIAG) fiber structure for large mode area laser amplifiers, in which a thin dielectric layer is placed between the low-index core and the high-index cladding. The introduced dielectric layer functions as a Fabry-Perot etalon. By letting the resonant wavelength of the Fabry-Perot layer coincide with the signal wavelength, the signal is gain-guided in the fiber core. Moreover, the pump is confined in the low-index core owing to the antiresonant reflection originated from the Fabry-Perot layer. Numerical results indicate that the leakage loss of the pump can be minified over two orders of magnitude in the proposed structure, and thus the end-pumping efficiency could be enhanced significantly. PMID:25836427

  8. Coupling of Solute Vibrational Modes with a Fabry-Perot Optical Cavity Mode

    NASA Astrophysics Data System (ADS)

    Dunkelberger, Adam; Compton, Ryan; Fears, Kenan; Spann, Bryan; Long, James; Simpkins, Blake; Owrutsky, Jeffrey

    2015-03-01

    Electronic transitions of systems confined in optical microcavities can strongly couple to cavity modes, giving rise to new, mixed-character modes. Recent studies have demonstrated similar coherent coupling between the vibrational modes of a thin polymer film and a Fabry-Perot optical cavity mode. This coupling manifests experimentally as a splitting of the transmissive cavity mode into two dispersive branches separated by the vacuum Rabi splitting. Here we present recent experimental results for the coupling of solution-phase compounds with an optical cavity. Solutions of W(CO)6, Mo(CO)6, and NCS- contained in cavities show strong coupling between the solute chromophores in the mid-infrared and cavity modes. We show that the methodology established with polymer-filled cavities is generally applicable to liquids but that the fluidity of the sample complicates the cavity construction. Varied cavity thicknesses can give rise to spatial gradients in coupling strength and difficulty in targeting a specific cavity-mode order. We also compare the transmission of the mixed vibrational-cavity modes in cavities constructed from either metallic or dielectric reflectors which impacts the cavity resonance line width. NRC Postdoctoral Fellow.

  9. Analysis of threshold conditions for generation of a closed mode in a Fabry-Perot semiconductor laser

    SciTech Connect

    Slipchenko, S. O. Podoskin, A. A.; Pikhtin, N. A.; Sokolova, Z. N.; Leshko, A. Y.; Tarasov, I. S.

    2011-05-15

    Threshold conditions for generation of a closed mode in the crystal of the Fabry-Perot semiconductor laser with a quantum-well active region are analyzed. It is found that main parameters affecting the closed mode lasing threshold for the chosen laser heterostructure are as follows: the optical loss in the passive region, the optical confinement factor of the closed mode in the gain region, and material gain detuning. The relations defining the threshold conditions for closed mode lasing in terms of optical and geometrical characteristics of the semiconductor laser are derived. It is shown that the threshold conditions can be satisfied at a lower material gain in comparison with the Fabry-Perot cavity mode due to zero output loss for the closed mode.

  10. Single-mode Fabry-Perot laser with deeply etched slanted double trenches

    NASA Astrophysics Data System (ADS)

    Li, Xun; Zhu, Zhongshu; Xi, Yanping; Han, Lin; Ke, Cheng; Pan, Yue; Huang, Weiping

    2015-08-01

    This work proposed and demonstrated a single-mode Fabry-Perot (FP) laser structure with a pair of deeply etched slanted trenches inside the cavity. We implemented the proposed mode selection scheme in conventional 1310 nm InAlGaAs/InP strained-layer multiple-quantum-well ridge waveguide FP laser diodes and obtained single-mode operation with a side-mode suppression ratio (SMSR) as high as 35 dB . The single-mode yield was approximately 55%, and other device performance measures such as the threshold and the slope efficiency were not greatly affected. Additionally, temperature cycling and aging tests show no exceptional disadvantages when compared with the performance of conventional FP lasers. Fiber-optic transmission tests show that the proposed device can send directly modulated 2.5 Gbps and 6.25 Gbps optical signals for distances of over 50 km in standard single-mode fiber. Thus, as a cost-effective solution, this device is promising as a replacement for conventional distributed feedback laser diodes in specific applications where single-mode operation is indispensable but precise control of the lasing wavelength and/or very high SMSR (e.g., > 40 dB ) are not required.

  11. Fabry-Perot Microcavity Modes in Single GaP/GaNP Core/Shell Nanowires.

    PubMed

    Dobrovolsky, Alexander; Stehr, Jan E; Sukrittanon, Supanee; Kuang, Yanjin; Tu, Charles W; Chen, Weimin M; Buyanova, Irina A

    2015-12-16

    Semiconductor nanowires (NWs) are attracting increasing interest as nanobuilding blocks for optoelectronics and photonics. A novel material system that is highly suitable for these applications are GaNP NWs. In this article, we show that individual GaP/GaNP core/shell nanowires (NWs) grown by molecular beam epitaxy on Si substrates can act as Fabry-Perot (FP) microcavities. This conclusion is based on results of microphotoluminescence (μ-PL) measurements performed on individual NWs, which reveal periodic undulations of the PL intensity that follow an expected pattern of FP cavity modes. The cavity is concluded to be formed along the NW axis with the end facets acting as reflecting mirrors. The formation of the FP modes is shown to be facilitated by an increasing index contrast with the surrounding media. Spectral dependence of the group refractive index is also determined for the studied NWs. The observation of the FP microcavity modes in the GaP/GaNP core/shell NWs can be considered as a first step toward achieving lasing in this quasidirect bandgap semiconductor in the NW geometry.

  12. Investigation of mode partition noise in Fabry-Perot laser diode

    NASA Astrophysics Data System (ADS)

    Guo, Qingyi; Deng, Lanxin; Mu, Jianwei; Li, Xun; Huang, Wei-Ping

    2014-09-01

    Passive optical network (PON) is considered as the most appealing access network architecture in terms of cost-effectiveness, bandwidth management flexibility, scalability and durability. And to further reduce the cost per subscriber, a Fabry-Perot (FP) laser diode is preferred as the transmitter at the optical network units (ONUs) because of its lower cost compared to distributed feedback (DFB) laser diode. However, the mode partition noise (MPN) associated with the multi-longitudinal-mode FP laser diode becomes the limiting factor in the network. This paper studies the MPN characteristics of the FP laser diode using the time-domain simulation of noise-driven multi-mode laser rate equation. The probability density functions are calculated for each longitudinal mode. The paper focuses on the investigation of the k-factor, which is a simple yet important measure of the noise power, but is usually taken as a fitted or assumed value in the penalty calculations. In this paper, the sources of the k-factor are studied with simulation, including the intrinsic source of the laser Langevin noise, and the extrinsic source of the bit pattern. The photon waveforms are shown under four simulation conditions for regular or random bit pattern, and with or without Langevin noise. The k-factors contributed by those sources are studied with a variety of bias current and modulation current. Simulation results are illustrated in figures, and show that the contribution of Langevin noise to the k-factor is larger than that of the random bit pattern, and is more dominant at lower bias current or higher modulation current.

  13. Selective excitation of Fabry-Perot or whispering-gallery mode-type lasing in GaN microrods

    SciTech Connect

    Baek, Hyeonjun; Hyun, Jerome K.; Chung, Kunook; Oh, Hongseok; Yi, Gyu-Chul

    2014-11-17

    Lasing from long semiconductor nanorods is dictated by Fabry-Perot (FP) resonances whereas that from large-diameter microrods is determined by whispering gallery modes (WGMs). Lengths and diameters intermediate between the two systems represent an important size regime for photonics and electronics, but have not been studied in detail. Here, we report on the detection of FP and WGM lasing emissions from a single GaN microrod, and demonstrate the ability to switch between the two lasing mechanisms by translating the excitation beam along the microrod. The competition between FP and WGM-type lasing was studied by finite-difference time-domain simulation and statistical analysis by measuring microrods of various diameters. Finally, control over the relative lasing intensities originating from either FPs or WGMs was demonstrated by tuning the polarization of the emission.

  14. Adaptive Optics at Optical Wavelengths: Test Observations of Kyoto 3DII Connected to Subaru Telescope AO188

    NASA Astrophysics Data System (ADS)

    Matsubayashi, K.; Sugai, H.; Shimono, A.; Akita, A.; Hattori, T.; Hayano, Y.; Minowa, Y.; Takeyama, N.

    2016-09-01

    Adaptive optics (AO) enables us to observe objects with high spatial resolution, which is important in most astrophysical observations. Most AO systems are operational at near-infrared wavelengths but not in the optical range, because optical observations require a much higher performance to obtain the same Strehl ratio as near-infrared observations. Therefore, to enable AO-assisted observations at optical wavelengths, we connected the Kyoto Tridimensional Spectrograph II (Kyoto 3DII), which can perform integral field spectroscopy, to the second generation AO system of the Subaru Telescope (AO188). We developed a new beam-splitter that reflects light below 594 nm for the wavefront sensors of AO188 and transmits above 644 nm for Kyoto 3DII. We also developed a Kyoto 3DII mount at the Nasmyth focus of the Subaru Telescope. In test observations, the spatial resolution of the combined AO188-Kyoto 3DII was higher than that in natural seeing conditions, even at 6500 Å. The full width at half maximum of an undersampled (1.5 spaxels) bright guide star (7.0 mag in the V-band) was 0.″12.

  15. Adaptive Optics at Optical Wavelengths: Test Observations of Kyoto 3DII Connected to Subaru Telescope AO188

    NASA Astrophysics Data System (ADS)

    Matsubayashi, K.; Sugai, H.; Shimono, A.; Akita, A.; Hattori, T.; Hayano, Y.; Minowa, Y.; Takeyama, N.

    2016-09-01

    Adaptive optics (AO) enables us to observe objects with high spatial resolution, which is important in most astrophysical observations. Most AO systems are operational at near-infrared wavelengths but not in the optical range, because optical observations require a much higher performance to obtain the same Strehl ratio as near-infrared observations. Therefore, to enable AO-assisted observations at optical wavelengths, we connected the Kyoto Tridimensional Spectrograph II (Kyoto 3DII), which can perform integral field spectroscopy, to the second generation AO system of the Subaru Telescope (AO188). We developed a new beam-splitter that reflects light below 594 nm for the wavefront sensors of AO188 and transmits above 644 nm for Kyoto 3DII. We also developed a Kyoto 3DII mount at the Nasmyth focus of the Subaru Telescope. In test observations, the spatial resolution of the combined AO188–Kyoto 3DII was higher than that in natural seeing conditions, even at 6500 Å. The full width at half maximum of an undersampled (1.5 spaxels) bright guide star (7.0 mag in the V-band) was 0.″12.

  16. Commissioning MOS and Fabry-Perot modes for the Robert Stobie Spectrograph on the Southern African Large Telescope

    NASA Astrophysics Data System (ADS)

    Koeslag, A. R.; Williams, T. B.; Nordsieck, K. H.; Romero-Colmenero, E.; Vaisanen, P. H.; Maartens, D. S.

    2014-07-01

    The Southern African Large Telescope (SALT) currently has three instruments: the imaging SALTICAM, the new High Resolution Spectrograph (HRS) which is in the process of being commissioned and the Robert Stobie Spectrograph (RSS). RSS has multiple science modes, of which long slit spectroscopy was originally commissioned; We have commissioned two new science modes: Multi Object Spectroscopy (MOS) and Fabry-Perot (FP). Due to the short track times available on SALT it is vital that acquisition is as efficient as possible. This paper will discuss how we implemented these modes in software and some of the challenges we had to overcome. MOS requires a slit-mask to be aligned with a number of stars. This is done in two phases: in MOS calibration the positions of the slits are detected using a through-slit image and RA/DEC database information, and in MOS acquisition the detector sends commands to the telescope control system (TCS) in an iterative and interactive fashion for fine mask/detector alignment to get the desired targets on the slits. There were several challenges involved with this system, and the user interface evolved to make the process as efficient as possible. We also had to overcome problems with the manufacturing process of the slit-masks. FP requires the precise alignment each of the two etalons installed on RSS. The software makes use of calibration tables to get the etalons into roughly aligned starting positions. An exposure is then done using a calibration arc lamp, producing a ring pattern. Measurement of the rings allows the determination of the adjustments needed to properly align the etalons. The software has been developed to optimize this process, along with software tools that allow us to fine tune the calibration tables. The software architecture allows the complexity of automating the FP calibration and procedures to be easily managed.

  17. Holographic Fabry-Perot spectrometer.

    PubMed

    Martínez-Matos, O; Rodrigo, José A; Vaveliuk, P; Calvo, M L

    2011-02-15

    We propose a spectrum analyzer based on the properties of a hologram recorded with the field transmitted by a Fabry-Perot etalon. The spectral response of this holographic Fabry-Perot spectrometer (HFPS) is analytically investigated in the paraxial approximation and compared with a conventional Fabry-Perot etalon of similar characteristics. We demonstrate that the resolving power is twice increased and the free spectral range (FSR) is reduced to one-half. The proposed spectrometer could improve the operational performance of the etalon because it can exhibit high efficiency and it would be insensible to environmental conditions such as temperature and vibrations. Our analysis also extends to another variant of the HFPS based on holographic multiplexing of the transmitted field of a Fabry-Perot etalon. This device increases the FSR, keeping the same HFPS performance.

  18. A wavelength tunable ONU transmitter based on multi-mode Fabry-Perot laser and micro-ring resonator for bandwidth symmetric TWDM-PON

    NASA Astrophysics Data System (ADS)

    Gao, Zhensen; Sun, Xiao; Zhang, Kaibin

    2016-02-01

    Wavelength tunable optical transmitter is an essential component for the newly standardized time and wavelength division multiplexed passive optical network (TWDM-PON), where tunable ONU with 10Gb/s bit rate is desired to provide 40Gb/s symmetric bandwidth. In this paper, a novel wavelength tunable optical transmitter is proposed by reusing legacy low speed multi-mode Fabry-Perot laser and connecting it with an integrated photonic chip with two coupled micro-ring resonators to generate a tunable single mode signal based on Vernier effect for 10Gb/s high speed modulation, which makes it as a promising solution for colorless ONU in future symmetric TWDM-PON.

  19. Preliminary Fabry Perot testing - 1986

    SciTech Connect

    Benner, D.E.

    1987-04-30

    Fabry Perot interferometry is a method of determining instantaneous velocities of an object in motion. The interferometer system is composed of the Fabry Perot interferometer, a laser, an electronic streak camera, and several focusing lenses. The first tests discussed were done on exploding bridgewire devices. During these tests, several system parameters were changed. These changes did not seem to affect the data, which appeared to be consistent. The second tests performed focused on slapper-type devices. It was determined that sandblasted, vapor-deposited aluminum on the slapper material would be required to yield quality data. Streak camera failure prevented much data from being collected. An effort is being made to replace the current streak camera. After it is replaced, a Fabry Perot and velocity interferometry system for any reflector comparison will be made. The results will be published as the conclusion to this report.

  20. Preliminary Fabry Perot testing - 1986

    NASA Astrophysics Data System (ADS)

    Benner, D. E.

    1987-04-01

    Fabry Perot interferometry is a method of determining instantaneous velocities of an object in motion. The interferometer system is composed of the Fabry Perot interferometer, a laser, an electronic streak camera, and several focusing lenses. The first tests discussed were done on exploding bridgewire devices. During these tests, several system parameters were changed. These changes did not seem to affect the data, which appeared to be consistent. The second tests performed focused on slapper-type devices. It was determined that sandblasted, vapor-deposited aluminum on the slapper material would be required to yield quality data. Streak camera failure prevented much data from being collected. An effort is being made to replace the current streak camera. After it is replaced, a Fabry Perot and velocity interferometry system for any reflector comparison will be made. The results will be published as the conclusion to this report.

  1. Conjugate Fabry-Perot cavity pair for improved astro-comb accuracy.

    PubMed

    Li, Chih-Hao; Chang, Guoqing; Glenday, Alexander G; Langellier, Nicholas; Zibrov, Alexander; Phillips, David F; Kärtner, Franz X; Szentgyorgyi, Andrew; Walsworth, Ronald L

    2012-08-01

    We propose a new astro-comb mode-filtering scheme composed of two Fabry-Perot cavities (coined "conjugate Fabry-Perot cavity pair"). Simulations indicate that this new filtering scheme makes the accuracy of astro-comb spectral lines more robust against systematic errors induced by nonlinear processes associated with power-amplifying and spectral-broadening optical fibers.

  2. Sapphire-fiber-based intrinsic Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Wang, Anbo; Gollapudi, Sridhar; Murphy, Kent A.; May, Russell G.; Claus, Richard O.

    1992-01-01

    A sapphire optical fiber intrinsic Fabry-Perot interferometric sensor is demonstrated. A length of multimode sapphire fiber that functions as a Fabry-Perot cavity is spliced to a silica single-mode fiber. The interferometric signals of this sensor are produced by the interference between the reflection from the silica-sapphire fiber splice and the reflection from the free end face of the sapphire fiber. This sensor has been demonstrated for temperature measurement. A resolution of 0.2 C has been obtained over a measurement range of 310 C to 976 C.

  3. All-silica, large mode area, single mode photonic bandgap fibre with Fabry-Perot resonant structures

    NASA Astrophysics Data System (ADS)

    Várallyay, Zoltán; Kovács, Péter

    2016-03-01

    All-silica, photonic crystal fibres consisting of a low index, silica core surrounded by higher index inclusions embedded in a silica matrix to form a photonic bandgap cladding were numerically analysed. The aim of the investigations was to modify the guiding properties of the fibre by introducing resonant structural entities. These structural modifications are realised by altering the refractive index of certain high index inclusions in the photonic crystal cladding resulting in mode coupling between the core mode and the mode propagated in the modified index region. This results in an increased effective core area of the fundamental core mode and consequently decreased nonlinearity as well as modified effective index compared to the effective index of the unmodified structure and resonant dispersion profile that can be used for pulse compression or optical delay purposes.

  4. Curvature sensor based on a Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Monteiro, Catarina; Ferreira, Marta S.; Kobelke, Jens; Schuster, Kay; Bierlich, Jörg; Frazão, Orlando

    2016-05-01

    A curvature sensor based on a Fabry-Perot interferometer is proposed. A capillary tube of silica is fusion spliced between two single mode fibers, producing a Fabry-Perot cavity. The light propagates in air, when passing through the capillary tube. Two different cavities are subjected to curvature and temperature. The cavity with shorter length shows insensitivity to both measurands. The larger cavity shows two operating regions for curvature measurement, where a linear response is shown, with a maximum sensitivity of 18.77pm/m-1 for the high curvature radius range. When subjected to temperature, the sensing head produces a similar response for different curvature radius, with a sensitivity of 0.87pm/°C.

  5. Hollow-core fiber Fabry-Perot photothermal gas sensor.

    PubMed

    Yang, Fan; Tan, Yanzhen; Jin, Wei; Lin, Yuechuan; Qi, Yun; Ho, Hoi Lut

    2016-07-01

    A highly sensitive, compact, and low-cost trace gas sensor based on photothermal effect in a hollow-core fiber Fabry-Perot interferometer (FPI) is described. The Fabry-Perot sensor is fabricated by splicing a piece of hollow-core photonic bandgap fiber (HC-PBF) to single-mode fiber pigtails at both ends. The absorption of a pump beam in the hollow core results in phase modulation of probe beam, which is detected by the FPI. Experiments with a 2 cm long HC-PBF with femtosecond laser drilled side-holes demonstrated a response time of less than 19 s and noise equivalent concentration (NEC) of 440 parts-per-billion (ppb) using a 1 s lock-in time constant, and the NEC goes down to 117 ppb (2.7×10-7 in absorbance) by using 77 s averaging time.

  6. Principle and applications of Faraday-Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Di, Nan; Zhao, Jianlin

    2010-10-01

    A Faraday-Fabry-Perot (FFP) cavity, composed of an Fabry-Perot (FP) cavity and a piece of Faraday magneto-optical material, is presented. The principle of FFP cavity and its polarization modulation effect are described by use of optical matrix analysis. The result shows that the Faraday rotation is able to be magnified by more than two orders of magnitude in resonant FFP cavity, while different elliptically polarized lights are obtained in non-resonant cavity. Furthermore two novel applications, that is, optical isolator based on passive FFP cavity (FOI) and Faraday-Zeeman dual-frequency laser (FZDL) based on active FFP cavity whose eigen modes operate as circularly polarized lights and whose frequency difference can be adjusted continuously by magnetic field, are introduced. The principles, typical parameters and performance characteristics are analyzed in both applications.

  7. Hollow-core fiber Fabry-Perot photothermal gas sensor.

    PubMed

    Yang, Fan; Tan, Yanzhen; Jin, Wei; Lin, Yuechuan; Qi, Yun; Ho, Hoi Lut

    2016-07-01

    A highly sensitive, compact, and low-cost trace gas sensor based on photothermal effect in a hollow-core fiber Fabry-Perot interferometer (FPI) is described. The Fabry-Perot sensor is fabricated by splicing a piece of hollow-core photonic bandgap fiber (HC-PBF) to single-mode fiber pigtails at both ends. The absorption of a pump beam in the hollow core results in phase modulation of probe beam, which is detected by the FPI. Experiments with a 2 cm long HC-PBF with femtosecond laser drilled side-holes demonstrated a response time of less than 19 s and noise equivalent concentration (NEC) of 440 parts-per-billion (ppb) using a 1 s lock-in time constant, and the NEC goes down to 117 ppb (2.7×10-7 in absorbance) by using 77 s averaging time. PMID:27367092

  8. Fabry-Perot observations of comet Austin

    NASA Technical Reports Server (NTRS)

    Schultz, David; Scherb, F.; Roesler, F. L.; Li, G.; Harlander, J.; Roberts, T. P. P.; Vandenberk, D.; Nossal, S.; Coakley, M.; Oliversen, Ronald J.

    1990-01-01

    Preliminary results of a program to observe Comet Austin (1990c1) from 16 April to 4 May and from 11 May to 27 May 1990 using the West Auxiliary of the McMath Solar Telescope on Kitt Peak, Arizona were presetned. The observations were made with a 15 cm duel-etalon Fabry-Perot scanning and imaging spectrometer with two modes of operation: a high resolution mode with a velocity resolution of 1.2 km/s and a medium resolution mode with a velocity resolution 10 km/s. Scanning data was obtained with an RCA C31034A photomultiplier tube and imaging data was obtained with a Photometrics LN2 cooled CCD camera with a 516 by 516 Ford chip. The results include: (1) information on the coma outflow velocity from high resolution spectral profiles of (OI)6300 and NH2 emissions, (2) gaseous water production rates from medium resolution observation of (OI)6300, (3) spectra of H2O(+) emissions in order to study the ionized component of the coma, (4) spatial distribution of H2O(+) emission features from sequences of velocity resolved images (data cubes), and (5) spatial distribution of (OI)6300 and NH2 emissions from medium resolution images. The field of view on the sky was 10.5 arcminutes in diameter. In the imaging mode the CCD was binned 4 by 4 resulting in 7.6 sec power pixel and a subarray readout for a field of view of 10.5 min.

  9. Surface Plasmons in Fabry-Perot Microcavities

    NASA Astrophysics Data System (ADS)

    Gregory, Stephen

    2000-05-01

    We have developed a technique for creating a tunable Fabry-Perot microcavity by flattening a tunneling microscope tip to create a mirror which is then opposed to a semitransparent metal-film mirror. The latter is deposited on a glass prism through which light can be directed into the cavity and which transmits light emitted by the cavity. With this arrangement we can reproducibly investigate behavior as the mirror separation is tuned down to contact. The modes usually associated with optical cavities are free-space solutions of Maxwell's equations and are populated by photons. However, in a microscopic cavity we must also consider near-field phenomena such as surface-plasmons at the surfaces of the mirrors. These can be excited by a laser beam incident on the prism at an appropriate angle. Surface-plasmon solutions include coupled modes involving both mirrors, which are radially confined in the microcavity. We are studying interconversion of photons and surface-plasmons and the lifetimes of both types of excitations, in particular as these are modified by cavity quantum electrodynamic effects.

  10. Strained layer Fabry-Perot device

    DOEpatents

    Brennan, Thomas M.; Fritz, Ian J.; Hammons, Burrell E.

    1994-01-01

    An asymmetric Fabry-Perot reflectance modulator (AFPM) consists of an active region between top and bottom mirrors, the bottom mirror being affixed to a substrate by a buffer layer. The active region comprises a strained-layer region having a bandgap and thickness chosen for resonance at the Fabry-Perot frequency. The mirrors are lattice matched to the active region, and the buffer layer is lattice matched to the mirror at the interface. The device operates at wavelengths of commercially available semiconductor lasers.

  11. Laser micromachined and acid-etched Fabry-Perot cavities in silica fibres

    NASA Astrophysics Data System (ADS)

    Machavaram, V. R.; Tuck, C. J.; Teagle, M. C.; Badcock, R. A.; Fernando, G. F.

    2006-01-01

    This paper reports on two techniques for creating Fabry-Perot cavities in conventional single- and multi-mode optical fibres. The authors have reported previously on the design and fabrication of extrinsic fibre Fabry-Perot interferometric multi-functional sensors. Here, the authors report on two novel techniques for creating intrinsic fibre optic sensors based on the Fabry-Perot etalon. The first technique involved the use of hydrofluoric acid to preferentially etch the core of the optical fibre. This technique is simple to carry out and provides a cost-effective means for manufacturing intrinsic fibre Fabry-Perot sensors. In the second technique, a 157 nm excimer laser along with a custom-designed beam delivery system was used to ablate (micro-machine) near-paralleled walled cavities through the diameter of the optical fibre (outer diameter of 125 μm). The paper details the experimental methodology and the associated instrumentation for the two techniques. The acid etched and laser ablated cavities were characterised using a 3-D surface profiler, optical and scanning electron microscopy. The feasibility of using these cavities as intrinsic fibre Fabry-Perot strain sensors is demonstrated. This was achieved by surface-mounting the acid etched cavities on to composite tensile test specimens. The output from the optical fibre devices was compared with surface-mounted electrical resistance strain gauges.

  12. Nanocomposite polyacrylamide based open cavity fiber Fabry-Perot humidity sensor.

    PubMed

    Yao, Jun; Zhu, Tao; Duan, De-Wen; Deng, Ming

    2012-11-01

    A humidity sensor with a low temperature sensitivity is proposed and demonstrated by coating a nanocomposite hygrometer polyacrylamide in an open interferometric cavity of a fiber Fabry-Perot interferometer. In this paper the Fabry-Perot structure is formed by splicing one short section of single mode fiber between two sections of single mode fiber with a larger offset fusing method. Experimental results show that relative humidity (RH) sensitivity of the sensor is ∼0.1 nm/(1% RH) in the range of 38% to 78% RH and ∼5.868 nm/(1%RH) in the range of 88% to 98% RH, respectively.

  13. Nanocomposite polyacrylamide based open cavity fiber Fabry-Perot humidity sensor.

    PubMed

    Yao, Jun; Zhu, Tao; Duan, De-Wen; Deng, Ming

    2012-11-01

    A humidity sensor with a low temperature sensitivity is proposed and demonstrated by coating a nanocomposite hygrometer polyacrylamide in an open interferometric cavity of a fiber Fabry-Perot interferometer. In this paper the Fabry-Perot structure is formed by splicing one short section of single mode fiber between two sections of single mode fiber with a larger offset fusing method. Experimental results show that relative humidity (RH) sensitivity of the sensor is ∼0.1 nm/(1% RH) in the range of 38% to 78% RH and ∼5.868 nm/(1%RH) in the range of 88% to 98% RH, respectively. PMID:23128715

  14. Simultaneous measurement of pressure and temperature by employing Fabry-Perot interferometer based on pendant polymer droplet.

    PubMed

    Sun, Bing; Wang, Yiping; Qu, Junle; Liao, Changrui; Yin, Guolu; He, Jun; Zhou, Jiangtao; Tang, Jian; Liu, Shen; Li, Zhengyong; Liu, Yingjie

    2015-02-01

    We investigated a novel and ultracompact polymer-capped Fabry-Perot interferometer, which is based on a polymer capped on the endface of a single mode fiber (SMF). The proposed Fabry-Perot interferometer has advantages of easy fabrication, low cost, and high sensitivity. The variation of the Fabry-Perot cavity length can be easily controlled by using the motors of a normal arc fusion splicer. Moreover, the enhanced mechanical strength of the Fabry-Perot interferometer makes it suitable for high sensitivity pressure and temperature sensing in harsh environments. The proposed interferometer exhibits a wavelength shift of the interference fringes that corresponds to a temperature sensitivity of 249 pm/°C and a pressure sensitivity of 1130 pm/MPa, respectively, around the wavelength of 1560 nm.

  15. Simultaneous measurement of pressure and temperature by employing Fabry-Perot interferometer based on pendant polymer droplet.

    PubMed

    Sun, Bing; Wang, Yiping; Qu, Junle; Liao, Changrui; Yin, Guolu; He, Jun; Zhou, Jiangtao; Tang, Jian; Liu, Shen; Li, Zhengyong; Liu, Yingjie

    2015-02-01

    We investigated a novel and ultracompact polymer-capped Fabry-Perot interferometer, which is based on a polymer capped on the endface of a single mode fiber (SMF). The proposed Fabry-Perot interferometer has advantages of easy fabrication, low cost, and high sensitivity. The variation of the Fabry-Perot cavity length can be easily controlled by using the motors of a normal arc fusion splicer. Moreover, the enhanced mechanical strength of the Fabry-Perot interferometer makes it suitable for high sensitivity pressure and temperature sensing in harsh environments. The proposed interferometer exhibits a wavelength shift of the interference fringes that corresponds to a temperature sensitivity of 249 pm/°C and a pressure sensitivity of 1130 pm/MPa, respectively, around the wavelength of 1560 nm. PMID:25836063

  16. Stable fiber-based Fabry-Perot cavity

    SciTech Connect

    Steinmetz, T.; Colombe, Y.; Hunger, D.; Haensch, T. W.; Balocchi, A.; Warburton, R. J.; Reichel, J.

    2006-09-11

    The development of a fiber-based, tunable optical cavity with open access is reported. The cavity is of the Fabry-Perot type and is formed with miniature spherical mirrors positioned on the end of single- or multimode optical fibers by a transfer technique, which involves lifting a high-quality mirror from a smooth convex substrate, either a ball lens or microlens. The cavities typically have a finesse of {approx}1000 and a mode volume of 600 {mu}m{sup 3}. The detection of small ensembles of cold Rb atoms guided through such a cavity on an atom chip is demonstrated.

  17. Silk fibroin diaphragm-based fiber-tip Fabry-Perot pressure sensor.

    PubMed

    Cheng, Linghao; Wang, Cengzhong; Huang, Yunyun; Liang, Hao; Guan, Bai-Ou

    2016-08-22

    A miniature fiber-optic Fabry-Perot is built on the tip of a single mode fiber with a thin silk fibroin film as the diaphragm for pressure measurement. The silk fibroin film is regenerated from aqueous silk fibroin solution obtained by an environmentally benign fabrication process, which exhibits excellent optical and physicochemical properties, such as transparency in visible and near infrared region, membrane-forming ability, good adhesion, and high mechanical strength. The resulted Fabry-Perot pressure sensor is therefore highly biocompatible and shows good airtightness with a response of 12.3 nm/kPa in terms of cavity length change.

  18. High-temperature fiber-optic Fabry-Perot interferometric sensors.

    PubMed

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  19. Silk fibroin diaphragm-based fiber-tip Fabry-Perot pressure sensor.

    PubMed

    Cheng, Linghao; Wang, Cengzhong; Huang, Yunyun; Liang, Hao; Guan, Bai-Ou

    2016-08-22

    A miniature fiber-optic Fabry-Perot is built on the tip of a single mode fiber with a thin silk fibroin film as the diaphragm for pressure measurement. The silk fibroin film is regenerated from aqueous silk fibroin solution obtained by an environmentally benign fabrication process, which exhibits excellent optical and physicochemical properties, such as transparency in visible and near infrared region, membrane-forming ability, good adhesion, and high mechanical strength. The resulted Fabry-Perot pressure sensor is therefore highly biocompatible and shows good airtightness with a response of 12.3 nm/kPa in terms of cavity length change. PMID:27557238

  20. Robust Fabry-Perot interference in dual-gated Bi2Se3 devices

    NASA Astrophysics Data System (ADS)

    Finck, A. D. K.; Kurter, C.; Huemiller, E. D.; Hor, Y. S.; Van Harlingen, D. J.

    2016-05-01

    We study Fabry-Perot interference in hybrid devices, each consisting of a mesoscopic superconducting disk deposited on the surface of a three-dimensional topological insulator. Such structures are hypothesized to contain protected zero modes known as Majorana fermions bound to vortices. The interference manifests as periodic conductance oscillations of magnitude ˜ 0.1 e 2 / h . These oscillations show no strong dependence on bulk carrier density or sample thickness, suggesting that they result from phase coherent transport in surface states. However, the Fabry-Perot interference can be tuned by both top and back gates, implying strong electrostatic coupling between the top and bottom surfaces of topological insulator.

  1. High-temperature fiber-optic Fabry-Perot interferometric sensors

    SciTech Connect

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-15

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  2. Velocimetry of fast surfaces at LLNL using Fabry-Perot interferometry

    SciTech Connect

    McMillan, C.F.; Goosman, D.R.; Parker, N.L.; Steinmetz, L.L.; Chau, H.H.; Huen, T.; Whipkey, R.K.; Perry, S.J.

    1987-05-20

    This report describes the use of the Fabry-Perot interferometer in the fringe mode to measure velocities of fast moving reflecting surfaces. The Doppler shift theory applicable to this situation is described. Formulae are derived for the analysis of the effects of shocked, dispersive, moving transparent media on velocity measurements, including expressions for the velocity of light in a moving medium with moving boundaries. The Fabry-Perot method is compared with other techniques such as VISAR interferometry. A standard configuration is described in detail. Methods of alignment, calibration, and operation are included. Several methods of analysis are compared. (JDH)

  3. High-temperature fiber-optic Fabry-Perot interferometric sensors.

    PubMed

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved. PMID:26026548

  4. Extrinsic Fabry-Perot ultrasonic detector

    NASA Astrophysics Data System (ADS)

    Kidwell, J. J.; Berthold, John W., III

    1996-10-01

    We characterized the performance of a commercial fiber optic extrinsic Fabry-Perot interferometer for use as an ultrasonic sensor, and compared the performance with a standard lead zirconate titanate (PZT) detector. The interferometer was unstabilized. The results showed that the fiber sensor was about 12 times less sensitive than the PZT detector. Ultrasonic frequency response near 100 kHz was demonstrated. We describe the design of the fiber sensor, the details of the tests performed, and potential applications.

  5. An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

    NASA Technical Reports Server (NTRS)

    Taghavi-Larigani, Shervin; VanZyl, Jakob

    2009-01-01

    We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

  6. Striped Fabry-Perots: Improved efficiency for velocimetry

    SciTech Connect

    McMillan, C.; Steinmetz, L.

    1990-07-01

    Removing a narrow stripe of the reflective coating from the input mirror of a Fabry-Perot interferometer can dramatically increase the amount of light transmitted through the system; we have observed gains in excess of 50 when we compare a conventional Fabry-Perot with the striped Fabry-Perot under similar lighting conditions. The stripe affects the distribution of light in the Fabry-Perot peaks causing them to be lower in the center of the pattern. We examine this distribution, and discuss its application in analyzing velocities. 6 refs., 6 figs., 1 tab.

  7. Millimeter-long fiber Fabry-Perot cavities.

    PubMed

    Ott, Konstantin; Garcia, Sebastien; Kohlhaas, Ralf; Schüppert, Klemens; Rosenbusch, Peter; Long, Romain; Reichel, Jakob

    2016-05-01

    We demonstrate fiber Fabry-Perot (FFP) cavities with concave mirrors that can be operated at cavity lengths as large as 1.5 mm without significant deterioration of the finesse. This is achieved by using a laser dot machining technique to shape spherical mirrors with ultralow roughness and employing single-mode fibers with large mode area for good mode matching to the cavity. Additionally, in contrast to previous FFPs, these cavities can be used over an octave-spanning frequency range with adequate coatings. We also show directly that shape deviations caused by the fiber's index profile lead to a finesse decrease as observed in earlier attempts to build long FFP cavities, and show a way to overcome this problem.

  8. Millimeter-long fiber Fabry-Perot cavities.

    PubMed

    Ott, Konstantin; Garcia, Sebastien; Kohlhaas, Ralf; Schüppert, Klemens; Rosenbusch, Peter; Long, Romain; Reichel, Jakob

    2016-05-01

    We demonstrate fiber Fabry-Perot (FFP) cavities with concave mirrors that can be operated at cavity lengths as large as 1.5 mm without significant deterioration of the finesse. This is achieved by using a laser dot machining technique to shape spherical mirrors with ultralow roughness and employing single-mode fibers with large mode area for good mode matching to the cavity. Additionally, in contrast to previous FFPs, these cavities can be used over an octave-spanning frequency range with adequate coatings. We also show directly that shape deviations caused by the fiber's index profile lead to a finesse decrease as observed in earlier attempts to build long FFP cavities, and show a way to overcome this problem. PMID:27137597

  9. An economic Fabry-Perot wavelength reference

    NASA Astrophysics Data System (ADS)

    Fżrész, Gábor; Glenday, Alex; Latham, Christian

    2014-07-01

    Precision radial velocity (PRV) measurements are key in studying exoplanets, and so are wavelength calibrators in PRV instruments. ThAr lamps offer an affordable but somewhat limited solution for the visible passband. Laser frequency combs are ideal calibrators, except the (still) narrow wavelength coverage and large price tag. White light Fabry-Perot (FP) calibrators offer frequency-comb like properties in a more affordable and less complicated package1. Using a commercial solid FP etalon and off-the shelf components we have constructed an economic FP calibrator suitable for observatories on a smaller budget.

  10. Analysis of Fabry-Perot Velocimeter Records

    SciTech Connect

    Avara, G

    2001-08-03

    Program demonstration and user instructions are presented for FabryVB5. This computer program was created for use in analyzing Fabry-Perot interferometer records that detail the velocity time histories of fast moving surfaces. Graphical curves representing peak fringe positions and fiducial timing dots are extracted from a digitized film record or from a CCD digital image. An analysis is demonstrated on a sample velocimeter record along with some mathematical formula and routine operations. Routines used to analyze calibration records on streak camera distortions are illustrated in an appendix. This is a Microsoft Visual Basic{trademark} version for the PC.

  11. Fiber Fabry-Perot interferometer for curvature sensing

    NASA Astrophysics Data System (ADS)

    Monteiro, Catarina S.; Ferreira, Marta S.; Silva, Susana O.; Kobelke, Jens; Schuster, Kay; Bierlich, Jörg; Frazão, Orlando

    2016-07-01

    A curvature sensor based on an Fabry-Perot (FP) interferometer was proposed. A capillary silica tube was fusion spliced between two single mode fibers, producing an FP cavity. Two FP sensors with different cavity lengths were developed and subjected to curvature and temperature. The FP sensor with longer cavity showed three distinct operating regions for the curvature measurement. Namely, a linear response was shown for an intermediate curvature radius range, presenting a maximum sensitivity of 68.52 pm/m-1. When subjected to temperature, the sensing head produced a similar response for different curvature radii, with a sensitivity varying from 0.84 pm/°C to 0.89 pm/°C, which resulted in a small cross-sensitivity to temperature when the FP sensor was subjected to curvature. The FP cavity with shorter length presented low sensitivity to curvature.

  12. Stable CW Single-Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking

    NASA Technical Reports Server (NTRS)

    Duerksen, Gary L.; Krainak, Michael A.

    1999-01-01

    Previously, single-frequency semiconductor laser operation using fiber Bragg gratings has been achieved by two methods: 1) use of the FBG as the output coupler for an anti-reflection-coated semiconductor gain element'; 2) pulsed operation of a gain-switched Fabry-Perot laser diode with FBG-optical and RF-electrical feedback. Here, we demonstrate CW single frequency operation from a non-AR coated Fabry-Perot laser diode using only FBG optical feedback. We coupled a nominal 935 run-wavelength Fabry-Perot laser diode to an ultra narrow band (18 pm) FBG. When tuned by varying its temperature, the laser wavelength is pulled toward the centerline of the Bragg grating, and the spectrum of the laser output is seen to fall into three discrete stability regimes as measured by the side-mode suppression ratio.

  13. Dynamic model and stability analysis of a laser using a nonlinear Fabry-Perot etalon as a cavity mirror

    SciTech Connect

    Li, S.; Pons, R. . Dept. of Fisica); Zhang, Y. . Telecommunications Engineering Dept.)

    1994-08-01

    In this paper, the authors study a laser using a nonlinear Fabry-Perot etalon as a cavity mirror. First, using the semiclassical laser theory and the differential equation for the lossy nonlinear Fabry-Perot etalon, they develop dynamic equations describing this system for single-mode operation. In this model, the frequency-pulling effect, a finite response time of the nonlinear medium, and a finite-cavity round-trip time of the Fabry-Perot etalon are included. Second, based on this model, they analyze the stability of this laser and give some numerical results. The results show that (1) this system can exist in the stable state and in the unstable state; (2) there are not only saddle-node bifurcations but also Hopf bifurcations; (3) the detuning parameter will effect the characteristics of the bistability and the number and distribution of Hopf bifurcation points.

  14. High-pressure and high-temperature characteristics of a Fabry-Perot interferometer based on photonic crystal fiber.

    PubMed

    Wu, Chuang; Fu, H Y; Qureshi, Khurram Karim; Guan, Bai-Ou; Tam, H Y

    2011-02-01

    A fiber-optic Fabry-Perot interferometer was constructed by splicing a short length of photonic crystal fiber to a standard single-mode fiber. The photonic crystal fiber functions as a Fabry-Perot cavity and serves as a direct sensing probe without any additional components. Its pressure and temperature responses in the range of 0-40 MPa and 25°C-700°C were experimentally studied. The proposed sensor is easy to fabricate, potentially low-cost, and compact in size, which makes it very attractive for high-pressure and high-temperature sensing applications. PMID:21283207

  15. Micromachined Fabry-Perot interferometric pressure sensor for automotive combustion engine

    SciTech Connect

    Lee, S.B.; Yu, C.M.; Ciarlo, D.R.; Sheem, S.K.

    1994-09-01

    In this paper, the authors report a dynamic cylinder pressure sensor for automotive combustion engine. The pressure is sensed by measuring the pressure-induced deflection of a membrane via a Fabry-Perot optical interferometric effect. The sensor is micromachined on a silicon wafer to minimize the cost and the size and to enhance the device quality in high-volume production mode. As a preliminary test, they measured the pressure of an air compressor using the micromachined miniature sensor.

  16. Temperature-independent refractometer based on fiber-optic Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Li, Jiacheng; Qiao, Xueguang; Wang, Ruohui; Rong, Qiangzhou; Bao, Weijia; Shao, Zhihua; Yang, Tingting

    2016-04-01

    A miniature fiber-optic refractometer based on Fabry-Perot interferometer (FPI) has been proposed and experimentally demonstrated. The sensing head consists of a short section of photonics crystal fiber (PCF) spliced to a single mode fiber (SMF), in which the end-face of the PCF is etched to remove holey structure with hydrofluoric (HF) acid. A Fabry-Perot interference spectrum is achieved based on the reflections from the fusion splicing interface and the end-face of the core of PCF. The interference fringe is sensitive to the external refractive index (RI) with an intensity-referenced sensitivity of 358.27 dB/RIU ranging from 1.33 to 1.38. The sensor has also been implemented for the concentration measurement of λ-phage DNA solution. In addition, the dip intensity is insensitive to the ambient temperature variation, making it a good candidate for temperature-independent bio-sensing area.

  17. A miniature extrinsic fiber Fabry-Perot pressure sensor based on fiber etching

    NASA Astrophysics Data System (ADS)

    Ge, Yixian; Wang, Ming; Yang, Chundi

    2009-10-01

    This paper presents a miniature fiber optic pressure sensor based on Fabry-Perot interference fabricated on the tip of a single mode (SM) fiber. The sensor measures only 125μm in diameter. A Fabry-Perot cavity and a thin silica diaphragm are fabricated by simple techniques involving only fusion splicing, cleaving, and wet chemical etching. Interference pattern of the sensor is analyzed and issues in sensor design are discussed. The overall chemical reaction of the fiber wet etching is specifically represented. Pressure testing system is carried out. By tracing a peak point in the interference spectrum, the gap length of the sensor can be demodulated. The sensor is made entirely of fused silica, whose structure has good stability, cabinet, simple for fabrication and low cost. It may also find uses in medical applications.

  18. A fiber Fabry-Perot interferometer based on a PVA coating for humidity measurement

    NASA Astrophysics Data System (ADS)

    Su, Dan; Qiao, Xueguang; Rong, Qiangzhou; Sun, Hao; Zhang, Jing; Bai, Zhengyuan; Du, Yanying; Feng, Dingyi; Wang, Yupeng; Hu, Manli; Feng, Zhongyao

    2013-01-01

    A fiber Fabry-Perot interferometer (FPI) for humidity measurement based on a Polyvinyl alcohol (PVA) film is proposed and experimentally demonstrated. This FPI is fabricated by coating a PVA film on the ending face of a Single-mode fiber (SMF) to form a Fabry-Perot cavity. A well-confined interference spectrum with a free spectra range (FSR) of 15 nm is obtained. Several saturated salt solutions are employed to obtain the different humidity environments in the inclosed containers, of which the relative humidity values range from 7% RH to 91.2% RH. The proposed FPI sensor is sensitive to the humidity change, and a sensitivity of 0.07 nm/(1%) is obtained. Therefore, the characteristics of compact size, low cost and simple fabrication identify it a good candidate for environment monitoring application.

  19. A miniature extrinsic fiber Fabry-Perot pressure sensor based on fiber etching

    NASA Astrophysics Data System (ADS)

    Ge, Yixian; Zhou, Junping; Wang, Tingting

    2011-11-01

    A miniature fiber optic pressure sensor based on Fabry-Perot interference fabricated on the tip of a single mode (SM) fiber is presented. The sensor measures only 125μm in diameter. A Fabry-Perot cavity and a thin silica diaphragm are fabricated by simple techniques involving only cleaving, wet chemical etching and fusion splicing. Interference pattern of the sensor is analyzed and issues in sensor design are discussed. The overall chemical reaction of the fiber wet etching is specifically represented. Pressure testing system is carried out. By tracing a peak point in the interference spectrum, the gap length of the sensor can be demodulated. Experimental results show the sensor has a good linearity. The sensor is made entirely of fused silica, whose structure has good stability, cabinet, simple for fabrication and low cost.

  20. Fiber-coupled short Fabry-Perot resonators

    SciTech Connect

    Stone, J.; Marcuse, D. )

    1989-05-01

    Fabry-Perot resonators intended as filters in wavelength-multiplexed optical communications systems may have to be very short (on the order of 10 {mu}m) in order to increase their free spectral range. Short, yet tunable cavities can be designed as air gaps between two fibers placed in close proximity with highly reflecting mirrors deposited on their ends. However, an air-gap resonator with plane mirrors between closely spaced fiber ends may yield low throughout because of the poor match between the modes of typical single-mode fibers and the resonant mode in the air-gap cavity. The throughput can be improved by confining the resonant mode by means of a hollow dielectric tube placed inside the resonator. This paper compares short fiber-coupled Fabry-Parot resonators with and without an inserted hollow dielectric waveguide and derives expressions for their transmission losses. The authors show that the throughput of both types of resonator can be improved significantly by using a special fiber with large mode size to couple to the resonator. The special fiber is then spliced to a conventional single-mode fiber. They conclude that the resonator with an inserted hollow dielectric waveguide offers increased throughput for resonators with high finesse.

  1. Fabry-Perot interferometer based Mie Doppler lidar for low tropospheric wind observation.

    PubMed

    Xia, Haiyun; Sun, Dongsong; Yang, Yuanhong; Shen, Fahua; Dong, Jingjing; Kobayashi, Takao

    2007-10-10

    Similar in principle to recent implementations of a lidar system at 355 nm [Opt. Lett. 25, 1231 (2000), Appl. Opt. 44, 6023 (2005)], an incoherent-detection Mie Doppler wind lidar at 1064 nm was developed and deployed in 2005 [Opt. Rev. 12, 409 (2005)] for wind measurements in the low troposphere, taking advantage of aerosol scattering for signal enhancement. We present a number of improvements made to the original 1064 nm system to increase its robustness for long-period operation. These include a multimode fiber for receiving the reference signal, a mode scrambler to allow uniform illumination over the Fabry-Perot interferometer, and a fast scannable Fabry-Perot interferometer for calibration and for the determination of outgoing laser frequency during the wind observation. With these improvements in stability, the standard deviation of peak transmission and FWHM of the Fabry-Perot interferometer was determined to be 0.49% and 0.36%, respectively. The lidar wind measurements were validated within a dynamic range of +/-40 m/s. Comparison experiments with both wind profiler radar and Vaisala wiresonde show good agreement with expected observation error. An example of 24 h continuous observations of wind field and aerosol backscatter coefficients in the boundary layer with 1 min and 30 m temporal and spatial resolution and 3 m/s tolerated wind velocity error is presented and fully demonstrates the stability and robustness of this lidar.

  2. Direct inscription of intrinsic Fabry-Perot interferometers in optical fiber tapers with a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Li, Jinlong; Zhang, Xiaobei; Wang, Wenyuan; Pang, Fufei; Liu, Yunqi; Wang, Tingyun

    2011-12-01

    In this work, we report a sensing configuration of the fiber taper intrinsic Fabry-Perot interferometer directly inscribed in single-mode optical fiber tapers with different waist diameters from 14 to 80 μm using a femtosecond laser micromachining system. By controlling the inscribing depth and intensity of the fs laser pulse, the fringe visibility can exceed 9.0 dB when the fiber taper waist diameter is around 15 μm, which is sufficient for most sensing applications. The sensor sensitivity depends on the fiber taper waist diameter, while a smaller diameter corresponds to a large sensitivity. Different free spectral ranges can be achieved for various cavity lengths. Such a structure can combine the high sensitivity properties of fiber taper sensors with the high resolution features of Fabry-Perot interferometer sensors. Meanwhile, this structure can have a number of outstanding advantages, such as its small size, unique geometry, easy fabrication, low cost and capability for mass production. These fiber taper intrinsic Fabry-Perot interferometer sensors have high potential in fast detection and high precision measurement while maintaining superior reliability for chemical and biological sensing.

  3. Swift: A Widefield Imaging Fabry Perot for Sofia

    NASA Technical Reports Server (NTRS)

    Stacey, Gordon J.

    1999-01-01

    Contract was to pursue feasibility studies of the SOFIA Widefield Imaging Fabry-Perot (SWIFT). SWIFT was proposed as a two color 18 to 40 microns imaging Fabry-Perot that utilized two Rockwell/Boeing 256 x 256 pixel Si:Sb BIBs as detective devices. The colors were to be split between 26 and 30 microns using a MgO dichroic. The resolution achieving devices were to be a pair of cryogenic fully tunable scanning Fabry-Perot interferometers (FPIs), two in each band. For high resolving powers, a third, fixed FPI is inserted into the beam. The FPI mirrors were to be made of free standing metal mesh. We also proposed to look into a long wavelength (40 to 210 microns) band during the feasibility study period. We produced a proposal to USRA, submitted in July 1997 that substantially refined our ideas. We decided the long wavelength science was compelling, so the baseline wavelength coverage for SWIFT was widened to 17 to 205 microns. Under typical operations, we proposed to simultaneously image in two bands: 22 to 38 microns, and 50 to 205 microns. The bands were to be split by a cold CaF2 dichroic. The short wavelength (SW) band was to employ a 256 x 256 pixel Boeing/Rockwell Si:Sb BIB array, and the long wavelength (LW) band was to employ a Goddard 6 x 32 (upgradable to 32 x 32) element array of monolithic silicon "pop-up" bolometers as detective devices. The two color capability doubled the data taking efficiency, and ensured "perfect" registration between the images obtained in each band. For the SW band, the beam was to be fully sampled (0.7" pixels, 1.4 in. beam) at 17 microns, and over sampled at longer wavelengths. Even so, SWIFT has a very large (3 ft x 3 ft) field of view. To match the SW and LW fields of view (initially in one dimension only, but in 2-dimensions with 32 x 32 upgrade), SWIFT was to under sample at 63 microns (5.6 in pixels, 5.2 in beam) resulting in a 0.56 x 3 in (upgrade to 3 in x 3 in) field of view. Each band has both Lo-Res (R triple bond

  4. Fabrication of Fabry-Perot Interferometer Sensors and Characterization of their Performances for Aircraft Inspection

    NASA Technical Reports Server (NTRS)

    Pendergrass, LeRuth Q.

    1995-01-01

    This work provides the information for fabricating Fabry-Perot Interferometer sensors and their performances. The Fabry-Perot Interferometer sensors developed here will be used for the detection of flaws in aircraft structures. The sequel also contains discussion of the experimental setups for the Ultrasonic technique and the Fabry-Perot Interferometer.

  5. Atmospheric temperature sensing with a multiorder Fabry-Perot interferometer.

    PubMed

    Wang, J; Drayson, S R; Hayes, P B

    1989-12-01

    A Fabry-Perot interferometer has a periodic response. By matching the free spectral range of a Fabry-Perot interferometer (FPI) with the period of the CO(2) spectrum, considerable advantages of throughput and spectral resolution can be achieved, leading to high spectral resolution and vertical resolution for atmospheric temperature sounders. In this paper, the concept of a high resolution multiorder Fabry-Perot interferometer using portions of the 15-microm and 4.3-microm bands of CO(2)for the purpose of atmospheric temperature sounding is discussed. Suitable sounding spectral positions, FPI free spectral range, and weighting functions are calculated. An effective spectral resolution of 0.02 cm(-1) can be achieved by the proposed sounder with a FPI finess of ~100 which is within the present state-of-the-art technology in the infrared region, leading to considerable improvement in the vertical resolution of the atmospheric temperature sounder. PMID:20555996

  6. The South Pole Imaging Fabry Perot Interferometer (SPIFI)

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Bradford, C. M.; Swain, M. R.; Jackson, J. M.; Bolato, A. D.; Davidson, J. A.; Savage, M.

    1996-01-01

    The design and construction of the South Pole imaging Fabry-Perot interferometer (SPIFI) is reported. The SPIFI is a direct detection imaging spectrometer for use in the far infrared and submillimeter bands accessible to the 1.7 m telescope at the South Pole, and in the submillimeter bands accessible to the 15 m James Clerk Maxwell Telescope (JCMT), HI. It employs a 5 x 5 silicon bolometer array and three cryogenic Fabry Perot interferometers in series in order to achieve velocity resolutions of between 300 km/s and 30 km/s over the entire field of view with a resolution of up to 1 km/s at the center pixel. The scientific justification for the instrument is discussed, considering the spectral lines available to SPIFI. The optical path, the cryogenic Fabry-Perot, the adiabatic demagnetization refrigerator and the detector array are described. The instrument's sensitivity is presented and compared with coherent systems.

  7. Novel tunable Fabry-Perot filters for FBG sensing system

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Tong, Xinglin; Liu, Xin; Chen, Ting

    2008-12-01

    Tunable filters with a wide tunable rang have been found wide applications and be the key component in fiber optical communication system and fiber sensor system. It is hard to fabricate a fiber Fabry-Perot tunable filter. In this paper, the principles of Fabry-Perot filter is introduced, and a novel tunable Fabry-Perot filter is designed and fabricated. The fabricated process of the tunable filter is described and the transmission spectrum of tunable F-P filter in experiment is given and discussed. The tunable F-P filter has the advantages of simple structure, low modulated voltage and cost effectiveness. The filter can be applied to wavelength interrogation in fiber Bragg grating (FBG) sensing system to detect the drift of the fiber Bragg wavelength.

  8. Performance of a dual Fabry-Perot cavity refractometer.

    PubMed

    Egan, Patrick F; Stone, Jack A; Hendricks, Jay H; Ricker, Jacob E; Scace, Gregory E; Strouse, Gregory F

    2015-09-01

    We have built and characterized a refractometer that utilizes two Fabry-Perot cavities formed on a dimensionally stable spacer. In the typical mode of operation, one cavity is held at vacuum, and the other cavity is filled with nitrogen gas. The differential change in length between the cavities is measured as the difference in frequency between two helium-neon lasers, one locked to the resonance of each cavity. This differential change in optical length is a measure of the gas refractivity. Using the known values for the molar refractivity and virial coefficients of nitrogen, and accounting for cavity length distortions, the device can be used as a high-resolution, multi-decade pressure sensor. We define a reference value for nitrogen refractivity as n-1=(26485.28±0.3)×10(-8) at p=100.0000  kPa, T=302.9190  K, and λ(vac)=632.9908  nm. We compare pressure determinations via the refractometer and the reference value to a mercury manometer.

  9. Performance of a dual Fabry-Perot cavity refractometer.

    PubMed

    Egan, Patrick F; Stone, Jack A; Hendricks, Jay H; Ricker, Jacob E; Scace, Gregory E; Strouse, Gregory F

    2015-09-01

    We have built and characterized a refractometer that utilizes two Fabry-Perot cavities formed on a dimensionally stable spacer. In the typical mode of operation, one cavity is held at vacuum, and the other cavity is filled with nitrogen gas. The differential change in length between the cavities is measured as the difference in frequency between two helium-neon lasers, one locked to the resonance of each cavity. This differential change in optical length is a measure of the gas refractivity. Using the known values for the molar refractivity and virial coefficients of nitrogen, and accounting for cavity length distortions, the device can be used as a high-resolution, multi-decade pressure sensor. We define a reference value for nitrogen refractivity as n-1=(26485.28±0.3)×10(-8) at p=100.0000  kPa, T=302.9190  K, and λ(vac)=632.9908  nm. We compare pressure determinations via the refractometer and the reference value to a mercury manometer. PMID:26368682

  10. Vibration-induced elastic deformation of Fabry-Perot cavities

    SciTech Connect

    Chen Lisheng; Hall, John L.; Ye Jun; Yang Tao; Zang Erjun; Li Tianchu

    2006-11-15

    We perform a detailed numerical analysis of Fabry-Perot cavities used for state-of-the-art laser stabilization. Elastic deformation of Fabry-Perot cavities with various shapes and mounting methods is quantitatively analyzed using finite-element analysis. We show that with a suitable choice of mounting schemes it is feasible to minimize the susceptibility of the resonator length to vibrational perturbations. This investigation offers detailed information on stable optical cavities that may benefit the development of ultrastable optical local oscillators in optical atomic clocks and precision measurements probing the fundamental laws of physics.

  11. Simulation experiments to generate broadband chaos using dual-wavelength optically injected Fabry-Perot laser

    NASA Astrophysics Data System (ADS)

    Obaid, Hafiz Muhammad; Khawar Islam, Muhammad; Obaid Ullah, Muhammad

    2016-08-01

    Broadband chaos can be generated by beating two wavelengths in a hybrid arrangement of Fabry-Perot (FP) Laser and Fiber ring cavity by injecting dual wavelengths. The bandwidth of generated chaos can be controlled by detuning different modes of FP Laser for beating. The bandwidth of generated chaos increased to many folds depending upon the injected strength and wavelength spacing matched to FP laser modes. The bandwidth enhancement in different simulation experiments conducted is optimized by varying different parameters of FP laser and cavity. The waveforms are analyzed and Lyapunov exponents are calculated in order to validate the existence of high bandwidth non-pulsating chaos.

  12. Photonic crystal fiber Fabry-Perot interferometers with high-reflectance internal mirrors

    NASA Astrophysics Data System (ADS)

    Fan, Rong; Hou, Yuanbin; Sun, Wei

    2015-06-01

    We demonstrated an in-line micro fiber-optic Fabry-Perot interferometer with an air cavity which was created by multi-step fusion splicing a muti-mode photonic crystal fiber (MPCF) to a standard single mode fiber (SMF). The fringe visibility of the interference pattern was up to 20 dB by reshaping the air cavity. Experimental results showed that such a device could be used as a highly sensitive strain sensor with the sensitivity of 4.5 pm/μɛ. Moreover, it offered some other outstanding advantages, such as the extremely compact structure, easy fabrication, low cost, and high accuracy.

  13. Silicon Carbide Mounts for Fabry-Perot Interferometers

    NASA Technical Reports Server (NTRS)

    Lindemann, Scott

    2011-01-01

    Etalon mounts for tunable Fabry- Perot interferometers can now be fabricated from reaction-bonded silicon carbide structural components. These mounts are rigid, lightweight, and thermally stable. The fabrication of these mounts involves the exploitation of post-casting capabilities that (1) enable creation of monolithic structures having reduced (in comparison with prior such structures) degrees of material inhomogeneity and (2) reduce the need for fastening hardware and accommodations. Such silicon carbide mounts could be used to make lightweight Fabry-Perot interferometers or could be modified for use as general lightweight optical mounts. Heretofore, tunable Fabry-Perot interferometer structures, including mounting hardware, have been made from the low-thermal-expansion material Invar (a nickel/iron alloy) in order to obtain the thermal stability required for spectroscopic applications for which such interferometers are typically designed. However, the high mass density of Invar structures is disadvantageous in applications in which there are requirements to minimize mass. Silicon carbide etalon mounts have been incorporated into a tunable Fabry-Perot interferometer of a prior design that originally called for Invar structural components. The strength, thermal stability, and survivability of the interferometer as thus modified are similar to those of the interferometer as originally designed, but the mass of the modified interferometer is significantly less than the mass of the original version.

  14. A Fabry-Perot Solid Etalon for Teaching.

    ERIC Educational Resources Information Center

    Bruce, P. J.; And Others

    1986-01-01

    Describes a solid etalon Fabry-Perot interferometer, discussing free spectral range, instrumental finesse, and temperature effects. Provides schematic of temperature control/display circuit. Explains use of 100 millimeter camera lens and 10 power micrometer eyepiece for resolving rings and measure diameters. (JM)

  15. Development of the Fabry-Perot Spectrometer Application

    NASA Technical Reports Server (NTRS)

    Browne, Kathryn

    2015-01-01

    Methane is a greenhouse gas with global warming effects 20 times more detrimental than carbon dioxide. Currently, only aircraft missions measure methane and do not provide continuous monitoring, This presentation will cover the Fabry-Perot spectrometer which will provide continuous monitoring of methane. It will also cover the development of the software used to extract and process the data the spectrometer collects.

  16. Characterization of miniature fiber-optic Fabry-Perot interferometric sensors based on hollow silica tube

    NASA Astrophysics Data System (ADS)

    Jia, Pinggang; Fang, Guocheng; Wang, Daihua

    2016-09-01

    A miniature fiber-optic Fabry-Perot interferometer (MOFPI) fabricated by splicing a hollow silica tube (HST) with inner diameter of 4 µm to the end of a single-mode fiber is investigated and experimentally demonstrated. The theoretical relationship between the free spectrum range and the length of HST is verified by fabricating several MOFPIs with different lengths. We characterize the MOFPIs for temperature, liquid refractive index, and strain. Experimental results show that the sensitivities of the temperature, liquid refractive index, and strain are 16.42 pm/°C,-118.56 dB/RIU, and 1.21 pm/µɛ, respectively.

  17. An All Fiber Intrinsic Fabry-Perot Interferometer Based on an Air-Microcavity

    PubMed Central

    Jáuregui-Vázquez, Daniel; Estudillo-Ayala, Julián M.; Rojas-Laguna, Roberto; Vargas-Rodríguez, Everardo; Sierra-Hernández, Juan M.; Hernández-García, Juan C.; Mata-Chávez, Ruth I.

    2013-01-01

    In this work an Intrinsic Fabry-Perot Interferometer (IFPI) based on an air-microcavity is presented. Here the air microcavity, with silica walls, is formed at a segment of a hollow core photonic crystal fiber (HCPCF), which is fusion spliced with a single mode fiber (SMF). Moreover, the spectral response of the IFPI is experimentally characterized and some results are provided. Finally, the viability to use the IFPI to implement a simple, compact size, and low cost refractive index sensor is briefly analyzed. PMID:23673676

  18. Nanofiber Fabry-Perot microresonator for nonlinear optics and cavity quantum electrodynamics.

    PubMed

    Wuttke, C; Becker, M; Brückner, S; Rothhardt, M; Rauschenbeutel, A

    2012-06-01

    We experimentally realize a Fabry-Perot-type optical microresonator near the cesium D2 line wavelength based on a tapered optical fiber, equipped with two fiber Bragg gratings that enclose a subwavelength diameter waist. Owing to the very low taper losses, the finesse of the resonator reaches F=86 while the on-resonance transmission is T=11%. The characteristics of our resonator fulfill the requirements of nonlinear optics and cavity quantum electrodynamics in the strong coupling regime. These characteristics, combined with the demonstrated ease of use and advantageous mode geometry, open a realm of applications.

  19. Temperature characteristics of silicon core optical fiber Fabry-Perot interferometer.

    PubMed

    Zhang, Shaolin; Zhao, Ziwen; Chen, Na; Pang, Fufei; Chen, Zhenyi; Liu, Yunqi; Wang, Tingyun

    2015-04-01

    Silicon core optical fiber expanded silicon photonics to specialty fiber platform. Although great challenges still exist for the fiber fabrication, the presence of semiconductor material has already given optical fiber new features and enormous possibilities for fiber-based devices and sensors. In this Letter, an all fiber silicon cavity Fabry-Perot interferometer was made by splicing silicon core silica cladding fiber with conventional single-mode silica fiber. The cavity shows high temperature sensitivity around 82 pm/°C due to the larger thermo-optical coefficient of silicon material compared with that of silica material. PMID:25831333

  20. An all fiber intrinsic Fabry-Perot Interferometer based on an air-microcavity.

    PubMed

    Jáuregui-Vázquez, Daniel; Estudillo-Ayala, Julián M; Rojas-Laguna, Roberto; Vargas-Rodríguez, Everardo; Sierra-Hernández, Juan M; Hernández-García, Juan C; Mata-Chávez, Ruth I

    2013-01-01

    In this work an Intrinsic Fabry-Perot Interferometer (IFPI) based on an air-microcavity is presented. Here the air microcavity, with silica walls, is formed at a segment of a hollow core photonic crystal fiber (HCPCF), which is fusion spliced with a single mode fiber (SMF). Moreover, the spectral response of the IFPI is experimentally characterized and some results are provided. Finally, the viability to use the IFPI to implement a simple, compact size, and low cost refractive index sensor is briefly analyzed. PMID:23673676

  1. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    PubMed

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity. PMID:26625075

  2. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    PubMed

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

  3. Zeolite thin film-coated fiber sensors based on Fabry-Perot interferometer for detection of chemical vapors

    NASA Astrophysics Data System (ADS)

    Ning, Xiangping; Zhao, Chunliu; Shi, Feifei; Kang, Juan

    2015-06-01

    A novel zeolite-coated fiber sensors for detection of volatile organic compounds (VOCs) based on the Fabry-Perot interferometer was proposed and demonstrated. The sensor comprised a polycrystalline silicalite thin film grown up on the cleaved end face of a standard single-mode fiber. The inline Fabry-Perot cavity was composed by the end face of the single-mode fiber and the thin film. The sensor device operated by measuring the interference signal, which was a function of the amount of chemical vapor adsorption in its crystalline micro porous structure. Experimental results showed that the proposed VOC sensor worked well and the sensitivities were 2.78×10-3 dB/ppm when the concentration ranged from 350 ppm to 2100 ppm and 1.23×10-3 dB/ppm when the concentration ranged from 2100 ppm to 5250 ppm.

  4. Two-wavelength quadrature multipoint detection of partial discharge in power transformers using fiber Fabry-Perot acoustic sensors

    NASA Astrophysics Data System (ADS)

    Dong, Bo; Han, Ming; Wang, Anbo

    2012-06-01

    A reliable and low-cost two-wavelength quadrature interrogating method has been developed to demodulate optical signals from diaphragm-based Fabry-Perot interferometric fiber optic sensors for multipoint partial discharge detection in power transformers. Commercial available fused-silica parts (a wafer, a fiber ferrule, and a mating sleeve) and a cleaved optical single mode fiber were bonded together to form an extrinsic Fabry-Perot acoustic sensor. Two lasers with center wavelengths separated by a quarter of the period of sensor interference fringes were used to probe acousticwave- induced diaphragm vibration. A coarse wavelength-division multiplexing (CWDM) add/drop multiplexer was used to separate the reflected two wavelengths before two photo detectors. Optical couplers were used to distribute mixed laser light to each sensor-detector module for multiplexing purpose. Sensor structure, detection system design and experiment results are presented.

  5. Fabry-Perot interferometer utilized for displacement measurement in a large measuring range

    SciTech Connect

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-09-15

    The optical configuration of a Fabry-Perot interferometer is uncomplicated. This has already been applied in different measurement systems. For the displacement measurement with the Fabry-Perot interferometer, the result is significantly influenced by the tilt angles of the measurement mirror in the interferometer. Hence, only for the rather small measuring range, the Fabry-Perot interferometer is available. The goal of this investigation is to enhance the measuring range of Fabry-Perot interferometer by compensating the tilt angles. To verify the measuring characteristic of the self-developed Fabry-Perot interferometer, some comparison measurements with a reference standard have been performed. The maximum deviation of comparison experiments is less than 0.3 {mu}m in the traveling range of 30 mm. The experimental results show that the Fabry-Perot interferometer is highly stable, insensitive to environment effects, and can meet the measuring requirement of the submicrometer order.

  6. Fiber optic, Fabry-Perot high temperature sensor

    NASA Technical Reports Server (NTRS)

    James, K.; Quick, B.

    1984-01-01

    A digital, fiber optic temperature sensor using a variable Fabry-Perot cavity as the sensor element was analyzed, designed, fabricated, and tested. The fiber transmitted cavity reflection spectra is dispersed then converted from an optical signal to electrical information by a charged coupled device (CCD). A microprocessor-based color demodulation system converts the wavelength information to temperature. This general sensor concept not only utilizes an all-optical means of parameter sensing and transmitting, but also exploits microprocessor technology for automated control, calibration, and enhanced performance. The complete temperature sensor system was evaluated in the laboratory. Results show that the Fabry-Perot temperature sensor has good resolution (0.5% of full seale), high accuracy, and potential high temperature ( 1000 C) applications.

  7. Micromachined Tunable Fabry-Perot Filters for Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    Barclay, Richard; Bier, Alexander; Chen, Tina; DiCamillo, Barbara; Deming, Drake; Greenhouse, Matthew; Henry, Ross; Hewagama, Tilak; Jacobson, Mindy; Loughlin, James; Krebs, Carolyn A. (Technical Monitor)

    2002-01-01

    Micromachined Fabry-Perot tunable filters with a large clear aperture (12.5 to 40 mm) are being developed as an optical component for wide-field imaging 1:1 spectroscopy. This program applies silicon micromachining fabrication techniques to miniaturize Fabry-Perot filters for astronomical science instruments. The filter assembly consists of a stationary etalon plate mated to a plate in which the etalon is free to move along the optical axis on silicon springs attached to a stiff silicon support ring. The moving etalon is actuated electrostatically by electrode pairs on the fixed and moving etalons. To reduce mass, both etalons are fabricated by applying optical coatings to a thin freestanding silicon nitride film held flat in drumhead tension rather than to a thick optical substrate. The design, electro-mechanical modeling, fabrication, and initial results will be discussed. The potential application of the miniature Fabry-Perot filters will be briefly discussed with emphasis on the detection of extra-solar planets.

  8. Highly sensitive force sensor based on optical microfiber asymmetrical Fabry-Perot interferometer.

    PubMed

    Gong, Yuan; Yu, Cai-Bin; Wang, Ting-Ting; Liu, Xiu-Ping; Wu, Yu; Rao, Yun-Jiang; Zhang, Ming-Lei; Wu, Hui-Juan; Chen, Xiao-Xiao; Peng, Gang-Ding

    2014-02-10

    An asymmetrical Fabry-Perot interferometric (AFPI) force sensor is fabricated based on a narrowband reflection of low-reflectivity fiber Bragg grating (LR-FBG) and a broadband Fresnel reflection of the cleaved fiber end. The AFPI sensor includes a section of microfiber made by tapering and it achieves a force sensitivity of 0.221 pm/μN with a tapered microfiber of 40 mm length and 6.1 μm waist diameter. Compared with similar AFPI structure in 125 μm-diameter single mode fiber, the force sensitivity of the microfiber AFPI structure is greatly enhanced due to its smaller diameter and can be optimized for different force scales by controlling the diameter. The fabrication process of the AFPI sensor is simple and cost-effective. The AFPI sensor has better multiplexing capacity than conventional extrinsic fiber-optic Fabry-Perot sensors, while it also release the requirement on the wavelength matching of the FBG-pair-based FPI.

  9. Long-term stability testing of optical fibre Fabry-Perot temperature sensors

    NASA Astrophysics Data System (ADS)

    Polyzos, Dimitrios; Jinesh, Mathew; MacPherson, William N.; Maier, Robert R. J.

    2016-05-01

    Applications of fibre optic sensors at high temperatures have gained a huge interest recently, as they appeared to be suitable for temperature recording in harsh environments. In this paper, we are demonstrating two intrinsic Fabry-Perot (F-P) fibre optic sensors for high temperature monitoring. The sensors are consisting of a 125μm diameter single mode fibre (SMF28) and a 125μm diameter PCF ESM-12B pure fused silica fibre spliced to a SMF28, respectively. The result was a low finesse optical SMF-Cr-SMF, and SMF-Cr-PCF, sensor with cavity lengths varying from 50μm to 100μm. Both types of Fabry-Perot sensors were tested in a tube furnace over a temperature range from room temperature up to 1100°C. Following a number of annealing cycles, between the above mentioned temperatures range, very good repeatability of the phase response was achieved. During the cycling process, thermal stress relief takes place which makes the sensors suitable for temperature testing at temperatures just in excess of 1000°C. After initial cycling the sensors are subjected to long term stability tests. The phase response is stable, less than 4°C, over a period of 5 days at a temperature of 1050°C for both sensors. The temperature resolution is around 3°C.

  10. Highly sensitive force sensor based on optical microfiber asymmetrical Fabry-Perot interferometer.

    PubMed

    Gong, Yuan; Yu, Cai-Bin; Wang, Ting-Ting; Liu, Xiu-Ping; Wu, Yu; Rao, Yun-Jiang; Zhang, Ming-Lei; Wu, Hui-Juan; Chen, Xiao-Xiao; Peng, Gang-Ding

    2014-02-10

    An asymmetrical Fabry-Perot interferometric (AFPI) force sensor is fabricated based on a narrowband reflection of low-reflectivity fiber Bragg grating (LR-FBG) and a broadband Fresnel reflection of the cleaved fiber end. The AFPI sensor includes a section of microfiber made by tapering and it achieves a force sensitivity of 0.221 pm/μN with a tapered microfiber of 40 mm length and 6.1 μm waist diameter. Compared with similar AFPI structure in 125 μm-diameter single mode fiber, the force sensitivity of the microfiber AFPI structure is greatly enhanced due to its smaller diameter and can be optimized for different force scales by controlling the diameter. The fabrication process of the AFPI sensor is simple and cost-effective. The AFPI sensor has better multiplexing capacity than conventional extrinsic fiber-optic Fabry-Perot sensors, while it also release the requirement on the wavelength matching of the FBG-pair-based FPI. PMID:24663648

  11. Multi-wavelength fiber laser based on a fiber Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Estudillo-Ayala, J. M.; Jauregui-Vazquez, D.; Haus, J. W.; Perez-Maciel, M.; Sierra-Hernandez, J. M.; Avila-Garcia, M. S.; Rojas-Laguna, R.; Lopez-Dieguez, Y.; Hernandez-Garcia, J. C.

    2015-12-01

    In this work we report experimental studies of an erbium-doped fiber laser design that simultaneously emits up to three wavelengths. The laser cavity configuration has an all-fiber, Fabry-Perot interferometer, based on the insertion of air cavities in the fiber, near one end of a conventional single-mode fiber. The laser emissions have a side-mode suppression ratio over 25 dB, wavelength variations around 0.04 nm, and 2 dB power fluctuations. By using a simple, controlled fiber curvature technique cavity losses are varied over a section of convectional single-mode fiber and the laser output is switched between single-, dual-, and triple-wavelength emission. Moreover, by applying a refractive index change over the fiber filter the emission wavelengths are shifted. The fiber laser offers a compact, simple, and low-cost design for a multiple wavelength outputs that can be adopted in future applications.

  12. Multichannel Fabry-Perot spectrometer for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Jennings, Donald E.; Boyle, R. J.

    1986-01-01

    A multichannel design which makes use of the radiation normally rejected in a Fabry-Perot spectrometer is described, with application to infrared astronomy. The present optical design minimizes the diameters of the etalon and optics. The use of spherical mirrors ensures that no radiation is lost through the entrance aperture, and the beams can be completely collimated at the etalon. Laboratory studies demonstrate that the ability to employ eight channels increases by a factor of four the flux integrated during a given time period compared with that of a single-channel instrument. The spectrometer is nondispersive, and the source can be imaged at each of several output spectral positions.

  13. Holographic liquid crystal polarization grating with Fabry-Perot structure.

    PubMed

    Sakamoto, Moritsugu; Yamaguchi, Haruki; Noda, Kohei; Sasaki, Tomoyuki; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2016-03-15

    A holographic liquid crystal polarization grating with a Fabry-Perot structure was developed. Because of its resonant structure, the device offers high levels of control of the diffraction properties of incident-polarized light beams, depending on the resonance conditions. The diffracted light beams are emitted in both the reflection and transmission directions, and the device thus works as a multibranch polarization grating with double optical paths, unlike a conventional polarization grating. These device features were experimentally demonstrated and were also explained theoretically.

  14. Holographic liquid crystal polarization grating with Fabry-Perot structure.

    PubMed

    Sakamoto, Moritsugu; Yamaguchi, Haruki; Noda, Kohei; Sasaki, Tomoyuki; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2016-03-15

    A holographic liquid crystal polarization grating with a Fabry-Perot structure was developed. Because of its resonant structure, the device offers high levels of control of the diffraction properties of incident-polarized light beams, depending on the resonance conditions. The diffracted light beams are emitted in both the reflection and transmission directions, and the device thus works as a multibranch polarization grating with double optical paths, unlike a conventional polarization grating. These device features were experimentally demonstrated and were also explained theoretically. PMID:26977643

  15. Formation of Fabry-Perot resonances in double-barrier chaotic billiards

    NASA Astrophysics Data System (ADS)

    Macêdo, A. M.; Souza, Andre M.

    2005-06-01

    We study wave transport through a chaotic quantum billiard attached to two waveguides via barriers of arbitrary transparencies in the semiclassical limit of a large number of open scattering channels. We focus attention on the ergodic regime, which is described by using a random-matrix approach to chaotic resonance scattering together with an extended version of Nazarov’s circuit theory. By varying the relative strength of the barriers’ transparencies a reorganization of the relevant resonances in the energy interval where transport takes place leads to a full suppression of high transmission modes. We provide a detailed quantitative description of the process by means of both numerical and analytical evaluations of the average density of transmission eigenvalues. We show that the density of Fabry-Perot modes can be used as a kind of order parameter for this quantum transition. A diagram is presented as a function of the transparencies of the barriers exhibiting the transport regimes and the transition lines.

  16. High-resolution multi-heterodyne spectroscopy based on Fabry-Perot quantum cascade lasers

    SciTech Connect

    Wang, Yin; Wang, Wen; Wysocki, Gerard; Soskind, Michael G.

    2014-01-20

    In this Letter, we present a method of performing broadband mid-infrared spectroscopy with conventional, free-running, continuous wave Fabry-Perot quantum cascade lasers (FP-QCLs). The measurement method is based on multi-heterodyne down-conversion of optical signals. The sample transmission spectrum probed by one multi-mode FP-QCL is down-converted to the radio-frequency domain through an optical multi-heterodyne process using a second FP-QCL as the local oscillator. Both a broadband multi-mode spectral measurement as well as high-resolution (∼15 MHz) spectroscopy of molecular absorption are demonstrated and show great potential for development of high performance FP-laser-based spectrometers for chemical sensing.

  17. Dual-band Fabry-Perot lasing from single ZnO microbelt

    NASA Astrophysics Data System (ADS)

    Zhu, Qiuxiang; Qin, Feifei; Lu, Junfeng; Zhu, Zhu; Shi, Zengliang; Xu, Chunxiang

    2016-10-01

    Dual-band semiconductor microbelt lasing are promising for multifunctional applications ranging from optical communication to spectroscopy analysis. Here, we demonstrated a dual-band Fabry-Perot (F-P) lasing from both length and width directions in a single ZnO microbelt. The lasing performance, spectral variation and mode structure significantly depended on the cavity size, which corresponded to the length and width of the ZnO microbelts. The resonant process and mechanism were investigated systematically through the experimental analysis and numerically FDTD simulation. The results of the dual-band F-P lasing modes and wide lasing wavelength are helpful to design the dual-wavelength electronic and optoelectronic devices.

  18. In-line fiber-optic Fabry-Perot refractive-index tip sensors

    NASA Astrophysics Data System (ADS)

    Rao, Yun-Jiang

    2008-10-01

    We propose and demonstrate two novel in-line fiber-optic tip sensors for practical refractive-index (RI) measurement, which are based on an intrinsic Fabry-Perot interferometer (IFPI) formed by a section of conventional single-mode fiber or endlessly single-mode photonic crystal fiber (EPCF), respectively. Such an IFPI sensor has the advantages of easy fabrication, low joint and transmission losses, low-cost and good fringe visibility. Simultaneous measurement of RI and temperature can be realized by determination of the cavity length change and the fringe visibility of such an IFPI, respectively. In addition, it is found that the fringe visibility of the IFPI is insensitive to temperature change, providing a practical way to measure refractive index with self temperature compensation and offers a refractive-index resolution of ~10-5 in its linear operating range. The experimental data agree well with the theoretical results.

  19. Hydrocarbon gas detection with microelectromechanical Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Mannila, Rami; Tuohiniemi, Mikko; Mäkynen, Jussi; Näkki, Ismo; Antila, Jarkko

    2013-05-01

    VTT Technical Research Centre of Finland has developed microelectromechanical (MEMS) Fabry-Perot interferometer (FPI) for hydrocarbon measurements. Fabry-Perot interferometer is a structure where is two highly reflective surfaces separated by a tunable air gap. The MEMS FPI is a monolithic device, i.e. it is made entirely on one substrate in a batch process, without assembling separate pieces together. The gap is adjusted by moving the upper mirror with electrostatic force, so there are no actual moving parts. The manufactured MEMS FPIs have been characterized. The tuning wavelength range of the MEMS FPI is 2.8-3.5 μm and its spectral resolution is 50-60 nm. VTT has designed and manufactured a handheld size demonstrator device based on the technology presented in this abstract. This device demonstrates gas detecting by measuring cigarette lighter gas and various plastic materials transmission spectra. The demonstrator contains light source, gas cell, MEMS FPI, detector and control electronics. It is connected to a laptop by USB connection, additional power supply or connection is not needed.

  20. Atmospheric spectra from a multiplex Fabry-Perot interferometer

    SciTech Connect

    Snell, H.E.; Cook, W.B.; Hays, P.B.

    1994-12-31

    Remote sensing of major and minor constituents in the earth`s atmosphere is of great importance to the study of climate and global change. Because much of remote sensing involves placing instrumentation in environments that are not easily accessible, such as balloons, spacecraft, or remote field stations, it is usually necessary that the instrumentation be compact, lightweight, and rugged. This paper describes the development of a new type of remote sensing instrument the authors have chosen to call the Multiplex Fabry-Perot Interferometer (MFPI). They will present atmospheric spectra obtained with the working prototype instrument. The MFPI is a Fabry-Perot interferometer for which the etalon plate separation is changed over a large optical distance during a measurement. When the resulting interferogram is Fourier transformed the multiple reflections within the etalon cavity produce a spectrum analogous to that which would be produced by an array of Michelson interferometers. However, for high spectral resolution measurements the scan distance required by the MFPI is much less than for the comparable Michelson. The MFPI will be ideal for remote sensing applications where weight, size, and mechanical reliability are primary considerations.

  1. The IRAF Fabry-Perot analysis package: Ring fitting

    NASA Technical Reports Server (NTRS)

    Shopbell, P. L.; Bland-Hawthorn, J.; Cecil, G.

    1992-01-01

    As introduced at ADASSI, a Fabry-Perot analysis package for IRAF is currently under development as a joint effort of ourselves and Frank Valdes of the IRAF group. Although additional portions of the package were also implemented, we report primarily on the development of a robust ring fitting task, useful for fitting the calibration rings obtained in Fabry-Perot observations. The general equation of an ellipse is fit to the shape of the rings, providing information on ring center, ellipticity, and position angle. Such parameters provide valuable information on the wavelength response of the etalon and the geometric stability of the system. Appropriate statistical weighting is applied to the pixels to account for increasing numbers with radius, the Lorentzian cross-section, and uneven illumination. The major problems of incomplete, non-uniform, and multiple rings are addressed with the final task capable of fitting rings regardless of center, cross-section, or completion. The task requires only minimal user intervention, allowing large numbers of rings to be fit in an extremely automated manner.

  2. Fiber Bragg grating Fabry-Perot cavity sensor based on pulse laser demodulation technique

    NASA Astrophysics Data System (ADS)

    Gao, Fangfang; Chen, Jianfeng; Liu, Yunqi; Wang, Tingyun

    2011-12-01

    We demonstrate a fiber laser sensing technique based on fiber Bragg grating Fabry-Perot (FBG-FP) cavity interrogated by pulsed laser, where short pulses generated from active mode-locked erbium-doped fiber ring laser and current modulated DFB laser are adopted. The modulated laser pulses launched into the FBG-FP cavity produce a group of reflected pulses. The optical loss in the cavity can be determined from the power ratio of the first two pulses reflected from the cavity. This technique does not require high reflectivity FBGs and is immune to the power fluctuation of the light source. Two short pulse laser sources were compared experimentally with each other on pulse width, pulse stability, pulse chirp and sensing efficiency.

  3. Enhancement of Rayleigh scattering in a two-dimensional Fabry-Perot resonator loaded with impurities.

    PubMed

    Sadreev, Almas F

    2016-07-01

    We study wave transmission through a Fabry-Perot resonator (FPR) loaded with point-like impurities. We show both analytically in the framework of the coupled mode theory and numerically that there are two different regimes for transmission dependent on the quality of the FPR mirrors. For low quality, we obtain transmittance very similar to the clean FPR with slightly shifted Lorentz peaks. However, for good quality, the transmittance peaks are strongly reduced and substituted with Gaussian peaks because of multiple scattering of waves by each impurity. As a side effect, we observe the angular (channel) conversion in the disordered FPR. We demonstrate that the resonant peaks are dependent on the concentration of impurities to pave a way for resonant measurement of the concentration.

  4. Graphene-based electromagnetically induced transparency with coupling Fabry-Perot resonators.

    PubMed

    Zhuang, Huawei; Kong, Fanmin; Li, Kang; Sheng, Shiwei

    2015-08-20

    We investigate the plasmonic analog of electromagnetically induced transparency (EIT) using two adjacent graphene-based Fabry-Perot (F-P) resonators side coupling to a nanoribbon waveguide. By the coupling mode theory in time and F-P resonant model, the destructive interference from the coupling of the two F-P resonators results in the EIT-like optical response. The induced peak and width of the transparency window can be dynamically manipulated by varying the coupling distance of the two resonators, and the transparent window is easily shifted by tuning the resonator length or the chemical potential of the graphene nanoribbon. In order to verify the characteristics of slow light, the group index profile is analyzed at different coupling distances. The proposed graphene-based EIT-like system could open up new opportunities for potential applications in plasmonic slow light and optical information buffering devices.

  5. Diaphragm-free fiber-optic Fabry-Perot interferometer based on tapered hollow silica tube

    NASA Astrophysics Data System (ADS)

    Fang, Guocheng; Jia, Pinggang; Liang, Ting; Tan, Qiulin; Hong, Yingping; Liu, Wenyi; Xiong, Jijun

    2016-07-01

    A miniature fiber-optic Fabry-Perot interferometer fabricated by splicing a diaphragm-free hollow silica tube to a single-mode fiber and fusing the inner core to a taper is presented. The tapered zone forces lights to propagate from the fiber core into the silica tube, and the lights is reflected from the end faces of the optical fiber and the hollow silica tube. The contrast ratio of the interference fringe is determined by the minimum inner diameter of hollow silica tube. The responses of the proposed interferometer to high-temperature, gas refractive index, liquid refractive index and pressure were measured and were found to be linear with sensitivities of 16.26 pm/°C, 610.47 nm/RIU, -122.36 dB/RIU and 1.56 pm/kPa, respectively.

  6. An optimized strain demodulation method for PZT driven fiber Fabry-Perot tunable filter

    NASA Astrophysics Data System (ADS)

    Sheng, Wenjuan; Peng, G. D.; Liu, Yang; Yang, Ning

    2015-08-01

    An optimized strain-demodulation-method based on piezo-electrical transducer (PZT) driven fiber Fabry-Perot (FFP) filter is proposed and experimentally demonstrated. Using a parallel processing mode to drive the PZT continuously, the hysteresis effect is eliminated, and the system demodulation rate is increased. Furthermore, an AC-DC compensation method is developed to address the intrinsic nonlinear relationship between the displacement and voltage of PZT. The experimental results show that the actual demodulation rate is improved from 15 Hz to 30 Hz, the random error of the strain measurement is decreased by 95%, and the deviation between the test values after compensation and the theoretical values is less than 1 pm/με.

  7. A simple Fabry-Perot pressure sensor fabricated on fiber optic tip

    NASA Astrophysics Data System (ADS)

    Di Palma, Pasquale; Natale, Daniele; Campopiano, Stefania; Iadicicco, Agostino

    2016-05-01

    In this work, we demonstrate an extrinsic pressure sensor realized on single mode fiber tip by means of simple fabrication steps and with low-cost instrumentations. The sensing element consists in a Fabry-Perot cavity: one reflecting surface is the end of the optical fiber, precisely cut, and the other one is a metallic diaphragm. Under the action of the external pressure, the metallic diaphragm bends changing the optical cavity length and, consequently, the characteristics of the reflected signal. The holder structure, which allows the alignment of the fiber tip and reflecting diaphragm, consists in a commercial zirconia ferule with external diameter of Dex = 2.5 mm. Despite its simplicity and cost-effectiveness, the achieved results show performance comparable to more complex and expensive configurations. By using an aluminum plate as reflecting diaphragm. sensitivity ranging in the 70-130pm/mmHg is experimentally.

  8. Fabry-Perot cavity based on silica tube for strain sensing at high temperatures.

    PubMed

    Ferreira, Marta S; Roriz, Paulo; Bierlich, Jörg; Kobelke, Jens; Wondraczek, Katrin; Aichele, Claudia; Schuster, Kay; Santos, José L; Frazão, Orlando

    2015-06-15

    In this work, a Fabry-Perot cavity based on a new silica tube design is proposed. The tube presents a cladding with a thickness of ~14 μm and a hollow core. The presence of four small rods, of ~20 μm diameter each, placed in diametrically opposite positions ensure the mechanical stability of the tube. The cavity, formed by splicing a section of the silica tube between two sections of single mode fiber, is characterized in strain and temperature (from room temperature to 900 °C). When the sensor is exposed to high temperatures, there is a change in the response to strain. The influence of the thermal annealing is investigated in order to improve the sensing head performance. PMID:26193580

  9. Versatile fiber-coupled system for simultaneous photon correlation spectroscopy and Fabry-Perot interferometry

    SciTech Connect

    Bogoslovov, R.B.; Shelton, D.P.; Selser, J.C.; Piet, G.; Peng, S.

    2004-10-01

    We demonstrate an experimental setup utilizing fiber-optic detection and coupling of scattered light into existing photon correlation spectroscopy (PCS) and Fabry-Perot (F-P) interferometry systems. The performance of the fiber coupled F-P as a high-resolution interferometer is considered in detail. Several practical issues and limitations are discussed, including the selection of optic and fiber-optic components, collimation, effects of the fiber mode structure and core diameter, and alignment issues. A series of test measurements on standard systems with well known properties shows that the proposed fiber-optic design meets the performance expectations for both PCS and F-P instruments and presents an attractive alternative to the classical pinhole design.

  10. Fiber Fabry-Perot tip sensor based on multimode photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Wu, Di; Huang, Yu; Fu, Jian-Yu; Wang, Guo-Yin

    2015-03-01

    We propose a novel Fabry-Perot interferometer (FPI) sensor for simultaneous measurement of refractive index (RI) and temperature based on Fresnel reflection and the thermo-optic effect of silica. The sensor head consists of a short section of multimode photonic crystal fiber (MPCF) and a conventional single mode fiber (SMF), where two thin films are formed by collapsing the air holes of MPCF with a commercialized fusion splicer. Experimental results show that such a device has a linear RI sensitivity of ~21.52 dB/RIU (RI unit) and a linear optical path difference (OPD) temperature sensitivity of ~25 nm/°C. In addition, a high RI resolution of about ~1.7×10-5 is obtained by using the Fourier transformation to decompose the spectral response in different spatial frequencies. Low-cost, easy fabrication and high resolution make it appropriate for practical applications.

  11. A miniature fiber-optic temperature sensor based on a Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Rong, Qiangzhou; Sun, Hao; Qiao, Xueguang; Zhang, Jing; Hu, Manli; Feng, Zhongyao

    2012-04-01

    A miniature fiber Fabry-Perot interferometer (FFPI) for temperature measurement is proposed and demonstrated. The sensor consists of a section of single-mode fiber (SMF) tip coated with a thin film of polyvinyl alcohol (PVA) at the end of the fiber tip. A well-defined interference pattern is obtained as the result of the FFPI based on Fresnel reflection. The sensing head is extremely sensitive to ambient temperature, and provides a stable temperature sensitivity with a maximum value up to 173.5 pm °C-1 above 80 °C. This proposed sensor has advantages of low cost, ultra-compactness, a small degree of hysteresis and high stability.

  12. Continuous-Wave Single-Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking Using Feedback from a Fiber Bragg Grating

    NASA Technical Reports Server (NTRS)

    Duerksen, Gary L.; Krainak, Michael A.

    1998-01-01

    Single-frequency operation of uncoated Fabry-Perot laser diodes is demonstrated by phase- locking the laser oscillations through self-injection seeding with feedback from a fiber Bragg grating. By precisely tuning the laser temperature so that an axial-mode coincides with the short-wavelength band edge of the grating, the phase of the feedback is made conjugate to that of the axial mode, locking the phase of the laser oscillations to that mode.

  13. The VELOPT code for estimating performance of a Fabry-Perot velocimeter

    SciTech Connect

    Goosman, D.R.

    1992-04-09

    The VELOPT code calculates an estimate of the performance of a Fabry- Perot (FP) velocimeter. The code is a macro-driven, Symphony spreadsheet written for an IBM PC. VELOPT is designed to be used in conjunction with the POWER codes, which estimate the amount of light entering a collection fiber and the ratio of collected light to light leaving the laser fiber. In this model a velocimeter system, single- frequency laser output illuminates a moving test surface through a lens. Reflected light from the test surface is concentrated by a lens into an optical collection fiber. The collected light is presented to a mode scrambler, a cylinder lens, a filter, and then to a striped Fabry-Perot interferometer (FPI). Light leaving the FPI is imaged via spherical lenses and one mirror onto the slit of an electronic streak camera. The image is intensified within the camera, and then is recorded on film. VELOPT takes 47 user inputs that describe the FP velocimeter system. The primary outputs from the code include the following estimates for each of the first four fringes: Energy per unit area reaching the film; optical density expected on both Polaroid 667 and TMAX3200 films; velocity and time resolution; and statistical smoothness of the streak records. Twenty-six other secondary output quantities for each fringe are also calculated. The finesse limitation due to the finite size of the mirrors is calculated in detail by the routine WALKOFF, which is internal to VELOPT. An estimate of the reduction in effective fill time of the FPI due to the finite spatial resolution of the streak camera is also calculated by VELPOPT.

  14. Influence of cavity loss on an extrinsic Fabry-Perot cavity intensity-based pressure sensor

    NASA Astrophysics Data System (ADS)

    Lż, Tao

    2015-09-01

    We present an extrinsic Fabry-Perot cavity intensity-based pressure sensor that mainly comprises a single-mode fiber end and an elastic monocrystalline silicon layer bonded to a silicon diaphragm. We investigated the influence of cavity loss on the performance indexes (PIS) of the intensity-based extrinsic Fabry-Perot cavity optical fiber pressure sensor. A buffer unit made of three incompressible oil cavities attenuated outside pressure and transformed pressure information into cavity length microchange information. Experimental results indicated that, under center quadrature-points within the linear regions of adjacent fringes, for an applied 40 kPa external pressure, cavity length was modulated by pressures of 69.9 kPa-109.9 kPa, 150.1 kPa-190 kPa, 220.1 kPa-259.9 kPa, and 279.9 kPa-319.9 kPa, output intensity ranges increased as 1 μW, 1.02 μW, 1.03 μW, and 1.05 μW, sensitivity increased as 0.01909 μW/kPa, 0.01986 μW/kPa, 0.02127 μW/kPa, and 0.02387 μW/kPa, but linearity degraded, as indicated by the standard deviation of linear fits of 0.02607, 0.02664, 0.02935, and 0.04879 due to cavity loss. Furthermore, the pressure ranges within the same quarter period decreased as 40 kPa, 37.45 kPa, 32.4 kPa, and 30.15 kPa. Consequently, the same lengths of linear regions within adjacent fringes of an approximately sinusoidal curve corresponded to different measurement ranges, linearities, and sensitivities. Initial cavity length must be chosen to optimize both signal strength and the PIS studied here in manufacturing this type sensor.

  15. Influence of cavity loss on an extrinsic Fabry-Perot cavity intensity-based pressure sensor.

    PubMed

    Lű, Tao

    2015-09-01

    We present an extrinsic Fabry-Perot cavity intensity-based pressure sensor that mainly comprises a single-mode fiber end and an elastic monocrystalline silicon layer bonded to a silicon diaphragm. We investigated the influence of cavity loss on the performance indexes (PIS) of the intensity-based extrinsic Fabry-Perot cavity optical fiber pressure sensor. A buffer unit made of three incompressible oil cavities attenuated outside pressure and transformed pressure information into cavity length microchange information. Experimental results indicated that, under center quadrature-points within the linear regions of adjacent fringes, for an applied 40 kPa external pressure, cavity length was modulated by pressures of 69.9 kPa-109.9 kPa, 150.1 kPa-190 kPa, 220.1 kPa-259.9 kPa, and 279.9 kPa-319.9 kPa, output intensity ranges increased as 1 μW, 1.02 μW, 1.03 μW, and 1.05 μW, sensitivity increased as 0.01909 μW/kPa, 0.01986 μW/kPa, 0.02127 μW/kPa, and 0.02387 μW/kPa, but linearity degraded, as indicated by the standard deviation of linear fits of 0.02607, 0.02664, 0.02935, and 0.04879 due to cavity loss. Furthermore, the pressure ranges within the same quarter period decreased as 40 kPa, 37.45 kPa, 32.4 kPa, and 30.15 kPa. Consequently, the same lengths of linear regions within adjacent fringes of an approximately sinusoidal curve corresponded to different measurement ranges, linearities, and sensitivities. Initial cavity length must be chosen to optimize both signal strength and the PIS studied here in manufacturing this type sensor.

  16. Influence of cavity loss on an extrinsic Fabry-Perot cavity intensity-based pressure sensor.

    PubMed

    Lű, Tao

    2015-09-01

    We present an extrinsic Fabry-Perot cavity intensity-based pressure sensor that mainly comprises a single-mode fiber end and an elastic monocrystalline silicon layer bonded to a silicon diaphragm. We investigated the influence of cavity loss on the performance indexes (PIS) of the intensity-based extrinsic Fabry-Perot cavity optical fiber pressure sensor. A buffer unit made of three incompressible oil cavities attenuated outside pressure and transformed pressure information into cavity length microchange information. Experimental results indicated that, under center quadrature-points within the linear regions of adjacent fringes, for an applied 40 kPa external pressure, cavity length was modulated by pressures of 69.9 kPa-109.9 kPa, 150.1 kPa-190 kPa, 220.1 kPa-259.9 kPa, and 279.9 kPa-319.9 kPa, output intensity ranges increased as 1 μW, 1.02 μW, 1.03 μW, and 1.05 μW, sensitivity increased as 0.01909 μW/kPa, 0.01986 μW/kPa, 0.02127 μW/kPa, and 0.02387 μW/kPa, but linearity degraded, as indicated by the standard deviation of linear fits of 0.02607, 0.02664, 0.02935, and 0.04879 due to cavity loss. Furthermore, the pressure ranges within the same quarter period decreased as 40 kPa, 37.45 kPa, 32.4 kPa, and 30.15 kPa. Consequently, the same lengths of linear regions within adjacent fringes of an approximately sinusoidal curve corresponded to different measurement ranges, linearities, and sensitivities. Initial cavity length must be chosen to optimize both signal strength and the PIS studied here in manufacturing this type sensor. PMID:26429470

  17. A novel Michelson Fabry-Perot hybrid interference sensor based on the micro-structured fiber

    NASA Astrophysics Data System (ADS)

    Zhang, Yaxun; Zhang, Yu; Wang, Zhenzhen; Liu, Zhihai; Wei, Yong; Zhao, Enming; Yang, Xinghua; Zhang, Jianzhong; Yang, Jun; Yuan, Libo

    2016-09-01

    We propose and demonstrate a novel Michelson Fabry-Perot hybrid fiber interference sensor. By integrating a Michelson interferometer in a two-core fiber and a Fabry-Perot interferometer in a micro silica-capillary, we produce the Michelson Fabry-Perot hybrid interference sensor. Owing to the structure characteristic of the micro-structured fiber, this hybrid fiber interference sensor can achieve the measurement of the axial strain and radial bending simultaneously. The measurement sensitivity of the axial train is 0.015 nm/με and the measurement sensitivity of the radial bending is 1.393 nm/m-1.

  18. Focused ion beam post-processing of optical fiber Fabry-Perot cavities for sensing applications.

    PubMed

    André, Ricardo M; Pevec, Simon; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Marques, Manuel B; Donlagic, Denis; Bartelt, Hartmut; Frazão, Orlando

    2014-06-01

    Focused ion beam technology is combined with chemical etching of specifically designed fibers to create Fabry-Perot interferometers. Hydrofluoric acid is used to etch special fibers and create microwires with diameters of 15 μm. These microwires are then milled with a focused ion beam to create two different structures: an indented Fabry-Perot structure and a cantilever Fabry-Perot structure that are characterized in terms of temperature. The cantilever structure is also sensitive to vibrations and is capable of measuring frequencies in the range 1 Hz - 40 kHz.

  19. A switchable dual-wavelength fiber laser based on asymmetric fiber Bragg grating Fabry-Perot cavity with a SESAM

    NASA Astrophysics Data System (ADS)

    Huang, Kaiqiang; Li, Qi; Chen, Haiyan

    2016-04-01

    A switchable dual-wavelength fiber laser with an asymmetric fiber Bragg grating (FBG)-Fabry-Perot (FP) cavity based a semiconductor saturable absorber mirror (SESAM) is proposed and experimentally demonstrated. The proof of concept device consists of a FGB laser with an asymmetric FBG-FP cavity, a SESAM as mode loss modulator, and a intracavity FBG as wavelength selector by changing its operation temperature. The results demonstrate the new concept of dual-wavelength fiber laser based SESAM with asymmetric FBG-FP cavity and the technical feasibility.

  20. Micro Extrinsic Fiber-Optic Fabry-Perot Interferometric Sensor Based on Erbium- and Boron-Doped Fibers

    NASA Astrophysics Data System (ADS)

    Rao, Yun-Jiang; Xu, Bing; Ran, Zeng-Ling; Gong, Yuan

    2010-02-01

    Micro extrinsic Fabry-Perot interferometers (MEFPIs), with cavity lengths of up to ~ 9 μm and maximum fringe contrast of ~ 19 dB, are fabricated by chemically etching Er- and B-doped optical fibers and then splicing the etched fiber to a single-mode fiber, for the first time to the best of our knowledge. The strain and temperature responses of the MEFPI sensors are investigated experimentally. Good linearity and high sensitivity are achieved. Such a type of MEFPI sensor is cost-effective and suitable for mass production, indicating its great potential for a wide range of applications.

  1. Highly sensitive curvature and displacement sensing setup based on an all fiber micro Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Jauregui-Vazquez, D.; Estudillo-Ayala, J. M.; Castillo-Guzman, A.; Rojas-Laguna, R.; Selvas-Aguilar, R.; Vargas-Rodriguez, E.; Sierra-Hernandez, J. M.; Guzman-Ramos, V.; Flores-Balderas, A.

    2013-11-01

    A highly sensitive curvature and displacement sensing arrangement based on an all optical fiber micro Fabry-Perot Interferometer (MFPI) is presented. Here, the MFPI spectral fringes contrast is decreased due to curvature effects occurring within a segment of single mode fiber (SMF). Therefore by detecting optical power variations, at certain wavelengths, it was possible to determine curvature and displacement changes. For this setup the achieved curvature sensitivity was 0.3 dB/m-1 and the curvature resolution was 31.5×10-3 m-1. Finally some experimental results are provided to support the viability of this low cost sensing arrangement.

  2. Intrinsic Fabry-Perot optical fiber sensors and their multiplexing

    DOEpatents

    Wang, Anbo

    2007-12-11

    An intrinsic Fabry-Perot optical sensor includes a thin film sandwiched between two fiber ends. When light is launched into the fiber, two reflections are generated at the two fiber/thin film interfaces due to a difference in refractive indices between the fibers and the film, giving rise to the sensor output. In another embodiment, a portion of the cladding of a fiber is removed, creating two parallel surfaces. Part of the evanescent fields of light propagating in the fiber is reflected at each of the surfaces, giving rise to the sensor output. In a third embodiment, the refractive index of a small portion of a fiber is changed through exposure to a laser beam or other radiation. Interference between reflections at the ends of the small portion give rise to the sensor output. Multiple sensors along a single fiber are multiplexed using an optical time domain reflectometry method.

  3. Photoacoustic imaging using an 8-beam Fabry-Perot scanner

    NASA Astrophysics Data System (ADS)

    Huynh, Nam; Ogunlade, Olumide; Zhang, Edward; Cox, Ben; Beard, Paul

    2016-03-01

    The planar Fabry Perot (FP) photoacoustic scanner has been shown to provide exquisite high resolution 3D images of soft tissue structures in vivo to depths up to approximately 10mm. However a significant limitation of current embodiments of the concept is low image acquisition speed. To increase acquisition speed, a novel multi-beam scanner architecture has been developed. This enables a line of equally spaced 8 interrogation beams to be scanned simultaneously across the FP sensor and the photoacoustic signals detected in parallel. In addition, an excitation laser operating at 200Hz was used. The combination of parallelising the detection and the high pulse repetition frequency (PRF) of the excitation laser has enabled dramatic reductions in image acquisition time to be achieved. A 3D image can now be acquired in 10 seconds and 2D images at video rates are now possible.

  4. Fourier transform spectrometer based on Fabry-Perot interferometer.

    PubMed

    Al-Saeed, Tarek A; Khalil, Diaa A

    2016-07-10

    We analyze the Fourier transform spectrometer based on a symmetric/asymmetric Fabry-Perot interferometer. In this spectrometer, the interferogram is obtained by recording the intensity as a function of the interferometer length. Then, we recover the spectrum by applying the discrete Fourier transform (DFT) directly on the interferogram. This technique results in spectral harmonic overlap and fictitious wavenumber components outside the original spectral range. For this purpose, in this work, we propose a second method to recover the spectrum. This method is based on expanding the DFT of the interferogram and the spectrum by a Haar or box function. By this second method, we recovered the spectrum and got rid of the fictitious spectral components and spectral harmonic overlap.

  5. Analysis and design of tunable fiber Fabry-Perot filter

    NASA Astrophysics Data System (ADS)

    Qi, Haibing; Yu, Yonglin

    2008-12-01

    The effective reflectivity of planar tunable filter fiber Fabry-Perot (TF-FFP) caused by coupling losses would led to the change of tuning range and the full width half maximum (FWHM) in the process of gap distance tuning. The general transfer function expression of FFP is developed by Gaussian beams model and coupling losses. A method that is by appropriate unsymmetrical reflectivity of fiber end can increase the tuning range and reduce the FWHM is proposed, the obtained parameters may be useful for the analysis and design of other TF-FFP. At last the initial gap position and reflectivities of both ends of TF-FFP are designed theoretically for C-band and C+L-band respectively.

  6. HTS Fabry-Perot resonators for the far infrared

    NASA Astrophysics Data System (ADS)

    Keller, Philipp; Prenninger, Martin; Pechen, Evgeny V.; Renk, Karl F.

    1996-06-01

    We report on far infrared (FIR) Fabry-Perot resonators (FPR) with high temperature superconductor (HTS) thin films as mirrors. For the fabrication of FPR we use two parallel MgO plates covered with YBa2Cu3O7-delta thin films on adjacent sides. We have measured the far-infrared transmissivity at 10 K with a Fourier transform infrared spectrometer. Very sharp resonances can be observed for frequencies below 6 THz where the MgO is transparent. The finesse (width of the first order resonance) is comparable to the FPR with metallic meshes as reflectors that are applied in the FIR spectroscopy and astronomy. We have also shown that thin films of gold are not adequate substitute to HTS thin films and not suitable for the fabrication of high-quality FPR due to the ohmic losses.

  7. Fabry-Perot observations of Comet Halley H2O(+)

    NASA Astrophysics Data System (ADS)

    Scherb, F.; Magee-Sauer, K.; Roesler, F. L.; Harlander, J.

    1990-07-01

    Fabry-Perot scanning spectrometer observations of Comet Halley's H2O(+) emissions have yielded 6158.64 and 6158.85 A spin doublet data at distances in the range of 0 to 2 million km from the comet heat in the antisunward direction. Cometary plasma outflow velocities were ascertained on the basis of the emissions' Doppler shifts, yielding results that were mostly but not exclusively consistent with the plasma's constant antisunward acceleration; the acceleration varied from night to night of observations over a 30-300 cm/sec range. The unusual plasma kinematics of December 14-15, 1985, and January 10, 1986, may be associated with the tail-disconnection activity observed by others.

  8. Micromachined fiber optic Fabry-Perot underwater acoustic probe

    NASA Astrophysics Data System (ADS)

    Wang, Fuyin; Shao, Zhengzheng; Hu, Zhengliang; Luo, Hong; Xie, Jiehui; Hu, Yongming

    2014-08-01

    One of the most important branches in the development trend of the traditional fiber optic physical sensor is the miniaturization of sensor structure. Miniature fiber optic sensor can realize point measurement, and then to develop sensor networks to achieve quasi-distributed or distributed sensing as well as line measurement to area monitoring, which will greatly extend the application area of fiber optic sensors. The development of MEMS technology brings a light path to address the problems brought by the procedure of sensor miniaturization. Sensors manufactured by MEMS technology possess the advantages of small volume, light weight, easy fabricated and low cost. In this paper, a fiber optic extrinsic Fabry-Perot interferometric underwater acoustic probe utilizing micromachined diaphragm collaborated with fiber optic technology and MEMS technology has been designed and implemented to actualize underwater acoustic sensing. Diaphragm with central embossment, where the embossment is used to anti-hydrostatic pressure which would largely deflect the diaphragm that induce interferometric fringe fading, has been made by double-sided etching of silicon on insulator. By bonding the acoustic-sensitive diaphragm as well as a cleaved fiber end in ferrule with an outer sleeve, an extrinsic Fabry-Perot interferometer has been constructed. The sensor has been interrogated by quadrature-point control method and tested in field-stable acoustic standing wave tube. Results have been shown that the recovered signal detected by the sensor coincided well with the corresponding transmitted signal and the sensitivity response was flat in frequency range from 10 Hz to 2kHz with the value about -154.6 dB re. 1/μPa. It has been manifest that the designed sensor could be used as an underwater acoustic probe.

  9. A high-finesse fiber optic Fabry-Perot interferometer based magnetic-field sensor

    NASA Astrophysics Data System (ADS)

    Chen, Feifei; Jiang, Yi; Gao, Hongchun; Jiang, Lan

    2015-08-01

    A high-finesse extrinsic Fabry-Perot interferometric sensor for the measurement of weak dc magnetic fields is demonstrated. The Fabry-Perot cavity is formed by aligning the fiber end-face and the TbDyFe rod end-face, and each end-face is coated by a mirror with a micro-lens. The length of the TbDyFe rod is changed by the variation of an applied dc magnetic field, leading a change of the Fabry-Perot cavity length. By interrogating the white-light interferometric spectrum, the wavelength of the resonant peak is tracked and the length of the Fabry-Perot cavity is obtained. The sensor exhibits a high sensitivity of 1510 nm/mT with a magnetic resolution of 25 nT.

  10. Uses of Fabry-Perot velocimeters in studies of high explosives detonation

    SciTech Connect

    Breithaupt, R.D.; Tarver, C.M.

    1990-08-27

    The Fabry Perot has become an important and valuable tool by which explosive performance information can be obtained relatively easily and inexpensively. Principle uses of the Fabry Perot have been free surface, and particle velocity measurements in one dimensional studies of explosive performance. In the cylinder test, it has been very useful to resolve early wall motions. We have refined methods of characterizing new explosives i.e. equation of state, C-J pressure, via the cylinder shot, flat plate, and particle velocity techniques. All of these use Fabry Perot as one of the principle diagnostics. Each of these experimental techniques are discussed briefly and some of the results obtained. Modeling developed to fit Fabry-Perot results are described along with future testing.

  11. Demonstrations Using a Fabry-Perot. I. Multiple-Slit Interference

    ERIC Educational Resources Information Center

    Roychoudhuri, Chandrasekhar

    1975-01-01

    Describes a demonstration technique for showing multiple-slit interference patterns with the use of a Fabry-Perot etalon and a laser beam. A simple derivation of the analytical expression for such fringes is presented. (Author/CP)

  12. Method and apparatus for a Fabry-Perot multiple beam fringe sensor

    NASA Technical Reports Server (NTRS)

    James, Kenneth A. (Inventor); Quick, William H. (Inventor); Strahan, Virgil H. (Inventor)

    1986-01-01

    A method and, in one embodiment of the invention, the resulting apparatus for implementing a unique multiple beam fringe sensor that is adapted to be interfaced with a low cost, compact fiber optic transmission system in order to provide an accurate digital representation of a physical parameter (e.g. temperature) of a remote sample. The sensor is fabricated so as to include a Fabry-Perot gap formed between the ends of two mated optical fibers. By examining the optical characteristics of light that is transmitted through the Fabry-Perot sensor gap, an indication of gap width can be ascertained. Accordingly, a change in Fabry-Perot sensor gap width is related to a change in the particular physical parameter to be measured. In another embodiment of the invention, a second unique multiple beam fringe sensor having a Fabry-Perot gap is disclosed that is also adapted to provide an accurate digital representation of a physical parameter (e.g. temperature) of a remote sample. The sensor may be fabricated in two segments. A fiber containing segment includes each of a driving optical fiber for supplying incident light signals to the Fabry-Perot gap and a sensing optical fiber for receiving output light signals that have been transmitted twice through the Fabry-Perot gap, the optical characteristics of which output signals provide an indication of the parameter to be sensed. A transducer segment includes the Fabry-Perot gap formed therein and means responsive to the physical parameter for changing the width of the Fabry-Perot gap and, accordingly, the optical characteristics of the light signals passing therethrough.

  13. Engineering-reflected phase in Fabry-Perot sensors with resonant mirrors.

    PubMed

    Gellineau, Antonio; Wong, Yu-Po; Solgaard, Olav

    2013-12-01

    Fabry-Perot cavities made with photonic crystal (PC) mirrors and other resonant structures exhibit nontraditional characteristics due to the strong wavelength dependence of their reflected phase. This Letter describes how engineering the phase of PC mirrors enables sensors that are tolerant to variations in laser center frequency and line width. Reflection spectra measurements of Fabry-Perot cavities made with PC mirrors were collected as a function of wavelength and cavity length, providing experimental verification of theory and simulations.

  14. Influence of intensity loss in the cavity of a folded Fabry-Perot interferometer on interferometric signals

    SciTech Connect

    Shyu, Lih-Horng; Chang, Chung-Ping; Wang, Yung-Cheng

    2011-06-15

    Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, the intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.

  15. Influence of intensity loss in the cavity of a folded Fabry-Perot interferometer on interferometric signals.

    PubMed

    Shyu, Lih-Horng; Chang, Chung-Ping; Wang, Yung-Cheng

    2011-06-01

    Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, the intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.

  16. Experimental Studies of Alignment Tolerance and High Temperature Performance of A Fabry-Perot Interferometric Pressure Sensor

    NASA Astrophysics Data System (ADS)

    Padron, Ivan; Fiory, Anthony; Ravindra, Nuggehalli

    2008-03-01

    Fabry-Perot interferometry is one of the most reliable of the several optical techniques that can be utilized to facilitate the fabrication of an optical sensor. Devices based on this technique can provide high degree of sensitivity, versatility and immunity to environmental noise. The Fabry-Perot Interferometric Sensor (FPIS), to be discussed in this presentation, consists of a Fabry-Perot cavity formed between two bonded surfaces: a corrugated diaphragm with a center rigid body (or boss) which deflects under external pressure and keeps a high alignment tolerance and a glass surface with an optical fiber insert. The Fabry-Perot cavity and optical fiber have been used as the sensing element and interconnect, respectively. The Fabry-Perot cavity has been fabricated using the MEMS technology. Micromachining techniques make Fabry-Perot sensors very attractive by reducing the size and cost of the sensing element.

  17. Subwavelength Fabry-Perot resonator: a pair of quantum dots incorporated with gold nanorod

    PubMed Central

    2012-01-01

    The two apexes of an elongated gold nanorod (GNR) irradiated by a plane wave are shown to be the hotspots at the longitudinal plasmon modes. This phenomenon implies that a pair of quantum dots (QDs) located at these apexes might be excited simultaneously if the excitation band of QDs coincides with one of these modes. Consequently, a coherent emission of the two emitters could happen subsequently. In the following coherent emission, these two-level emitters are simulated as two oscillating dipoles (bi-dipole) with some possible phase differences. Our results show that the maximum radiative and nonradiative powers of the bi-dipole occur at the longitudinal plasmon dipole, quadrupole, sextupole, and octupole modes of GNR. Moreover, the strongest emissions are induced by the in-phase bi-dipole coupled to the odd modes and the 180° out-of-phase one to the even modes, respectively. The excitation and emission behaviors of a pair of QDs incorporated with GNR demonstrate the possibility of using this structure as a subwavelength resonator of Fabry-Perot type. In addition, the correlation between these modes of the GNR and the dispersion relation of gold nanowire is also discussed. PMID:23031423

  18. Fabry-Perot Interferometer for Column CO2

    NASA Technical Reports Server (NTRS)

    Heaps, William S.; Kawa, Randolph; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision approx. 0.3%). No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise detection required to measure column CO2 at the target specification. The objective of this program is to construct a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. To date we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also measuring signal and noise levels in actual sunlight to evaluate component performance.

  19. Monolithic Fabry-Perot Wavelength Tunable Filter with Electrothermal Actuation

    NASA Astrophysics Data System (ADS)

    Kim, Chang Kyu; Lee, Myung Lae; Jun, Chi-Hoon; Choi, Chang Auck

    2005-02-01

    We report on a micromachined monolithic Fabry-Perot wavelength tunable filter with a thick moving structure operated by an electrothermal actuation. The monolithic structure simplifies the fabrication process and the electrothermal actuation mechanism reduces the required operation voltage. For the wet etching of the AlGaAs sacrificial layer, an HCl-based solution rather than a HF-based one was used because it results in a larger selectivity between the AlxGa1-xAs layers and less damage to the suspended structure. The wavelength tuning range of the 7.64-μm-thick structure was 47 nm for the power consumption of 5 mW, which results in the high tuning efficiency of ˜9.9 nm/mW. The wide tuning range of 81.2 nm for the 5.2-μm-thick structure, that is not possible with an electrostatic actuation mechanism due to the occurrence of breakdown, is achieved at the driving voltage below 5.7 V. Due to the simplicity of fabrication and the ease of integration, this structure is advantageous for use in wavelength tunable light sources and photodetectors.

  20. Optical fiber Fabry-Perot interferometer for microorganism growth detection

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohui; Jiang, Mingshun; Sui, Qingmei; Luo, Shuyang; Geng, Xiangyi

    2016-07-01

    An optical fiber Fabry-Perot interferometer (FPI) based on hollow-core photonic crystal fiber (HCPCF) for microorganism growth detection is proposed and demonstrated. The FPI is formed by splicing both ends of a short section of HCPCF to SMFs and cleaving the SMF pigtail to a proper length. By measuring the fringe contrast of interference pattern, the refractive index (RI) changes of analyte during microorganism growth can be obtained. RI response of the sensor was investigated theoretically and experimentally. It shows linear response with sensitivity of -136 dB/RIU and good repeatability. Temperature response was also tested and the result confirms the low temperature cross-sensitivity of the sensor. Detection of yeast growth in liquid medium by the FPI sensor was conducted and the result shows the characteristic of typical yeast growth curve. With its advantages of high RI sensitivity, low temperature cross-sensitivity, capability for real-time measurement and so on, this FPI sensor has great potential in biosensing.

  1. Optical fiber Fabry-Perot sensors for smart structures

    NASA Astrophysics Data System (ADS)

    Lee, C. E.; Alcoz, J. J.; Yeh, Y.; Gibler, W. N.; Atkins, R. A.; Taylor, H. F.

    1992-06-01

    The paper describes the operation principles and the construction, performance, and application of optical fiber Fabry-Perot interferometers (FFPIs) utilizing internal mirrors, developed for sensing temperature, strain, acoustic waves, and other physical perturbations in structural materials. It is shown that the internal-mirror FFPI sensors have a good mechanical strength which make it possible for the sensors to endure mechanical stresses experienced during the embedding process, and provide high sensitivity and point-sensing and ultrasound pressure. A digital signal processor is described. the 29th International Conference on the Applications of the Mössbauer Effect (ICAME 2007) held in Kanpur, India, 14-19 October 2007, PART IV/VII 30 2008 11 19 2008 11 18 2008 7 2008 Springer Science+Business Media B.V. 2008 9819 10.1007/s10751-008-9819-1 17 57Fe-Mössbauer study of electrically conducting barium iron vanadate glass after heat treatment 115 121 2008 9 17 2008 10 9 Spr

  2. Fabry-Perot Interferometer for Column CO2

    NASA Technical Reports Server (NTRS)

    Heaps, William S.; Kawa, S. Randolph; Krebs, Carolyn A. (Technical Monitor)

    2002-01-01

    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision is less than .3%). No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise detection required to measure column CO2 at the target specification. The objective of this program is to construct a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. To date we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also undertaking some measurements of signal and noise levels for actual sunlight reflecting from the ground in order to evaluate the potential of some components to meet the exacting requirements of this measurement.

  3. Phase modulating two Fabry-Perot interferometry and its application to nanometrology

    NASA Astrophysics Data System (ADS)

    Gou, Bin; Zhu, Lei; Miao, Jian; Huang, Yu; Wei, Tao; Zhu, Ruogu

    2010-10-01

    We discuss how to expend the SPM of double beam interferometer to multi-beam interferometer or Fabry-Perot interferometer and deduce the corresponding theoretical results in this paper. Besides the introduction section 1 the principle of Fabry-Perot interferometer and how to simplify the representation of its intensity are described in section 2. Two typical conditions such as (1) nearby the maximum and fineness coefficient F, the light phase θ satisfied the condition F sin2θ < 1 or (2) offset the maximum and F θ satisfied the condition F sin2θ > 1 considered. Phase modulating Fabry-Perot interferometry and theoretical results for 1, ramp, 2, saw teeth, 3, sinusoidal voltage modulating or SPM Fabry-Perot interferometer are deduced in section 3. It should be noted that the construction of double Fabry-Perot interferometer for nanometrology and the experimental results are stated in section 4. Our measurement resolution could be arrived in <0.3nm using the method of time space difference.

  4. Application of High-Temperature Extrinsic Fabry-Perot Interferometer Strain Sensor

    NASA Technical Reports Server (NTRS)

    Piazza, Anthony

    2008-01-01

    In this presentation to the NASA Aeronautics Sensor Working Group the application of a strain sensor is outlined. The high-temperature extrinsic Fabry-Perot interferometer (EFPI) strain sensor was developed due to a need for robust strain sensors that operate accurately and reliably beyond 1800 F. Specifically, the new strain sensor would provide data for validating finite element models and thermal-structural analyses. Sensor attachment techniques were also developed to improve methods of handling and protecting the fragile sensors during the harsh installation process. It was determined that thermal sprayed attachments are preferable even though cements are simpler to apply as cements are more prone to bond failure and are often corrosive. Previous thermal/mechanical cantilever beam testing of EFPI yielded very little change to 1200 F, with excellent correlation with SG to 550 F. Current combined thermal/mechanical loading for sensitivity testing is accomplished by a furnace/cantilever beam loading system. Dilatometer testing has can also be used in sensor characterization to evaluate bond integrity, evaluate sensitivity and accuracy and to evaluate sensor-to-sensor scatter, repeatability, hysteresis and drift. Future fiber optic testing will examine single-mode silica EFPIs in a combined thermal/mechanical load fixture on C-C and C-SiC substrates, develop a multi-mode Sapphire strain-sensor, test and evaluate high-temperature fiber Bragg Gratings for use as strain and temperature sensors and attach and evaluate a high-temperature heat flux gauge.

  5. Asymmetric tunable Fabry-Perot cavity using switchable polymer stabilized cholesteric liquid crystal optical Bragg mirror

    NASA Astrophysics Data System (ADS)

    Sathaye, Kedar S.; Dupont, Laurent; de Bougrenet de la Tocnaye, Jean-Louis

    2012-03-01

    Optical properties of an asymmetric Fabry-Perot (FP) cavity interferometer made up of a conventional metallic mirror and a polymer stabilized cholesteric liquid crystal (PSCLC) Bragg mirror have been investigated. The first FP cavity design comprises a gold mirror, an isotropic layer made up of the polymer glue, a quarter wave plate to convert the input linearly polarized modes into the circularly polarized modes inside the cavity, and the PSCLC Bragg mirror, all sandwiched between two indium tin oxide glass plates. The second FP cavity has a layer of conducting polymer deposited on the quarter-wave plate to apply the electric field only to the cholesteric stack. To have reflectivity above 95% in visible range we implement 30 layers of cholesteric liquid crystal in a planar Grandjean texture. The device compactness and the mirror parallelism due to the monolithic fabrication of FP are advantageous from the technical point of view. We test the FP tunability by shifting the resonance wavelength through an entire period; by applying electric field and/or by varying the temperature.

  6. Plasmon coupled Fabry-Perot lasing enhancement in graphene/ZnO hybrid microcavity

    PubMed Central

    Li, Jitao; Jiang, Mingming; Xu, Chunxiang; Wang, Yueyue; Lin, Yi; Lu, Junfeng; Shi, Zengliang

    2015-01-01

    The response of graphene surface plasmon (SP) in the ultraviolet (UV) region and the realization of short-wavelength semiconductor lasers not only are two hot research areas of great academic and practical significance, but also are two important issues lacked of good understanding. In this work, a hybrid Fabry-Perot (F-P) microcavity, comprising of monolayer graphene covered ZnO microbelt, was constructed to investigate the fundamental physics of graphene SP and the functional extension of ZnO UV lasing. Through the coupling between graphene SP modes and conventional optical microcavity modes of ZnO, improved F-P lasing performance was realized, including the lowered lasing threshold, the improved lasing quality and the remarkably enhanced lasing intensity. The underlying mechanism of the improved lasing performance was proposed based on theoretical simulation and experimental characterization. The results are helpful to design new types of optic and photoelectronic devices based on SP coupling in graphene/semiconductor hybrid structures. PMID:25786359

  7. A multi-wavelength erbium-doped fiber ring laser using an intrinsic Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Jauregui-Vazquez, D.; Rojas-Laguna, R.; Estudillo-Ayala, J. M.; Hernandez-Garcia, J. C.; Lopez-Dieguez, Y.; Sierra-Hernandez, J. M.

    2016-10-01

    In this experimental paper, a multi-wavelength erbium-doped ring fiber laser based on an all fiber intrinsic Fabry-Perot interferometer is presented and demonstrated. The interferometer was fabricated by an arc and splicing technique using hollow core photonic crystal fiber (HCPCF) and conventional single mode fiber (SMF28). The fiber laser can be operated in single, dual and triple lasing mode by applying a transversal load over the all fiber interferometer. The laser spectrums present minimal mode spacing of 1 nm, high wavelength stability and power fluctuations around 0.5 dB. The average signal to noise ratio (SNR) of the laser emissions spectrum is around 35 dB. This fiber laser offers low cost, compactness and high wavelength stability.

  8. Tunable Fabry-Perot filter in cobalt doped fiber formed by optically heated fiber Bragg gratings pair

    NASA Astrophysics Data System (ADS)

    Li, Ying; Zhou, Bin; Zhang, Liang; He, Sailing

    2015-06-01

    In this paper, a tunable fiber Fabry-Perot (F-P) filter by all-optical heating is proposed. Two high reflective fiber Bragg gratings (FBG) fabricated in cobalt doped single mode fiber form the F-P cavity. The cobalt-doped fiber used here is an active fiber, and it transforms optical power from a control laser into heat effectively due to the nonradiative processes. The generated heat raises the refraction index of the fiber and enlarges the F-P cavity's length, realizing the all-optical tuning characteristics. By adjusting the power of the control laser, the resonant wavelength of our proposed fiber F-P filter can be high precisely controlled. The cavity length of the filter is carefully designed to make sure the longitude mode spacing is comparable to the grating bandwidth, making it single mode operating.

  9. Rayleigh Scattering Measurements Using a Tunable Liquid Crystal Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Mielke-Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.

    2010-01-01

    Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous density, velocity, and temperature measurements. The Fabry-Perot interferometer or etalon is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating these flow properties. This paper investigates the use of a tunable liquid crystal (LC) Fabry-Perot etalon in Rayleigh scattering experiments at NASA Glenn Research Center. The LC etalon provides a robust interferometry system that can be tuned rapidly by adjusting the voltage applied to the liquid crystal interface. Tuning the interferometer is often necessary to control the physical locations of the concentric interference fringes when Rayleigh light is imaged through the LC etalon. The LC etalon diagnostic system was tested in a 1-cm diameter nozzle flow in two different scattering configurations to evaluate its usefulness for Rayleigh measurements compared to a traditional non-tunable fused silica Fabry-Perot etalon.

  10. Use of PZT's for adaptive control of Fabry-Perot etalon plate figure

    NASA Technical Reports Server (NTRS)

    Skinner, WIlbert; Niciejewski, R.

    2005-01-01

    A Fabry Perot etalon, consisting of two spaced and reflective glass flats, provides the mechanism by which high resolution spectroscopy may be performed over narrow spectral regions. Space based applications include direct measurements of Doppler shifts of airglow absorption and emission features and the Doppler broadening of spectral lines. The technique requires a high degree of parallelism between the two flats to be maintained through harsh launch conditions. Monitoring and adjusting the plate figure by illuminating the Fabry Perot interferometer with a suitable monochromatic source may be performed on orbit to actively control of the parallelism of the flats. This report describes the use of such a technique in a laboratory environment applied to a piezo-electric stack attached to the center of a Fabry Perot etalon.

  11. Distributed torsion sensor based on cascaded coaxial cable Fabry-Perot interferometers

    NASA Astrophysics Data System (ADS)

    Cheng, Baokai; Zhu, Wenge; Hua, Liwei; Liu, Jie; Li, Yurong; Nygaard, Runar; Xiao, Hai

    2016-07-01

    Cascaded coaxial cable Fabry-Perot interferometers (FPI) are studied and demonstrated for distributed torsion measurement. Multiple weak reflectors are implemented on a coaxial cable so that any two consecutive reflectors can form a Fabry-Perot cavity. By fixing the cable sensor in a helical form on a shaft, the distributed torsion of the shaft can be measured by the cascaded Fabry-Perot cavities. A test on a single section shows that the sensor has a linear response with a sensitivity of 1.834 MHz (rad/m)-1 in the range of twisted rate from 0 to 8.726 rad m-1. The distributed torsion sensing capability is useful in drilling process monitoring, structure health monitoring and machine failure detection.

  12. Biochemical sensing with a polymer-based micromachined Fabry-Perot sensor.

    PubMed

    Zhang, Tianhua; Talla, Shantan; Gong, Zhongcheng; Karandikar, Sukrut; Giorno, Rebecca; Que, Long

    2010-08-16

    A white-light source operated polymer-based micromachined Fabry-Perot biochemical sensor is reported. As a refractive-index sensitive optical sensor, its transducing signal varies upon the changes of the effective refractive index in the Fabry-Perot cavity. This sensor is fabricated from PDMS and glass. More specifically, this sensor is a micromachined Fabry-Perot interferometer (microFPI) and is fabricated by bonding a glass substrate and the soft-lithographically patterned PDMS. Several biochemicals have been detected with the microFPI biochemical sensors. Measurements show that rabbit IgG at a concentration of as low as 5 to 50 ng/ml can be detected even without any performance optimization of the devices.

  13. Enhanced random lasing in ZnO nanocombs assisted by Fabry-Perot resonance.

    PubMed

    Chen, Yungting; Chen, Yangfang

    2011-04-25

    The ultraviolet random lasing behavior of an ensemble of ZnO nanocombs has been demonstrated. It is found that the Fabry-Perot resonance induced by nanocomb geometry can greatly enhance random lasing action with a low threshold condition. Besides, the emission spectra exhibit few sharp lasing peaks with a full width at half maximum (FWHM) of less than 0.3 nm and a narrow background emission with a FWHM of about 5 nm. Cathodoluminescence mapping images are utilized to analyze the Fabry-Perot resonance phenomenon. The resonant effect on the lasing system is further confirmed by nanocombs with different resonant cavity lengths. The unique lasing behavior induced by the simultaneous occurrence of Fabry-Perot resonance and random laser action shown here may open up a new possibility for the creation of highly efficient light emitting devices.

  14. Two-dimensional photonic-crystal-based Fabry-Perot etalon.

    PubMed

    Ho, Chong Pei; Pitchappa, Prakash; Kropelnicki, Piotr; Wang, Jian; Cai, Hong; Gu, Yuandong; Lee, Chengkuo

    2015-06-15

    We demonstrate the design, fabrication, and characterization of a polycrystalline-silicon-based photonic crystal Fabry-Perot etalon, which is aimed to work in the mid-infrared wavelengths. The highly reflective mirrors required in a Fabry-Perot etalon are realized by freestanding polycrystalline-silicon-based photonic crystal membranes with etched circular air holes. A peak reflection of 96.4% is observed at 3.60 μm. We propose a monolithic CMOS-compatible fabrication process to configure two such photonic crystal mirrors to be in parallel to form a Fabry-Perot etalon; a filtered transmission centered at 3.51 μm is observed. The quality factor measured is around 300, which is significantly higher than in existing works. This creates the possibility of using such devices for high-resolution applications such as gas sensing and hyperspectral imaging.

  15. Method and apparatus for a Fabry-Perot multiple beam fringe sensor

    NASA Technical Reports Server (NTRS)

    James, Kenneth A. (Inventor); Quick, William H. (Inventor); Strahan, Virgil H. (Inventor)

    1982-01-01

    A method and the resulting apparatus for implementing a unique multiple beam fringe sensor that is adapted to be interfaced with a low cost, compact fiber optic transmission system in order to provide an accurate digital representation of a physical parameter (e.g. temperature) of a remote sample. The sensor is fabricated so as to include a Fabry-Perot gap formed between the ends of two mated optical fibers. By examining the optical characteristics of light that is transmitted through the Fabry-Perot sensor gap, an indication of gap width can be ascertained. Accordingly, a change in Fabry-Perot sensor gap width is related to a change in the particular physical parameter to be measured.

  16. Gamma radiation resistant Fabry-Perot fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Liu, Hanying; Miller, Don W.; Talnagi, Joseph

    2002-08-01

    The Nuclear Regulatory Commission (NRC) in 1998 completed a study of emerging technologies that could be applicable to measurement systems in nuclear power plants [H. M. Hashemian [et al.], "Advanced Instrumentation and Maintenance Technologies for Nuclear Power Plants," NUREG/CR-5501 (1998)]. This study concluded that advanced fiber optic sensing technology is an emerging technology that should be investigated. It also indicated that there had been very little research related to performance evaluation of fiber optic sensors in nuclear plant harsh environments, although substantial research has been performed on nuclear radiation effects on optical fibers in the last two decades. A type of Fabry-Perot fiber optic temperature sensor, which is manufactured by Fiso Technologies in Canada, is qualified to be a candidate for potential applications in nuclear radiation environment due to its unique signal processing technique and its resistance to power loss. The gamma irradiation effects on this type of sensors are investigated in this article. Two sensors were irradiated in a gamma irradiation field and one of them was irradiated up to a total gamma dose of 133 Mrad. The sensor on-line performance was monitored during each gamma irradiation test. Furthermore, the sensor static and dynamic performance before and after each irradiation test were evaluated according to the Standard ISA-dS67.06.01 ("Performance Monitoring for Nuclear Safety-Related Instrument Channels in Nuclear Power Plants", Standard ISA-dS67.06.01, Draft 7, Instrument Society of America, 1999). Although several abnormal phenomena were observed, analysis shows that gamma irradiation is not accredited to the abnormal behavior, which implies that this type of sensor is suitable to a gamma irradiation environment with a high gamma dose.

  17. A miniature cryogenic scanning Fabry-Perot interferometer for mid-IR to submm astronomical observations

    NASA Astrophysics Data System (ADS)

    Parshley, Stephen C.; Vavagiakis, Eve M.; Nikola, Thomas; Stacey, Gordon J.

    2014-07-01

    We have designed and evaluated a Miniature Cryogenic Scanning Fabry-Perot (MCSF) interferometer which can be inserted into the optical path of a mid-IR camera to observe fine structure lines in the 25-40 μm wavelength regime. The MCSF uses free standing metal meshes as its filters and can scan over a length of ~2 mm. The short wavelength range in which the MCSF will be used requires very tight fabrication tolerances to maintain the parallelism of the meshes to within 0.15 μm and to obviate the need for dynamic parallelizing adjusters. A monolithic notch flexure design delivers these properties and minimizes the number of moving parts, maximizing reliability. The scanning mechanism includes a cryogenic stepper motor that drives a miniature fine-adjustment screw via a worm gear assembly. This allows for a step resolution of 1 step ~ 14 nm when operating in full step mode. Finite Element Analysis of the MCSF's monolithic flexure guided the design and confirmed that the MCSF will remain within required limits over the course of operation. We developed the MCSF for use in the mid-IR camera FORCAST on the 2.5 meter SOFIA telescope.

  18. Evaluation of Fabry-Perot polymer film sensors made using hard dielectric mirror deposition

    NASA Astrophysics Data System (ADS)

    Buchmann, Jens; Zhang, Edward; Scharfenorth, Chris; Spannekrebs, Bastian; Villringer, Claus; Laufer, Jan

    2016-03-01

    Fabry-Perot (FP) polymer film sensors offer high acoustic sensitivity, small element sizes, broadband frequency response and optical transmission to enable high resolution, backward mode photoacoustic (PA) imaging. Typical approaches to sensor fabrication involve the deposition of stacks of alternating dielectric materials to form interferometer mirrors, which are separated by a polymer spacer. If hygroscopic soft dielectric materials are used, a protective polymer layer is typically required. In this study, methods for the deposition of water-resistant, hard dielectric materials onto polymers were explored to improve the robustness and performance of the sensors. This involved the optimisation of the fabrication process, the optical and acoustic characterisation of the sensors, and a comparison of the frequency response with the output of an acoustic forward model. The mirrors, which were separated by a 20 μm Parylene spacer, consisted of eight double layers of Ta2O5 and SiO2 deposited onto polymer substrates using temperature-optimised electron vapour deposition. The free spectral range of the interferometer was 32 nm, its finesse FR = 91, and its visibility V = 0.72. The noise-equivalent pressure was 0.3 kPa (20 MHz bandwidth). The measured frequency response was found to be more resonant at 25 MHz compared to sensors with soft dielectric mirrors, which was also in good agreement with the output of a forward model of the sensor. The sensors were used in a PA scanner to acquire 3-D images in tissue phantoms.

  19. Underwater pressure measurement using fibre optic extrinsic Fabry-Perot interferometric (EFPI) sensors

    NASA Astrophysics Data System (ADS)

    Duraibabu, Dinesh Babu; Poeggel, Sven; Lewis, Elfed; Newe, Thomas

    2014-05-01

    A fibre optic extrinsic Fabry Perot Interferometer (EFPI) sensor is developed for monitoring pressure in the underwater and sub-seabed under simulated conditions. The sensor is robust in design and is fabricated entirely from Silica glass. The EFPI is formed at the tip of the fibre, where the single mode is spliced to a 200μm capillary, sealed by a 200μm Multimode, which forms the diaphragm. The diaphragm thickness is reduced by polishing and etching with hydrofluoric (HF) acid to about 2-3μm for a high sensitivity. The thickness of the diaphragm is monitored online during polishing and HF etching. The spectrum of the fibre optic sensor (FOS) is interrogated using a broad band optical light source and an optical spectrometer. The sensitivity of the sensor achieved is 0.6cmH2O, excellent for small depth-changes. Experimental measurements with saturated salt water and chlorophyll pigmentation of different standards were tested, to simulate the sub-sea conditions where a stability of 0.7cmH2O was reached with a drift of less than 10% under the simulated conditions.

  20. Fabry-Perot interferometer based on etched side-hole fiber for microfluidic refractive index sensing

    NASA Astrophysics Data System (ADS)

    Wu, Shengnan; Yan, Guofeng; Zhou, Bin; He, Sailing

    2015-08-01

    In this paper, we present a novel fiber-optic open-cavity Fabry-Perot interferometer (FPI), which is specially designed for microfluidic refractive index (RI) sensing. An etching Side-hole fiber (SHF) was sandwiched between in two single-mode-fibers (SMF) and then a cavity was opened up by chemical etching method in the SHF. The minute order of the etching process endow such FPIs with low cost and ease of fabrication. For further microfluidic sensing test, the FPI was integrated with a cross microfluidic slit that was fabricated through photolithography. The refractive index response of the FPI was characterized using sodium hydroxide solution with RI range from 1.3400 to 1.3470. Experimental results show that FPIs with different length of open-cavity have the similar liner RI response with different RI sensitivities. The optimal RI sensitivity of more than 1138 nm/RI can be achieved with open-cavity length of 56 μm. The temperature response was also investigated, which shows that FPIs exhibit a very low temperature cross-sensitivities of 4.00 pm/ °C and 1.95 pm/ °C corresponding FPIs with cavity length of 123 μm and 56 μm, respectively. Such good performance renders the FPI a promising in-line microfluidic sensor for temperature-insensitive RI sensing.

  1. Optical fibre Fabry-Perot relative humidity sensor based on HCPCF and chitosan film

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohui; Jiang, Mingshun; Sui, Qingmei; Geng, Xiangyi

    2016-09-01

    An optical fibre Fabry-Perot interferometer (FPI) sensor for relative humidity (RH) measurement is proposed. The FPI is formed by splicing a short section of hollow-core photonic crystal fibre(HCPCF) to single mode fibre and covering a chitosan film at the end of HCPCF. The refractive index of chitosan and film thickness will change with ambient RH, leading to the change in the reflected interference spectrum of FPI. RH response of the FPI sensor is analysed theoretically and demonstrated experimentally. It shows nonlinear response to RH values from 35 to 95%RH. The interference fringe shifts to shorter wavelength as RH increases with a maximum sensitivity of 0.28 nm/%RH at high RH level. And the fringe contrast also decreases as RH increases with an available maximum sensitivity of 0.5 dB/%RH. The sensor shows good stability and fast response time less than 1 min. With its advantages of compact structure, good performance, simple and safe fabrication, the proposed optical fibre FPI sensor has great potential for RH sensing.

  2. a CMOS Millimeter-Wave Transceiver Embedded in a Semi-Confocal Fabry-Perot Cavity

    NASA Astrophysics Data System (ADS)

    Drouin, Brian; Tang, Adrian; Schlecht, Erich T.; Brageot, Emily; Daly, Adam M.; Gu, Qun Jane; Ye, Yu; Shu, Ran; Chang, M.-C. Frank; Kim, Rod M.

    2016-06-01

    The extension of radio-frequency CMOS circuitry into millimeter wavelengths promises the extension of spectroscopic techniques in compact, power efficient systems. We are now exploring the use of CMOS millimeter devices for low-mass, low-power instrumentation capable of remote or in-situ detection of gas composition during space missions. We have chosen to develop a Flygare-Balle type spectrometer, with a semi-confocal Fabry-Perot cavity to amplify the pump power of a mm-wavelength CMOS transmitter that is directly coupled to the planar mirror of the cavity. Since the initial report last year describing the designs, we have built a pulsed transceiver system at 89-104 GHz inside a 5 cm base length cavity and demonstrated cavity finesse up to 3000, allowing for modes with 30 MHz bandwidth and a sufficient cavity amplification factor for mW class transmitters. System and component testing revealed that the power-amplifier design (embedded in the chip) was faulty and the transceiver peak power is only 10 microwatts, which is insufficient for molecular excitation on the timescale of the gas residence time within the beam. An improved power amplifier circuit has been designed and is currently under fabrication, meanwhile, we have also developed a tunable synthesizer (embedded in the same chip) that allows for tuning over the full bandwidth at increments of 10 MHz. The presentation will cover these capabilities, describing the system and component tests, as well as any new developments.

  3. Temperature sensitivity characteristics of HCPCF-based Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohui; Jiang, Mingshun; Sui, Qingmei; Song, Furong

    2016-01-01

    Optical fiber Fabry-Perot interferometers (FPIs) formed by splicing hollow-core photonic crystal fiber (HCPCF) to single mode fiber (SMF) are proposed, and the temperature sensitivity characteristics are investigated theoretically and experimentally. Interestingly, the HCPCF-based FPIs with different structures have different responses to temperature: the FPI formed by a short HCPCF and a long SMF pigtail has a linear wavelength response to temperature with a sensitivity of 9.17 pm/°C and its fringe contrast is nearly temperature-insensitive; while the FPI with a long HCPCF and a short SMF cap is temperature-insensitive both for wavelength and fringe contrast. Refractive index (RI) test results show good linear response based on fringe contrast. Thus the HCPCF-based FPI sensors can be applied to temperature detection and RI measurement simultaneously with negligible cross-sensitivity or completely temperature-independent measurement by using different structures. Due to the advantages of small size, robust structure, easy fabrication, low cost and good fringe visibility, the HCPCF-based FPI sensors have broad application prospect in the fields of biology, chemistry and so on.

  4. Hybrid structured fiber-optic Fabry-Perot interferometer for simultaneous measurement of strain and temperature.

    PubMed

    Zhou, Ai; Qin, Boyang; Zhu, Zheng; Zhang, Yaxun; Liu, Zhihai; Yang, Jun; Yuan, Libo

    2014-09-15

    We fabricate and experimentally demonstrate a hybrid structured Fabry-Perot interferometer (FPI) embedded in the middle of a fiber line for simultaneous measurement of axial strain and temperature. The FPI is composed of a silica-cavity cascaded to a spheroidal air-cavity, both of which are formed in a hollow annular core fiber (HACF). The fabrication process of the FPI includes only a fusion splice between a single-mode fiber and a HACF and several electrical arc discharges at the HACF near the splice point. Experimental results show that the strain and temperature sensitivities of the air-cavity can be 5.2 pm/με and 1.3 pm/C°, respectively, and those of the silica-cavity can be 1.1 pm/με and 13 pm/C°, respectively. The different sensitivities of silica-cavity and air-cavity to strain and temperature enable us to implement simultaneous sensing in strain and temperature. PMID:26466247

  5. Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass

    SciTech Connect

    Chen Jihuan; Zhao Jiarong; Huang Xuguang; Huang Zhenjian

    2010-10-10

    A simple fiber-optic sensor based on Fabry-Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry-Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.

  6. Use of gamma ray radiation to parallel the plates of a Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Skinner, Wilbert R.; Hays, Paul B.; Anderson, Sally M.

    1987-01-01

    The use of gamma radiation to parallel the plates of a Fabry-Perot etalon is examined. The method for determining the etalon parallelism, and the procedure for irradiating the posts are described. Changes in effective gap for the etalon over the surface are utilized to measure the parallelism of the Fabry-Perot etalon. An example in which this technique is applied to an etalon of fused silica plates, which are 132 mm in diameter and coded with zinc sulfide and cryolite, with Zerodur spaces 2 cm in length. The effect of the irradiation of the posts on the thermal performance of the etalon is investigated.

  7. In-fiber Fabry-Perot refractometer assisted by a long-period grating.

    PubMed

    Mosquera, L; Sáez-Rodriguez, D; Cruz, J L; Andrés, M V

    2010-02-15

    We present an optical fiber refractometer based on a Fabry-Perot interferometer defined by two fiber Bragg gratings and an intracavity long-period grating that makes the light confined in the resonator interact with the surrounding medium. The external refractive index is monitored by the resonant frequencies of the Fabry-Perot interferometer, which can be measured either in transmission or in reflection. In this first experiment, wavelength shifts measured with a resolution of 0.1 pm have allowed one to establish a refractive index detection limit of 2.1x10(-5).

  8. Limits of DWDM with gratings and Fabry-Perots and alternate solutions

    NASA Astrophysics Data System (ADS)

    Roychoudhuri, Chandrasekhar; Lee, DongIk; Jiang, Yongyuan; Kittaka, Shigeo; Nara, Masatoshi; Serikov, Vladimir V.; Oikawa, Masahiro

    2003-08-01

    High resolution DWDM devices based on the principles of gratings (planar, Bragg, AWG, etc.) and Fabry-Perots (etalon, Lummer-Gehrke plate, etc.) suffer from inherent limitations due to (i) temporal pulse stretching of data, and (ii) broadening of time integrated spectral (demuxed) fringes. While the relation, dνFdt >1, can account for these limitations, our analysis imply that dnF does not represent real, physical frequencies. We explain the broader implications of this interpretation in designing DWDM devices based on gratings and Fabry-Perots and illustrate how to use prisms, photonic crystals and non-linear devices for very high data rate per channel.

  9. In-fiber Fabry-Perot refractometer assisted by a long-period grating.

    PubMed

    Mosquera, L; Sáez-Rodriguez, D; Cruz, J L; Andrés, M V

    2010-02-15

    We present an optical fiber refractometer based on a Fabry-Perot interferometer defined by two fiber Bragg gratings and an intracavity long-period grating that makes the light confined in the resonator interact with the surrounding medium. The external refractive index is monitored by the resonant frequencies of the Fabry-Perot interferometer, which can be measured either in transmission or in reflection. In this first experiment, wavelength shifts measured with a resolution of 0.1 pm have allowed one to establish a refractive index detection limit of 2.1x10(-5). PMID:20160835

  10. Polymeric optofluidic Fabry-Perot sensor by direct laser machining and hot embossing.

    PubMed

    Wu, Jing; Day, Daniel; Gu, Min

    2011-05-01

    We present a polymeric-based Fabry-Perot optofluidic sensor fabricated by combining direct laser machining and hot embossing. This technique provides a more elegant solution to conventional hot embossing by increasing the production rate, improving the reproducibility, and further reducing the cost, providing a large working area and flexibility in design modification and customization. As a proof of concept, a Fabry-Perot (F-P) optofluidic sensor was fabricated in polymethyl methacrylate (PMMA) from a micromachined stamp. The experimental results of the sensor agree well with analytical calculations and show a sensitivity of 2.13×10⁻³ RIU/nm for fluid refractive index change.

  11. All-fiber, long-active-length Fabry-Perot strain sensor

    NASA Astrophysics Data System (ADS)

    Pevec, Simon; Donlagic, Denis

    2011-08-01

    This paper presents a high-sensitivity, all-silica, all-fiber Fabry-Perot strain-sensor. The proposed sensor provides a long active length, arbitrary length of Fabry-Perot cavity, and low intrinsic temperature sensitivity. The sensor was micro-machined from purposely-developed sensor-forming fiber that is etched and directly spliced to the lead-in fiber. This manufacturing process has good potential for cost-effective, high-volume production. Its measurement range of over 3000 μɛ, and strain-resolution better than 1 μɛ were demonstrated by the application of a commercial, multimode fiber-based signal processor.

  12. High temperature Fabry-Perot-based strain sensor for ceramic barrier filters

    SciTech Connect

    Weinstein, S.J.; Vuppala, V.; Gunther, M.; Wang, A.; Murphy, K.; Claus, R.O.

    1993-11-01

    We report results from a program to develop fiber-optic sensor-based instrumentation methods to allow in-situ analysis of ceramic barrier filters. The sensor was an extrinsic Fabry-Perot cavity created between ends of two longitudinally aligned fibers. Filters instrumented with these fiber sensors were tested in a combustor simulator. These tests were performed using silica optical fibers capable of withstanding the high temperature and harsh chemical environment of the combustor. The single-ended approach of the reflective Fabry-Perot sensors is well suited for thermal strain measurements. Results from several tests are presented

  13. The multibeam Fabry-Perot velocimeter: Efficient measurement of high velocities

    SciTech Connect

    1996-07-01

    In support of the Laboratory`s scientific stockpile stewardship mission, we have developed a multibeam Fabry-Perot velocimetry system to more efficiently measure continuous velocities during our experiments. These data are invaluable for testing the adequacy of our hydrodynamic computer modeling codes. A new fiber optic system and Laboratory-designed optical devices allow us to obtain five or even ten continuous velocity records from an experiment using just one Fabry-Perot interferometer. Before the advent of this system, we could obtain only one record per interferometer. We have also developed a dual-cavity interferometer that greatly facilitates reading the interference fringes recorded during our experiments.

  14. Solar CIV Vacuum-Ultraviolet Fabry-Perot Interferometers

    NASA Technical Reports Server (NTRS)

    Gary, G. Allen; West, Edward A.; Rees, David; McKay, Jack A.; Zukic, Maumer; Herman, Peter

    2006-01-01

    Aims: A tunable, high spectral resolution, high effective finesse, vacuum ultraviolet (VUV) Fabry-Perot interferometer (PPI) is designed for obtaining narrow-passband images, magnetograms, and Dopplergrams of the transition region emission line of CIV (155 nm). Methods: The integral part of the CIV narrow passband filter package (with a 2-10 pm FWHM) consists of a multiple etalon system composed of a tunable interferometer that provides high-spectral resolution and a static low-spectral resolution interferometer that allows a large effective free spectral range. The prefilter for the interferometers is provided by a set of four mirrors with dielectric high-reflective coatings. A tunable interferometer, a VUV piezoelectric-control etalon, has undergone testing using the surrogate F2 eximer laser line at 157 nm for the CIV line. We present the results of the tests with a description of the overall concept for a complete narrow-band CIV spectral filter. The static interferometer of the filter is envisioned as being hudt using a set of fixed MgF2 plates. The four-mirror prefilter is designed to have dielectric multilayer n-stacks employing the design concept used in the Ultraviolet Imager of NASA's Polar Spacecraft. A dual etalon system allows the effective free spectral range to be commensurate with the prefilter profile. With an additional etalon, a triple etalon system would allow a spectrographic resolution of 2 pm. The basic strategy has been to combine the expertise of spaceflight etalon manufacturing with VUV coating technology to build a VUV FPI which combines the best attributes of imagers and spectrographs into a single compact instrument. Results. Spectro-polarimetry observations of the transition region CIV emission can be performed to increase the understanding of the magnetic forces, mass motion, evolution, and energy release within the solar atmosphere at the base of the corona where most of the magnetic field is approximately force-free. The 2D imaging

  15. A CMOS millimeter-wave transceiver embedded in a semi-confocal Fabry-Perot cavity for molecular spectroscopy.

    PubMed

    Drouin, Brian J; Tang, Adrian; Schlecht, Erich; Brageot, Emily; Gu, Q Jane; Ye, Y; Shu, R; Frank Chang, Mau-Chung; Kim, Y

    2016-08-21

    The extension of radio frequency complementary metal oxide semiconductor (CMOS) circuitry into millimeter wavelengths promises the extension of spectroscopic techniques in compact, power efficient systems. We are now beginning to use CMOS millimeter devices for low-mass, low-power instrumentation capable of remote or in situ detection of gas composition during space missions. We have chosen to develop a Flygare-Balle type spectrometer, with a semi-confocal Fabry-Perot cavity to amplify the pump power of a mm-wavelength CMOS transmitter that is directly coupled to the planar mirror of the cavity. We have built a pulsed transceiver system at 92-105 GHz inside a 3 cm base length cavity and demonstrated quality factor up to 4680, allowing for modes with 20 MHz bandwidth, with a sufficient cavity amplification factor for mW class transmitters. This work describes the initial gas measurements and outlines the challenges and next steps. PMID:27544098

  16. Ultra-narrow angle-tunable Fabry-Perot bandpass interference filter for use as tuning element in infrared lasers

    NASA Astrophysics Data System (ADS)

    Kischkat, Jan; Peters, Sven; Semtsiv, Mykhaylo P.; Wegner, Tristan; Elagin, Mikaela; Monastyrskyi, Grygorii; Flores, Yuri; Kurlov, Sergii; Masselink, W. Ted

    2014-11-01

    We have developed a bandpass infrared interference filter with sufficiently narrow bandwidth to be potentially suitable for tuning a self-stabilizing external-cavity quantum-cascade laser (ECQCL) in single-mode operation and describe the process parameters for fabrication of such filters with central wavelengths in the 3-12 μm range. The filter has a passband width of 6 nm or 0.14% with peak transmission of 55% and a central wavelength of approximately 4.0 μm. It can be tuned through over 4% by tilting with respect to the incident beam and offers orders of magnitude larger angular dispersion than diffraction gratings. We compare filters with single-cavity and coupled-cavity Fabry-Perot designs.

  17. Passive signal processing for a miniature Fabry-Perot interferometric sensor with a multimode laser-diode source

    NASA Astrophysics Data System (ADS)

    Ezbiri, A.; Tatam, R. P.

    1995-09-01

    A passive signal-processing technique for addressing a miniature low-finesse fiber Fabry-Perot interferometric sensor with a multimode laser diode is reported. Two modes of a multimode laser diode separated by 3 nm are used to obtain quadrature outputs from an \\similar 20 - mu m cavity. Wavelength-division demultiplexing combined with digital signal processing is used to recover the measurand-induced phase change. The technique is demonstrated for the measurement of vibration. The signal-to-noise ratio is \\similar 70 dB at 500 Hz for \\similar pi /2 rad displacement of the mirror, which results in a minimum detectable signal of \\similar 200 mu rad H z-1/2 . A quantitative discussion of miscalibration and systematic errors is presented.

  18. A CMOS millimeter-wave transceiver embedded in a semi-confocal Fabry-Perot cavity for molecular spectroscopy

    NASA Astrophysics Data System (ADS)

    Drouin, Brian J.; Tang, Adrian; Schlecht, Erich; Brageot, Emily; Gu, Q. Jane; Ye, Y.; Shu, R.; Frank Chang, Mau-chung; Kim, Y.

    2016-08-01

    The extension of radio frequency complementary metal oxide semiconductor (CMOS) circuitry into millimeter wavelengths promises the extension of spectroscopic techniques in compact, power efficient systems. We are now beginning to use CMOS millimeter devices for low-mass, low-power instrumentation capable of remote or in situ detection of gas composition during space missions. We have chosen to develop a Flygare-Balle type spectrometer, with a semi-confocal Fabry-Perot cavity to amplify the pump power of a mm-wavelength CMOS transmitter that is directly coupled to the planar mirror of the cavity. We have built a pulsed transceiver system at 92-105 GHz inside a 3 cm base length cavity and demonstrated quality factor up to 4680, allowing for modes with 20 MHz bandwidth, with a sufficient cavity amplification factor for mW class transmitters. This work describes the initial gas measurements and outlines the challenges and next steps.

  19. A CMOS millimeter-wave transceiver embedded in a semi-confocal Fabry-Perot cavity for molecular spectroscopy.

    PubMed

    Drouin, Brian J; Tang, Adrian; Schlecht, Erich; Brageot, Emily; Gu, Q Jane; Ye, Y; Shu, R; Frank Chang, Mau-Chung; Kim, Y

    2016-08-21

    The extension of radio frequency complementary metal oxide semiconductor (CMOS) circuitry into millimeter wavelengths promises the extension of spectroscopic techniques in compact, power efficient systems. We are now beginning to use CMOS millimeter devices for low-mass, low-power instrumentation capable of remote or in situ detection of gas composition during space missions. We have chosen to develop a Flygare-Balle type spectrometer, with a semi-confocal Fabry-Perot cavity to amplify the pump power of a mm-wavelength CMOS transmitter that is directly coupled to the planar mirror of the cavity. We have built a pulsed transceiver system at 92-105 GHz inside a 3 cm base length cavity and demonstrated quality factor up to 4680, allowing for modes with 20 MHz bandwidth, with a sufficient cavity amplification factor for mW class transmitters. This work describes the initial gas measurements and outlines the challenges and next steps.

  20. Ultracompact optical fiber Fabry-Perot interferometer based on in-line integrated sub-micron silicon film

    NASA Astrophysics Data System (ADS)

    Micco, A.; Quero, G.; Crescitelli, A.; Ricciardi, A.; Cusano, A.

    2013-05-01

    In this work, an ultra compact in line fiber optic Fabry-Perot interferometer is presented. The interferometric structure consists of a thin (< 1 μm) amorphous silicon layer in line integrated into a standard single mode optical fiber by means of an electric arc discharge technique. The device exhibits low loss (1.46 dB) and high interference fringe visibility (~ 30% in linear scale) both in reflection and transmission due to the high refractive index contrast between silica and α-Si. A high linear temperature sensitivity up to 75 pm/°C is demonstrated in the range 15-52 °C. The proposed device is simple, compact, cost effective and attractive for point monitoring sensing application in ultra-high temperature sensing in harsh environments.

  1. Micro fiber-optic Fabry-Perot interferometer fabricated by chemical etching of Er-doped fiber

    NASA Astrophysics Data System (ADS)

    Gong, Yuan; Rao, Yun-Jiang; Guo, Yu; Wu, Yu; Ran, Zeng-Ling

    2009-10-01

    Micro extrinsic fiber-optic Fabry-Perot interferometers (MEFPI) are fabricated by chemically etching Er-doped fiber and then splicing the etched fiber to a single-mode fiber, for the first time to our knowledge. By using the mixture of Hydrochloric (HCl) acid and Hydrofluoric (HF) acid as etching solution, a cavity length of up to ~27 μm and a maximum fringe contrast of ~24dB are obtained. Experimental results show that the MEFPI is insensitive to temperature change but highly sensitive to strain, with temperature and strain sensitivities of ~0.65 pm/°C and 3.15 pm/ μɛ, respectively. Such type of MEFPI sensors based on the etched Er-doped fiber is compact, cost-effective and especially suitable for mass production, offering great potential for a wide range of applications.

  2. Employing split-band technique and Fabry Perot etalon filter to improve directly modulated fiber optical CATV system performances

    NASA Astrophysics Data System (ADS)

    Lu, Hai-Han; Patra, Ardhendu Sekhar; Wu, Hsiao-Wen; Tzeng, Shah-Jye; Ho, Wen-Jeng; Yee, Hoshin

    2008-07-01

    We proposed and demonstrated a directly modulated NTSC 77-channel fiber optical CATV transport system using split-band technique at the transmitting site and Fabry-Perot (FP) etalon filter at the receiving site to improve system performance. Good performance of carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple beat (CTB) were obtained in our proposed systems over a 100-km standard single-mode fiber (SMF) transmission. Employing a FP etalon filter in fiber optical CATV transport systems is useful in real network, as it is simple, passive, and potentially low cost. This proposed system reveals an outstanding one with simpler and more economic advantages than that of externally modulated transport system.

  3. Large temperature sensitivity of fiber-optic extrinsic Fabry-Perot interferometer based on polymer-filled glass capillary

    NASA Astrophysics Data System (ADS)

    Zhang, Guilin; Yang, Minghong; Wang, Min

    2013-12-01

    A novel and low cost fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is proposed. The EFPI is fabricated at the fiber tip by inserting a single mode fiber (SMF) into a partially polymer-filled glass capillary to form an air micro-cavity, which can be precisely controlled with a three-dimensional translation stage. The optimal EFPI has a loss less than 10 dB and a fringe visibility more than 30 dB. Application of the EFPI for temperature measurement is experimentally demonstrated. Due to the high thermal expansion coefficient (TEC) of the polymer, the sensor exhibits a good linear response and large temperature sensitivity of ˜5.2 nm/°C, which is almost three orders larger than that of the current F-P temperature sensors. Therefore, it may be applied to the surrounding temperature sensing.

  4. Cost-effective wavelength-tunable fiber laser using self-seeding Fabry-Perot laser diode.

    PubMed

    Yeh, Chien-Hung; Shih, Fu Y; Wang, Chia H; Chow, Chi W; Chi, Sien

    2008-01-01

    We propose and experimentally demonstrate a continuous wave (CW) tunable-wavelength fiber laser using self-seeding Fabry-Perot laser diode (FP-LD) without optical amplifier inside gain cavity. By employing a tunable bandpass filter (TBF) and a fiber reflected mirror (FRM) within a gain cavity, the fiber laser can lase a single-longitudinal wavelength due to the self-seeding operation. The proposed tunable wavelength laser has a good performance of the output power (> -15 dBm) and optical side-mode suppression ratio (> 40 dB) in the wavelength tuning range of 1533.75 to 1560.95 nm. In addition, the output stabilities of the fiber laser are also investigated. PMID:18521175

  5. Enhanced chiral response from the Fabry-Perot cavity coupled meta-surfaces

    NASA Astrophysics Data System (ADS)

    Yang, Ze-Jian; Hu, De-Jiao; Gao, Fu-Hua; Hou, Yi-Dong

    2016-08-01

    The circular dichroism (CD) signal of a two-dimensional (2D) chiral meta-surface is usually weak, where the difference between the transmitted (or reflected) right and left circular polarization is barely small. We present a general method to enhance the reflective CD spectrum, by adding a layer of reflective film behind the meta-surface. The light passes through the chiral meta-surface and propagates towards the reflector, where it is reflected back and further interacts with the chiral meta-surface. The light is reflected back and forth between these two layers, forming a Fabry-Perot type resonance, which interacts with the localized surface plasmonic resonance (LSPR) mode and greatly enhances the CD signal of the light wave leaving the meta-surface. We numerically calculate the CD enhancing effect of an L-shaped chiral meta-surface on a gold film in the visible range. Compared with the single layer meta-surface, the L-shaped chiral meta-surface has a CD maximum that is dramatically increased to 1. The analysis of reflection efficiency reveals that our design can be used to realize a reflective circular polarizer. Corresponding mode analysis shows that the huge CD originates from the hybrid mode comprised of FP mode and LSPR. Our results provide a general approach to enhancing the CD signal of a chiral meta-surface and can be used in areas like biosensing, circular polarizer, integrated photonics, etc. Project supported by the National Natural Science Foundation of China (Grant No. 61377054).

  6. Development of tunable Fabry-Perot spectral camera and light source for medical applications

    NASA Astrophysics Data System (ADS)

    Kaarre, M.; Kivi, S.; Panouillot, P. E.; Saari, H.; Mäkynen, J.; Sorri, I.; Juuti, M.

    2013-05-01

    VTT has developed a fast, tunable Fabry-Perot (FP) filter component and applied it in making small, lightweight spectral cameras and light sources. One application field where this novel technology is now tested is medical field. A demonstrator has been made to test the applicability of FP based spectral filtering in the imaging of retina in visible light wavelength area.

  7. Low-Cost, Single-Frequency Sources for Spectroscopy Using Conventional Fabry-Perot Diode Lasers

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Duerksen, Gary L.

    1999-01-01

    Commercial (uncoated) Fabry-Perot laser diodes are converted to single-frequency spectroscopy sources by passively locking the laser frequency to the band edge of a fiber Bragg grating, which phase-locks the laser oscillations through self-injection seeding.

  8. A new fiber-tip Fabry-Perot interferometer and its application for pressure measurement

    NASA Astrophysics Data System (ADS)

    Wang, Guanjun; Liu, Shen; Zhao, Jing; Liao, Changrui; Xu, Xizhen; Wang, Yiping

    2015-07-01

    This paper reports a new silica fiber-tip Fabry-Perot interferometer with thin film and large surface area characteristic for high pressure and vacuum degree detection simultaneously, which is fabricated by etching a flat fiber tip into concave surface firstly, with subsequent arc jointing the concave fiber into a inline Fabry-Perot cavity, then drawing one surface of the F-P cavity into several micrometers scale by arc discharge and finally etching the surface into sub-micrometer scale integrally. As the silica fiber-tip Fabry-Perot interferometer film thickness could be tailored very thinly by HF acid solution, plus the surface area of thin film could be expanded during the chemical etching process, the variation of the bubble cavity length is very sensitive to the inner/outer pressure difference of the fiber-tip Fabry-Perot interferometer. Experimental result shows an high sensitivity of 780nm/MPa is feasible. Such configuration has the advantages of lowcost, ease of fabrication and compact size, which make it a promising candidate for pressure and vacuum measurement.

  9. Transfer functions of double- and multiple-cavity Fabry Perot filters driven by Lorentzian sources

    NASA Astrophysics Data System (ADS)

    Marti, Javier; Capmany, Jose

    1996-12-01

    We derive expressions for the transfer functions of double- and multiple-cavity Fabry Perot filters driven by laser sources with Lorentzian spectrum. These are of interest because of their applications in sensing and channel filtering in optical frequency-division multiplexing networks.

  10. Low-Cost, Single-Frequency Sources for Spectroscopy using Conventional Fabry-Perot Diode Lasers

    NASA Technical Reports Server (NTRS)

    Duerksen, Gary L.; Krainak, Michael A.

    1999-01-01

    Commercial (uncoated) Fabry-Perot laser diodes are converted to single-frequency spectroscopy sources by passively locking the laser frequency to the band edge of a fiber Bragg grating, which phase-locks the laser oscillations through self-injection seeding.

  11. Magnetic field sensing with an in-line Fabry-Perot interferometer based on capillary optical fiber and Terfenol-D

    NASA Astrophysics Data System (ADS)

    Gouvêa, Paula M. P.; Costa, Greice K. B.; Soares, Larissa M. B.; Pereira, João. M. B.; Fávero, Fernando C.; Braga, Arthur M. B.; Bruno, Antonio C.; Carvalho, Isabel C. S.

    2015-09-01

    In this paper we discuss results obtained with an in-line Fabry-Perot interferometer (FPI) built by splicing a small section of capillary fiber between two pieces of standard single mode fiber, resulting in a rectangular air cavity. The FPIs were characterized regarding sensitivity to temperature and longitudinal strain. The FPIs were bonded to pieces of Terfenol-D, a magnetostrictive alloy, to be used as magnetic field sensors. Fiber Bragg Gratings were also bonded to Terfenol-D for comparison. The FPI based on capillary optical fiber and Terfenol-D showed a higher sensitivity to an applied magnetic field when compared to an FBG.

  12. In-Fiber Fabry-Perot and Mach-Zehnder interferometers based on hollow optical fiber fabricated by arc fusion splicing with small lateral offsets

    NASA Astrophysics Data System (ADS)

    Duan, De-Wen; Rao, Yun-Jiang; Xu, Lai-Cai; Zhu, Tao; Deng, Ming; Wu, Di; Yao, Jun

    2011-10-01

    Two kinds of in-line all-fiber interferometers, including tip Fabry-Perot interferometer and compact Mach-Zehnder interferometer, are proposed and demonstrated by fusion splicing a short section of hollow optical fiber (HOF) to the end of single-mode fiber (SMF) and sandwiching a section of HOF in between two sections of SMF, respectively. In both interferometers, a small lateral offset is introduced to induce the optical path difference required to form the interferometer. Temperature responses of both types of interferometers are studied experimentally. It is anticipated that such easy making, compact and low-cost fiber-optic interferometers could find important applications in practice.

  13. Gaussian-optics-based optical modeling and characterization of a Fabry-Perot microcavity for sensing applications.

    PubMed

    Guo, Dagang; Lin, Rongming; Wang, Weijun

    2005-08-01

    A generalized study has been carried out on the modeling of a Fabry-Perot microcavity for sensing applications. Different analytical models on transmission characteristics of a Fabry-Perot microcavity are established by using plane-wave-based techniques, such as the Macleod characteristic matrix technique, the transfer matrix technique, and Smith's technique. A novel Gaussian-optics-based model for a Fabry-Perot microcavity illuminated by a laser beam is then developed and validated. The influence of laser beam waist on microcavity optical response is investigated, and the required minimal beam waist size is explored to ensure a useful optical response for sensing applications that can be accurately predicted by plane-wave optics. Also, the perturbations of microcavity performance induced by different types of microcavity mirror imperfections are discussed, based on the novel optical model. The prototype of the proposed Fabry-Perot microcavity for sensing applications has been successfully fabricated and characterized.

  14. Measurements of the phase shift on reflection for low-order infrared Fabry-Perot interferometer dielectric stack mirrors.

    PubMed

    Mielke, S L; Ryan, R E; Hilgeman, T; Lesyna, L; Madonna, R G; Van Nostrand, W C

    1997-11-01

    A simple technique based on a Fizeau interferometer to measure the absolute phase shift on reflection for a Fabry-Perot interferometer dielectric stack mirror is described. Excellent agreement between the measured and predicted phase shift on reflection was found. Also described are the salient features of low-order Fabry-Perot interferometers and the demonstration of a near ideal low-order (1-10) Fabry-Perot interferometer through minimizing the phase dispersion on reflection of the dielectric stack. This near ideal performance of a low-order Fabry-Perot interferometer should enable several applications such as compact spectral imagers for solid and gas detection. The large free spectral range of such systems combined with an active control system will also allow simple interactive tuning of wavelength agile laser sources such as CO(2) lasers, external cavity diode lasers, and optical parametric oscillators.

  15. Stable CW Single-Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking

    NASA Technical Reports Server (NTRS)

    Duerksen, Gary L.; Krainak, Michael A.

    1998-01-01

    Previously, single-frequency semiconductor laser operation using fiber Bragg gratings (FBG) has been achieved by two methods: (1) use of the FBG as the output coupler for an anti-reflection-coated semiconductor gain element; (2) pulsed operation of a gain-switched Fabry-Perot laser diode with FBG-optical and RF-electrical feedback. Here, we demonstrate CW single frequency operation from a non-AR coated Fabry-Perot laser diode using only FBG optical feedback.

  16. Stable CW Single Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking

    NASA Technical Reports Server (NTRS)

    Duerksen, Gary L.; Krainak, Michael A.

    1999-01-01

    Previously, single-frequency semiconductor laser operation using fiber Bragg gratings has been achieved by tWo methods: 1) use of the FBG as the output coupler for an anti-reflection-coated semiconductor gain element'; 2) pulsed operation of a gain-switched Fabry-Perot laser diode with FBG-optical and RF-electrical feedback'. Here, we demonstrate CW single frequency operation from a non-AR coated Fabry-Perot laser diode using only FBG optical feedback.

  17. Time-resolved spectral measurements on a multielectrode DFB laser using a Fabry-Perot interferometer. [Distributed feedback laser

    SciTech Connect

    Davis, M.G.; O'Dowd, R.F. . Dept. of Electronic Engineering)

    1994-01-01

    A Fabry-Perot interferometer based time-resolved spectral measurement system capable of transform limited performance is described here. The system results from a model developed for the Fabry-Perot interferometer from which the mirror reflectivity emerges as the critical parameter in determining both the temporal and spectral response. Using this system, the response of a multi-electrode DFB laser under a number of different modulation formats is investigated.

  18. Nonlinear optical processing with Fabry-Perot interferometers containing phase recording media

    NASA Technical Reports Server (NTRS)

    Bartholomew, B. J.; Lee, S. H.

    1980-01-01

    New techniques in nonlinear optical processing are explored, based on the operation of intensity level selection as performed by a Fabry-Perot interferometer containing a phase object. The image being processed is recorded on a medium between the mirrors as a spatially varying phase shift less than pi. The interferometer only transmits light through those portions of the object that corresponds to a single value of the phase and hence to a single intensity level in the input. More complicated operations such as thresholding and analog-to-digital conversion are performed by modulating the light source as the different levels are selected. Photoresist and lithium niobate have been used as phase objects, and experimental data for both are presented. Three kinds of Fabry-Perot interferometers have been used to demonstrate nonlinear processing using coherent and incoherent light. Color images have been produced with black and white inputs and white light illumination.

  19. FIFI: The MPE Garching/UC Berkeley Far-Infrared Imaging Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Geis, Norbert; Genzel, Reinhard; Haggerty, M.; Herrmann, F.; Jackson, J.; Madden, Suzanne C.; Nikola, T.; Poglitsch, Albrecht; Rumitz, M.; Stacey, G. J.

    1995-01-01

    We describe the performance characteristics of the MPE Garching/UC Berkeley Far-Infrared Imaging Fabry-Perot Interferometer (FIFI) for the Kuiper Airborne Observatory (KAO). The spectrometer features two or three cryogenic tunable Fabry-Perot filters in series giving spectral resolution R of up to 10(exp 5) in the range of 40 microns less than lambda less than 200 microns, and an imaging 5x5 array of photoconductive detectors with variable focal plane plate scale. The instrument works at background limited sensitivity of up to 2 x 10(exp -19) W cm(exp -2) Hz(exp -1/2) per pixel per resolution element at R = 10(exp 5) on the KAO.

  20. Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review

    PubMed Central

    Islam, Md. Rajibul; Ali, Muhammad Mahmood; Lai, Man-Hong; Lim, Kok-Sing; Ahmad, Harith

    2014-01-01

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed. PMID:24763250

  1. Development of a Fabry-Perot Interferometer for Ultra-Precise Measurements of Column CO2

    NASA Technical Reports Server (NTRS)

    Wilson, Emily L.; Georgieva, Elena M.; Heaps, William S.

    2005-01-01

    A passive Fabry-Perot based instrument is described for detecting column CO2 through absorption measurements at 1.58 microns . In this design, solar flux reaches the instrument platform and is directed through two channels. In the first channel, transmittance fi5nges from a Fabry-Perot interferometer are aligned with CO2 absorption lines so that absorption due to CO2 is primarily detected. The second channel encompasses the same frequency region as the first, but is comparatively more sensitive to changes in the solar flux than absorption due to CO2. The ratio of these channels is sensitive to changes in the total CO2 column, but not to changes in solar flux. This inexpensive instrument will offer high precision measurements (error 4%) in a compact package. Design of this instrument and preliminary ground-based measurements of column CO2 are presented here as well as strategies for deployment on aircraft and satellite platforms.

  2. Design and Fabrication of Integrated Fabry-Perot Type Color Reflector for Reflective Displays.

    PubMed

    Cho, Seong M; Cheon, Sang Hoon; Kim, Tae-Youb; Ah, Chil Seong; Song, Juhee; Ryu, Hojun; Chu, Hye Yong

    2016-05-01

    A Fabry-Perot type integrated color reflector, with red/blue/green colors as subpixels, was designed and fabricated with Si substrate. Ag films were used as reflective mirror layers, SiO2 films were used as Fabry-Perot cavity layers and W films were used as partially reflective layers for the cavity. To minimize the effects of the thickness variation of the oxide cavity layers, the structure of the color reflector was optimized, and the differential deposition scheme was devised and applied in the fabrication process. The integrated color reflector was successfully fabricated with the proposed fabrication scheme. The measured white reflectance was > 45% in the visible spectrum range and -49% at 550 nm wavelength. The fabricated reflector had moderate color gamut of 17% of the National Television System Committee (NTSC) standard and it showed very high white reflectivity. The fabricated color reflector is expected to be applicable to reflective displays. PMID:27483867

  3. Low threshold Fabry-Perot optofluidic resonator fabricated by femtosecond laser micromachining.

    PubMed

    Simoni, F; Bonfadini, S; Spegni, P; Lo Turco, S; Lucchetta, D E; Criante, L

    2016-07-25

    We report the realization and characterization of an optofluidic microlaser based on a Fabry-Perot resonator fabricated by exploiting two direct writing fabrication techniques: the femtosecond laser micromachining and the inkjet printing technology. In this way a standard Fabry-Perot cavity has been integrated into an optofluidic chip. When using rhodamine 6G dissolved in ethanol at concentration of 5∙10-3 mol/l, laser emission was detected at a threshold energy density of 1.8 μJ/mm2 at least one order of magnitude lower than state-of-the-art optofluidic lasers. Linewidth below ~0.6 nm was measured under these conditions with a quality factor Q~103. These performances and robustness of the device makes it an excellent candidate for biosensing, security and environment monitoring applications. PMID:27464188

  4. Sensing Properties of a Fabry-Perot Dielectric Structure and Dimer Nanoparticles

    DOE PAGES

    Polemi, A.; Shuford, K. L.

    2012-01-01

    We investigate the use of a Fabry-Perot dielectric structure combined with differently shaped nanoparticles for Surface Enhanced Raman Scattering. In particular, we show how an ideal two-layer Fabry-Perot configuration enhances the local surface field of silver nanoparticles positioned on the surface of the structure. We develop the concept using disc dimers and then extend the discussion to bowtie nanoparticles. The structure is excited by a single emitter, which couples to the nanoparticles through the dielectric layers, producing a wide aperture field that can be used to excite multiple dimers. We show how an array of nanoparticles can be properly arrangedmore » in order to increase the total scattering signal generated from the structure. The layered geometry produces robust field properties in between nanoparticles, making the overall sensing characteristics less sensitive to the interparticle seperation distance and incident polarization.« less

  5. Low threshold Fabry-Perot optofluidic resonator fabricated by femtosecond laser micromachining.

    PubMed

    Simoni, F; Bonfadini, S; Spegni, P; Lo Turco, S; Lucchetta, D E; Criante, L

    2016-07-25

    We report the realization and characterization of an optofluidic microlaser based on a Fabry-Perot resonator fabricated by exploiting two direct writing fabrication techniques: the femtosecond laser micromachining and the inkjet printing technology. In this way a standard Fabry-Perot cavity has been integrated into an optofluidic chip. When using rhodamine 6G dissolved in ethanol at concentration of 5∙10-3 mol/l, laser emission was detected at a threshold energy density of 1.8 μJ/mm2 at least one order of magnitude lower than state-of-the-art optofluidic lasers. Linewidth below ~0.6 nm was measured under these conditions with a quality factor Q~103. These performances and robustness of the device makes it an excellent candidate for biosensing, security and environment monitoring applications.

  6. Design and Fabrication of Integrated Fabry-Perot Type Color Reflector for Reflective Displays.

    PubMed

    Cho, Seong M; Cheon, Sang Hoon; Kim, Tae-Youb; Ah, Chil Seong; Song, Juhee; Ryu, Hojun; Chu, Hye Yong

    2016-05-01

    A Fabry-Perot type integrated color reflector, with red/blue/green colors as subpixels, was designed and fabricated with Si substrate. Ag films were used as reflective mirror layers, SiO2 films were used as Fabry-Perot cavity layers and W films were used as partially reflective layers for the cavity. To minimize the effects of the thickness variation of the oxide cavity layers, the structure of the color reflector was optimized, and the differential deposition scheme was devised and applied in the fabrication process. The integrated color reflector was successfully fabricated with the proposed fabrication scheme. The measured white reflectance was > 45% in the visible spectrum range and -49% at 550 nm wavelength. The fabricated reflector had moderate color gamut of 17% of the National Television System Committee (NTSC) standard and it showed very high white reflectivity. The fabricated color reflector is expected to be applicable to reflective displays.

  7. Coherent electron transparent tunneling through a single barrier within a Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Stolle, Jason; Baum, Chaz; Amann, Ryan; Haman, Ryan; Call, Tanner; Li, Wei

    2016-07-01

    Electromagnetic wave and quantum DeBroglie wave have many parallels between each other. We investigate the quantum mechanical counterpart of electromagnetic resonant tunneling through a non-absorbing metal layer. It is confirmed that an electron also has transparent transmission through a single barrier within a Fabry-Perot like cavity. This tunneling structure is actually a distortion of the Fabry-Perot echelon. We find that for a specific resonant electron energy, the cavity length is related to the electron's DeBroglie wavelength; and the single barrier can be located at a series positions with an interval equal to a half of the DeBroglie wavelength, not just at the center of the cavity. This tunneling phenomenon will have novel applications in quantum devices such as the resonant tunneling diode and scanning tunneling microscope. The results of this paper should also have impact on related electromagnetic research and application.

  8. Silicon-based on-chip electrically tunable sidewall Bragg grating Fabry-Perot filter.

    PubMed

    Zhang, Weifeng; Ehteshami, Nasrin; Liu, Weilin; Yao, Jianping

    2015-07-01

    We report the design, fabrication, and testing of a silicon-based on-chip electrically tunable sidewall Bragg grating Fabry-Perot filter. Spectral measurement shows that the filter has a narrow notch in reflection of approximately 46 pm, a Q-factor of 33,500, and an extinction ratio of 16.4 dB. DC measurement shows that the average central wavelength shift rates with forward and reverse bias are -1.15  nm/V and 4.2  pm/V, respectively. Due to strong light confinement in the Fabry-Perot cavity, the electro-optic frequency response shows that the filter has a 3-dB modulation bandwidth of ∼5.6  GHz. The performance of using the filter to perform modulation of a 3.5  Gb/s2(7)-1 nonreturn-to-zero pseudorandom binary sequence is evaluated.

  9. Reflectivity enhanced refractive index sensor based on a fiber-integrated Fabry-Perot microresonator.

    PubMed

    Wieduwilt, T; Dellith, J; Talkenberg, F; Bartelt, H; Schmidt, M A

    2014-10-20

    We discuss a fiber-integrated refractive index sensor with strongly improved detection performance. The resonator has been implemented by means of focused-ion beam milling of a step index fiber and shows a sensitivity of about 1.15µm/RIU. Coating the resonator walls led to a strongly improved mirror reflectivity by a factor of about 26. Design rules for device optimization and a detailed mathematical analysis are discussed, revealing that the sensor operates as an optimized Fabry-Perot resonator. We also show that the performance of such kind of Fabry-Perot sensors is, in general, limited by the detection limit function - a quantity depending on the cavitiy's finesse and on the measurement capabilities used.

  10. Resolution limits of extrinsic Fabry-Perot interferometric displacement sensors utilizing wavelength scanning interrogation.

    PubMed

    Ushakov, Nikolai; Liokumovich, Leonid

    2014-08-10

    The factors limiting the resolution of displacement sensors based on the extrinsic Fabry-Perot interferometer were studied. An analytical model giving the dependency of extrinsic Fabry-Perot interferometric (EFPI) resolution on the parameters of an optical setup and a sensor interrogator was developed. The proposed model enables one to either estimate the limit of possible resolution achievable with a given setup, or derive the requirements for optical elements and/or a sensor interrogator necessary for attaining the desired sensor resolution. An experiment supporting the analytical derivations was performed, demonstrating a large dynamic measurement range (with cavity length from tens of microns to 5 mm), a high baseline resolution (from 14 pm), and good agreement with the model.

  11. Manipulating the optical bistability at terahertz frequency in the Fabry-Perot cavity with graphene.

    PubMed

    Jiang, Leyong; Guo, Jun; Wu, Leiming; Dai, Xiaoyu; Xiang, Yuanjiang

    2015-11-30

    We investigate theoretically the optical bistability from a Fabry-Perot cavity with graphene in the terahertz (THz) frequency. It is demonstrated that the optical bistablility in this cavity can be realized due to the electric field enhancement and the giant third-order nonlinear conductivity of graphene. The optical bistable behavior is strongly dependent on the transmission amplitude of the mirror and the position of the graphene in the cavity. It is especially important that the hysterical behaviors of the transmitted light rely on the optical conductivity of graphene, making the Fabry-Perot cavity to be a good candidate for dynamic tunable optical bistable device in the THz frequencies, owing to the possibility of high tunability of graphene conductivity by means of external electrostatic or magnetostatic field.

  12. Chronology of Fabry-Perot interferometer fiber-optic sensors and their applications: a review.

    PubMed

    Islam, Md Rajibul; Ali, Muhammad Mahmood; Lai, Man-Hong; Lim, Kok-Sing; Ahmad, Harith

    2014-04-24

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.

  13. Analyzing the temperature sensitivity of Fabry-Perot sensor using multilayer graphene diaphragm.

    PubMed

    Li, Cheng; Liu, Qianwen; Peng, Xiaobin; Fan, Shangchun

    2015-10-19

    A miniature Fabry-Perot interferometric sensor with an ultra-high temperature sensitivity was constructed by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule with an inner diameter of 125 μm, and van der Waals interactions between the graphene diaphragm and its substrate created a low finesse Fabry-Perot interferometer with a cavity length of 42.86 μm. Temperature testing demonstrated a temperature-induced cavity length change of 352 nm/°C with a good linearity in the range of 20-60 °C. The result conformed well to the proposed analytical models relating to thermal expansion of trapped gas, thermal-optical property of graphene diaphragm and deflection behavior of bulged graphene blister. However, the ultra-thin diaphragm exhibited a small deflection deformation characteristic due to the applied higher loads.

  14. Hydrogen production rates from ground-based Fabry-Perot observations of comet Kohoutek

    NASA Technical Reports Server (NTRS)

    Scherb, F.

    1981-01-01

    The only ground-based observations of a cometary hydrogen corona that have been obtained up to the present were carried out during the appearance of comet Kohoutek (1973 XII). Hydrogen Balmer alpha (H-alpha) emission from the gas cloud surrounding the comet was detected using a Fabry-Perot spectrometer at Kitt Peak National Observatory. These observations have been reexamined using (1) recently obtained solar full-disk Lyman beta emission line profiles, (2) a new calibration of the absolute sensitivity of the Fabry-Perot spectrometer based on comparison of NGC 7000 with standard stars and the planetary nebula NGC 7662, and (3) corrections for atmospheric extinction instead of the geocoronal H-alpha comparison method used previously to obtain comet H-alpha intensities. The new values for hydrogen production rates are in good agreement with results obtained from Lyman alpha observations of comet Kohoutek.

  15. Phase-Demodulation Error of a Fiber-Optic Fabry Perot Sensor with Complex Reflection Coefficients

    NASA Astrophysics Data System (ADS)

    Kilpatrick, James M.; MacPherson, William N.; Barton, James S.; Jones, Julian D. C.

    2000-03-01

    The influence of reflector losses attracts little discussion in standard treatments of the Fabry Perot interferometer yet may be an important factor contributing to errors in phase-stepped demodulation of fiber optic Fabry Perot (FFP) sensors. We describe a general transfer function for FFP sensors with complex reflection coefficients and estimate systematic phase errors that arise when the asymmetry of the reflected fringe system is neglected, as is common in the literature. The measured asymmetric response of higher-finesse metal dielectric FFP constructions corroborates a model that predicts systematic phase errors of 0.06 rad in three-step demodulation of a low-finesse FFP sensor ( R 0 . 05 ) with internal reflector losses of 25%.

  16. Deep Fabry-Perot imaging of NGC 6240: Kinematic evidence for merging galaxies

    NASA Technical Reports Server (NTRS)

    Hawthorn, J. Bland; Wilson, A. S.; Tully, R. B.

    1990-01-01

    The authors have observed the superluminous, infrared galaxy NGC 6240 (z = 0.025) at H alpha with the Hawaii Imaging Fabry-Perot Interferometer (HIFI - Bland and Tully 1989). During the past decade, observational evidence from all wavebands indicates that the unusual appearance of NGC 6240 has resulted from a collision between two gas-rich systems, a view which is supported by our spectrophotometric data. However, the origin of the enormous infrared luminosity (4 times 10(exp 11) solar luminosity) detected by the Infrared Astronomy Satellite (IRAS) remains highly controversial, where opinions differ on the relative roles of large-scale shocks, massive star formation or a buried 'active' nucleus. These mechanisms are discussed in the light of the author's Fabry-Perot observations.

  17. All-fiber, long-active-length Fabry-Perot strain sensor.

    PubMed

    Pevec, Simon; Donlagic, Denis

    2011-08-01

    This paper presents a high-sensitivity, all-silica, all-fiber Fabry-Perot strain-sensor. The proposed sensor provides a long active length, arbitrary length of Fabry-Perot cavity, and low intrinsic temperature sensitivity. The sensor was micro-machined from purposely-developed sensor-forming fiber that is etched and directly spliced to the lead-in fiber. This manufacturing process has good potential for cost-effective, high-volume production. Its measurement range of over 3000 µε, and strain-resolution better than 1 µε were demonstrated by the application of a commercial, multimode fiber-based signal processor. PMID:21934926

  18. Modeling of multi-cavity Fabry-Perot optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Wierzba, Paweł

    2015-12-01

    Reflectance characteristics of a two-cavity extrinsic Fabry-Perot optical fiber sensor were investigated using computer modeling. Calculations were performed using a plane wave-based approach, selected for clarity of results. Based on the modeling results, it can be concluded that the two-cavity Fabry-Perot interferometer can be used to measure two different quantities, such as refractive index and temperature, independently. It is also possible to use one of its cavities as a wavelength or optical path length reference, especially when a tunable laser is used as a light source. Spectral signal processing needed in such sensor is not substantially more complicated than that used in single cavity sensors.

  19. Chronology of Fabry-Perot interferometer fiber-optic sensors and their applications: a review.

    PubMed

    Islam, Md Rajibul; Ali, Muhammad Mahmood; Lai, Man-Hong; Lim, Kok-Sing; Ahmad, Harith

    2014-01-01

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed. PMID:24763250

  20. A hybrid demodulation method of fiber-optic Fabry-Perot pressure sensor

    NASA Astrophysics Data System (ADS)

    Yu, Le; Lang, Jianjun; Pan, Yong; Wu, Di; Zhang, Min

    2013-12-01

    The fiber-optic Fabry-Perot pressure sensors have been widely applied to measure pressure in oilfield. For multi-well it will take a long time (dozens of seconds) to demodulate downhole pressure values of all wells by using only one demodulation system and it will cost a lot when every well is equipped with one system, which heavily limits the sensor applied in oilfield. In present paper, a new hybrid demodulation method, combining the windowed nonequispaced discrete Fourier Transform (nDFT) method with segment search minimum mean square error estimation (MMSE) method, was developed, by which the demodulation time can be reduced to 200ms, i.e., measuring 10 channels/wells was less than 2s. Besides, experimental results showed the demodulation cavity length of the fiber-optic Fabry-Perot sensor has a maximum error of 0.5 nm and consequently pressure measurement accuracy can reach 0.4% F.S.

  1. An analytical study on bistability of Fabry-Perot semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Wang, Gang; Chen, Shuqiang; Yang, Huajun

    2016-09-01

    Optical bistabilities have been considered to be useful for sensor applications. As a typical nonlinear device, Fabry-Perot semiconductor optical amplifiers (FPSOAs) exhibit bistability under certain conditions. In this paper, the bistable characteristics in FPSOAs are investigated theoretically. Based on Adams's relationship between the incident optical intensity I in and the z-independent average intracavity intensity I av, an analytical expression of the bistable loop width in SOAs is derived. Numerical simulations confirm the accuracy of the analytical result.

  2. Shot noise in gravitational-wave detectors with Fabry-Perot arms.

    PubMed

    Lyons, T T; Regehr, M W; Raab, F J

    2000-12-20

    Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry-Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian-French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms. PMID:18354690

  3. Diode laser frequency stabilization using a low cost, low finesse Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Hastings, Hannah; Jaber, Noura B.; Piatt, Georgia; Gregoric, Vincent C.; Carroll, Thomas J.; Noel, Michael W.

    2016-05-01

    Our lab employs low cost, low finesse Fabry-Perot cavities to stabilize the frequency of diode lasers used in ultra-cold Rydberg atom experiments. To characterize the stability of this technique, we perform a self-heterodyne linewidth measurement. For comparison, we also measure the linewidth when using a saturated absorption spectrometer to provide frequency stability. This work is supported by the National Science Foundation under Grants No. 1205895 and No. 1205897.

  4. Characteristics of Extrinsic Fabry-Perot Interferometric (EFPI) Fiber-Optic Strain Gages

    NASA Technical Reports Server (NTRS)

    Hare, David A.; Moore, Thomas C., Sr.

    2000-01-01

    The focus of this paper is a comparison of the strain-measuring characteristics of one type of commercially available fiber-optic strain sensor with the performance of conventional resistance strain gages. Fabry-Perot type fiber-optic strain sensors were selected for this testing program. Comparative testing is emphasized and includes load testing at room temperature with apparent strain characterization cryogenically and at elevated temperatures. The absolute accuracy of either of these types of strain gages is not addressed.

  5. Continuous and discrete wavelength tuning in Er:Yb fiber Fabry--Perot lasers

    SciTech Connect

    Hsu, K.; Miller, C.M.; Kringlebotn, J.T.; Payne, D.N.

    1995-02-15

    Continuous and discrete single-frequency tuning in the 1.5-{mu}m wavelength region are demonstrated by incorporation of erbium:ytterbium phosphosilicate fibers in single and compound fiber Fabry--Perot cavity configurations. Continuous wavelength tuning was obtained over 3.3 nm in a single-cavity laser of 218-{mu}m cavity length. Discrete wavelength tuning was achieved over 9.59 nm in a compound-cavity laser having a 2-mm gain section.

  6. Multiwavelength erbium fiber ring laser using Sagnac loop and Fabry-Perot laser diode

    NASA Astrophysics Data System (ADS)

    Yeh, C.-H.; Shih, F.-Y.; Chen, C.-T.; Lee, C.-N.; Chi, S.

    2008-03-01

    We propose and demonstrate experimentally a simply multiple-wavelength erbium compound ring fiber laser employing a Sagnac interferometer with erbium-doped fiber amplifier (EDFA) and Fabry-Perot laser diode (FP-LD). The proposed laser has the advantage of simply structure and easy fabrication, lower insertion loss and cost-effective. Based on the Sagnac fiber laser scheme, the proposed laser can lase eight wavelengths simultaneously. Moreover, the optical output stability of the ring laser has been also discussed.

  7. Differential Radiometers Using Fabry-Perot Interferometric Technique for Remote Sensing of Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Georgieva, Elena M.; Heaps,William S.; Wilson, Emily L.

    2007-01-01

    A new type of remote sensing radiometer based upon the Fabry-Perot interferometric technique has been developed at NASA's Goddard Space Flight Center and tested from both ground and aircraft platform. The sensor uses direct or reflected sunlight and has channels for measuring column concentration of carbon dioxide at 1570 nm, oxygen lines sensitive to pressure and temperature at 762 and 768 nm, and water vapor (940 nm). A solid Fabry-Perot etalon is used as a tunable narrow bandpass filter to restrict the measurement to the gas of interest's absorption bands. By adjusting the temperature of the etalon, which changes the index of refraction of its material, the transmission fringes can be brought into nearly exact correspondence with absorption lines of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosphere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The technique is applicable to different chemical species. We have performed simulations and instrument design studies for CH4, "Cot isotope, and CO detection. Index Terms- Absorbing media, Atmospheric measurements, Fabry-Perot interferometers, Optical interferometry, Remote sensing.

  8. Polymer waveguide Fabry-Perot resonator for high-frequency ultrasound detection.

    PubMed

    Tadayon, Mohammad Amin; Baylor, Martha-Elizabeth; Ashkenazi, Shai

    2014-12-01

    Piezoelectric technology is the backbone of most medical ultrasound imaging arrays; however, signal transduction efficiency severely deteriorates in scaling the technology to element size smaller than 0.1 mm, often required for high-frequency operation (>20 MHz). Optical sensing and generation of ultrasound has been proposed and studied as an alternative technology for implementing sub-millimeter size arrays with element size down to 10 μm. The application of thin polymer film Fabry-Perot resonators has been demonstrated for high-frequency ultrasound detection; however, their sensitivity is limited by light diffraction loss. Here, we introduce a new method to increase the sensitivity of an optical ultrasound receiver by utilizing a waveguide between the mirrors of the Fabry-Perot resonator. This approach eliminates diffraction loss from the cavity, and therefore the finesse is only limited by mirror loss and absorption. By applying this method, we have achieved noise equivalent pressure of 178 Pa over a bandwidth of 30 MHz or 0.03 Pa/Hz1/2, which is about 20-fold better than a similar device without a waveguide. The finesse of the tested Fabry-Perot resonator was around 200. This result is 5 times higher than the finesse measured in the same device outside the waveguide region.

  9. Application of conventional CCD cameras with Fabry-Perot spectrometers for airglow observations

    SciTech Connect

    Coakley, M.M.; Roesler, F.L.

    1994-12-31

    This paper describes Fabry-Perot/CCD annular summing applied to airglow observations. Criteria are developed for determining the optimal rectangular format CCD chip configuration which minimizes dark and read noise. The relative savings in integration time of the imaging Fabry-Perot/CCD system over the pressure-scanned Fabry-Perot/PMT system is estimated for the optimal configuration through calculations of the signal to noise ratios for three extreme (but typical) cases of source and background intensity. The largest savings in integration time in estimated for the daysky thermospheric [O{sup 1}D] (6,300 {angstrom}) case where the bright ({approximately} 5 {times} 10{sup 6}R/{angstrom}) Rayleigh-scattered background dominates the read noise. The long integration times required to obtain useful signal to noise ratios for the faint ({approximately} 10R) nightsky exospheric hydrogen Balmer-{alpha} (6,563 {angstrom}) reduce the importance of the read noise term and yield large savings in integration time. The significance of the read noise term is greatly increased with the very short estimated integration times required for bright ({approximately} 200 R) nightsky lines such as thermospheric [O{sup 1}D]. Alternate CCD formats and applications methods that reduce read noise and provide improved performance in the latter case are compared against the CCD annular summing technique.

  10. Fiber-Optic Temperature Sensor Using a Thin-Film Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn

    1997-01-01

    A fiber-optic temperature sensor was developed that is rugged, compact, stable, and can be inexpensively fabricated. This thin-film interferometric temperature sensor was shown to be capable of providing a +/- 2 C accuracy over the range of -55 to 275 C, throughout a 5000 hr operating life. A temperature-sensitive thin-film Fabry-Perot interferometer can be deposited directly onto the end of a multimode optical fiber. This batch-fabricatable sensor can be manufactured at a much lower cost than can a presently available sensor, which requires the mechanical attachment of a Fabry-Perot interferometer to a fiber. The principal disadvantage of the thin-film sensor is its inherent instability, due to the low processing temperatures that must be used to prevent degradation of the optical fiber's buffer coating. The design of the stable thin-film temperature sensor considered the potential sources of both short and long term drifts. The temperature- sensitive Fabry-Perot interferometer was a silicon film with a thickness of approx. 2 microns. A laser-annealing process was developed which crystallized the silicon film without damaging the optical fiber. The silicon film was encapsulated with a thin layer of Si3N4 over coated with aluminum. Crystallization of the silicon and its encapsulation with a highly stable, impermeable thin-film structure were essential steps in producing a sensor with the required long-term stability.

  11. FABSOAR--A Fabry-Perot Spectrometer for Oxygen A-band Research Final Technical Report

    SciTech Connect

    Watchorn, Steven

    2010-09-10

    Because this was a Phase I project, it did not add extensively to the body of A-band knowledge. There was no basic research performed on that subject. The principal addition was that a mechanical and optical design for a triple-etalon Fabry-Perot interferometer (FABSOAR) capable of A-band sensing was sketched out and shown to be within readily feasible instrument fabrication parameters. The parameters for the proposed triple-etalon Fabry-Perot were shown to be very similar to existing Fabry-Perots built by Scientific Solutions. The mechanical design for the FABSOAR instrument incorporated the design of previous Scientific Solutions imagers, condensing the three three-inch-diameter etalons into a single, sturdy tube. The design allowed for the inclusion of a commercial off-the-shelf (COTS) filter wheel and a thermocooled CCD detector from Andor. The tube has supports to mount to a horizontal or vertical opticaltable surface, and was to be coupled to a Scientific Solutions pointing head at the Millstone Hill Observatory in Massachusetts for Phase II calibration and testing.

  12. Design and experimental research of a high-precision wavelength controller for tunable fiber Fabry-Perot filters

    NASA Astrophysics Data System (ADS)

    Qi, Hai-bing; Wei, Shu-hua; Wei, Chen

    2013-03-01

    A high-precision wavelength controller is presented in this paper. It is necessary to find out the difference between the central wavelength of a tunable fiber Fabry-Perot (FFP) filter and that of the input laser, while the wavelength controller operates at the states of wavelength-scanning and wavelength-locking modes. Firstly, a dynamic simulation model of tunable FFP filter is established, and the dynamic characteristic of tunable FFP filter modulated by an alternating current (AC) signal is simulated. Then the measuring time at wavelength-scanning mode compared with the theory time is discussed, and this time difference shows the difference between the central wavelength of a tunable FFP filter and that of the input laser. At last, the effects on wavelength-locking precision of time delays, including the time delay of opened-loop circuit, the time constant of the closed-loop circuit and the intrinsic hysteresis of piezoelectric (PZT) element, are analyzed. A wavelength controller of tunable FFP filter is designed and prepared. The experimental results at wavelength-locking mode show that a high locking precision is obtained.

  13. Switchable and multi-wavelength linear fiber laser based on Fabry-Perot and Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Gutierrez-Gutierrez, J.; Rojas-Laguna, R.; Estudillo-Ayala, J. M.; Sierra-Hernández, J. M.; Jauregui-Vazquez, D.; Vargas-Treviño, M.; Tepech-Carrillo, L.; Grajales-Coutiño, R.

    2016-09-01

    In this manuscript, switchable and multi-wavelength erbium-doped fiber laser arrangement, based on Fabry-Perot (FPI) and Mach-Zehnder (MZI) interferometers is presented. Here, the FPI is composed by two air-microcavities set into the tip of conventional single mode fiber, this one is used as a partially reflecting mirror and lasing modes generator. And the MZI fabricated by splicing a segment of photonic crystal fiber (PCF) between a single-mode fiber section, was set into an optical fiber loop mirror that acts as full-reflecting and wavelength selective filter. Both interferometers, promotes a cavity oscillation into the fiber laser configuration, besides by curvature applied over the MZI, the fiber laser generates: single, double, triple and quadruple laser emissions with a signal to noise ratio (SNR) of 30 dB. These laser emissions can be switching between them from 1525 nm to 1534 nm by adjusting the curvature radius over the MZI. This laser fiber offers a wavelength and power stability at room temperature, compactness and low implementation cost. Moreover the linear laser proposed can be used in several fields such as spectroscopy, telecommunications and fiber optic sensing systems.

  14. Determination of refractive index dispersion using fiber-optic low-coherence Fabry-Perot interferometer: implementation and validation

    NASA Astrophysics Data System (ADS)

    Karpienko, Katarzyna; Wróbel, Maciej S.; Jędrzejewska-Szczerska, Małgorzata

    2014-07-01

    We present the implementation and validation of low-coherence Fabry-Perot interferometer for refractive index dispersion measurements of liquids. A measurement system has been created with the use of four superluminescent diodes with different optical parameters, a fiber-optic coupler and an optical spectrum analyzer. The Fabry-Perot interferometer cavity has been formed by the fiber-optic end and mirror surfaces mounted on a micromechanical stage. The positive result of the validation procedure has been determined through statistical analysis. All obtained results were 99.999% statistically significant and were characterized by a strong positive correlation (r>0.98). The accuracy of the measured result of implemented low-coherence Fabry-Perot interferometer sensor is from 83% to 94%, which proves that the sensor can be used in the measurement of refractive index dispersion of liquids.

  15. Study of Fabry-Perot Etalon Stability and Tuning for Spectroscopic Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Clem, Michelle M.; Mielke-Fagan, Amy F.; Elam, Kristie A.

    2010-01-01

    The Fabry-Perot interferometer is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating flow properties such as gas velocity and temperature. Rayleigh scattered light from a focused laser beam can be directly imaged through a solid Fabry-Perot etalon onto a CCD detector to provide the spectral content of the scattered light. The spatial resolution of the measurements is governed by the locations of interference fringes. The location of the fringes can be changed by altering the etalon?s physical characteristics, such as thickness and index of refraction. For a fused silica solid etalon the physical properties can be adjusted by changing the etalon temperature; hence changing the order of the interference pattern and the physical fringe locations. Controlling the temperature of the etalon can provide for a slow time-response spatial scanning method for this type of etalon system. A custom designed liquid crystal Fabry-Perot (LCFP) can provide for a fast time-response method of scanning the etalon system. Voltage applied to the liquid crystal interface sets the etalon?s properties allowing Rayleigh measurements to be acquired at varying spatial locations across the image of the laser beam over a very short time period. A standard fused silica etalon and a tunable LCFP etalon are characterized to select the system that is best suited for Rayleigh scattering measurements in subsonic and supersonic flow regimes. A frequency-stabilized laser is used to investigate the apparent frequency stability and temperature sensitivity of the etalon systems. Frequency stability and temperature sensitivity data of the fused silica and LCFP etalon systems are presented in this paper, along with measurements of the LCFP etalon?s tuning capabilities. Rayleigh scattering velocity measurements with both etalon systems are presented, in an effort to determine which etalon is better suited to provide optical flow

  16. Velocity distribution of neutral species during magnetron sputtering by Fabry-Perot interferometry

    SciTech Connect

    Britun, N.; Han, J. G.; Oh, S.-G.

    2008-04-07

    The velocity distribution of a metallic neutral species sputtered in a dc magnetron discharge was measured using a planar Fabry-Perot interferometer and a hollow cathode lamp as a reference source. The measurement was performed under different angles of view relative to the target surface. The velocity distribution function in the direction perpendicular to the target becomes asymmetrical as the Ar pressure decreases, whereas it remains nearly symmetrical when the line of sight is parallel to the target surface. The average velocity of the sputtered Ti atoms was measured to be about 2 km/s.

  17. Development of an embedded Fabry Perot Fiber Optic Strain Rosette Sensor (FP-FOSRS)

    NASA Technical Reports Server (NTRS)

    Carman, Gregory P.; Lesko, John J.; Case, Scott W.; Fogg, Brian; Claus, Richard O.

    1992-01-01

    We investigate the feasibility of utilizing a Fabry-Perot Fiber Optic Strain Rosette Sensor (FP-FOSRS) for the evaluation of the internal strain state of a material system. We briefly describe the manufacturing process for this sensor and point out some potential problem areas. Results of an embedded FP-FOSRS in an epoxy matrix with external resistance strain gauges applied for comparative purposes are presented. We show that the internal and external strain measurements are in close agreement. This work lays the foundation for embedding this sensor in actual composite laminas.

  18. Ground-based observations of equatorial thermosphere dynamics with a Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Meriwether, J. W., Jr.; Biondi, M. A.

    1984-01-01

    Fabry-Perot determinations of thermospheric temperatures from 630.0 nm nightglow line width measurements were carried out for the period April to August, 1983. The nightly variation of the thermospheric temperature measured on 53 nights is compared with MSIS model predictions and found to agree occasionally with the model but, on the average, to exceed model predictions by approximately 180 K. The largest differences, 400 to 500 K occur during strongly increasing geomagnetic activity. Significant differences occur both during high geomagnetic/low solar activity and during low geomagnetic/high solar activity.

  19. A hyperspectral imager based on a Fabry-Perot interferometer with dielectric mirrors.

    PubMed

    Zucco, Massimo; Pisani, Marco; Caricato, Valentina; Egidi, Andrea

    2014-01-27

    In this paper we present a new hyperspectral imager based on a Fabry-Perot interferometer with low reflectivity dielectric mirrors. This set-up has been validated by measuring hypercubes of scenes containing emitting bodies and reflective surfaces in the visible region and compared with success with reference spectra. The system is based on dielectric mirrors which, with respect to similar systems based on metallic mirrors, have lower losses at lower cost and are available off-the-shelf. The spectra calculation is carried out with a Fourier transform based algorithm which takes into account the not negligible dispersion of the mirrors.

  20. In-fiber Fabry-Perot interferometer for strain and magnetic field sensing.

    PubMed

    Costa, Greice K B; Gouvêa, Paula M P; Soares, Larissa M B; Pereira, João M B; Favero, Fernando; Braga, Arthur M B; Palffy-Muhoray, Peter; Bruno, Antonio C; Carvalho, Isabel C S

    2016-06-27

    In this paper we discuss the results obtained with an in-fiber Fabry-Perot interferometer (FPI) used in strain and magnetic field (or force) sensing. The intrinsic FPI was constructed by splicing a small section of a capillary optical fiber between two pieces of standard telecommunication fiber. The sensor was built by attaching the FPI to a magnetostrictive alloy in one configuration and also by attaching the FPI to a small magnet in another. Our sensors were found to be over 4 times more sensitive to magnetic fields and around 10 times less sensitive to temperature when compared to sensors constructed with Fiber Bragg Grating (FBG).

  1. Emulation of Fabry-Perot and Bragg resonators with temporal optical solitons.

    PubMed

    Voytova, T; Oreshnikov, I; Yulin, A V; Driben, R

    2016-06-01

    The scattering of weak dispersive waves (DWs) on several equally spaced temporal solitons is studied. It is shown by systematic numerical simulations that the reflection of the DWs from the soliton trains strongly depends on the distance between the solitons. The dependence of the reflection and transmission coefficients on the inter-soliton distance and the frequency of the incident waves are studied in detail, revealing fascinating quasi-periodic behavior. The analogy between the observed nonlinear phenomena in the temporal domain and the usual Fabry-Perot and Bragg resonators is discussed.

  2. Measurement of unsteady gas temperature with optical fibre Fabry-Perot microsensors

    NASA Astrophysics Data System (ADS)

    Kilpatrick, J. M.; MacPherson, W. N.; Barton, J. S.; Jones, J. D. C.; Buttsworth, D. R.; Jones, T. V.; Chana, K. S.; Anderson, S. J.

    2002-05-01

    We describe the application of thin-film optical fibre Fabry-Perot (FFP) microsensors to high-bandwidth measurement of unsteady total temperature in transonic gas flows. An aerodynamic probe containing two temperature sensitive FFP microsensors was deployed in the rotor exit flow region of a gas turbine research rig. Measurements reveal gas temperature oscillations typically 4 K peak to peak at the blade passing frequency of 10 kHz with components to the third harmonic detected in the power spectrum of the temperature signal.

  3. A Fabry-Perot interferometer for sub-meV x-ray energy resolution

    SciTech Connect

    Caticha, A.; Aliberti, K.; Caticha-Ellis, S.

    1996-09-01

    The optical theory of Fabry-Perot interferometers (FPIs) for x rays using dynamically diffracting thin perfect crystals as reflectors is developed. Application to a device using high diffraction orders in silicon crystals of thickness of the order of 100 {mu}m or more shows that energy resolutions of the order of a tenth of a meV are achievable. The effect that various features, such as gap and mirror thickness, lattice mismatches, etc., have on the FPI resonances is studied. {copyright} {ital 1996 American Institute of Physics.}

  4. Nanodiamonds in Fabry-Perot cavities: a route to scalable quantum computing

    NASA Astrophysics Data System (ADS)

    Greentree, Andrew D.

    2016-02-01

    The negatively-charged nitrogen-vacancy colour centre in diamond has long been identified as a platform for quantum computation. However, despite beautiful proof of concept experiments, a pathway to true scalability has proven elusive. Now a group from Oxford and Grenoble-Alpes have shown coupling between nitrogen-vacancy centres and open Fabry-Perot cavities in a way that proves a clear route to scalable quantum computing (Johnson et al 2015 New J. Phys. 17 122003). And all at the relatively balmy temperature of 77 K.

  5. In-fiber Fabry-Perot interferometer for strain and magnetic field sensing.

    PubMed

    Costa, Greice K B; Gouvêa, Paula M P; Soares, Larissa M B; Pereira, João M B; Favero, Fernando; Braga, Arthur M B; Palffy-Muhoray, Peter; Bruno, Antonio C; Carvalho, Isabel C S

    2016-06-27

    In this paper we discuss the results obtained with an in-fiber Fabry-Perot interferometer (FPI) used in strain and magnetic field (or force) sensing. The intrinsic FPI was constructed by splicing a small section of a capillary optical fiber between two pieces of standard telecommunication fiber. The sensor was built by attaching the FPI to a magnetostrictive alloy in one configuration and also by attaching the FPI to a small magnet in another. Our sensors were found to be over 4 times more sensitive to magnetic fields and around 10 times less sensitive to temperature when compared to sensors constructed with Fiber Bragg Grating (FBG). PMID:27410621

  6. A Fabry-Perot interferometer for accurate measurement of temporal changes in stellar Doppler shift

    NASA Technical Reports Server (NTRS)

    Mcmillan, R. S.; Smith, P. H.; Frecker, J. E.; Merline, W. J.; Perry, M. L.

    1986-01-01

    The scrambling of incident light by an optical filter, and the stability obtainable through wavelength calibration by means of a tilt-tunable Fabry-Perot etalon, allow the accurate observation of Doppler shift changes in stellar absorption lines. Distinct, widely spaced monochromatic images of the entrance aperture are formed in the focal plane of the camera through a sampling of about 350 points on the profile of the stellar spectrum by successive orders of interferometric transmission through the etalon. Changes in Doppler shift modify the relative intensities of these images, in proportion to the slope of the spectral profile at each point sampled.

  7. High-sensitivity Fabry-Perot interferometric pressure sensor based on a nanothick silver diaphragm.

    PubMed

    Xu, Feng; Ren, Dongxu; Shi, Xiaolong; Li, Can; Lu, Weiwei; Lu, Lu; Lu, Liang; Yu, Benli

    2012-01-15

    We present a fiber-optic extrinsic Fabry-Perot interferometer pressure sensor based on a nanothick silver diaphragm. The sensing diaphragm, with a thickness measured in a few hundreds of nanometers, is fabricated by the electroless plating method, which provides a simple fabrication process involving a high-quality diaphragm at a low cost. The sensor exhibits a relatively linear response within the pressure variation range of 0-50 kPa, with a high pressure sensitivity of 70.5 nm/kPa. This sensor is expected to have potential applications in the field of highly sensitive pressure sensors. PMID:22854444

  8. High-finesse micro-lens fiber-optic extrinsic Fabry Perot interferometric sensors

    NASA Astrophysics Data System (ADS)

    Jiang, Yi; Tang, Caijie

    2008-10-01

    Micro-lenses are produced on two mirror-coated fiber ends in an extrinsic Fabry-Perot interferometer (EFPI) by curing epoxy droplets to obtain a high-finesse resonator. The high-finesse resonator is easy to construct, and can be used as a highly sensitive sensor at a low cost. The experimental results show that a temperature resolution of 0.025 °C and a strain resolution of 0.0625 µɛ can be achieved with such an EFPI.

  9. Miniature low-cost extrinsic Fabry-Perot interferometer for low-pressure detection

    NASA Astrophysics Data System (ADS)

    Poeggel, Sven; Tosi, Daniele; Leen, Gabriel; Lewis, Elfed

    2013-04-01

    A miniature optical fiber pressure sensor based on extrinsic Fabry-Perot interferometer (EFPI) is presented. The sensing probe has 0.2 mm outer diameter, and is based on an all-silica biocompatible structure, with a pressure sensitivity <1 nm/kPa. The probe is complemented by a fiber Bragg grating (FBG), in proximity of the EFPI tip, for temperature compensation. Interrogation is based on a low-cost white-light setup, whereas several pressure detection algorithms have been developed. Preliminary experimental validation and medical applications are discussed.

  10. Fast response Fabry-Perot interferometer microfluidic refractive index fiber sensor based on concave-core photonic crystal fiber.

    PubMed

    Tian, Jiajun; Lu, Zejin; Quan, Mingran; Jiao, Yuzhu; Yao, Yong

    2016-09-01

    We report a fast response microfluidic Fabry-Perot (FP) interferometer refractive index (RI) fiber sensor based on a concave-core photonic crystal fiber (CPCF), which is formed by directly splicing a section CPCF with a section of single mode fiber. The CPCF is made by cleaving a section of multimode photonic crystal fiber with an axial tension. The shallow concave-core of CPCF naturally forms the FP cavity with a very short cavity length. The inherent large air holes in the cladding of CPCF are used as the open channels to let liquid sample come in and out of FP cavity. In order to shorten the liquid channel length and eliminate the harmful reflection from the outside end face of the CPCF, the CPCF is cleaved with a tilted tensile force. Due to the very small cavity capacity, the short length and the large sectional area of the microfluidic channels, the proposed sensor provides an easy-in and easy-out structure for liquids, leading to great decrement of the measuring time. The proposed sensor exhibits fast measuring speed, the measuring time is less than 359 and 23 ms for distilled water and pure ethanol, respectively. We also experimentally study and demonstrate the superior performances of the sensor in terms of high RI sensitivity, good linear response, low temperature cross-sensitivity and easy fabrication.

  11. A Highly Sensitive Fiber-Optic Fabry-Perot Interferometer Based on Internal Reflection Mirrors for Refractive Index Measurement.

    PubMed

    Li, Xuefeng; Shao, Yujiao; Yu, Yuan; Zhang, Yin; Wei, Shaowen

    2016-05-31

    In this study, a new type of highly sensitive fiber-optic Fabry-Perot interferometer (FFPI) is proposed with a high sensitivity on a wide refractive index (RI) measurement range based on internal reflection mirrors of micro-cavity. The sensor head consists of a single-mode fiber (SMF) with an open micro-cavity. Since light reflections of gold thin films are not affected by the RI of different measuring mediums, the sensor is designed to improve the fringe visibility of optical interference through sputtering the gold films of various thicknesses on the inner surfaces of the micro-cavity, as a semi-transparent mirror (STM) and a total-reflection mirror (TRM). Experiments have been carried out to verify the feasibility of the sensor's design. It is shown that the fabricated sensor has strong interference visibility exceeding 15 dB over a wide measurement range of RI, and the sensor sensitivity is higher than 1160 nm/RIU, and RI resolution is better than 1.0 × 10(-6) RIU.

  12. A Highly Sensitive Fiber-Optic Fabry-Perot Interferometer Based on Internal Reflection Mirrors for Refractive Index Measurement.

    PubMed

    Li, Xuefeng; Shao, Yujiao; Yu, Yuan; Zhang, Yin; Wei, Shaowen

    2016-01-01

    In this study, a new type of highly sensitive fiber-optic Fabry-Perot interferometer (FFPI) is proposed with a high sensitivity on a wide refractive index (RI) measurement range based on internal reflection mirrors of micro-cavity. The sensor head consists of a single-mode fiber (SMF) with an open micro-cavity. Since light reflections of gold thin films are not affected by the RI of different measuring mediums, the sensor is designed to improve the fringe visibility of optical interference through sputtering the gold films of various thicknesses on the inner surfaces of the micro-cavity, as a semi-transparent mirror (STM) and a total-reflection mirror (TRM). Experiments have been carried out to verify the feasibility of the sensor's design. It is shown that the fabricated sensor has strong interference visibility exceeding 15 dB over a wide measurement range of RI, and the sensor sensitivity is higher than 1160 nm/RIU, and RI resolution is better than 1.0 × 10(-6) RIU. PMID:27258273

  13. Fast response Fabry-Perot interferometer microfluidic refractive index fiber sensor based on concave-core photonic crystal fiber.

    PubMed

    Tian, Jiajun; Lu, Zejin; Quan, Mingran; Jiao, Yuzhu; Yao, Yong

    2016-09-01

    We report a fast response microfluidic Fabry-Perot (FP) interferometer refractive index (RI) fiber sensor based on a concave-core photonic crystal fiber (CPCF), which is formed by directly splicing a section CPCF with a section of single mode fiber. The CPCF is made by cleaving a section of multimode photonic crystal fiber with an axial tension. The shallow concave-core of CPCF naturally forms the FP cavity with a very short cavity length. The inherent large air holes in the cladding of CPCF are used as the open channels to let liquid sample come in and out of FP cavity. In order to shorten the liquid channel length and eliminate the harmful reflection from the outside end face of the CPCF, the CPCF is cleaved with a tilted tensile force. Due to the very small cavity capacity, the short length and the large sectional area of the microfluidic channels, the proposed sensor provides an easy-in and easy-out structure for liquids, leading to great decrement of the measuring time. The proposed sensor exhibits fast measuring speed, the measuring time is less than 359 and 23 ms for distilled water and pure ethanol, respectively. We also experimentally study and demonstrate the superior performances of the sensor in terms of high RI sensitivity, good linear response, low temperature cross-sensitivity and easy fabrication. PMID:27607621

  14. A Fabry-Perot fiber-optic ultrasonic hydrophone for the simultaneous measurement of temperature and acoustic pressure.

    PubMed

    Morris, Paul; Hurrell, Andrew; Shaw, Adam; Zhang, Edward; Beard, Paul

    2009-06-01

    A dual sensing fiber-optic hydrophone that can make simultaneous measurements of acoustic pressure and temperature at the same location has been developed for characterizing ultrasound fields and ultrasound-induced heating. The transduction mechanism is based on the detection of acoustically- and thermally-induced thickness changes in a polymer film Fabry-Perot interferometer deposited at the tip of a single mode optical fiber. The sensor provides a peak noise-equivalent pressure of 15 kPa (at 5 MHz, over a 20 MHz measurement bandwidth), an acoustic bandwidth of 50 MHz, and an optically defined element size of 10 microm. As well as measuring acoustic pressure, temperature changes up to 70 degrees C can be measured, with a resolution of 0.34 degrees C. To evaluate the thermal measurement capability of the sensor, measurements were made at the focus of a high-intensity focused ultrasound (HIFU) field in a tissue mimicking phantom. These showed that the sensor is not susceptible to viscous heating, is able to withstand high intensity fields, and can simultaneously acquire acoustic waveforms while monitoring induced temperature rises. These attributes, along with flexibility, small physical size (OD approximately 150 microm), immunity to Electro-Magnetic Interference (EMI), and low sensor cost, suggest that this type of hydrophone may provide a practical alternative to piezoelectric based hydrophones. PMID:19507943

  15. Optical generation of tunable microwave and millimeter waves by using asymmetric fiber Bragg grating Fabry-Perot cavity fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, Cong; Wang, Meng; Li, Qi; Huang, Kaiqiang; Chen, Haiyan

    2014-10-01

    In this presentation, we propose and experimentally demonstrate a novel optical generation of microwave and millimeter wave signals by using asymmetric fiber Bragg grating Fabry-Perot cavity fiber laser, dual-wavelength emission can be achieved with wavelength separation of 0.68nm corresponding to the millimeter wave signal at 85GHz. By appropriately adjusting the operation temperature of intracavity fiber Bragg grating, the frequency of millimeter wave signal generated can be tunable. Our experimental results demonstrate the new concept of optical generation of microwave and millimeter wave signals by using asymmetric fiber Bragg grating Fabry-Perot cavity dual-wavelength fiber laser and the technical feasibility.

  16. A simultaneous interrogation system for intensity-type sensor/fiber Bragg grating/extrinsic Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Jiang, Yi; Tang, Caijie

    2009-02-01

    A simultaneous interrogation system for an intensity-type sensor, fiber Bragg grating and an extrinsic Fabry-Perot interferometer is demonstrated. The three types of sensors occupy different wavelengths ranging from 1524 nm to 1563 nm, and all sensors are wavelength-division multiplexed and interrogated in one demodulation system. Experimental results show that a wavelength resolution of 2 pm for fiber Bragg grating, a loss resolution of 0.1 dB for an intensity-type sensor and a cavity-length resolution of 3.5 nm for an extrinsic Fabry-Perot interferometer are obtained. The cross-talk between the different sensors is also examined.

  17. Effect of small variations in the refractive index of the ambient medium on the spectrum of a bent fibre-optic Fabry - Perot interferometer

    SciTech Connect

    Kulchin, Yurii N; Vitrik, O B; Gurbatov, S O

    2011-09-30

    The phase of light propagating through a bent optical fibre is shown to depend on the refractive index of the medium surrounding the fibre cladding when there is resonance coupling between the guided core mode and cladding modes. This shifts the spectral maxima in the bent fibre-optic Fabry - Perot interferometer. The highest phase and spectral sensitivities achieved with this interferometer configuration are 0.71 and 0.077, respectively, and enable changes in the refractive index of the ambient medium down to 5 Multiplication-Sign 10{sup -6} to be detected. This makes the proposed approach potentially attractive for producing highly stable, precision refractive index sensors capable of solving a wide range of liquid refractometry problems.

  18. Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry

    DOEpatents

    Yeung, E.S.; Woodruff, S.D.

    1984-06-19

    A refractive index and absorption detector are disclosed for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded. 10 figs.

  19. Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry

    DOEpatents

    Yeung, Edward S.; Woodruff, Steven D.

    1984-06-19

    A refractive index and absorption detector for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded.

  20. Fabry-Perot Based Radiometers for Precise Measurement of Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Heaps, William S.; Wilson, Emily L.; Georgieva, Elena

    2007-01-01

    Differential radiometers based upon the Fabry-Perot interferometer have been developed and demonstrated that exhibit very great sensitivity to changes in the atmospheric column of carbon dioxide, oxygen, and water vapor. These instruments employ a solid Fabry-Perot etalon that is tuned to the proper wavelength by changing the temperature. By choosing the thickness of the etalon its multiple pass bands can be made to align with regularly space absorption features of the molecule under investigation. Use of multiple absorption features improves the optical throughput of the instrument and improves the stability of the instrument response with respect to environmental changes. Efforts are underway at Goddard to extend this technique to the carbon 13 isotope of carbon dioxide and to methane. These instruments are intrinsically rugged and can be made rather small and inexpensively. They therefore hold promise for widespread use in ground based networks for calibration of satellite instruments such as OCO and GOSAT. Results will be presented for ground based and airborne operations for these systems. The effects of atmospheric scattering, pointing errors, pressure broadening and temperature effects will be discussed with regard to achieving precision better than .5% required for validation of carbon dioxide column measured from space. Designs permitting the extension of the technique to an even larger number of atmospheric species will be discussed along with theoretical analysis of potential system performance.

  1. Nonlinear regression method for estimating neutral wind and temperature from Fabry-Perot interferometer data.

    PubMed

    Harding, Brian J; Gehrels, Thomas W; Makela, Jonathan J

    2014-02-01

    The Earth's thermosphere plays a critical role in driving electrodynamic processes in the ionosphere and in transferring solar energy to the atmosphere, yet measurements of thermospheric state parameters, such as wind and temperature, are sparse. One of the most popular techniques for measuring these parameters is to use a Fabry-Perot interferometer to monitor the Doppler width and breadth of naturally occurring airglow emissions in the thermosphere. In this work, we present a technique for estimating upper-atmospheric winds and temperatures from images of Fabry-Perot fringes captured by a CCD detector. We estimate instrument parameters from fringe patterns of a frequency-stabilized laser, and we use these parameters to estimate winds and temperatures from airglow fringe patterns. A unique feature of this technique is the model used for the laser and airglow fringe patterns, which fits all fringes simultaneously and attempts to model the effects of optical defects. This technique yields accurate estimates for winds, temperatures, and the associated uncertainties in these parameters, as we show with a Monte Carlo simulation. PMID:24514183

  2. Two Fabry-Perot interferometers for high precision wavelength calibration in the near-infrared

    NASA Astrophysics Data System (ADS)

    Schäfer, Sebastian; Reiners, Ansgar

    2012-09-01

    The most frequently used standard light sources for spectroscopic high precision wavelength calibration are hollow cathode lamps. These lamps, however, do not provide homogeneous line distribution and intensities. Particularly in the infrared, the number of useful lines is severely limited and the spectrum is contaminated by lines of the filler gas. With the goal of achieving sub m/s stability in the infrared, as required for detecting earthlike extra-solar planets, we are developing two passively stabilized Fabry-Perot interferometers for the red visible (600-1050nm) and near infrared wavelength regions (900-1350nm). Each of the two interferometers can produce ~15,000 lines of nearly constant brightness. The Fabry-Perot interferometers aim at a RV calibration precision of 10cm/s and are optimized in line shape and spacing for the infrared planet hunting CARMENES spectrograph that is currently being built for the Calar Alto 3.5m telescope. Here we present the first results of our work.

  3. Hyperspectral Infrared Imaging of Flames Using a Spectrally Scanning Fabry-Perot Filter

    NASA Technical Reports Server (NTRS)

    Rawlins, W. T.; Lawrence, W. G.; Marinelli, W. J.; Allen, M. G.; Piltch, N. (Technical Monitor)

    2001-01-01

    The temperatures and compositions of gases in and around flames can be diagnosed using infrared emission spectroscopy to observe molecular band shapes and intensities. We have combined this approach with a low-order scanning Fabry-Perot filter and an infrared camera to obtain spectrally scanned infrared emission images of a laboratory flame and exhaust plume from 3.7 to 5.0 micrometers, at a spectral resolution of 0.043 micrometers, and a spatial resolution of 1 mm. The scanning filter or AIRIS (Adaptive Infrared Imaging Spectroradiometer) is a Fabry-Perot etalon operating in low order (mirror spacing = wavelength) such that the central spot, containing a monochromatic image of the scene, is viewed by the detector array. The detection system is a 128 x 128 liquid-nitrogen-cooled InSb focal plane array. The field of view is controlled by a 50 mm focal length multielement lens and an V4.8 aperture, resulting in an image 6.4 x 6.4 cm in extent at the flame and a depth of field of approximately 4 cm. Hyperspectral images above a laboratory CH4/air flame show primarily the strong emission from CO2 at 4.3 micrometers, and weaker emissions from CO and H2O. We discuss techniques to analyze the spectra, and plans to use this instrument in microgravity flame spread experiments.

  4. Tunable Fabry-Perot etalon-based long-wavelength infrared imaging spectroradiometer.

    PubMed

    Marinelli, W J; Gittins, C M; Gelb, A H; Green, B D

    1999-04-20

    Imaging spectrometry enables passive, stand-off detection and analysis of the chemical composition of gas plumes and surfaces over wide geographic areas. We describe the use of a long-wavelength infrared imaging spectroradiometer, comprised of a low-order tunable Fabry-Perot etalon coupled to a HgCdTe detector array, to perform multispectral detection of chemical vapor plumes. The tunable Fabry-Perot etalon used in this research provides coverage of the 9.5-14-microm spectral region with a resolution of 7-9 cm(-1). The etalon-based imaging system provides the opportunity to image a scene at only those wavelengths needed for chemical species identification and quantification and thereby minimize the data volume necessary for selective species detection. We present initial results using a brassboard imaging system for stand-off detection and quantification of chemical vapor plumes against near-ambient-temperature backgrounds. These data show detection limits of 22 parts per million by volume times meter (ppmv x m) and 0.6 ppmv x m for dimethyl methyphosphonate and SF6, respectively, for a gas/background DeltaT of 6 K. The system noise-equivalent spectral radiance is approximately 2 microW cm(-2) sr(-1) microm(-1). Model calculations are presented comparing the measured sensitivity of the sensor to the anticipated signal levels for two chemical release scenarios.

  5. Compton scattering off polarized electrons with a high-finesse Fabry-Perot Cavity at Jlab

    SciTech Connect

    Nicolas Falletto; Martial Authier; Maud Baylac; M. Boyer; Francois Bugeon; Etienne Burtin; Christian Cavata; Nathalie Colombel; G. Congretel; R. Coquillard; G. Coulloux; Bertrand Couzy; P Deck; Alain Delbart; D. Desforges; A. Donati; B. Duboue; Stephanie Escoffier; F. Farci; Bernard Frois; P Girardot; J Guillotau; C Henriot; Claude Jeanney; M Juillard; J. P. Jorda; P. Legou; David Lhuillier; Y Lussignol; Phillippe Mangeot; X. Martin; Frederic Marie; Jacques Martino; M. Maurier; Bernard Mazeau; J.F. Millot; F. Molinie; J.-P. Mols; Jean-pierre Mouly; M. Mur; Damien Neyret; T. Pedrol; Stephane Platchkov; G. Pontet; Thierry Pussieux; Yannick Queinec; Philippe Rebourgeard; J. C. Sellier; Gerard Tarte; Christian Veyssiere; Andre Zakarian; Pierre Bertin; Alain Cosquer; Jian-ping Chen; Joseph Mitchell; J.-M. Mackowski; L. Pinard

    2001-03-01

    We built and commissioned a new type of Compton polarimeter to measure the electron beam polarization at the Thomas Jefferson National Accelerator Facility (Virginia, USA). The heart of this polarimeter is a high-finesse monolithic Fabry-Perot cavity. Its purpose is to amplify a primary 300 mW laser beam in order to improve the signal to noise ratio of the polarimeter. It is the first time that a high-finesse Fabry-Perot cavity is enclosed in the vacuum of a particle accelerator to monitor the beam polarization by Compton polarimetry. The measured finesse and amplification gain of the cavity are F=26000 and G=7300. The electron beam crosses this high-power photon source at an angle of 23 mrad in the middle of the cavity where the photon beam power density is estimated to be 0.85MW/cm2. We have used this facility during the HAPPEX experiment (April-July 1999) and we give a preliminary measurement of Compton scattering asymmetry.

  6. Modified Fabry-Perot interferometer for displacement measurement in ultra large measuring range.

    PubMed

    Chang, Chung-Ping; Tung, Pi-Cheng; Shyu, Lih-Horng; Wang, Yung-Cheng; Manske, Eberhard

    2013-05-01

    Laser interferometers have demonstrated outstanding measuring performances for high precision positioning or dimensional measurements in the precision industry, especially in the length measurement. Due to the non-common-optical-path structure, appreciable measurement errors can be easily induced under ordinary measurement conditions. That will lead to the limitation and inconvenience for in situ industrial applications. To minimize the environmental and mechanical effects, a new interferometric displacement measuring system with the common-optical-path structure and the resistance to tilt-angle is proposed. With the integration of optomechatronic modules in the novel interferometric system, the resolution up to picometer order, high precision, and ultra large measuring range have been realized. For the signal stabilization of displacement measurement, an automatic gain control module has been proposed. A self-developed interpolation model has been employed for enhancing the resolution. The novel interferometer can hold the advantage of high resolution and large measuring range simultaneously. By the experimental verifications, it has been proven that the actual resolution of 2.5 nm can be achieved in the measuring range of 500 mm. According to the comparison experiments, the maximal standard deviation of the difference between the self-developed Fabry-Perot interferometer and the reference commercial Michelson interferometer is 0.146 μm in the traveling range of 500 mm. With the prominent measuring characteristics, this should be the largest dynamic measurement range of a Fabry-Perot interferometer up till now.

  7. Nonlinear regression method for estimating neutral wind and temperature from Fabry-Perot interferometer data.

    PubMed

    Harding, Brian J; Gehrels, Thomas W; Makela, Jonathan J

    2014-02-01

    The Earth's thermosphere plays a critical role in driving electrodynamic processes in the ionosphere and in transferring solar energy to the atmosphere, yet measurements of thermospheric state parameters, such as wind and temperature, are sparse. One of the most popular techniques for measuring these parameters is to use a Fabry-Perot interferometer to monitor the Doppler width and breadth of naturally occurring airglow emissions in the thermosphere. In this work, we present a technique for estimating upper-atmospheric winds and temperatures from images of Fabry-Perot fringes captured by a CCD detector. We estimate instrument parameters from fringe patterns of a frequency-stabilized laser, and we use these parameters to estimate winds and temperatures from airglow fringe patterns. A unique feature of this technique is the model used for the laser and airglow fringe patterns, which fits all fringes simultaneously and attempts to model the effects of optical defects. This technique yields accurate estimates for winds, temperatures, and the associated uncertainties in these parameters, as we show with a Monte Carlo simulation.

  8. Contact grating device with Fabry-Perot resonator for effective terahertz light generation.

    PubMed

    Tsubouchi, Masaaki; Nagashima, Keisuke; Yoshida, Fumiko; Ochi, Yoshihiro; Maruyama, Momoko

    2014-09-15

    A novel design for a contact grating device with an incorporated Fabry-Perot resonator is proposed for high-power terahertz (THz) light generation. We deposited a multilayer consisting of Ta(2)O(5) and Al(2)O(3) on a magnesium-doped stoichiometric LiNbO(3) substrate and fabricated grating grooves on the outermost layer. The multilayer was designed such that conditions for a Fabry-Perot resonator were satisfied for light diffracted by the grating. Consequently, the fraction of light transmitted into the LiNbO(3) substrate, i.e., the diffraction efficiency, was enhanced by the resonator. The diffraction efficiency of the fabricated device was 71%, which is close to the calculated value of 78% from the optimized design. THz light generation was also demonstrated with the contact grating device. The THz output of 0.41 μJ was obtained using near-infrared pump light of 2.7 mJ.

  9. [Quartz-enhanced photoacoustic spectroscopy trace gas detection system based on the Fabry-Perot demodulation].

    PubMed

    Lin, Cheng; Zhu, Yong; Wei, Wei; Zhang, Jie; Tian, Li; Xu, Zu-Wen

    2013-05-01

    An all-optical quartz-enhanced photoacoustic spectroscopy system, based on the F-P demodulation, for trace gas detection in the open environment was proposed. In quartz-enhanced photoacoustic spectroscopy (QEPAS), an optical fiber Fabry-Perot method was used to replace the conventional electronic demodulation method. The photoacoustic signal was obtained by demodulating the variation of the Fabry-Perot cavity between the quartz tuning fork side and the fiber face. An experimental system was setup. The experiment for detection of water vapour in the open environment was carried on. A normalized noise equivalent absorption coefficient of 2.80 x 10(-7) cm(-1) x W x Hz(-1/2) was achieved. The result demonstrated that the sensitivity of the all-optical quartz-enhanced photoacoustic spectroscopy system is about 2.6 times higher than that of the conventional QEPAS system. The all-optical quartz-enhanced photoacoustic spectroscopy system is immune to electromagnetic interference, safe in flammable and explosive gas detection, suitable for high temperature and high humidity environments and realizable for long distance, multi-point and network sensing.

  10. Formation of super-resolution spot through nonlinear Fabry-Perot cavity structures: theory and simulation.

    PubMed

    Wei, Jingsong; Wang, Rui; Yan, Hui; Fan, Yongtao

    2014-04-01

    This study explores how interference manipulation breaks through the diffraction limit and induces super-resolution nano-optical hot spots through the nonlinear Fabry-Perot cavity structure. The theoretical analytical model is established, and the numerical simulation results show that when the thickness of the nonlinear thin film inside the nonlinear Fabry-Perot cavity structure is adjusted to centain value, the constructive interference effect can be formed in the central point of the spot, which causes the nanoscale optical hot spot in the central region to be produced. The simulation results also tell us that the hot spot size is sensitive to nonlinear thin film thickness, and the accuracy is required to be up to nanometer or even subnanometer scale, which is very large challenging for thin film deposition technique, however, slightly changing the incident laser power can compensate for drawbacks of low thickness accuracy of nonlinear thin films. Taking As(2)S(3) as the nonlinear thin film, the central hot spot with a size of 40nm is obtained at suitable nonlinear thin film thickness and incident laser power. The central hot spot size is only about λ/16, which is very useful in super-high density optical recording, nanolithography, and high-resolving optical surface imaging.

  11. Single resonance monolithic Fabry-Perot filters formed by volume Bragg gratings and multilayer dielectric mirrors

    NASA Astrophysics Data System (ADS)

    Lumeau, Julien; Koc, Cihan; Mokhun, Oleksiy; Smirnov, Vadim; Lequime, Michel; Glebov, Leonid B.

    2012-02-01

    High efficiency reflecting volume Bragg gratings (VBGs) recorded in PTR glass plates have shown un-preceded performances that make them very good candidates for narrowband spectral filtering with sub-nanometer spectral widths. However, decreasing the bandwidth to value below 30-50 pm is very challenging as it requires increasing the thickness of the RBG to more than 15-20 mm. To overcome this limitation, we propose a new approach which is a monolithic Fabry-Perot cavity which consists from a reflecting VBG with a multilayer dielectric mirror (MDM) deposited on its surface. A VBG with a grating vector perpendicular to its surface and a MDM produce a Fabry-Perot resonator with a single transmission band inside of the reflection spectrum of the VBG. We present a theoretical description of this new class of filters that allow achieving a single ultra-narrowband resonance associated with several hundred nanometers rejection band. Then we show the methods for designing and fabricating such filter. Finally, we present the steps that we followed in order to fabricate a first prototype for 852 nm and 1062 nm region that demonstrates a 30 pm bandwidth, 90+% transmission at resonance and a good agreement with theoretical simulation.

  12. Diaphragm-based extrinsic Fabry-Perot interferometric optical fiber pressure sensor

    NASA Astrophysics Data System (ADS)

    Wang, Qiaoyun; Wang, Wenhua; Jiang, Xinsheng; Yu, Qingxu

    2010-10-01

    A new structure of diaphragm-based extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor is presented. A double holes silica ferrule with 1.8mm outside diameter is used to align the fiber. The Fabry-Perot (F-P) cavity is formed between the fiber end facet and inner surface of the diaphragm. The diaphragm is attached to the top of ferrule by carbon dioxide (CO2) laser thermal fusion bonding system. One hole of ferrule is used to align the fiber to the diaphragm and the other is used to balance the pressure inside and outside of F-P cavity. The diameter of the sensor head is only 1.8mm. In the pressure measurement, the pressure sensitivity of this sensor is about 25.89nm/KPa and the temperature dependence is approximately 6nm/°C. The sensor has a linear response in the range from 0 to 3KPa. This structure of sensor can eliminate the thermally induced inner pressure changes of F-P cavity. Furthermore, the sensor with the temperature compensate can be used to detect the liquid level. The fabrication of this kind sensor is simple and low cost. And the advantages of this sensor are high sensitivity, immune to electromagnetic interference (EMI) and high temperature resistance.

  13. Fiber-optic extrinsic Fabry-Perot interferometer strain sensor with <50 pm displacement resolution using three-wavelength digital phase demodulation.

    PubMed

    Schmidt, M; Werther, B; Fuerstenau, N; Matthias, M; Melz, T

    2001-04-01

    A fiber-optic extrinsic Fabry-Perot interferometer strain sensor (EFPI-S) of ls = 2.5 cm sensor length using three-wavelength digital phase demodulation is demonstrated to exhibit <50 pm displacement resolution (<2nm/m strain resolution) when measuring the cross expansion of a PZT-ceramic plate. The sensing (single-mode downlead-) and reflecting fibers are fused into a 150/360 microm capillary fiber where the fusion points define the sensor length. Readout is performed using an improved version of the previously described three-wavelength digital phase demodulation method employing an arctan-phase stepping algorithm. In the resent experiments the strain sensitivity was varied via the mapping of the arctan - lookup table to the 16-Bit DA-converter range from 188.25 k /V (6 Volt range 1130 k ) to 11.7 k /Volt (range 70 k ).

  14. Ultra-high sensitivity Fabry-Perot interferometer gas refractive index fiber sensor based on photonic crystal fiber and Vernier effect.

    PubMed

    Quan, Mingran; Tian, Jiajun; Yao, Yong

    2015-11-01

    An ultra-high sensitivity open-cavity Fabry-Perot interferometer (FPI) gas refractive index (RI) sensor based on the photonic crystal fiber (PCF) and Vernier effect is proposed and demonstrated. The sensor is prepared by splicing a section of PCF to a section of fiber tube fused with a section of single mode fiber. The air holes running along the cladding of the PCF enable the gas to enter or leave the cavity freely. The reflection beam from the last end face of the PCF is used to generate the Vernier effect, which significantly improves the sensitivity of the sensor. Experimental results show that the proposed sensor can provide an ultra-high RI sensitivity of 30899 nm/RIU. This sensor has potential applications in fields such as gas concentration analyzing and humidity monitoring.

  15. Ultra-high sensitivity Fabry-Perot interferometer gas refractive index fiber sensor based on photonic crystal fiber and Vernier effect.

    PubMed

    Quan, Mingran; Tian, Jiajun; Yao, Yong

    2015-11-01

    An ultra-high sensitivity open-cavity Fabry-Perot interferometer (FPI) gas refractive index (RI) sensor based on the photonic crystal fiber (PCF) and Vernier effect is proposed and demonstrated. The sensor is prepared by splicing a section of PCF to a section of fiber tube fused with a section of single mode fiber. The air holes running along the cladding of the PCF enable the gas to enter or leave the cavity freely. The reflection beam from the last end face of the PCF is used to generate the Vernier effect, which significantly improves the sensitivity of the sensor. Experimental results show that the proposed sensor can provide an ultra-high RI sensitivity of 30899 nm/RIU. This sensor has potential applications in fields such as gas concentration analyzing and humidity monitoring. PMID:26512476

  16. A tunable, solid, Fabry-Perot etalon for solar seismology

    NASA Technical Reports Server (NTRS)

    Rust, David M.; Burton, Clive H.; Leistner, Achim J.

    1986-01-01

    A solid etalon has been designed and fabricated from a 50-mm diameter wafer of optical-quality lithium niobate. The finished etalon has a free spectral range of 0.325 nm at 588 nm. The parallel faces are coated with silver, and the central 15-mm aperture of the etalon has a finesse of 18.6. The reflective faces double as electrodes, and application of voltage will shift the passband. This feature was used in a servo circuit to stabilize the passband against temperature and tilt-induced drifts to better than three parts in one billion. Operated in the stabilized mode for day-long sessions, this filter alternately samples the wings of a narrow atomic absorption line in the solar spectrum and produces a signal proportional to velocity on the solar disk. The Fourier transform of this signal yields information on acoustic waves in the solar interior.

  17. The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

    PubMed

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-01-01

    The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

  18. Power-ratio tunable dual-wavelength laser using linearly variable Fabry-Perot filter as output coupler.

    PubMed

    Wang, Xiaozhong; Wang, Zhongfa; Bu, Yikun; Chen, Lujian; Cai, Guoxiong; Huang, Wencai; Cai, Zhiping; Chen, Nan

    2016-02-01

    For a linearly variable Fabry-Perot filter, the peak transmission wavelengths change linearly with the transverse position shift of the substrate. Such a Fabry-Perot filter is designed and fabricated and used as an output coupler of a c-cut Nd:YVO4 laser experimentally in this paper to obtain a 1062 and 1083 nm dual-wavelength laser. The peak transmission wavelengths are gradually shifted from 1040.8 to 1070.8 nm. The peak transmission wavelength of the Fabry-Perot filter used as the output coupler for the dual-wavelength laser is 1068 nm and resides between 1062 and 1083 nm, which makes the transmissions of the desired dual wavelengths change in opposite slopes with the transverse shift of the filter. Consequently, powers of the two wavelengths change in opposite directions. A branch power, oppositely tunable 1062 and 1083 nm dual-wavelength laser is successfully demonstrated. Design principles of the linear variable Fabry-Perot filter used as an output coupler are discussed. Advantages of the method are summarized.

  19. Long-term instrumental parameter investigation of a Fabry-Perot spectrometer at an isolated field station.

    PubMed

    Hernandez, G; McCarthy, M P

    2011-05-01

    To insure that long-term determinations of Doppler width and shift--derived from observations of atmospheric emissions--are internally consistent and reliable, we have developed a method to both continuously and nonintrusively determine and monitor the instrumental constants of the Fabry-Perot spectrometer making the observations. We have used this method at our isolated field experiment at South Pole, Antarctica, because the instrument is only accessible to us for a few days every year. Here we report both the method and the Fabry-Perot stability results for the past 22 years of operation. The method involves the description of real Fabry-Perot instrumental constants as a small departure from those of an ideal Fabry-Perot. In general, this model is applicable for most observations. However, experimentally, there are times when the small-departure model is not applicable, thus indicating how to best reduce the observations into physical quantities for the utmost consistency in the geophysical results.

  20. Fabry-Perot Interferometer-Based Electrooptic Modulator using LiNbO3 and Organic Thin Films

    NASA Technical Reports Server (NTRS)

    Banks, C.; Frazier, D.; Penn, B.; Abdeldayem, H.; Sharma, A.; Yelleswarapu, C.; Leyderman, Alexander; Correa, Margarita; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    We report the study of a Fabry-Perot electro-optical modulator using thin crystalline film NPP, and Crystalline LiNbO3. We are able to observe 14, and 60 percent degree of modulation. Measurements were carried using a standard lock-in amplifier with a silicon detector. The proposal to design a Fabry-Perot electro-optic modulator with an intracavity electro-optically active organic material was based on the initial results using poled polymer thin films. The main feature of the proposed device is the observation that in traditional electrooptic modulators like a Packets cell, it requires few kilovolts of driving voltage to cause a 3 dB modulation even in high figure-of-merit electrooptic materials like LiNbO3. The driving voltage for the modulator can be reduced to as low as 10 volts by introducing the electrooptic material inside die resonant cavity of a Fabry-Perot modulator. This is because the transmission of the Fabry-Perot cavity varies nonlinearly with the change of refractive index or phase of light due to applied electric field.

  1. Transmissive in-fiber Fabry-Perot etalons as tunable dispersion compensators and dispersion-slope compensators.

    PubMed

    Shu, Xuewen; Sugden, Kate

    2003-10-15

    We report for what is believed to be the first time the use of transmissive fiber Bragg grating-based Fabry-Perot etalons for tunable dispersion compensation and dispersion-slope compensation. The resulting device has a number of advantages, such as low cost, ease of fabrication, full optical fiber compatibility, and simplicity. PMID:14587768

  2. All-fiber micro-machined Fabry-Perot strain sensor

    NASA Astrophysics Data System (ADS)

    Pevec, Simon; Đonlagić, Denis

    2012-04-01

    This paper presents the design, fabrication process, and experimental evaluation of a high-sensitivity, all-silica, all-fiber, micro machined Fabry-Perot strain-sensor. This sensor has a short Fabry-Perot cavity and thus allows for the application of low-resolution spectral interrogation systems; in our case the commercial white light signal interrogator was used. The fabrication process includes the design and production of special sensor-forming optical-fiber. This fiber includes a central titanium-doped region, a phosphorus doped-ring surrounding a titanium doped region, and pure silica cladding in order to produce the proposed sensor, two sections of sensor forming fiber are cleaved and etched in a HF/IPA solution. The phosphorus-doped region etches at a considerably higher rate than the other fiber-sections, and thus creates a deep gutter on the cleaved fibers frontal surface. The titanium-doped region etches at a rate that is, to some extent, higher than the etching-rate of pure silica, and thus creates a slightly retracted surface relative to the pure silica fiber-cladding. The etched fibers are then re-spliced to create an all-silica strain sensor in "double configuration", which has a section of etched sensor-forming fiber on both sides. Thus this sensor has a long active length, whilst the length of the Fabry-Perot cavity can be adjusted by a titanium-doping level. The central titanium-doped region also creates a waveguide structure that is used to deliver light to the cavity through one of the fibers. The proposed fabrication process is cost-effective and suitable for high-volume production. The greatest achievement of the depicted in-line strain sensor is the extension of its active sensor length, which is more than 50 times greater than the sensor-cavity's length, and is thus approximately 50 times more sensitive to strain. This sensor also exhibits low-intrinsic temperature sensitivity.

  3. Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel; Mahadevan, Suvrath; Ramsey, Lawrence; Hearty, Fred; Wilson, John; Holtzman, Jon; Redman, Stephen; Nave, Gillian; Nidever, David; Nelson, Matt; Venditti, Nick; Bizyaev, Dmitry; Fleming, Scott

    2014-05-01

    We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astrophotonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units that can yield a stable and repeatable output spectrum. An FFP is a unique alternative to a traditional etalon, as the interferometric cavity is made of single-mode fiber rather than an air-gap spacer. This design allows for excellent collimation, high spectral finesse, rigid mechanical stability, insensitivity to vibrations, and no need for vacuum operation. The device we have tested is a commercially available product from Micron Optics.10 Our development path is targeted toward a calibration source for the Habitable-Zone Planet Finder (HPF), a near-infrared spectrograph designed to detect terrestrial-mass planets around low-mass stars, but this reference could also be used in many existing and planned fiber-fed spectrographs as we illustrate using the Apache Point Observatory Galactic Evolution Experiment (APOGEE) instrument. With precise temperature control of the fiber etalon, we achieve a thermal stability of 100 μK and associated velocity uncertainty of 22 cm s-1. We achieve a precision of ≈2 m s-1 in a single APOGEE fiber over 12 hr using this new photonic reference after removal of systematic correlations. This high precision (close to the expected photon-limited floor) is a testament to both the excellent intrinsic wavelength stability of the fiber interferometer and the stability of the APOGEE instrument design. Overall instrument velocity precision is 80 cm s-1 over 12 hr when averaged over all 300 APOGEE fibers and after removal of known trends and pressure correlations, implying the fiber etalon is intrinsically stable to significantly higher precision.

  4. Measurement of reflection phase using thick-gap Fabry-Perot etalon.

    PubMed

    Yung, Tsz Kit; Gao, Wensheng; Leung, Ho Ming; Zhao, Qiuling; Wang, Xia; Tam, Wing Yim

    2016-09-10

    We report measurement of the reflection phase of a dielectric (glass)/titanium (Ti) surface in the visible wavelength using a thick-gap Fabry-Perot (FP) interferometry technique. Using a two-beam interference model for the reflection peaks and troughs of the FP etalon, we obtain the air-gap spacing of the etalon and, more importantly, the reflection phase of the etalon substrate. We find systematic dependence of the as-measured reflection phase on the air-gap spacing due to the numerical aperture effect of the measuring objective. However, the relative reflection phase of Ti with respect to glass is independent of the air-gap spacing. As a demonstration of our approach in the optical characterization of small metamaterial samples, we also measure the reflection phase of a micron-sized 2D Au sawtooth nanoarray. The experiment is in good agreement with the model simulation. PMID:27661366

  5. Measurement of refractive index dispersion of a fused silica plate using Fabry-Perot interference.

    PubMed

    Lee, Choonghwan; Choi, Heejoo; Jin, Jonghan; Cha, Myoungsik

    2016-08-10

    We used Fabry-Perot interferometry to measure the refractive indices of a fused silica plate at four different wavelengths ranging from 544 to 1550 nm, giving a detailed analysis on the uncertainty of this experimental method. Because of a small expanded uncertainty of 2.7×10-5(k=1.96) obtained using the experimental method, it was possible to make corrections to the existing Sellmeier formula [J. Opt. Soc. Am.55, 1205 (1965)JOSAAH0030-394110.1364/JOSA.55.001205] for our fused silica sample. The corrected Sellmeier formula resulted in a group index value larger than that evaluated using the Malitson's Sellmeier formula by 3×10-4. We verified this by comparing it with the group index measured with spectral domain interferometry at 1530 nm. PMID:27534471

  6. Simulations of imaging Fabry-Perot interferometers for measuring upper-atmospheric temperatures and winds.

    PubMed

    Huang, Yiyi; Makela, Jonathan J; Swenson, Gary R

    2012-06-10

    We apply an onion-peeling inversion to simulated imaging Fabry-Perot interferometer (FPI) observations for retrieving altitude profiles of neutral temperatures and winds in the thermosphere in order to investigate the effects of realistic gradients in thermospheric parameters on the retrieved parameters. A forward model is developed that simulates the interference spectrum observed by an FPI using the redline (630.0 nm) and greenline (557.7 nm) emissions simulated based on climatological models. This forward model is applicable to both ground- and satellite-based simulations and generates a two-dimensional interference ring pattern. We simulate both a single-band ground-based FPI and a dual-band satellite-based FPI in order to study the effects of realistic vertical and horizontal gradients on the retrieved parameters.

  7. High resolution signal-processing method for extrinsic Fabry-Perot interferometric sensors

    NASA Astrophysics Data System (ADS)

    Xie, Jiehui; Wang, Fuyin; Pan, Yao; Wang, Junjie; Hu, Zhengliang; Hu, Yongming

    2015-03-01

    In this paper, a signal-processing method for optical fiber extrinsic Fabry-Perot interferometric sensors is presented. It achieves both high resolution and absolute measurement of the dynamic change of cavity length with low sampling points in wavelength domain. In order to improve the demodulation accuracy, the reflected interference spectrum is cleared by Discrete Wavelet Transform and adjusted by the Hilbert transform. Then the cavity length is interrogated by the cross correlation algorithm. The continuous tests show the resolution of cavity length is only 36.7 pm. Moreover, the corresponding resolution of cavity length is only 1 pm on the low frequency range below 420 Hz, and the corresponding power spectrum shows the possibility of detecting the ultra-low frequency signals based on spectra detection.

  8. Stable and rugged etalon for the Dynamics Explorer Fabry-Perot interferometer. 1: Design and construction.

    PubMed

    Rees, D; Fuller-Rowell, T J; Lyons, A; Killeen, T L; Hays, P B

    1982-11-01

    This is one of two papers which describe the development and performance of a very stable and rugged etalon designed for use in the Fabry-Perot interferometer, one of the instruments of the NASA Dynamics Explorer satellite mission, and which will obtain global measurements of the thermospheric and mesospheric wind and temperature with an accuracy of aporoximately 10 m/sec. The etalon consists of two flat plates of fused silica, with spacers constructed of Zerodur (a polycrystalline glass ceramic of extremely low expansion coefficient) which are cemented together using cyanoacrylic adhesives. This provides adequate mechanical integrity and stability for any space flight application and has a thermal expansion coefficient of the etalon cavity of <10(-7)/ degrees C.

  9. Gas detection with microelectromechanical Fabry-Perot interferometer technology in cell phone

    NASA Astrophysics Data System (ADS)

    Mannila, Rami; Hyypiö, Risto; Korkalainen, Marko; Blomberg, Martti; Kattelus, Hannu; Rissanen, Anna

    2015-06-01

    VTT Technical Research Centre of Finland has developed a miniaturized optical sensor for gas detection in a cell phone. The sensor is based on a microelectromechanical (MEMS) Fabry-Perot interferometer, which is a structure with two highly reflective surfaces separated by a tunable air gap. The MEMS FPI is a monolithic device, i.e. it is made entirely on one substrate in a batch process, without assembling separate pieces together. The gap is adjusted by moving the upper mirror with electrostatic force, so there are no actual moving parts. VTT has designed and manufactured a MEMS FPI based carbon dioxide sensor demonstrator which is integrated to a cell phone shield cover. The demonstrator contains light source, gas cell, MEMS FPI, detector, control electronics and two coin cell batteries as a power source. It is connected to the cell phone by Bluetooth. By adjusting the wavelength range and customizing the MEMS FPI structure, it is possible to selectively sense multiple gases.

  10. Fabry-Perot observations of Comet Halley H sub 2 O(+)

    SciTech Connect

    Scherb, F.; Roesler, F.L.D.; Harlander, J.; Magee-sauer, K. Glassboro State College, NJ )

    1990-07-01

    Fabry-Perot scanning spectrometer observations of Comet Halley's H{sub 2}O(+) emissions have yielded 6158.64 and 6158.85 A spin doublet data at distances in the range of 0 to 2 million km from the comet heat in the antisunward direction. Cometary plasma outflow velocities were ascertained on the basis of the emissions' Doppler shifts, yielding results that were mostly but not exclusively consistent with the plasma's constant antisunward acceleration; the acceleration varied from night to night of observations over a 30-300 cm/sec range. The unusual plasma kinematics of December 14-15, 1985, and January 10, 1986, may be associated with the tail-disconnection activity observed by others. 30 refs.

  11. Advancement of Optical Component Control for an Imaging Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Cook, William B.; Flood, Michael A.; Campbell, Joel F.; Boyer, Charles M.

    2009-01-01

    Risk mitigation activities associated with a prototype imaging Fabry-Perot Interferometer (FPI) system are continuing at the NASA Langley Research Center. The system concept and technology center about enabling and improving future space-based atmospheric composition missions, with a current focus on observing tropospheric ozone around 9.6 micron, while having applicability toward measurement in different spectral regions and other applications. Recent activities have focused on improving an optical element control subsystem to enable precise and accurate positioning and control of etalon plates; this is needed to provide high system spectral fidelity critical for enabling the required ability to spectrally-resolve atmospheric line structure. The latest results pertaining to methodology enhancements, system implementation, and laboratory characterization testing will be reported

  12. Faraday-active Fabry-Perot resonator: transmission, reflection, and emissivity.

    PubMed

    Liptuga, Anatoliy; Morozhenko, Vasyl; Pipa, Viktor; Venger, Evgen; Kostiuk, Theodor

    2012-05-01

    The propagation of light within a semiconductor Faraday-active Fabry-Perot resonator is investigated theoretically and experimentally. It is shown that an external magnetic field radically changes the angular and spectral characteristics of transmission, reflection, and emissivity of the resonator not only for polarized, but also for unpolarized, light. Suppression of interference patterns and phase inversion of the interference extrema were observed in both monochromatic and polychromatic light. The investigations were carried out for the plane-parallel plates of n-InAs in the spectral range of free charge carrier absorption. The results can be used to create new controllable optical and spectroscopic devices for investigation of Faraday-active material properties and for control of parameters of plane-parallel layers and structures.

  13. Design of a reconfigurable optical add/drop multiplexer based on tunable Fabry-Perot array

    NASA Astrophysics Data System (ADS)

    Ye, Jiansen; Wang, Xin; Li, Zhuo; Yang, Yang; Xu, Rui; Shi, Rui

    2015-08-01

    With the development of optical fiber communication, dense wavelength division multiplexing (DWDM) system is important for the rapid management of multi-wavelength in the core node of the optical transmission network. In this paper, a reconfigurable optical add-drop multiplexer (ROADM) based on the tunable Fabry-Perot (F-P) array is proposed. An optical switch with high isolation and low crosstalk is designed by using the characteristics of filtering and tuning for the F-P array. The principle, structure, and function of the tunable F-P array are introduced. The characteristics of filtering and tuning for the F-P filter are also calculated, and the factor for the isolation, crosstalk, response time and insertion loss are analyzed. A single physical channel ROADM with 16 signal channels, which operates in C-band, is designed and optimized by simulation.

  14. Practical Fabry-Perot displacement interferometry in ambient air conditions with subnanometer accuracy

    NASA Astrophysics Data System (ADS)

    Voigt, Dirk; van de Nes, Arthur S.; van den Berg, Steven A.

    2014-07-01

    Fabry-Perot displacement interferometry (FPI) offers high sensitivity and resolution with direct traceability to optical frequency standards. FPI can provide means for demanding calibration tasks in precision engineering and high-tech systems. We report on our investigation of the measurement methodology applied to highest precision capacitive displacement sensors. We use a dedicated metrological FPI instrumentation that provides an actuated reference target with a relatively large traceable displacement stroke. The envisaged sub-nanometer measurement uncertainty seems very challenging under practical ambient atmospheric conditions and with the necessary sensor mounting components. In anticipation of these limitations, we propose a new FPI instrumental configuration with a very short cavity and discuss expected benefits, most importantly the very low sensitivity to air refractive index variations and the versatility for practical calibration purposes. We aim again for sub-nanometer measurement uncertainty and report on the status of the experimental set-up for this short cavity FPI.

  15. Fabry-Perot microcavity sensor for H2-breath-test analysis

    NASA Astrophysics Data System (ADS)

    Vincenti, Maria Antonietta; De Sario, Marco; Petruzzelli, V.; D'Orazio, Antonella; Prudenzano, Francesco; de Ceglia, Domenico; Scalora, Michael

    2007-10-01

    Leak detection of hydrogen for medical purposes, based on the monitoring of the optical response of a simple Fabry-Perot microcavity, is proposed to investigate either the occurrence of lactose intolerance, or lactose malabsorption condition. Both pathologic conditions result in bacterial overgrowth in the intestine, which causes increased spontaneous emission of H2 in the human breath. Two sensitivity figures of merit are introduced to inspect changes in the sensor response, and to relate the microcavity response to a pathologic condition, which is strictly related to a different level of exhaled hydrogen. Different sensor configurations using a metal-dielectric microcavity are reported and discussed in order to make the most of the well-known ability of palladium to spontaneously absorb hydrogen.

  16. Zodiacal light dynamics experiment: A wideband imaging Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Torr, D. G.; Young, E.; Torr, M. R.; Nagy, A. F.

    1978-01-01

    The Solar Probe will provide an ideal platform from which to study dynamics of dust particles near the sun by measuring the detailed character of the Fraunhofer structure of the zodiacal light. The suggested instrument is a wideband imaging Fabry-Perot interferometer with state of the art technology in both the optics and the detector. The instrument would function as a high-resolution imaging device providing wavelength resolution of 0.03 A over about a 20 A range. The wideband imaging capability would provide sky maps of the zodiacal light on a despun spacecraft without mechanical scanning. The Solar Probe mission would allow the velocity distribution of the dust to be mapped along most of the trajectory of the spacecraft.

  17. Development of Ultrasonic and Fabry-Perot Interferometer for Non-Destruction Inspection of Aging Aircraft

    NASA Technical Reports Server (NTRS)

    Smith, Alphonso C.

    1998-01-01

    Fabry-Perot Interferometer (FPI) sensor detection system was continued and refined modifications were made in the data acquisition and evaluation process during the last year. The ultrasonic and FPI detection system was improved from one to multiple sensor detectors. Physical models were developed to understand the physical phenomenon of this work. Multilayered flawed samples were fabricated for inspection by a prototype ultrasonic and FPI detection. Experimental data was verified with simulated results. Undergraduate students that were associated with this research gained valuable knowledge from this experience. This was a learning process helping students to understand the importance of research and its application to solve important technological problems. As a result of our students exposure to this research two and planning to continue this type of research work in graduate school. A prototype instrument package was laboratory tested an actual airframe structure for documentation purposes.

  18. Light trapping in an ensemble of pointlike impurity centers in a Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Kuraptsev, A. S.; Sokolov, I. M.

    2016-08-01

    We report the development of quantum microscopic theory of quasiresonant dipole-dipole interaction in the ensembles of impurity atoms imbedded into transparent dielectric and located in a Fabry-Perot cavity. On the basis of the general approach we study the simultaneous influence of the cavity and resonant dipole-dipole interaction on the shape of the line of atomic transition as well as on light trapping in dense impurity ensembles. We analyze this influence depending on the size of the ensemble, its density, as well as on rms deviation of the transition frequency shifts caused by the symmetry disturbance of the internal fields of the dielectric medium. Obtained results are compared with the case when the cavity is absent. We show that the cavity can essentially modify cooperative polyatomic effects.

  19. Optical enhancement of a Fabry-Perot interferometer for low luminance measurements

    SciTech Connect

    Dave, H.H.; Dave, J.H.; Allen, J.E. Jr.; Herrero, F.A.

    1994-12-31

    A high-quality, large numerical aperture Fresnel zone device is being developed to enhance the performance of a Fabry-Perot interferometer (FPI) system. As predicted by the theory, the contributions from the successive interference fringes transmitted by this multiple Fresnel aperture increase the throughput of the FPI system many fold. This versatile optical element can also function as a lens, an aperture and a filter resulting in a very compact system. For a given FPI resolution, a dramatic increase in the throughput and significant reduction in the instrument size attained by this experimental approach offers broad possibilities for major scientific advances for faint radiation measurements in several areas including astronomy, remote sensing of the atmosphere, X-ray microscopy, plasma research, and neutron imaging.

  20. Highly accurate spectral retardance characterization of a liquid crystal retarder including Fabry-Perot interference effects

    SciTech Connect

    Vargas, Asticio; Mar Sánchez-López, María del; García-Martínez, Pascuala; Arias, Julia; Moreno, Ignacio

    2014-01-21

    Multiple-beam Fabry-Perot (FP) interferences occur in liquid crystal retarders (LCR) devoid of an antireflective coating. In this work, a highly accurate method to obtain the spectral retardance of such devices is presented. On the basis of a simple model of the LCR that includes FP effects and by using a voltage transfer function, we show how the FP features in the transmission spectrum can be used to accurately retrieve the ordinary and extraordinary spectral phase delays, and the voltage dependence of the latter. As a consequence, the modulation characteristics of the device are fully determined with high accuracy by means of a few off-state physical parameters which are wavelength-dependent, and a single voltage transfer function that is valid within the spectral range of characterization.

  1. Enhanced Bulk-Edge Coulomb Coupling in Fractional Fabry-Perot Interferometers.

    PubMed

    von Keyserlingk, C W; Simon, S H; Rosenow, Bernd

    2015-09-18

    Recent experiments use Fabry-Perot (FP) interferometry to claim that the ν=5/2 quantum Hall state exhibits non-Abelian topological order. We note that the experiments appear inconsistent with a model neglecting bulk-edge Coulomb coupling and Majorana tunneling, so we reexamine the theory of FP devices. Even a moderate Coulomb coupling may strongly affect some fractional plateaus, but very weakly affect others, allowing us to model the data over a wide range of plateaus. While experiments are consistent with the ν=5/2 state harboring Moore-Read topological order, they may have measured Coulomb effects rather than an "even-odd effect" due to non-Abelian braiding. PMID:26431008

  2. High quality factor Er-doped Fabry-Perot microcavities by sol-gel processing

    NASA Astrophysics Data System (ADS)

    Li, Yigang; Fortes, Luís M.; Chiappini, Andrea; Ferrari, Maurizio; Almeida, Rui M.

    2009-10-01

    An optimized sol-gel process was developed to fabricate 1D photonic bandgap structures. Several erbium-doped Fabry-Perot microcavities were prepared and characterized. The thickest sample contained two Bragg mirrors, each having 12 distributed Bragg reflector periods of alternating silicate glass and titania layers. The total thickness of this sample reached ~12 µm. The Er3+ photoluminescence spectra at 1.5 µm were measured for the microcavities. A quality factor of 250 and an Er3+ photoluminescence enhancement of 96 times at 1.5 µm have been reached. The sol-gel processing details, the crystallization of the titania films and the refractive index of the deposited materials are discussed in detail. The simulated optical spectra of the microcavities were found to agree well with the actually measured curves. These results demonstrate that the present sol-gel processing technique is of potential interest for low cost fabrication of 1D photonic bandgap devices.

  3. Enhanced Bulk-Edge Coulomb Coupling in Fractional Fabry-Perot Interferometers.

    PubMed

    von Keyserlingk, C W; Simon, S H; Rosenow, Bernd

    2015-09-18

    Recent experiments use Fabry-Perot (FP) interferometry to claim that the ν=5/2 quantum Hall state exhibits non-Abelian topological order. We note that the experiments appear inconsistent with a model neglecting bulk-edge Coulomb coupling and Majorana tunneling, so we reexamine the theory of FP devices. Even a moderate Coulomb coupling may strongly affect some fractional plateaus, but very weakly affect others, allowing us to model the data over a wide range of plateaus. While experiments are consistent with the ν=5/2 state harboring Moore-Read topological order, they may have measured Coulomb effects rather than an "even-odd effect" due to non-Abelian braiding.

  4. Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis.

    PubMed

    Tosi, Daniele

    2015-10-29

    The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding.

  5. Sapphire hard X-ray Fabry-Perot resonators for synchrotron experiments.

    PubMed

    Tsai, Yi Wei; Wu, Yu Hsin; Chang, Ying Yi; Liu, Wen Chung; Liu, Hong Lin; Chu, Chia Hong; Chen, Pei Chi; Lin, Pao Te; Fu, Chien Chung; Chang, Shih Lin

    2016-05-01

    Hard X-ray Fabry-Perot resonators (FPRs) made from sapphire crystals were constructed and characterized. The FPRs consisted of two crystal plates, part of a monolithic crystal structure of Al2O3, acting as a pair of mirrors, for the backward reflection (0 0 0 30) of hard X-rays at 14.3147 keV. The dimensional accuracy during manufacturing and the defect density in the crystal in relation to the resonance efficiency of sapphire FPRs were analyzed from a theoretical standpoint based on X-ray cavity resonance and measurements using scanning electron microscopic and X-ray topographic techniques for crystal defects. Well defined resonance spectra of sapphire FPRs were successfully obtained, and were comparable with the theoretical predictions.

  6. Measurement of refractive index dispersion of a fused silica plate using Fabry-Perot interference.

    PubMed

    Lee, Choonghwan; Choi, Heejoo; Jin, Jonghan; Cha, Myoungsik

    2016-08-10

    We used Fabry-Perot interferometry to measure the refractive indices of a fused silica plate at four different wavelengths ranging from 544 to 1550 nm, giving a detailed analysis on the uncertainty of this experimental method. Because of a small expanded uncertainty of 2.7×10-5(k=1.96) obtained using the experimental method, it was possible to make corrections to the existing Sellmeier formula [J. Opt. Soc. Am.55, 1205 (1965)JOSAAH0030-394110.1364/JOSA.55.001205] for our fused silica sample. The corrected Sellmeier formula resulted in a group index value larger than that evaluated using the Malitson's Sellmeier formula by 3×10-4. We verified this by comparing it with the group index measured with spectral domain interferometry at 1530 nm.

  7. Fabry-Perot based metal-dielectric multilayered filters and metamaterials.

    PubMed

    Jen, Yi-Jun; Lee, Cheng-Chung; Lu, Kun-Han; Jheng, Ci-Yao; Chen, Yu-Jen

    2015-12-28

    The traditional three-layered metal-dielectric-metal Fabry-Perot filter is developed as a new metal-dielectric multilayered band-pass filter. Our design method allows metal and dielectric films to be alternatively arranged to achieve a narrow and high transmission peak and the peak height remains unchanged for any number of metal films arranged in the multilayer. Furthermore, the equivalent refractive index of a subwavelength metal-dielectric multilayer could be negative real at the passband of the filter and such metamaterial exhibits stronger figure of merit than a previous result. By choosing a material with high refractive index as the dielectric film, such metamaterial exhibits a pass band that depends weakly on the angle of incidence.

  8. Automatic system to relock a laser frequency to a Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Lee, Seung Koo; Han, Byoung Woong; Cho, D.

    2005-02-01

    We developed a system that allowed us to unlock and at a later time automatically relock a laser frequency to a medium-finesse Fabry-Perot cavity. The system can work as a chopping wheel or a shutter for a laser field built inside a cavity. The heart of our system is the flywheel circuit for the slower-acting servo loop and the automatic gain control circuit for the faster-acting servo loop. The flywheel circuit stores a correction for a slow frequency drift so that during the unlocked period the slow loop can be safely turned off. The automatic gain control lowers the fast loop gain during a relock process and increases the gain after the lock is secured. The system works reliably at a chopping frequency up to 70Hz, and relocks well after being unlocked for up to 10s.

  9. Fabry-Perot observations of NH2 emission from Comet Halley

    NASA Technical Reports Server (NTRS)

    Magee-Sauer, K.; Scherb, F.; Roesler, F. L.; Harlander, J.; Lutz, Barry L.

    1989-01-01

    The (0,8,0) cometary NH2 band lines have been isolated from both cometary and terrestrial OI 6300 A OH emissions in Fabry-Perot spectra of the emissions of Comet Halley near 6300 A. On the assumption that the major source of NH2 is NH3, these NH2 measurements limit NH3's abundance relative to H2O. The results thus obtained are noted to depend on the NH2 (0,8,0) band fluorescence efficiency factor g(B); using the g(B) value of A'Hearn (1982), the NH3 abundance is found to be about 0.1 percent of that of H2O, while the g(B) value of Tegler and Wyckoff (1989) yields a figure of 0.4 percent. Both results indicate a low NH3 abundance relative to water on Comet Halley.

  10. Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis

    PubMed Central

    Tosi, Daniele

    2015-01-01

    The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding. PMID:26528975

  11. Design of distributed FBG vibration measuring system based on Fabry-Perot tunable filter

    NASA Astrophysics Data System (ADS)

    Zhang, Cheng; Miao, Changyun; Li, Hongqiang; Gao, Hua; Gan, Jingmeng

    2011-11-01

    A distributed optical fiber grating wavelength interrogator based on fiber Fabry Perot tunable filter(FFP-TF) was proposed, which could measure dynamic strain or vibration of multi-sensing fiber gratings in one optical fiber by time division way. The wavelength demodulated mathematical model was built, the formulas of system output voltage and sensitivity were deduced and the method of finding static operating point was determined. The wavelength drifting characteristic of FFP-TF was discussed when the center wavelength of FFP-TF was set on the static operating point. A wavelength locking method was proposed by introducing a high-frequency driving voltage signal. A demodulated system was established based on Labview and its demodulated wavelength dynamic range is 290pm in theory. In experiment, by digital filtering applied to the system output data, 100Hz and 250Hz vibration signals were measured. The experiment results proved the feasibility of the demodulated method.

  12. Spectral-mismatch-induced resolution limit of interferometric fiber Fabry-Perot sensor system

    NASA Astrophysics Data System (ADS)

    Niu, Siliang; Ma, Lina; Xiong, Shuidong; Hu, Yongming

    2011-12-01

    The mismatch of fiber Bragg gratings (FBGs) in spectral profiles can lead to a severe degraded resolution of the constructed fiber Fabry-Perot (FFP) sensor system through its effect on the fringe visibility. The variation of visibility induced by spectral mismatch and the corresponding phase resolution limit are analyzed theoretically and experimentally. Theoretical analyses are based on the approximation of Gaussian profiles to the reflection spectra of weak FBGs, especially with consideration of side lobes. The investigation provides an insight into the evolution of the fringe visibility caused by spectral mismatch, and shows good agreement with experimental results. An optimum phase resolution of about 55 μrad/Hz 1/2 above 100 Hz is achieved for a nearly 4 m-long FFP sensor by matching spectral profiles of the gratings and balancing path length differences of the tandem interferometers.

  13. Wavelength readout system constructed of fiber Fabry-Perot tunable filter and virtual instrument

    NASA Astrophysics Data System (ADS)

    Lü, Chengang; Zhang, Ruifeng; Cheng, Pengfei; Li, Kejia; Wu, Xing; Ge, Chunfeng

    2010-08-01

    The wavelength readout system reported in this paper is chiefly constructed of fiber Fabry-Perot tunable filter (FFP-TF), data acquisition card and a virtual instrument with programmable NI Labview. By combining the dynamic scanning of FFP-TF in C waveband (1520nm-1570nm) with 50nm free spectral range (FSR) and 4000 standard finesse value, the wavelength of a tested laser diode (LD) could be detected accurately, while the spectrum is displayed on line with the help of a virtual instrument to make the spectroscopy quick analysis possible. Furthermore, the scheme can also be applied for wavelength interrogation in fiber Bragg grating (FBG) sensing system. Considering the practibility and economical efficiency of such a system, it will be of great significance to adopt such a wavelength readout system in fiber sensors used for construction, mining, aerospace,etc.

  14. On-chip optical phase locking of single growth monolithically integrated Slotted Fabry Perot lasers.

    PubMed

    Morrissey, P E; Cotter, W; Goulding, D; Kelleher, B; Osborne, S; Yang, H; O'Callaghan, J; Roycroft, B; Corbett, B; Peters, F H

    2013-07-15

    This work investigates the optical phase locking performance of Slotted Fabry Perot (SFP) lasers and develops an integrated variable phase locked system on chip for the first time to our knowledge using these lasers. Stable phase locking is demonstrated between two SFP lasers coupled on chip via a variable gain waveguide section. The two lasers are biased differently, one just above the threshold current of the device with the other at three times this value. The coupling between the lasers can be controlled using the variable gain section which can act as a variable optical attenuator or amplifier depending on bias. Using this, the width of the stable phase locking region on chip is shown to be variable.

  15. Readout of micromechanical cantilever sensor arrays by Fabry-Perot interferometry

    SciTech Connect

    Wehrmeister, Jana; Fuss, Achim; Saurenbach, Frank; Berger, Ruediger; Helm, Mark

    2007-10-15

    The increasing use of micromechanical cantilevers in sensing applications causes a need for reliable readout techniques of micromechanical cantilever sensor (MCS) bending. Current optical beam deflection techniques suffer from drawbacks such as artifacts due to changes in the refraction index upon exchange of media. Here, an adaptation of the Fabry-Perot interferometer is presented that allows simultaneous determination of MCS bending and changes in the refraction index of media. Calibration of the instrument with liquids of known refraction index provides an avenue to direct measurement of bending with nanometer precision. Versatile construction of flow cells in combination with alignment features for substrate chips allows simultaneous measurement of two MCS situated either on the same, or on two different support chips. The performance of the instrument is demonstrate in several sensing applications, including adsorption experiments of alkanethioles on MCS gold surfaces, and measurement of humidity changes in air.

  16. Simulations of imaging Fabry-Perot interferometers for measuring upper-atmospheric temperatures and winds.

    PubMed

    Huang, Yiyi; Makela, Jonathan J; Swenson, Gary R

    2012-06-10

    We apply an onion-peeling inversion to simulated imaging Fabry-Perot interferometer (FPI) observations for retrieving altitude profiles of neutral temperatures and winds in the thermosphere in order to investigate the effects of realistic gradients in thermospheric parameters on the retrieved parameters. A forward model is developed that simulates the interference spectrum observed by an FPI using the redline (630.0 nm) and greenline (557.7 nm) emissions simulated based on climatological models. This forward model is applicable to both ground- and satellite-based simulations and generates a two-dimensional interference ring pattern. We simulate both a single-band ground-based FPI and a dual-band satellite-based FPI in order to study the effects of realistic vertical and horizontal gradients on the retrieved parameters. PMID:22695656

  17. Faraday-Active Fabry-Perot Resonator: Transmission, Reflection, and Emissivity

    NASA Technical Reports Server (NTRS)

    Liptuga, Anatoliy; Morozhenko, Vasyl; Pipa, Viktor; Venger, Evgen; Kostiuk, Theodor

    2011-01-01

    The propagation of light within a semiconductor Faraday-active Fabry-Perot resonator (FAFR) is investigated theoretically and experimentally. It is shown that an external magnetic field radically changes the angular and spectral characteristics of transmission, reflection and emissivity of the resonator not only for polarized, but also for unpolarized light. Suppression of interference patterns and phase inversion of the interference extrema were observed in both monochromatic and polychromatic light. The investigations were carried out for the plane-parallel plates of n-InAs in the spectral range of free charge carrier absorption. The results can be used to create new controllable optical and spectroscopic devices for investigation of Faraday-active material properties and for control of parameters of plane-parallel layers and structures.

  18. Measurement of reflection phase using thick-gap Fabry-Perot etalon.

    PubMed

    Yung, Tsz Kit; Gao, Wensheng; Leung, Ho Ming; Zhao, Qiuling; Wang, Xia; Tam, Wing Yim

    2016-09-10

    We report measurement of the reflection phase of a dielectric (glass)/titanium (Ti) surface in the visible wavelength using a thick-gap Fabry-Perot (FP) interferometry technique. Using a two-beam interference model for the reflection peaks and troughs of the FP etalon, we obtain the air-gap spacing of the etalon and, more importantly, the reflection phase of the etalon substrate. We find systematic dependence of the as-measured reflection phase on the air-gap spacing due to the numerical aperture effect of the measuring objective. However, the relative reflection phase of Ti with respect to glass is independent of the air-gap spacing. As a demonstration of our approach in the optical characterization of small metamaterial samples, we also measure the reflection phase of a micron-sized 2D Au sawtooth nanoarray. The experiment is in good agreement with the model simulation.

  19. Study on high temperature Fabry-Perot fiber acoustic sensor with temperature self-compensation

    NASA Astrophysics Data System (ADS)

    Hu, Pan; Tong, Xinglin; Zhao, Minli; Deng, Chengwei; Guo, Qian; Mao, Yan; Wang, Kun

    2015-09-01

    A Fabry-Perot (F-P) fiber acoustic sensor, which can work under high-temperature harsh environment with temperature self-compensation, is designed and prepared. A condenser was used to maintain the sensor to work in a stable temperature environment. Because of the special structure of the sensor and the function of the condenser, the cavity variation of the sensor caused by changes of external temperature from -10°C to 500°C would not exceed 8 nm. The experimental results show that the sensor has a good frequency response in a range of 1 to 5 kHz and the field experiment results show that it could be used for hydraulic decoking online monitoring by judging the acoustic frequency spectrum.

  20. Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis.

    PubMed

    Tosi, Daniele

    2015-01-01

    The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding. PMID:26528975

  1. Striped-double cavity fabry-perot interferometers using both glass and air cavities

    SciTech Connect

    Perry, S; Steinmetz, L

    1998-07-08

    We have used piezo-driven Fabry-Perot interferometers in the past far many continuous velocity-time measurements of fast moving surfaces. In order to avoid the annoying drift of some of these devices, we have developed and used inexpensive, solid glass, striped etalons with lengths up to 64 mm. Usable apertures are 35 mm by 80 mm with a finess of 25. A roundabout technique was devised for double cavity operation. We built a passive thermal housing for temperature stability, with tilt and height adjustments. We have also developed and used our first fixed etalon air-spaced cavity with a rotatable glass double- cavity insert. The rotation allows the referee cavity fractional order to be adjusted separately from that of the main cavity. It needs very little thermal protection, and eliminates the need for a roundabout scheme for double cavity operation, but is more costly than the solid glass version I

  2. Fabry-Perot interferometer measurement of static temperature and velocity for ASTOVL model tests

    NASA Technical Reports Server (NTRS)

    Kourous, Helen E.; Seacholtz, Richard G.

    1995-01-01

    A spectrally resolved Rayleigh/Mie scattering diagnostic was developed to measure temperature and wing-spanwise velocity in the vicinity of an ASTOVL aircraft model in the Lewis 9 x 15 Low Speed Wind Tunnel. The spectrum of argon-ion laser light scattered by the air molecules and particles in the flow was resolved with a Fabry-Perot interferometer. Temperature was extracted from the spectral width of the Rayleigh scattering component, and spanwise gas velocity from the gross spectral shift. Nozzle temperature approached 800 K, and the velocity component approached 30 m/s. The measurement uncertainty was about 5 percent for the gas temperature, and about 10 m/s for the velocity. The large difference in the spectral width of the Mie scattering from particles and the Rayleigh scattering from gas molecules allowed the gas temperature to be measured in flow containing both naturally occurring dust and LDV seed (both were present).

  3. Inspection technique for cleaved optical fiber ends based on Fabry-Perot resonator

    NASA Astrophysics Data System (ADS)

    Kihara, Mitsuru; Watanabe, Hiroshi; Yajima, Yuichi; Toyonaga, Masanobu

    2011-05-01

    We present a novel inspection technique for cleaved optical fiber ends based on the Fabry-Perot resonator. The technique uses mainly laser diodes, an optical power meter, 3-dB coupler, and XY lateral adjustment stage. It can be achieved more easily than current imaging processing that uses a charge coupled device camera and video monitor. The inspected fiber end is considered failed or successful depending on whether both the measured return losses from the fiber end at two wavelengths are equal to ~14.7 dB. Experimentally obtained fiber end images were in good agreement with scanning electron microscope observation images. Thus, the proposed technique provides a simple and cost-effective way to inspect cleaved optical fiber ends.

  4. A Novel, Poly-Etalon, Fabry-Perot for Planetary Research

    NASA Technical Reports Server (NTRS)

    Kerr, Robert B.; Doe, Richard; Noto, John

    1997-01-01

    In an effort to develop a mechanically robust, high throughput and solid state spectrometer several liquid crystal Fabry-Perot etalons were constructed. The etalons were tested for spectral response, radiation resistance and optical transmission. The first year of this project was spent developing and understanding the properties of the liquid crystal etalons; in the second year an intensified all-sky imaging system was developed around a pair of LC etalons. The imaging system, developed jointly with SRI International represents a unique brassboard to demonstrate the use of LC etalons as tunable filters. The first set of etalons constructed in year one of this project were tested for spectral response and throughput while etalon surrogates were exposed to proton radiation simulating the exposure of an object in Low Earth Orbit (LEO). The 2" diameter etalons had a measure finesse of approximately 10 and were tunable over five orders. Liquid crystals exposed to proton irradiation showed no signs of damage. In year two two larger diameter (3") etalons were constructed with gaps of 3 and 5 microns. This pair of etalons is for use in a high resolution, all-sky spectral imager. The WATUMI imager system follows the heritage of all sky, narrow band, intensified imagers however it includes two LC Fabry-Perot etalons to provide tunability and the ability to switch wavelengths rapidly, an import consideration in auroral airglow imaging. This work also resulted in two publications and one poster presentation. The instrument will be uniquely capable, with superior throughput and speed, to measure optical airglow of multiple emission lines in harsh conditions.

  5. Fabry-Perot fiber pressure sensor based on white light interferometry and intensity demodulation method

    NASA Astrophysics Data System (ADS)

    Guo, Zhenwu; Li, Weixiang; Zhang, Dapeng; Pan, Yong; Meng, Qingbin; Liu, Guangwei; Ge, Fuwei; Zhang, Xian

    2009-05-01

    We have designed an intensity-demodulated sensing system based on Fabry-Perot interferometer and fiber Bragg grating (FBG) for pressure measurement. The structure of the sensor probe is presented. It is an optical fiber extrinsic Fabry-Perot interferometer(EFPI) composed of silica tube and optical fibers. The variable quantity of cavity length of the EFPI is equal to that of silica tube, which has direct proportion to external pressure. The sensing system is interrogated by broadband light. In order to compensate intensity fluctuation, we use an FBG as a narrow band filter to obtain the sensing signal and reference signal from white-light interference fringe returned from EFPI. The sensing signal is in the reflected beam from FBG, and the reference signal is contained in reflected beam and transmitted beam of FBG simultaneously. Then two output light signals are transformed into current signals by two photodiodes. Subsequently two current signals are processed at the same time. After the signals being treated with circuit, the inherent disadvantage of intensity-demodulated sensor is removed. It is also to say the sensing system has immunity from the drift of light source power and fluctuation in fiber attenuation by using only a FBG. Meanwhile, the system has advantages of fast response, simple circuitry, strong ability of intensity compensation and low cost. Experimental results show that the experimental data are consistent with theoretical analysis. The dynamic range of sensor is from 0 to 500KPa, and the resolution reaches to 0.5KPa. The sensing system can be used to measure pressure in inflammable and explosive circumstance such as oil height of super oil storage tanks.

  6. Sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure measurement.

    PubMed

    Liao, Changrui; Liu, Shen; Xu, Lei; Wang, Chao; Wang, Yiping; Li, Zhengyong; Wang, Qiao; Wang, D N

    2014-05-15

    We demonstrate a sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure sensing applications. The thinnest silica diaphragm, with a thickness of ∼320  nm, has been achieved by use of an improved electrical arc discharge technique. Such a sub-micron silica diaphragm breaks the sensitivity limitation imposed by traditional all-silica Fabry-Perot interferometric pressure sensors and, as a result, a high pressure sensitivity of ∼1036  pm/MPa at 1550 nm and a low temperature cross-sensitivity of ∼960  Pa/°C are achieved when a silica diaphragm of ∼500  nm in thickness is used. Moreover, the all-silica spherical structure enhanced the mechanical strength of the micro-cavity sensor, making it suitable for high sensitivity pressure sensing in harsh environments. PMID:24978213

  7. Fiber Optic Fabry-Perot Current Sensor Integrated with Magnetic Fluid Using a Fiber Bragg Grating Demodulation.

    PubMed

    Xia, Ji; Wang, Qi; Liu, Xu; Luo, Hong

    2015-07-09

    An optical fiber current sensor based on Fabry-Perot interferometer using a fiber Bragg grating demodulation is proposed. Magnetic fluid is used as a sensitive medium in fiber optical Fabry-Perot (F-P) cavity for the optical characteristic of magnetic-controlled refractive index. A Fiber Bragg grating (FBG) is connected after the F-P interferometer which is used to reflect the optical power at the Bragg wavelength of the interference transmission spectrum. The corresponding reflective power of the FBG will change with different external current intensity, due to the shift on the interference spectrum of the F-P interferometer. The sensing probe has the advantages of convenient measurement for its demodulation, low cost and high current measurement accuracy on account of its sensing structure. Experimental results show that an optimal sensitivity of 0.8522 nw/A and measurement resolution of 0.001 A is obtained with a FBG at 1550 nm with 99% reflectivity.

  8. Sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure measurement.

    PubMed

    Liao, Changrui; Liu, Shen; Xu, Lei; Wang, Chao; Wang, Yiping; Li, Zhengyong; Wang, Qiao; Wang, D N

    2014-05-15

    We demonstrate a sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure sensing applications. The thinnest silica diaphragm, with a thickness of ∼320  nm, has been achieved by use of an improved electrical arc discharge technique. Such a sub-micron silica diaphragm breaks the sensitivity limitation imposed by traditional all-silica Fabry-Perot interferometric pressure sensors and, as a result, a high pressure sensitivity of ∼1036  pm/MPa at 1550 nm and a low temperature cross-sensitivity of ∼960  Pa/°C are achieved when a silica diaphragm of ∼500  nm in thickness is used. Moreover, the all-silica spherical structure enhanced the mechanical strength of the micro-cavity sensor, making it suitable for high sensitivity pressure sensing in harsh environments.

  9. Measurement of high-intensity focused ultrasound fields using miniaturized all-silica fiber-optic Fabry-Perot hydrophones

    NASA Astrophysics Data System (ADS)

    Jia, Ping-Gang; Ke, Ding; Wang, Dai-Hua; Zeng, Lu-Yu; Jiang, Xin-Yin; Liu, Lei

    2014-11-01

    High-intensity focused ultrasounds (HIFUs), as a novel non-invasive surgery technology, have been used effectively for cancer therapy. In order to ensure the HIFU treatment safety, the acoustic pressure distributions and the size of the focal regions of HIFU fields need to be measured accurately. In this paper, the lateral sensitive and tip-sensitive all-silica fiberoptic Fabry-Perot ultrasonic hydrophone systems and the corresponding experimental setups are established to measure HIFU fields, respectively. The acoustic pressure distributions of the HIFU field along the X-axis, Y-axis, and Z-axis are compared in the degassed water by the lateral sensitive and tip-sensitive fiber-optic Fabry-Perot ultrasonic hydrophones. Experimental results show that the tip-sensitive configuration can measure the acoustic pressure distribution in the focal region with high accuracy than the lateral-sensitive configuration.

  10. Tuning operating point of extrinsic Fabry-Perot interferometric fiber-optic sensors using microstructured fiber and gas pressure.

    PubMed

    Tian, Jiajun; Zhang, Qi; Fink, Thomas; Li, Hong; Peng, Wei; Han, Ming

    2012-11-15

    Intensity-based demodulation of extrinsic Fabry-Perot interferometric (EFPI) fiber-optic sensors requires the light wavelength to be on the quadrature point of the interferometric fringes for maximum sensitivity. In this Letter, we propose a novel and remote operating-point tuning method for EFPI fiber-optic sensors using microstructured fibers (MFs) and gas pressure. We demonstrated the method using a diaphragm-based EFPI sensor with a microstructured lead-in fiber. The holes in the MF were used as gas channels to remotely control the gas pressure inside the Fabry-Perot cavity. Because of the deformation of the diaphragm with gas pressure, the cavity length and consequently the operating point can be remotely tuned for maximum sensitivity. The proposed operating-point tuning method has the advantage of reduced complexity and cost compared to previously reported methods. PMID:23164875

  11. Design of multistack Fabry-Perot structure with defect as tunable transmission filter for CWDM using FDTD method

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Rajorshi; Chakraborty, Rajib

    2015-06-01

    The translational symmetry of the periodicity in a photonic crystal can be disturbed by introducing a controlled defect in its periodicity. The photon localization causes a pass band in the photonic bandgap. Based on this concept, we are proposing the design of a tunable narrow band filter for multiple wavelengths used for coarse wave length division multiplexing (CWDM) system. To achieve that, a multiple stack Fabry Perot structure with suitable stack materials and controllable defect is considered. The proposed Fabry Perot structure consists of periodic layers of electro optic material Lithium Niobate (nH) and Magnesium Fluoride (nL). The optical length of each such layer is their corresponding quarter wave length width at the design wavelength λ0 (1.55 μm). The reflection band of the quarter wavelength multilayer structure is formed due to the periodic repetition of the (LH)NL, where L and H are the quarter wavelength width of the nL and nH material respectively and N is the number of bilayers. A quarter wave layer L is then inserted between the groups of (LH)N and (HL)N to form the Fabry Perot resonator structure which can be used for narrow band transmission filter. The simulation has been carried out in both FDTD and TMM method and compared. As the refractive index of the Lithium Niobate can be tuned electro-optically, the filter can also be made tunable.

  12. Response of a new low-coherence Fabry-Perot sensor to hematocrit levels in human blood.

    PubMed

    Jędrzejewska-Szczerska, Małgorzata

    2014-04-21

    In this paper, a low-coherence Fabry-Perot sensor with a spectrally measured signal processing response to the refractive index of liquids is presented. Optical fiber sensors are potentially capable of continuous measuring hematocrit levels in blood. Low-coherence Fabry-Perot interferometric sensors offer a robust solution, where information about the measurand is encoded in the full spectrum of light reflected from the sensing interferometer. The first step in the research on such sensor is the assessment of its performance under favorable conditions, i.e., using blood samples from healthy volunteers tested in vitro. Such an experiment was conducted using a sensor comprising a superluminescent diode source, an optical spectrum analyzer working as the detection setup and a sensing Fabry-Perot interferometer providing high interference contrast. The response of this sensor was recorded for several samples and compared with the reference laboratory method. The coefficient of determination (R²) for a linear relationship between the results given by both methods was 0.978 and the difference between these results was less than 1%. The presented results suggest that further research into the performance of the sensor is merited.

  13. All-optical clock recovery based on simultaneous external injection-locking and self-seeding of a Fabry-Perot laser diode

    NASA Astrophysics Data System (ADS)

    Fang, Xiaohui; Wai, Ping Kong A.; Lu, Chao; Tam, Hwa Yaw; Qureshi, Khurram K.

    2011-02-01

    We proposed and demonstrated a novel, simple, and low cost method for all-optical clock recovery based on the switching between two injection-locked longitudinal modes in a dc-biased multi-quantum-well Fabry-Perot laser diode (FP-LD). The dc biased FP-LD is simultaneously injection-locked by a return-to-zero data signal at one of the longitudinal modes of the FP-LD and self-seeded at another longitudinal mode by using a uniform fiber Bragg grating as a feedback component. The powers and detunes of the data signal and self-seeding signal are chosen such that self-seeding is realized in the FP-LD only when data signal power is low. Clock signals of data streams at different data rates can be obtained by tuning the optical delay line in the external self-seeding loop. We have demonstrated all-optical clock recovery at 10 GHz. The pulse width, time-bandwidth product, side mode suppression ration, root mean square timing jitter, and average power of the recovered clock signals are 50 ps, 0.5, 50 dB, 248 fs, and 3.6 dBm, respectively. Clock recovery is possible at wavelength within the gain band of the FP-LD. We also find and explore in the experiment the influence of detune between the external data signal and the nearest FP-LD longitudinal mode to the recovered clock.

  14. Colloidal pattern replication through contact photolithography operated in a 'Talbot-Fabry-Perot' regime.

    PubMed

    Emplit, Aline; Lian, Jian Xiang; Huynen, Isabelle; Vlad, Alexandru; Sarrazin, Michaël

    2014-04-11

    We describe a method for continuous colloidal pattern replication using contact photolithography. Cr-on-quartz masks are fabricated using colloidal nanosphere lithography and subsequently used as photolithography stamps. Hexagonal pattern arrangements with different dimensions (980, 620 and 480 nm, using colloidal particles with these respective diameters) have been studied. When the mask and the imaged resist layer were in intimate contact, a high fidelity pattern replica was obtained after photolithographic exposure and processing. In turn, the presence of an air gap in between was found to affect the projected image on the photoresist layer, with a strong dependence on the mask feature size and height of the air gap. Pattern replication, inversion and hybridization were achieved for the 980 nm period mask; no hybridization for the 620 nm one; and only pattern replication for the 480 nm one. These results are interpreted in the framework of a 'Talbot-Fabry-Perot' effect. Numerical simulations corroborate the experimental findings, providing insight into the processes involved and highlighting the important parameters affecting the exposure pattern. This approach allows complex subwavelength patterning and is relevant for three-dimensional layer-by-layer printing.

  15. Spectral imager based on Fabry-Perot interferometer for Aalto-1 nanosatellite

    NASA Astrophysics Data System (ADS)

    Mannila, Rami; Näsilä, Antti; Viherkanto, Kai; Holmlund, Christer; Näkki, Ismo; Saari, Heikki

    2013-09-01

    The Aalto-1 is a 3U-cubesat project coordinated by Aalto University. The satellite, Aalto-1, will be mainly built by students as project assignments and thesis works. The Aalto-1 is planned to launch on 2014. VTT Technical Research Centre of Finland is developing the main Earth observation payload, a miniaturized spectral imager unit, for the satellite. The spectral imager unit contains a spectral imager, a visible RGB-camera and control electronics of the cameras. Detailed design of the spectral imager unit has been completed and assembly of the spectral imager unit will be done in the autumn 2013. The spectral imager is based on a tunable Fabry-Perot interferometer (FPI) accompanied by an RGB CMOS image sensor. The FPI consists of two highly reflective surfaces separated by a tunable air gap and it is based on a piezo-actuated structure. The piezo-actuated FPI uses three piezo-actuators and is controlled in a closed capacitive feedback loop. The spectral resolution of the imager will be 8-15 nm at full width at half maximum and it will operate in the wavelength range 500-900 nm. Imaging resolution of the spectral imager is 1024x1024 pixels and the focal length of the optics is 32 mm and F-number is 3.4. Mass of the spectral imager unit is approximately 600 grams, and dimensions are 97 mm x 97 mm x 48 mm.

  16. TiO2 nanoparticle thin film-coated optical fiber Fabry-Perot sensor.

    PubMed

    Jiang, Mingshun; Li, Qiu-Shun; Wang, Jun-Nan; Jin, Zhongwei; Sui, Qingmei; Ma, Yaohong; Shi, Jianguo; Zhang, Faye; Jia, Lei; Yao, Wei-Guo; Dong, Wen-Fei

    2013-02-11

    In this paper, a novel TiO(2) nanoparticle thin film coated optical fiber Fabry-Perot (F-P) sensor had been developed for refractive index (RI) sensing by monitoring the shifts of the fringe contrast in the reflectance spectra. Using in situ liquid phase deposition approach, the TiO(2) nanoparticle thin film could be formed on the fiber surface in a controlled fashion. The optical properties of as-prepared F-P sensors were investigated both theoretically and experimentally. The results indicated that the RI sensitivity of F-P sensors could be effectively improved after the deposition of nanoparticle thin-films. It was about 69.38 dB/RIU, which was 2.6 times higher than that of uncoated one. The linear RI measurement range was also extended from 1.333~1.457 to 1.333~1.8423. More importantly, its optical properties exhibited the unique temperature-independent performance. Therefore, owing to these special optical properties, the TiO(2) nanoparticle thin film coated F-P sensors have great potentials in medical diagnostics, food quality testing, environmental monitoring, biohazard detection and homeland security, even at elevated temperature. PMID:23481766

  17. CIV Vacuum Ultraviolet Fabry-Perot Interferometers for Transition-Region Magnetography

    NASA Technical Reports Server (NTRS)

    Gary, G. Allen; West, Edward A.; Rees, David; Zukic, Maumer; Herman, Peter; Li, Jianzhao

    2006-01-01

    The vacuum ultraviolet region allows remote sensing of the upper levels of the solar atmosphere where the magnetic field dominates the physics. Obtaining an imaging interferometer that observes the transition region is the goal of this program. This paper gives a summary of our instrument development program (1998-2005) for a high-spectral-resolution, piezoelectric tunable Vacuum Ultraviolet Fabry-Perot Interferometer (VUV FPI) for obtaining narrow-passband images, magnetograms, and Dopplergrams of the transition region emission line of CN (155nm). A VUV interferometer will allow us to observe the magnetic field, flows, and heating events in the mid-transition region. The MSFC VUV FPI has measured values of FWHM approx. 9pm, FSR approx. 62pm, finesse approx. 5.3 and transmittance approx. 50% at 157nm. For the measurements, the University of Toronto's F2 eximer laser was used as an appropriate proxy for CIV 155nm. This has provided the first tunable interferometer with a FWHM compatible to VUV filter magnetograph.

  18. Electro-Mechanical Simulation of a Large Aperture MOEMS Fabry-Perot Tunable Filter

    NASA Technical Reports Server (NTRS)

    Kuhn, Jonathan L.; Barclay, Richard B.; Greenhouse, Matthew A.; Mott, D. Brent; Satyapal, Shobita; Powers, Edward I. (Technical Monitor)

    2000-01-01

    We are developing a micro-machined electrostatically actuated Fabry-Perot tunable filter with a large clear aperture for application in high through-put wide-field imaging spectroscopy and lidar systems. In the first phase of this effort, we are developing key components based on coupled electro-mechanical simulations. In particular, the movable etalon plate design leverages high coating stresses to yield a flat surface in drum-head tension over a large diameter (12.5 mm). In this approach, the cylindrical silicon movable plate is back etched, resulting in an optically coated membrane that is suspended from a thick silicon support ring. Understanding the interaction between the support ring, suspended membrane, and coating is critical to developing surfaces that are flat to within stringent etalon requirements. In this work, we present the simulations used to develop the movable plate, spring suspension system, and electrostatic actuation mechanism. We also present results from tests of fabricated proof of concept components.

  19. Optical fiber extrinsic Fabry-Perot interferometric (EFPI)-based biosensors

    NASA Astrophysics Data System (ADS)

    Elster, Jennifer L.; Jones, Mark E.; Evans, Mishell K.; Lenahan, Shannon M.; Boyce, Christopher A.; Velander, William H.; VanTassell, Roger

    2000-05-01

    A novel system incorporating optical fiber extrinsic Fabry- Perot interferometric (EFPI)-based sensors for rapid detection of biological targets is presented. With the appropriate configuration, the EFPI senor is able to measure key environmental parameters by monitoring the interferometric fringes resulting from an optical path differences of reflected signals. The optical fiber EFPI sensor has been demonstrated for strain, pressure, and temperature measurements and can be readily modified for refractive index measurements by allowing solutions to flow into an open cavity. The sensor allows for highly sensitive, real-time, refractive index measurements and by applying affinity coatings containing ligands within this cavity, specific binding of target molecules can be accomplished. As target molecules bind to the coating, there is an increased density within the film, causing a measurable refractive index change that correlates to the concentration of detected target molecules. This sensor platform offers enhanced sensing capabilities for clinical diagnostics, pharmaceutical screening, environmental monitoring, food pathogen detection, biological warfare agent detection, and industrial bioprocessing. Promising applications also exist for process monitoring within the food/beverage, petroleum, and chemical industry.

  20. Tunable MOEMS Fabry-Perot interferometer for miniaturized spectral sensing in near-infrared

    NASA Astrophysics Data System (ADS)

    Rissanen, A.; Mannila, R.; Tuohiniemi, M.; Akujärvi, A.; Antila, J.

    2014-03-01

    This paper presents a novel MOEMS Fabry-Perot interferometer (FPI) process platform for the range of 800 - 1050 nm. Simulation results including design and optimization of device properties in terms of transmission peak width, tuning range and electrical properties are discussed. Process flow for the device fabrication is presented, with overall process integration and backend dicing steps resulting in successful fabrication yield. The mirrors of the FPI consist of LPCVD (low-pressure chemical vapor) deposited polySi-SiN λ/4-thin film Bragg reflectors, with the air gap formed by sacrificial SiO2 etching in HF vapor. Silicon substrate below the optical aperture is removed by inductively coupled plasma (ICP) etching to ensure transmission in the visible - near infra-red (NIR), which is below silicon transmission range. The characterized optical properties of the chips are compared to the simulated values. Achieved optical aperture diameter size enables utilization of the chips in both imaging as well as single-point spectral sensors.

  1. Frequency measuring system using mirror gap stabilized Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Nishimiya, Nobuo; Yamaguchi, Yoko; Ohrui, Yoshinobu; Suzuki, Masao

    2004-02-01

    The mirror gap of a Fabry-Perot interferometer was stabilized with two laser diodes; one locked to the line frequency 385 243 555.14445 MHz of the F=3←1 in 5 D3/2←5 S1/2 ( 87Rb) and the other to the 385 284 566.3663 MHz of the F=4←2 in 5 D5/2←5 S1/2 ( 87Rb) [Opt. Commun. 102 (1993) 432]. The length of the mirror gap was adjusted to generate the zero-cross points simultaneously at both of the two line positions. The fringe signals obtained from an interferometer thus stabilized can be used as frequency markers having accuracies of the order of 10 10 depending on the finesse of the interferometer used. Based on measurement using Cs D1 hyperfine lines reported by Udem et al. [Phys. Rev. Lett. 82 (1999) 3568], the uncertainty of markers in the region 50 THz apart from the reference lines is ±5 MHz.

  2. A novel fiber optic Fabry-Perot structure with a micrometric diameter tip

    NASA Astrophysics Data System (ADS)

    Wang, Xingwei; Xu, Juncheng; Wang, Zhuang; Cooper, Kristie L.; Wang, Anbo

    2006-08-01

    This paper presents a novel fiber optic Fabry-Perot (FP) structure with a micrometric diameter tip. The fabrication of micro scale probes has become essential in intracellular surgery, in cell sensing, manipulation, and injection. It is of great importance in many fields, such as genetics, pathology, criminology, pharmacogenetics, and food safety. With such a tiny protrusion, the sensor can be inserted into micron size cells, say, for DNA analysis. With the FP cavity inside the fiber, the change of optical path difference (OPD) caused by the environment can be demodulated. In addition, the structure is intrinsically capable of temperature compensation. What's more, it is simple, cost-efficient, and compact. Last but not the least, the structure shows promise for nanometric protrusion. Once this goal is achieved, the sensor can be inserted into most cells. The sensor could pave the way for faster, more accurate medical diagnostic tests for countless conditions and may ultimately save lives by allowing earlier disease detection and intervention.

  3. Underwater blast wave pressure sensor based on polymer film fiber Fabry-Perot cavity.

    PubMed

    Wang, Junjie; Wang, Meng; Xu, Jian; Peng, Li; Yang, Minghong; Xia, Minghe; Jiang, Desheng

    2014-10-01

    This paper describes the theoretical and experimental aspects of an optical underwater shock wave sensor based on a polymer film optical fiber Fabry-Perot cavity manufactured by vacuum deposition technology. The transduction mechanism of the sensor involves a normally incident acoustic stress wave that changes the thickness of the polymer film, thereby giving rise to a phase shift. This transient interferometric phase is interrogated by a three-phase-step algorithm. Theoretically, the sensor-acoustic-field interaction principle is analyzed, and the phase modulation sensitivity based on the theory of waves in the layered media is calculated. Experimentally, a static calibration test and a dynamic calibration test are conducted using a piston-type pressure calibration machine and a focusing-type electromagnetic shock wave. Results indicate that the repeatability, hysteresis, nonlinearity, and the overall measurement accuracy of the sensor within the full pressure range of 55 MPa are 1.82%, 0.86%, 1.81%, and 4.49%, respectively. The dynamic response time is less than 0.767 μs. Finally, three aspects that need further study for practical use are pointed out.

  4. An optical fiber Fabry-Perot flow measurement technology based on partial bend structure

    NASA Astrophysics Data System (ADS)

    Yang, Huijia; Jiang, Junfeng; Zhang, Xuezhi; Pan, Yuheng; Zhu, Wanshan; Zhou, Xiang; Liu, Tiegen

    2016-08-01

    An optical fiber Fabry-Perot (F-P) flow measurement technology is presented, which is based on partial bend structure. A 90° partial bend structure is designed to achieve the non-probe flow measurement with a pressure difference. The fluid simulation results of partial bend structure show that the error of the pressure difference is below 0.05 kPa during steady flow. The optical fiber F-P sensor mounted on the elbow with pressure test accuracy of 1% full scale is used to measure the fluid flow. Flow test results show that when the flow varies from 1 m3/h to 6.5 m3/h at ambient temperature of 25 °C, the response time is 1 s and the flow test accuracy is 4.5% of the F-P flow test system, proving that the F-P flow test method based on partial bend structure can be used in fluid flow measurement.

  5. All-fiber upconversion high spectral resolution wind lidar using a Fabry-Perot interferometer.

    PubMed

    Shangguan, Mingjia; Xia, Haiyun; Wang, Chong; Qiu, Jiawei; Shentu, Guoliang; Zhang, Qiang; Dou, Xiankang; Pan, Jian-Wei

    2016-08-22

    An all-fiber, micro-pulse and eye-safe high spectral resolution wind lidar (HSRWL) at 1.5 μm is proposed and demonstrated by using a pair of upconversion single-photon detectors and a fiber Fabry-Perot scanning interferometer (FFP-SI). In order to improve the optical detection efficiency, both the transmission spectrum and the reflection spectrum of the FFP-SI are used for spectral analyses of the aerosol backscatter and the reference laser pulse. Taking advantages of high signal-to-noise ratio of the detectors and high spectral resolution of the FFP-SI, the center frequencies and the bandwidths of spectra of the aerosol backscatter are obtained simultaneously. Continuous LOS wind observations are carried out on two days at Hefei (31.843 °N, 117.265 °E), China. The horizontal detection range of 4 km is realized with temporal resolution of 1 minute. The spatial resolution is switched from 30 m to 60 m at distance of 1.8 km. In a comparison experiment, LOS wind measurements from the HSRWL show good agreement with the results from an ultrasonic wind sensor (Vaisala windcap WMT52). An empirical method is adopted to evaluate the precision of the measurements. The standard deviation of the wind speed is 0.76 m/s at 1.8 km. The standard deviation of bandwidth variation is 2.07 MHz at 1.8 km.

  6. Wavelength-switched phase interrogator for extrinsic Fabry-Perot interferometric sensors.

    PubMed

    Xia, Ji; Xiong, Shuidong; Wang, Fuyin; Luo, Hong

    2016-07-01

    We report on phase interrogation of extrinsic Fabry-Perot interferometric (EFPI) sensors through a wavelength-switched unit with a polarization-maintaining fiber Bragg grating (PMFBG). The measurements at two wavelengths are first achieved in one total-optical path. The reflected peaks of the PMFBG with two natural wavelengths are in mutually perpendicular polarization detection, and they are switched through an electro-optic modulator at a high switching speed of 10 kHz. An ellipse fitting differential cross multiplication (EF-DCM) algorithm is proposed for interrogating the variation of the gap length of the EFPI sensors. The phase demodulation system has been demonstrated to recover a minimum phase of 0.42  μrad/Hz at the test frequency of 100 Hz with a stable intensity fluctuation level of ±0.8  dB. Three EFPI sensors with different cavity lengths are tested at the test frequency of 200 Hz, and the results indicate that the system can achieve the demodulation of EFPI sensors with different cavity lengths stably.

  7. Analytical modelling of a refractive index sensor based on an intrinsic micro Fabry-Perot interferometer.

    PubMed

    Vargas-Rodriguez, Everardo; Guzman-Chavez, Ana D; Cano-Contreras, Martin; Gallegos-Arellano, Eloisa; Jauregui-Vazquez, Daniel; Hernández-García, Juan C; Estudillo-Ayala, Julian M; Rojas-Laguna, Roberto

    2015-10-15

    In this work a refractive index sensor based on a combination of the non-dispersive sensing (NDS) and the Tunable Laser Spectroscopy (TLS) principles is presented. Here, in order to have one reference and one measurement channel a single-beam dual-path configuration is used for implementing the NDS principle. These channels are monitored with a couple of identical optical detectors which are correlated to calculate the overall sensor response, called here the depth of modulation. It is shown that this is useful to minimize drifting errors due to source power variations. Furthermore, a comprehensive analysis of a refractive index sensing setup, based on an intrinsic micro Fabry-Perot Interferometer (FPI) is described. Here, the changes over the FPI pattern as the exit refractive index is varied are analytically modelled by using the characteristic matrix method. Additionally, our simulated results are supported by experimental measurements which are also provided. Finally it is shown that by using this principle a simple refractive index sensor with a resolution in the order of 2.15 × 10(-4) RIU can be implemented by using a couple of standard and low cost photodetectors.

  8. Measurement of thermal expansion coefficient of graphene diaphragm using optical fiber Fabry-Perot interference

    NASA Astrophysics Data System (ADS)

    Li, Cheng; Liu, Qianwen; Peng, Xiaobin; Fan, Shangchun

    2016-07-01

    Application of the Fabry-Perot (FP) interference method for determining the coefficient of thermal expansion (CTE) of a graphene diaphragm is investigated in this paper. A miniature extrinsic FP interferometric (EFPI) sensor was fabricated by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule with an inner diameter of 125 μm, and van der Waals interactions between the graphene diaphragm and its substrate created a low finesse FP interferometer with a cavity length of 36.13 μm. Double reference FP cavities using two cleaved optical fibers as reflectors were also constructed to differentially cancel the thermal expansion effects of the trapped gas and adhesive material. A temperature test demonstrated an approximate cavity length change of 166.1 nm °C-1 caused by film thermal expansion in the range of 20-60 °C. Then along with the established thermal deformation model of the suspended circular diaphragm, the calculated CTE ranging from  -9.98  ×  10-6 K-1 to  -2.09  ×  10-6 K-1 conformed well to the previously measured results. The proposed method would be applicable in other types of elastic materials as the sensitive diaphragm of an EFPI sensor over a wide temperature range.

  9. An optical fiber Fabry-Perot flow measurement technology based on partial bend structure.

    PubMed

    Yang, Huijia; Jiang, Junfeng; Zhang, Xuezhi; Pan, Yuheng; Zhu, Wanshan; Zhou, Xiang; Liu, Tiegen

    2016-08-01

    An optical fiber Fabry-Perot (F-P) flow measurement technology is presented, which is based on partial bend structure. A 90° partial bend structure is designed to achieve the non-probe flow measurement with a pressure difference. The fluid simulation results of partial bend structure show that the error of the pressure difference is below 0.05 kPa during steady flow. The optical fiber F-P sensor mounted on the elbow with pressure test accuracy of 1% full scale is used to measure the fluid flow. Flow test results show that when the flow varies from 1 m(3)/h to 6.5 m(3)/h at ambient temperature of 25 °C, the response time is 1 s and the flow test accuracy is 4.5% of the F-P flow test system, proving that the F-P flow test method based on partial bend structure can be used in fluid flow measurement.

  10. Dynamic interrogator for elastic wave sensing using Fabry Perot filters based on fiber Bragg gratings.

    PubMed

    Harish, Achar V; Varghese, Bibin; Rao, Babu; Balasubramaniam, Krishnan; Srinivasan, Balaji

    2015-07-01

    Use of in-fiber Fabry-Perot (FP) filters based on fiber Bragg gratings as both sensor as well as an interrogator for enhancing the detection limit of elastic wave sensing is investigated in this paper. The sensitivity of such a demodulation scheme depends on the spectral discrimination of the sensor and interrogator gratings. Simulations have shown that the use of in-fiber FP filters with high finesse provide better performance in terms of sensitivity compared to the demodulation using fiber Bragg gratings. Based on these results, a dynamic interrogator capable of sensing acoustic waves with amplitude of less than 1 micro-strain over frequencies of 10 kHz to several 100 kHz has been implemented. Frequency response of the fiber Bragg gratings in the given experimental setup has been compared to that of the conventional piezo sensors demonstrating that fiber Bragg gratings can be used over a relatively broad frequency range. Dynamic interrogator has been packaged in a compact box without any degradation in its performance.

  11. Analytical Modelling of a Refractive Index Sensor Based on an Intrinsic Micro Fabry-Perot Interferometer

    PubMed Central

    Vargas-Rodriguez, Everardo; Guzman-Chavez, Ana D.; Cano-Contreras, Martin; Gallegos-Arellano, Eloisa; Jauregui-Vazquez, Daniel; Hernández-García, Juan C.; Estudillo-Ayala, Julian M.; Rojas-Laguna, Roberto

    2015-01-01

    In this work a refractive index sensor based on a combination of the non-dispersive sensing (NDS) and the Tunable Laser Spectroscopy (TLS) principles is presented. Here, in order to have one reference and one measurement channel a single-beam dual-path configuration is used for implementing the NDS principle. These channels are monitored with a couple of identical optical detectors which are correlated to calculate the overall sensor response, called here the depth of modulation. It is shown that this is useful to minimize drifting errors due to source power variations. Furthermore, a comprehensive analysis of a refractive index sensing setup, based on an intrinsic micro Fabry-Perot Interferometer (FPI) is described. Here, the changes over the FPI pattern as the exit refractive index is varied are analytically modelled by using the characteristic matrix method. Additionally, our simulated results are supported by experimental measurements which are also provided. Finally it is shown that by using this principle a simple refractive index sensor with a resolution in the order of 2.15 × 10−4 RIU can be implemented by using a couple of standard and low cost photodetectors. PMID:26501277

  12. Accurate determination of solid and liquid dispersions from spectra channeled with the Fabry-Perot interferometer.

    PubMed

    Khashan, M A; Nassif, A Y

    1997-09-20

    The band spacing of the fringes of equal chromatic order of a thin Fabry-Perot interferometer is compared when this interferometer contains air, a solid, or a liquid. This comparison enables the dispersion of the group velocity of light in these media to be known accurately to 2.4 parts in one thousand. The Sellmeier dispersion function is used to deduce the refractive indices with the same degree of accuracy. The order-transformation method is used to find the exact order values from the roughly known optical thickness. The exact order values for air and the sample are used to find the refractive index accurately to approximately 3 x 10(-5). A least-squares fitting of the accurate experimental data to the Sellmeier dispersion function enables the coefficients of the latter to be more precisely defined for solids such as glass and mica and for liquids such as glycerin and distilled water. The atomic parameters such as the density of states and the absorption wavelengths in the ultraviolet region of the spectrum for the given samples are deduced from the more precisely found Sellmeier coefficients. PMID:18259554

  13. Fabry-Perot etalon aperture requirements for direct detection Doppler wind lidar from Earth orbit.

    PubMed

    McKay, J A

    1999-09-20

    The design of Fabry-Perot etalons for direct detection Doppler wind lidar from a satellite is considered for two direct detection methods, fringe imaging (multichannel) and double edge. The area solid-angle product of the etalon for each technique is derived and shown to be inherently larger, for a given etalon aperture, for the fringe imager than for the double-edge Doppler analyzer. Modeling of the Doppler measurement accuracy of a spaceflight direct detection wind lidar shows that a very large optical aperture, 2 m or more, is necessary. Optical throughput matching to a 2-m collector requires, for the fringe-imaging Doppler analyzer, an etalon with 60 mm aperture, whereas the double-edge technique would require two etalons of 200 mm aperture, or a split-aperture etalon of 400 mm working aperture. Because the two direct detection methods have been shown to have practically identical intrinsic sensitivities (measurement accuracies per unit signal), this difference in etalon dimensions may be a significant selection consideration. PMID:18324101

  14. Apodized fibre Bragg grating acousto-ultrasonic sensor under arbitrary strain using dual Fabry Perot filters

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Tsuda, Hiroshi; Akimune, Yoshio

    2007-01-01

    This paper describes a novel acousto-ultrasonic (AU) sensing system in which a fibre Bragg grating (FBG) is permanently built in a structure for in situ health monitoring. The AU wave detection using an FBG can be realized by a demodulation technique using an optical filter or light source narrower than the FBG spectrum. However, since the spectral wavelength shift induced from structural strain is much larger than the spectral oscillation induced from the AU wave, it is difficult for the demodulation wavelength to follow the spectral shift. For this work, we introduce a passive demodulation method regardless of the spectral shift based on an apodized FBG (AFBG) and dual fibre Fabry-Perot (FFP) filters. The free spectral range (FSR) of a high-finesse FFP filter is matched to the full-bandwidth of the AFBG without side lobes. Therefore, a part of the AFBG spectrum is always filtered by one of the multiple interferometric peaks. However, the wavelength regime near the maximum or minimum reflectivity of the AFBG provides insufficient sensitivity with respect to the wave. Therefore, another 1/4 FSR-biased FFP filter with the same FSR is simultaneously operated.

  15. Si-based tunable flattop photodetector with a stepped Fabry-Perot cavity.

    PubMed

    Wang, Wei; Huang, Yongqing; Duan, Xiaofeng; Tian, Jia; Guo, Jingwei; Ren, Xiaomin

    2012-04-01

    This paper presents the design and analysis of a Si-based tunable flattop photodetector realized by the introduction of a stepped Fabry-Perot cavity, which can be thermally tuned via applying tuning power on its tuning electrode. By using a transfer matrix method, the spectral response of the photodetector is simulated in detail, indicating a flattop line shape can be achieved with an optimum step height. A trade-off residing in this device between the free spectrum range and the ease of fabrication of step height is also revealed and analyzed. In the final design of the photodetector, 1 dB linewidth of 0.5 nm, 3 dB linewidth of 0.8 nm, 6 dB linewidth of 1.2 nm, peak quantum efficiency of 40%, tuning efficiency of 91 mW/nm are theoretically obtained. We discuss the epitaxial growth and fabrication of the photodetector in the end, exhibiting the mature technique available for this device.

  16. Underwater blast wave pressure sensor based on polymer film fiber Fabry-Perot cavity.

    PubMed

    Wang, Junjie; Wang, Meng; Xu, Jian; Peng, Li; Yang, Minghong; Xia, Minghe; Jiang, Desheng

    2014-10-01

    This paper describes the theoretical and experimental aspects of an optical underwater shock wave sensor based on a polymer film optical fiber Fabry-Perot cavity manufactured by vacuum deposition technology. The transduction mechanism of the sensor involves a normally incident acoustic stress wave that changes the thickness of the polymer film, thereby giving rise to a phase shift. This transient interferometric phase is interrogated by a three-phase-step algorithm. Theoretically, the sensor-acoustic-field interaction principle is analyzed, and the phase modulation sensitivity based on the theory of waves in the layered media is calculated. Experimentally, a static calibration test and a dynamic calibration test are conducted using a piston-type pressure calibration machine and a focusing-type electromagnetic shock wave. Results indicate that the repeatability, hysteresis, nonlinearity, and the overall measurement accuracy of the sensor within the full pressure range of 55 MPa are 1.82%, 0.86%, 1.81%, and 4.49%, respectively. The dynamic response time is less than 0.767 μs. Finally, three aspects that need further study for practical use are pointed out. PMID:25322237

  17. Microfluidic flowmeter based on micro "hot-wire" sandwiched Fabry-Perot interferometer.

    PubMed

    Li, Ying; Yan, Guofeng; Zhang, Liang; He, Sailing

    2015-04-01

    We present a compact microfluidic flowmeter based on Fabry-Perot interferometer (FPI). The FPI was composed by a pair of fiber Bragg grating reflectors and a micro Co(2+)-doped optical fiber cavity, acting as a "hot-wire" sensor. Microfluidic channels made from commercial silica capillaries were integrated with the FPIs on a chip to realize flow-rate sensing system. By utilizing a tunable pump laser with wavelength of 1480 nm, the proposed flowmeter was experimentally demonstrated. The flow rate of the liquid sample is determined by the induced resonance wavelength shift of the FPI. The effect of the pump power, microfluidic channel scale and temperature on the performance of our flowmeter was investigated. The dynamic response was also measured under different flow-rate conditions. The experimental results achieve a sensitivity of 70 pm/(μL/s), a dynamic range up to 1.1 μL/s and response time in the level of seconds, with a spatial resolution ~200 μm. Such good performance renders the sensor a promising supplementary component in microfluidic biochemical sensing system. Furthermore, simulation modal was built up to analyze the heat distribution of the "hot-wire" cavity and optimize the FPI structure as well.

  18. Microfluidic flowmeter based on micro "hot-wire" sandwiched Fabry-Perot interferometer.

    PubMed

    Li, Ying; Yan, Guofeng; Zhang, Liang; He, Sailing

    2015-04-01

    We present a compact microfluidic flowmeter based on Fabry-Perot interferometer (FPI). The FPI was composed by a pair of fiber Bragg grating reflectors and a micro Co(2+)-doped optical fiber cavity, acting as a "hot-wire" sensor. Microfluidic channels made from commercial silica capillaries were integrated with the FPIs on a chip to realize flow-rate sensing system. By utilizing a tunable pump laser with wavelength of 1480 nm, the proposed flowmeter was experimentally demonstrated. The flow rate of the liquid sample is determined by the induced resonance wavelength shift of the FPI. The effect of the pump power, microfluidic channel scale and temperature on the performance of our flowmeter was investigated. The dynamic response was also measured under different flow-rate conditions. The experimental results achieve a sensitivity of 70 pm/(μL/s), a dynamic range up to 1.1 μL/s and response time in the level of seconds, with a spatial resolution ~200 μm. Such good performance renders the sensor a promising supplementary component in microfluidic biochemical sensing system. Furthermore, simulation modal was built up to analyze the heat distribution of the "hot-wire" cavity and optimize the FPI structure as well. PMID:25968776

  19. All-fiber upconversion high spectral resolution wind lidar using a Fabry-Perot interferometer.

    PubMed

    Shangguan, Mingjia; Xia, Haiyun; Wang, Chong; Qiu, Jiawei; Shentu, Guoliang; Zhang, Qiang; Dou, Xiankang; Pan, Jian-Wei

    2016-08-22

    An all-fiber, micro-pulse and eye-safe high spectral resolution wind lidar (HSRWL) at 1.5 μm is proposed and demonstrated by using a pair of upconversion single-photon detectors and a fiber Fabry-Perot scanning interferometer (FFP-SI). In order to improve the optical detection efficiency, both the transmission spectrum and the reflection spectrum of the FFP-SI are used for spectral analyses of the aerosol backscatter and the reference laser pulse. Taking advantages of high signal-to-noise ratio of the detectors and high spectral resolution of the FFP-SI, the center frequencies and the bandwidths of spectra of the aerosol backscatter are obtained simultaneously. Continuous LOS wind observations are carried out on two days at Hefei (31.843 °N, 117.265 °E), China. The horizontal detection range of 4 km is realized with temporal resolution of 1 minute. The spatial resolution is switched from 30 m to 60 m at distance of 1.8 km. In a comparison experiment, LOS wind measurements from the HSRWL show good agreement with the results from an ultrasonic wind sensor (Vaisala windcap WMT52). An empirical method is adopted to evaluate the precision of the measurements. The standard deviation of the wind speed is 0.76 m/s at 1.8 km. The standard deviation of bandwidth variation is 2.07 MHz at 1.8 km. PMID:27557211

  20. Wavelength-switched phase interrogator for extrinsic Fabry-Perot interferometric sensors.

    PubMed

    Xia, Ji; Xiong, Shuidong; Wang, Fuyin; Luo, Hong

    2016-07-01

    We report on phase interrogation of extrinsic Fabry-Perot interferometric (EFPI) sensors through a wavelength-switched unit with a polarization-maintaining fiber Bragg grating (PMFBG). The measurements at two wavelengths are first achieved in one total-optical path. The reflected peaks of the PMFBG with two natural wavelengths are in mutually perpendicular polarization detection, and they are switched through an electro-optic modulator at a high switching speed of 10 kHz. An ellipse fitting differential cross multiplication (EF-DCM) algorithm is proposed for interrogating the variation of the gap length of the EFPI sensors. The phase demodulation system has been demonstrated to recover a minimum phase of 0.42  μrad/Hz at the test frequency of 100 Hz with a stable intensity fluctuation level of ±0.8  dB. Three EFPI sensors with different cavity lengths are tested at the test frequency of 200 Hz, and the results indicate that the system can achieve the demodulation of EFPI sensors with different cavity lengths stably. PMID:27367107

  1. Fabry-Perot measurements and analysis of TOW-2A liner collapse and jet formation

    SciTech Connect

    Simonson, S.C.; Winer, K.A.; Breithaupt, R.D.; Avara, G.R.; Baum, D.W.

    1996-07-01

    A TOW-2A 146 mm shaped charge was fired and observed with five beam Fabry-Perot laser velocimetry. The liner collapse velocities were measured at five lines of sight covering the outer half of the liner. A record of 8-10 {mu}s in length was obtained for each sight line The velocity records at late time differ for each location, reflecting the varying charge-to-mass ratio as the end of the liner is approached. The results were analyzed with the CALE-2D hydrodynamic simulation code. The calculations reproduce the jump-off times, the shapes of the velocity jumps and the late time velocity asymptotes, but they underestimate the jump-off velocities by 6-7%. The calculations show that there exist no features in the velocity records that require spallation to account for them. Rather, the standard Steinberg-Guinan material model adequately accounts for the response of this copper liner to LX-14.

  2. Differential-pressure-based fiber-optic temperature sensor using Fabry-Perot interferometry.

    PubMed

    Liu, Tiegen; Yin, Jinde; Jiang, Junfeng; Liu, Kun; Wang, Shuang; Zou, Shengliang

    2015-03-15

    We propose a novel fiber-optic Fabry-Perot interferometric (FFPI) temperature sensor based on differential pressure resulting from thermal expansion of sealed air. A thin silicon diaphragm is sandwiched between two micro-circular cavity-structured Pyrex plates to construct a FP and an air cavity. The thermal expansion of sealed air induces differential pressure variation between cavities and thus the deformation of thin diaphragm, which transfers temperature change into cavity length shift of FP interferometer. Theory analysis results indicate that the temperature-sensitivity can be designed flexibly by choosing the parameters of radius and thickness of silicon diaphragm, and the differential pressure between two cavities. Experimental results demonstrate that the temperature sensitivity of 6.07 nm/°C is achieved with the resolution of 0.10°C under the range of -50°C to 100°C, and the response time is around 1.3 s with temperature change from 28°C to 100°C. PMID:25768179

  3. Analytical modelling of a refractive index sensor based on an intrinsic micro Fabry-Perot interferometer.

    PubMed

    Vargas-Rodriguez, Everardo; Guzman-Chavez, Ana D; Cano-Contreras, Martin; Gallegos-Arellano, Eloisa; Jauregui-Vazquez, Daniel; Hernández-García, Juan C; Estudillo-Ayala, Julian M; Rojas-Laguna, Roberto

    2015-01-01

    In this work a refractive index sensor based on a combination of the non-dispersive sensing (NDS) and the Tunable Laser Spectroscopy (TLS) principles is presented. Here, in order to have one reference and one measurement channel a single-beam dual-path configuration is used for implementing the NDS principle. These channels are monitored with a couple of identical optical detectors which are correlated to calculate the overall sensor response, called here the depth of modulation. It is shown that this is useful to minimize drifting errors due to source power variations. Furthermore, a comprehensive analysis of a refractive index sensing setup, based on an intrinsic micro Fabry-Perot Interferometer (FPI) is described. Here, the changes over the FPI pattern as the exit refractive index is varied are analytically modelled by using the characteristic matrix method. Additionally, our simulated results are supported by experimental measurements which are also provided. Finally it is shown that by using this principle a simple refractive index sensor with a resolution in the order of 2.15 × 10(-4) RIU can be implemented by using a couple of standard and low cost photodetectors. PMID:26501277

  4. Dynamic interrogator for elastic wave sensing using Fabry Perot filters based on fiber Bragg gratings.

    PubMed

    Harish, Achar V; Varghese, Bibin; Rao, Babu; Balasubramaniam, Krishnan; Srinivasan, Balaji

    2015-07-01

    Use of in-fiber Fabry-Perot (FP) filters based on fiber Bragg gratings as both sensor as well as an interrogator for enhancing the detection limit of elastic wave sensing is investigated in this paper. The sensitivity of such a demodulation scheme depends on the spectral discrimination of the sensor and interrogator gratings. Simulations have shown that the use of in-fiber FP filters with high finesse provide better performance in terms of sensitivity compared to the demodulation using fiber Bragg gratings. Based on these results, a dynamic interrogator capable of sensing acoustic waves with amplitude of less than 1 micro-strain over frequencies of 10 kHz to several 100 kHz has been implemented. Frequency response of the fiber Bragg gratings in the given experimental setup has been compared to that of the conventional piezo sensors demonstrating that fiber Bragg gratings can be used over a relatively broad frequency range. Dynamic interrogator has been packaged in a compact box without any degradation in its performance. PMID:25783780

  5. Temperature-independent fiber salinity sensor based on Fabry-Perot interference.

    PubMed

    Zhang, Xinpu; Peng, Wei

    2015-04-20

    We present a novel fiber Fabry-Perot (FP) interference salinity sensor based on polyimide (PI) diaphragm. With an increase in water salinity, the PI diaphragm shrinks, and the PI diaphragm constriction causes the increase of the width of the air-gap, which causes the red shift of the interference fringes. We fabricated salinity sensor prototypes with different air-gap lengths and 20μm PI diaphragm. When salinity increases from 0mol/L to 5.47mol/L, the maximum sensitivity is 0.45nm/(mol/L). We verify that the sensitivity can be enhanced by reducing air-gap cavity length. We also choose appropriate air cavity length and PI diaphragm length to solve the cross-sensitivity between temperature and salinity. As a robust and ultra-compact salinity sensor, which is easy to be fabricated and need no alignment, this fiber interferometer can be applied for real-time salinity sensing applications. PMID:25969076

  6. Frequency division multiplexing of etrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Hao, Huali; Jing, Zhenguo; Peng, Wei; Cheng, Huaqi; Yu, Qi; Yao, Wenjuan; Li, Hong

    2011-08-01

    As an important member of optical fiber sensor, fiber optic Extrinsic Fabry-Perot Interferometric (EFPI) sensor has prospects for a wide range of industrial applications due to its small size, compact configuration, good reliability and flexibility. In a white light based fiber optic EFPI sensor system, which has the advantages of large dynamic range and high resolution, spectral analysis equipment is the most important part which takes the major cost of the system. Therefore, multiplexing spectral analysis equipment to measure multiple sensors simultaneously is an effective and necessary way that can save the cost of the whole sensor system. In this paper, a scheme based on the frequency division multiplexing of EFPI optical fiber sensors is proposed. Two EFPI sensors with different gap lengths are parallely connected through the optical fiber coupler. The overlapped interference spectrum of the two EFPI sensors is measured by using an optical spectrum analyzer, which is separated into two individual interference spectrums with a Finite Impuse Response (FIR) band-pass filter. Their envelope components are extracted with Hilbert transform, and then the interference spectrums are normalized by the envelope components. The respective gap lengths of the two EFPI sensors are achieved with the cross correlation calculation. Using this frequency division spectral analysis method, a two-channel multiplexing EFPI sensor system is implemented in the laboratory. The deployment of this frequency division multiplexing technology can greatly reduce the cost of the whole system which has extensive potential applications for distributed fiber optic EFPI sensor system.

  7. Ultrafast Fabry-Perot fiber-optic pressure sensors for multimedia blast event measurements.

    PubMed

    Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

    2013-02-20

    A shock wave (SW) is characterized as a large pressure fluctuation that typically lasts only a few milliseconds. On the battlefield, SWs pose a serious threat to soldiers who are exposed to explosions, which may lead to blast-induced traumatic brain injuries. SWs can also be used beneficially and have been applied to a variety of medical treatments due to their unique interaction with tissues and cells. Consequently, it is important to have sensors that can quantify SW dynamics in order to better understand the physical interaction between body tissue and the incident acoustic wave. In this paper, the ultrafast fiber-optic sensor based on the Fabry-Perot interferometric principle was designed and four such sensors were fabricated to quantify a blast event within different media, simultaneously. The compact design of the fiber-optic sensor allows for a high degree of spatial resolution when capturing the wavefront of the traveling SW. Several blast event experiments were conducted within different media (e.g., air, rubber membrane, and water) to evaluate the sensor's performance. This research revealed valuable knowledge for further study of SW behavior and SW-related applications. PMID:23434996

  8. An optical fiber Fabry-Perot flow measurement technology based on partial bend structure.

    PubMed

    Yang, Huijia; Jiang, Junfeng; Zhang, Xuezhi; Pan, Yuheng; Zhu, Wanshan; Zhou, Xiang; Liu, Tiegen

    2016-08-01

    An optical fiber Fabry-Perot (F-P) flow measurement technology is presented, which is based on partial bend structure. A 90° partial bend structure is designed to achieve the non-probe flow measurement with a pressure difference. The fluid simulation results of partial bend structure show that the error of the pressure difference is below 0.05 kPa during steady flow. The optical fiber F-P sensor mounted on the elbow with pressure test accuracy of 1% full scale is used to measure the fluid flow. Flow test results show that when the flow varies from 1 m(3)/h to 6.5 m(3)/h at ambient temperature of 25 °C, the response time is 1 s and the flow test accuracy is 4.5% of the F-P flow test system, proving that the F-P flow test method based on partial bend structure can be used in fluid flow measurement. PMID:27587096

  9. Switchable single-polarization dual-wavelength TDFL using PM Fabry-Perot filter

    NASA Astrophysics Data System (ADS)

    Liu, Shuo; Yan, Fengping; Liu, Peng; Zhang, Luna; Bai, Zhuoya; Yin, Bin; Zhou, Hong

    2016-05-01

    A switchable single-polarization (SP), dual-wavelength thulium-doped fiber laser using polarization maintaining (PM) Fabry-Perot (F-P) filter is proposed. A combination of the PM F-P filter, a polarization controller (PC) and a polarizer is used to ensure the SP lasing operation. A stable dual-wavelength lasing operation is obtained at 1941.82 nm and 1942.21 nm. By adjusting the PCs, the proposed laser can achieve SP single-wavelength lasing operation; the polarization extinction ratios are higher than 33 dB. When the pump power is higher than 2.98 W, the optical signal-to-noise ratios of the SP single-wavelength operation can reach 60 dB, and the output power variations are less than 0.32 dB (X-polarization) and 0.30 dB (Y-polarization). The slope efficiencies of SP lasing operation are 6.26% (X-polarization) and 8.79% (Y-polarization), respectively.

  10. Stable narrow linewidth ring fiber laser with a passive fiber Bragg grating Fabry-Perot etalon and a fiber saturable absorber

    NASA Astrophysics Data System (ADS)

    Dai, Zhiyong; Wu, Bo; Peng, Zengshou; Ou, Zhonghua; Liu, Yongzhi

    2008-12-01

    Narrow linewidth fiber lasers have become more and more necessary in field of coherent communication, fiber optic sensor, and high resolutions optical spectrum analysis, especially long-range distributed fiber sensing system. In this paper, a simple and stable narrow linewidth Er3+ -doped ring fiber laser is first proposed and experimentally demonstrated. In the cavity, a passive fiber Bragg grating Fabry-Perot (FBG F-P) etalon acts as mode-selecting device to greatly reduce the longitudinal-mode density, while a section un-pumped Er3+ -doped fiber serves as a saturable absorber to ensure the single longitudinal-mode (SLM) operation. Meanwhile the stability of lasing frequency is further improved by controlling the temperature of the FBG F-P, and then through varying the temperature the lasing wavelength tuning is achieved also. Finally stable SLM laser at 1550nm with linewidth about 7.5 kHz, maximum output power 39 mW and the corresponding slope efficiency 30% is acquired.

  11. Optically tunable Fano resonance in a grating-based Fabry-Perot cavity-coupled microring resonator on a silicon chip.

    PubMed

    Zhang, Weifeng; Li, Wangzhe; Yao, Jianping

    2016-06-01

    A grating-based Fabry-Perot (FP) cavity-coupled microring resonator on a silicon chip is reported to demonstrate an all-optically tunable Fano resonance. In the device, an add-drop microring resonator (MRR) is employed, and one of the two bus waveguides is replaced by an FP cavity consisting of two sidewall Bragg gratings. By choosing the parameters of the gratings, the resonant mode of the FP cavity is coupled to one of the resonant modes of the MRR. Due to the coupling between the resonant modes, a Fano resonance with an asymmetric line shape resulted. Measurement results show a Fano resonance with an extinction ratio of 22.54 dB, and a slope rate of 250.4 dB/nm is achieved. A further study of the effect of the coupling on the Fano resonance is performed numerically and experimentally. Thanks to the strong light-confinement capacity of the MRR and the FP cavity, a strong two-photon absorption induced nonlinear thermal-optic effect resulted, which is used to tune the Fano resonance optically.

  12. Performance Evaluation of Fabry-Perot Temperature Sensors in Nuclear Power Plant Measurements

    SciTech Connect

    Liu Hanying; Miller, Don W.; Talnagi, Joseph W.

    2003-08-15

    The Fiso Fabry-Perot fiber-optic temperature sensor was selected for performance evaluation and for potential application in nuclear power plants because of its unique interferometric sensing mechanism and data-processing technique, and its commercial availability. It employs a Fizeau interferometer and a charge-coupled device array to locate the position of the maximum interference fringe intensity, which is directly related to the environmental temperature. Consequently, the basic sensing mechanism is independent of the absolute transmitted light intensity, which is the most likely parameter to be affected by external harsh environments such as nuclear irradiation, high pressure/temperature, and cyclical vibration.This paper reports research on the performance of two Fiso Fabry-Perot temperature sensors in environmental conditions expected in nuclear power plants during both normal and abnormal (i.e., accident) conditions. The environmental conditions simulated in this paper include gamma-only ({sup 60}Co) irradiation, pressure/temperature environmental transient, and mixed neutron/gamma field, respectively.The first sensor exhibited no failure or degradation in performance during and following gamma-only irradiation in which a total dose of 15 kGy was delivered at a dose rate of 2.5 kGy/h. Following gamma irradiation, this sensor was then tested for 10.75 days in a thermohydraulic environment prescribed by the Institute of Electrical and Electronics Engineers IEEE323-1983. Intermittent behavior was observed throughout the latter portions of this test, and degradation in performance occurred after the test. Visual evaluation after opening the sensor head indicated that the internal welding methodology was the primary contributor to the observed behavior during this test. Further consultation with the vendor shows that the robustness and reliability of Fiso sensors can be substantially improved by modifying the internal welding methods.The second Fiso temperature

  13. Dual-frequency comb generation with differing GHz repetition rates by parallel Fabry-Perot cavity filtering of a single broadband frequency comb source

    NASA Astrophysics Data System (ADS)

    Mildner, Jutta; Meiners-Hagen, Karl; Pollinger, Florian

    2016-07-01

    We present a dual-comb-generator based on a coupled Fabry-Perot filtering cavity doublet and a single seed laser source. By filtering a commercial erbium-doped fiber-based optical frequency comb with CEO-stabilisation and 250 MHz repetition rate, two broadband coherent combs of different repetition rates in the GHz range are generated. The filtering doublet consists of two Fabry-Perot cavities with a tunable spacing and Pound-Drever-Hall stabilisation scheme. As a prerequisite for the development of such a filtering unit, we present a method to determine the actual free spectral range and transmission bandwidth of a Fabry-Perot cavity in situ. The transmitted beat signal of two diode lasers is measured as a function of their tunable frequency difference. Finally, the filtering performance and resulting beat signals of the heterodyned combs are discussed as well as the optimisation measures of the whole system.

  14. Development of the Double Etalon Fabry-Perot Interferometer for Determining Total and Tropospheric Ozone Concentrations

    NASA Technical Reports Server (NTRS)

    Cook, William

    1999-01-01

    Measuring and understanding the distribution of ozone through the lower levels of Earth's atmosphere are high priorities in global change and climate research. Of particular interest now is the global distribution of ozone in the upper troposphere and lower stratosphere. Global coverage of the stratospheric ozone is feasible only via remote sensing instruments on a space-based platform. And though extensive monitoring tropospheric ozone is possible using instruments flown aboard conventional aircraft, a space-based system would be significantly less costly and provide information over a much broader area and produce more uniform coverage. Here we describe the prototype of an instrument being developed to monitor, from an orbiting spacecraft, the ozone found in Earth's upper troposphere and lower stratosphere. Our new spectrometer is an infrared Fabry-Perot interferometer which uses two synchrounously tuned etalons: a high resolution narrow band device and a lower resolution broader band filtering etalon. The prototype is a scanning device making use of nearly collimated input radiation and a single element detector. As presently configured, it is capable of providing a resolution better than 0.07/cm with a spectral band width approximately 5/cm wide and centered at 1054.7/cm. For the future space-based emission device a modification of the the prototype was to be made to employ innovative circle-to-line detector optics, those developed or in development at UM/SPRL, and a focal plane array detector. These enhancements would enable a simultaneous recording of the entire spectral range of interest, but with simple detection electronics and a significant gain in signal-to-noise over that of the scanning version.

  15. Short-wave infrared (SWIR) spectral imager based on Fabry-Perot interferometer for remote sensing

    NASA Astrophysics Data System (ADS)

    Mannila, Rami; Holmlund, Christer; Ojanen, Harri J.; Näsilä, Antti; Saari, Heikki

    2014-10-01

    VTT Technical Research Centre of Finland has developed a spectral imager for short-wave infrared (SWIR) wavelength range. The spectral imager is based on a tunable Fabry-Perot interferometer (FPI) accompanied by a commercial InGaAs Camera. The FPI consists of two dielectric coated mirrors separated by a tunable air gap. Tuning of the air gap tunes also transmitted wavelength and therefore FPI acts as a tunable band bass filter. The FPI is piezo-actuated and it uses three piezo-actuators in a closed capacitive feedback loop for air gap tuning. The FPI has multiple order transmission bands, which limit free spectral range. Therefore spectral imager contains two FPI in a stack, to make possible to cover spectral range of 1000 - 1700 nm. However, in the first tests imager was used with one FPI and spectral range was limited to 1100-1600 nm. The spectral resolution of the imager is approximately 15 nm (FWHM). Field of view (FOV) across the flight direction is 30 deg. Imaging resolution of the spectral imager is 256 x 320 pixels. The focal length of the optics is 12 mm and F-number is 3.2. This imager was tested in summer 2014 in an unmanned aerial vehicle (UAV) and therefore a size and a mass of the imager were critical. Total mass of the imager is approximately 1200 grams. In test campaign the spectral imager will be used for forest and agricultural imaging. In future, because results of the UAV test flights are promising, this technology can be applied to satellite applications also.

  16. Large-aperture MOEMS Fabry-Perot interferometer for miniaturized spectral imagers

    NASA Astrophysics Data System (ADS)

    Rissanen, Anna; Langner, Andreas; Viherkanto, Kai; Mannila, Rami

    2015-02-01

    VTT's optical MEMS Fabry-Perot interferometers (FPIs) are tunable optical filters, which enable miniaturization of spectral imagers into small, mass producible hand-held sensors with versatile optical measurement capabilities. FPI technology has also created a basis for various hyperspectral imaging instruments, ranging from nanosatellites, environmental sensing and precision agriculture with UAVs to instruments for skin cancer detection. Until now, these application demonstrations have been mostly realized with piezo-actuated FPIs fabricated by non-monolithical assembly method, suitable for achieving very large optical apertures and with capacity to small-to-medium volumes; however large-volume production of MEMS manufacturing supports the potential for emerging spectral imaging applications also in large-volume applications, such as in consumer/mobile products. Previously reported optical apertures of MEMS FPIs in the visible range have been up to 2 mm in size; this paper presents the design, successful fabrication and characterization of MEMS FPIs for central wavelengths of λ = 500 nm and λ = 650 nm with optical apertures up to 4 mm in diameter. The mirror membranes of the FPI structures consist of ALD (atomic layer deposited) TiO2-Al2O3 λ/4- thin film Bragg reflectors, with the air gap formed by sacrificial polymer etching in O2 plasma. The entire fabrication process is conducted below 150 °C, which makes it possible to monolithically integrate the filter structures on other ICdevices such as detectors. The realized MEMS devices are aimed for nanosatellite space application as breadboard hyperspectral imager demonstrators.

  17. Fabry-Perot Velocities For Globular Cluster Stars: M15, M3, and M4

    NASA Astrophysics Data System (ADS)

    Gebhardt, Karl; Pryor, Carlton; Williams, T. B.; Hesser, James E.

    1994-12-01

    We are engaged in a continuing project that uses an imaging Fabry-Perot spectrophotometer on the 3.6-m CFHT and the 4 m and 1.5 m telescopes at CTIO to measure both absorption-line integrated-light velocity maps for globular clusters and velocities for large samples of cluster stars (Gebhardt, K., Pryor, C., Williams, T.B., & Hesser, J.E. 1994, AJ, 107, 2067; Gebhardt, et al. 1994, submitted). Our goals are to study such kinematic properties as rotation and the number of high-velocity stars, and to use the velocity dispersion profiles to determine non-parametric mass profiles using the technique of Gebhardt & Fischer (1995, January AJ). Here we present radial velocities with accuracies of 1--5 \\kms\\ for about 600 stars in the cusp cluster M15, 400 stars in the centrally-concentrated cluster M3, and 1900 stars in the nearby cluster M4. The M15 dataset contains three times more stellar velocities throughout the whole cluster and five times more in the inner 10'' than the previous study of Gebhardt & Fischer. This larger sample continues to show no evidence for a central cusp in the velocity dispersion profile. The M4 data constitute one of the largest radial velocity samples yet obtained for a globular cluster. The stars in the sample range from magnitude V=10 to V=18.5. V=18.5 is 2.5 magnitudes below the main-sequence turn-off, so these data are valuable first-epoch information for determining the main-sequence binary fraction. We present two-dimensional velocity maps, velocity dispersion profiles, and radial mass profiles for the three clusters.

  18. Deep Fabry-Perot Hα observations of two Sculptor group galaxies, NGC 247 and 300

    NASA Astrophysics Data System (ADS)

    Hlavacek-Larrondo, J.; Marcelin, M.; Epinat, B.; Carignan, C.; de Denus-Baillargeon, M.-M.; Daigle, O.; Hernandez, O.

    2011-09-01

    It has been suggested that diffuse ionized gas can extend all the way to the end of the H I disc, and even beyond, such as in the case of the warped galaxyNGC 253 (Bland-Hawthorn et al.). Detecting ionized gas at these radii could carry significant implications as to the distribution of dark matter in galaxies. With the aim of detecting this gas, we carried out a deep Hα kinematical analysis of two Sculptor group galaxies, NGC 247 and 300. The Fabry-Perot data were taken at the 36-cm Marseille Telescope in La Silla, Chile, offering a large field of view. With almost 20 hours of observations for each galaxy, very faint diffuse emission is detected. Typical emission measures of 0.1 cm-6 pc are reached. For NGC 247, emission extending up to a radius comparable with that of the H I disc (r˜ 13 arcmin) is found, but no emission is seen beyond the H I disc. For NGC 300, we detect ionized gas on the entirety of our field of view (rmax˜ 14 arcmin), and find that the bright H II regions are embedded in a diffuse background. Using the deep data, extended optical rotation curves are obtained, as well as mass models. These are the most extended optical rotation curves thus far for these galaxies. We find no evidence suggesting that NGC 247 has a warped disc, and to account for our non-detection of Hα emission beyond its H I disc, as opposed to the warped galaxy NGC 253, our results favour the model in which, only through a warp, ionization by hot young stars in the central region of a galaxy can let photons escape and ionize the interstellar medium in the outer parts.

  19. Fiber Fabry-Perot tunable filter for high-speed optical packet switching

    SciTech Connect

    Taranenko, N.L.; Tenbrink, S.C.; Hsu, K.; Miller, C.M.

    1997-01-01

    Tunable optical filters are important building blocks for All-Optical systems and networks. Fast optical tuning in several microseconds is necessary to perform high-speed optical packet switching. Multi- Gigabit/sec packet-switching will provide flexibility and higher network throughput when large numbers of users communicate simultaneously. One approach to achieve fast wavelength tuning is to use high-speed piezoelectrically-driven Fiber Fabry-Perot tunable filters (FFP-TFs). The requirement for tuning in microseconds raises a whole new set of challenges, such as ringing, thermostability and mechanical inertia control. It was shown that correlation between the mechanical resonance and optical response of the filter is important for the filter`s speed and for mounting hardware and control circuitry optimization. These features together with the FFP-TF`s high capacitance (approximately 0.25-0.5 microfarad) are being folded into building a special controller to substantially improve the shape of the driving signal and the response of the filter. The resultant controller enables tuning the high-speed FFP-TF three-orders-of- magnitude faster than that possible with standard commercial FFP-TFS. The fastest switching time achieved is 2.5 microseconds. As the result, a new packet-switched media access control protocol is being designed to minimize the searching time. The filter scans only once through the entire optical region and then tunes to all the required channels one after another in a few microseconds. It can help update Rainbow-2 Broadcast-and-Select High-Speed Wavelength Division Multiplexing All-Optical network that currently has a circuit- switched protocol using standard FFP-TFS.

  20. Micro-Mechanical Voltage Tunable Fabry-Perot Filters Formed in (111) Silicon. Degree awarded by Colorado Univ., Boulder, CO

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1997-01-01

    The MEMS (Micro-Electro-Mechanical-Systems) technology is quickly evolving as a viable means to combine micro-mechanical and micro-optical elements on the same chip. One MEMS technology that has recently gained attention by the research community is the micro-mechanical Fabry-Perot optical filter. A MEMS based Fabry-Perot consists of a vertically integrated structure composed of two mirrors separated by an air gap. Wavelength tuning is achieved by applying a bias between the two mirrors resulting in an attractive electrostatic force which pulls the mirrors closer. In this work, we present a new micro-mechanical Fabry-Perot structure which is simple to fabricate and is integratable with low cost silicon photodetectors and transistors. The structure consists of a movable gold coated oxide cantilever for the top mirror and a stationary Au/Ni plated silicon bottom mirror. The fabrication process is single mask level, self aligned, and requires only one grown or deposited layer. Undercutting of the oxide cantilever is carried out by a combination of RIE and anisotropic KOH etching of the (111) silicon substrate. Metallization of the mirrors is provided by thermal evaporation and electroplating. The optical and electrical characteristics of the fabricated devices were studied and show promissing results. A wavelength shift of 120nm with 53V applied bias was demonstrated by one device geometry using 6.27 micrometer air gap. The finesse of the structure was 2.4. Modulation bandwidths ranging from 91KHz to greater than 920KHz were also observed. Theoretical calculations show that if mirror reflectivity, smoothness, and parallelism are improved, a finesse of 30 is attainable. The predictions also suggest that a reduction of the air gap to 1 micrometer results in an increased wavelength tuning range of 175 nm with a CMOS compatible 4.75V.

  1. Development of Silicon-substrate Based Fabry-Perot Etalons for far-IR Astrophysics

    NASA Astrophysics Data System (ADS)

    Stacey, Gordon

    We propose to design, construct and test silicon-substrate-based (SSB) mirrors necessary for high performance Fabry-Perot interferometers (FPIs) to be used in the 25-40 um mid-IR band. These mirrors will be fabricated from silicon wafers that are anti-reflection coated (ARC) by micromachining an artificial dielectric meta-material on one side, and depositing optimized gold-metalized patterns on the other. Two mirrors with the metalized surfaces facing one-another form the Fabry-Perot cavity, also known as the FPI etalon. The exterior surfaces of the silicon mirrors are anti-reflection coated for both good transmission in the science band, and to prevent unwanted parasitic FPI cavities from forming between the four surfaces (one anti-reflection coated, one metalized for each mirror) of the FPI etalon. The mirrors will be tested within a Miniature Cryogenic Scanning Fabry-Perot (MCSF) that we have designed through support of a previous NASA grant (NNX09AB95G). This design is based on our long experience in constructing and using scanning FPI in the mid-IR to submm range, and fits within test-beds we have on hand that are suitable for both warm and cold tests. The key technologies are the ARC and tuned mirrors that are enabled by silicon nano-machining techniques. The creation of these SSB mirrors promises greatly improved performance over previous versions of mid-IR to submm-band FPIs that are based on mirrors made from free-standing metal mesh stretched over support rings. Performance is improved both structurally and in terms of sensitivity, and is measured as the product of the cavity finesse times transmission. Our electromagnetic modeling suggests that SSB mirrors will improve this product by a factor of 2 over the best free standing mesh etalons available. This translates into a factor of sqrt(2) improvement in sensitivity per etalon, or a full factor of 2 when used in a tandem (dual etalon) FPI spectrometer. The SSB improvements are due to both the stiff (~ 0

  2. Temperature Measurement Using all Fiber Fabry-Perot Interferometers Based on Phase Measurement Between Reference and Sensing Interferometer Spectral Characteristic

    NASA Astrophysics Data System (ADS)

    Njegovec, Matej; Đonlagic, Denis

    2010-04-01

    This paper presents the signal interrogator for fiber optic temperature sensors based on all-fiber miniature Fabry-Perot interferometers that are implemented by creation of the low reflectivity mirrors within optical fiber. This kind of Fabry-Perot interferometer has low finesse and nearly sinusoidal spectral characteristics. Since the optical path length between mirrors depends on refractive index and thereby temperature, change in sensor temperature shifts the sensor's spectral characteristics in wavelength domain. The presented measurement system is composed of the sensing interferometer and signal interrogator that further includes the reference interferometer. The reference interferometer is also an all-fiber interferometer with nearly identical length as sensing interferometer. The wavelength of the signal interrogator optical source was cyclically swept over available wavelength range while both interferometers' spectral responses were simultaneously recorded. The optical path length variation of the sensing interferometer was determined by direct phase difference measurement between both recorded sinusoidal spectral characteristics. This phase difference was directly correlated to the temperature difference between sensing and reference interferometer. Since reference interferometer was situated within the signal integrator its temperature was measured by the reference electrical sensors. Thus the proposed system can provide accurate absolute temperature measurements. In the proposed interrogator we used as an optical source a standard telecommunication DFB diode module with integrated thermo-electric cooler. Standard DFB diode can be shifted in wavelength for abut 2 nm, which allows interrogation of the Fabry-Perot interferometers having free spectral range below 2 nm. In case of an all fiber Fabry-Perot interferometers, this corresponds to interferometers with length that is more than 0.5 mm. Since recorded nearly sinusoidal spectral characteristics

  3. High precision frequency calibration of tunable diode lasers stabilized on an internally coupled Fabry-Perot interferometer.

    PubMed

    Clar, H J; Schieder, R; Reich, M; Winnewisser, G

    1989-05-01

    For very high precision molecular spectroscopy we use a tunable diode laser which is frequency locked to an internally coupled Fabry-Perot interferometer (icFPI). The spectra are calibrated by means of the interference pattern of an iodine stabilized He-Ne reference laser which is simultaneously coupled into the icFPI. In this paper the exact relation between the diode laser frequency and the He-Ne fringe number is derived and a convenient calibration procedure yielding a frequency accuracy of 5 x 10(-5) cm(-1) at 10 microm is described.

  4. Fiber-optic ultrasonic hydrophone using short Fabry-Perot cavity with multilayer reflectors deposited on small stub.

    PubMed

    Kim, Kyung-Su; Mizuno, Yosuke; Nakamura, Kentaro

    2014-04-01

    A fiber-optic probe with dielectric multilayer films deposited on a small stub is studied for mega-hertz ultrasonic-wave detection in water. The small stub with a short Fabry-Perot cavity and distributed reflectors is attached on the fiber end. The structure is mechanically strong and withstands intense ultrasonic pressure. Ultrasonic waves at 1.56MHz are successfully detected in water with a good signal-to-noise ratio. The working principle and the characteristics are studied by comparing the ultrasonic sensitivity with that of a conventional piezoelectric hydrophone. The distance response and directional response are also investigated.

  5. Active suppression of air refractive index fluctuation using a Fabry-Perot cavity and a piezoelectric volume actuator

    SciTech Connect

    Banh, Tuan Quoc; Ohkubo, Yuria; Murai, Yoshinosuke; Aketagawa, Masato

    2011-01-01

    Air refractive index fluctuation ({Delta}n{sub air}) is one of the largest uncertainty sources in precision interferometry systems that require a resolution of nanometer order or less. We introduce a method for the active suppression of {Delta}n{sub air} inside a normal air-environment chamber using a Fabry-Perot cavity and a piezoelectric volume actuator. The temporal air refractive index (n{sub air}) at a local point is maintained constant with an expanded uncertainty of {approx}4.2x10{sup -9} (k=2), a sufficiently low uncertainty for precise measurements unaffected by {Delta}n{sub air} to be made inside a chamber.

  6. Fiber-optic Fabry-Perot sensor based on graded-index multimode fiber: numerical simulations and experiments

    NASA Astrophysics Data System (ADS)

    Gong, Yuan; Zhao, Tian; Rao, Yun-Jiang; Wu, Yu; Guo, Yu

    2011-05-01

    Numerical simulations based on the ray-transfer-matrix (RTM) method is realized for explaining the principle of a graded-index multimode fiber (GI-MMF) based hybrid fiber Fabry-Perot (GI-FFP) sensor. It is verified by the numerical simulations and experimental results that the high fringe contrast of the reflective spectrum of the sensor is due to the periodic focusing effect of the GI-MMF. Experimental results are in good agreement with the theory. A typical GI-FFP sensor is fabricated and its response to the external refractive index is measured with a maximum sensitivity of ~160 dB/RIU.

  7. Q-switching of a high-power solid-state laser by a fast scanning Fabry-Perot interferometer

    SciTech Connect

    Baburin, N V; Borozdov, Yu V; Danileiko, Yu K; Denker, B I; Ivanov, A D; Osiko, Vyacheslav V; Sverchkov, S E; Sidorin, A V; Chikov, V A; Ifflander, R; Hack, R; Kertesz, I; Kroo, N

    1998-07-31

    An investigation was made of the suitability of a Q-switch, based on a piezoelectrically scanned short-base Fabry-Perot interferometer, for an Nd{sup 3+}:YAG laser with an average output radiation power up to 2 kW. The proposed switch made it possible to generate of giant pulses of 60 - 300 ns duration at a repetition rate of 20 - 100 kHz. Throughout the investigated range of the pulse repetition rates the average power was at least equal to that obtained by cw lasing. Special requirements to be satisfied by the interferometer, essential for efficient Q-switching, were considered. (control of laser radiation parameters)

  8. Diode-pumped, electrically tunable erbium-doped fiber-ring laser with fiber Fabry-Perot etalon

    SciTech Connect

    Zyskind, J.L.; Sulfoff, J.W.; Stone, J.; DiGiovanni, D.J.; Stulz, L.W.

    1992-05-22

    An all fiber, diode-pumped, electrically tunable ring laser is reported. Gain is provided by an erbium-doped fiber and tuning by a Fiber Fabry-Perot etalon. The threshold at 1.566 um is 2.9 mW, the slope efficiency is 0.15 and the output 4.2 mW with 32 mW of pump power. The output wavelength can be tuned from 1.525 to 1.586 um with a variation in power of less than 3.5 dB.

  9. Low-cost miniature fiber-optic extrinsic Fabry-Perot interferometric pressure sensor for biomedical applications

    NASA Astrophysics Data System (ADS)

    Poeggel, Sven; Tosi, Daniele; Leen, Gabriel; Lewis, Elfed

    2013-06-01

    A fiber-optic pressure sensor based in extrinsic Fabry-Perot interferometer (EFPI) is presented and discussed. The sensing probe is based on an inexpensive all-silica biocompatible design, with 0.2 mm outer diameter, suitable for disposable operation in medical catheters. A white-light interrogation system has been implemented, achieving a target accuracy of 1 mmHg and pressure stability of 1 mmHg/hour for long-term operation. A fiber Bragg grating (FBG) is added in proximity of the sensing tip, compensating temperature variations with 0.5°C accuracy. Design, simulation, and preliminary experimental validation are discussed.

  10. Multiwavelength erbium-doped fiber ring laser employing Fabry-Perot etalon inside cavity operating in room temperature

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Wu, Y. F.; Shih, F. Y.; Wang, C. H.; Chi, S.

    2009-08-01

    In this investigation, we propose and demonstrate a simple and cost-effective erbium-doped fiber (EDF) ring laser using a Fabry-Perot etalon inside a linear cavity and employing the accurate fiber cavity length to satisfy the least common multiple number for generating multiwavelength in C-band at room temperature. Furthermore, the center wavelength of the lasing wavelength bands can be adjusted to 1541.02, 1551.32, and 1562.03 nm, respectively. The wavelength separation in each wavelength band is 0.34 nm. Moreover, the output stability of the multiwavelength laser has also been discussed and analyzed.

  11. Transferring the Rb+ hyperfine-structure stability to a Fabry-Perot resonator used as a frequency standard for astronomical spectrographs

    NASA Astrophysics Data System (ADS)

    Huke, Philipp; Holzhüter, Hanno; Reiners, Ansgar

    2015-06-01

    We report on the experimental realization of locking a Fabry-Perot interferometer (FPI) onto a stabilized diode laser for the calibration of astronomical spectrographs. The external cavity diode laser (ECDL) is stabilized to the 85Rb+ F* = 2 --> F = 3 transition with a pump-probe setup. The stability of the 85Rb+ reached between optical clocks is on the order of 10-13.1 and can be used to reduce the linewidth / drift of the ECDL to a few kHz.2 The measured linewidth of the transition is around 20 MHz due to unavoidable misalignment between pump- and probe-beam, power- and Doppler-broadening at room temperature.2 The aim is to transfer this stability to a FPI that can be used as optical frequency standard: Therefore the phase of the light reflected from the FPI is observed using the Pound-Drever-Hall method. The theoretically reachable stability of a few mHz/Hz3 is limited by different noise factors. In order to identify these noise factors we a) follow the calculation of noise factors given by, 4 b) calculate the contribution of misalignment and insufficient mode matching by applying the generalized matrix-formalism, 5 and c) estimate the contribution of the initial laser linewidth and the present electronic noise sources.

  12. Cascaded fiber-optic Fabry-Perot interferometers with Vernier effect for highly sensitive measurement of axial strain and magnetic field.

    PubMed

    Zhang, Peng; Tang, Ming; Gao, Feng; Zhu, Benpeng; Fu, Songnian; Ouyang, Jun; Shum, Perry Ping; Liu, Deming

    2014-08-11

    We report a highly sensitive fiber-optic sensor based on two cascaded intrinsic fiber Fabry-Perot interferometers (IFFPIs). The cascaded IFFPIs have different free spectral ranges (FSRs) and are formed by a short section of hollow core photonic crystal fiber sandwiched by two single mode fibers. With the superposition of reflective spectrum with different FSRs, the Vernier effect will be generated in the proposed sensor and we found that the strain sensitivity of the proposed sensor can be improved from 1.6 pm/με for a single IFFPI sensor to 47.14 pm/με by employing the Vernier effect. The sensor embed with a metglas ribbon can be also used to measure the magnetic field according to the similar principle. The sensitivity of the magnetic field measurement is achieved to be 71.57 pm/Oe that is significantly larger than the 2.5 pm/Oe for a single IFFPI sensor. PMID:25321041

  13. Strain and high-temperature discrimination using a Type II fiber Bragg grating and a miniature fiber Fabry-Perot interferometer.

    PubMed

    Jiang, Yajun; Yang, Dexing; Yuan, Yuan; Xu, Jian; Li, Dong; Zhao, Jianlin

    2016-08-10

    A novel method for simultaneous measurement of strain and high temperature using a Type II fiber Bragg grating (FBG) and a miniature fiber Fabry-Perot interferometer (MFFPI) is proposed. The MFFPI is produced by fusion splicing a short section of quartz capillary tube with two single-mode fibers, and then it is exposed by a focused femtosecond laser and a phase mask to inscribe a Type II FBG nearby. The reflection spectrum of this sensor is the superposition of the reflection spectrum of the FBG and the interference fringe of the MFFPI. This sensor shows perfect high-temperature and strain responses. Because of the different responses to the uniform variations of strain and temperature, by measuring the reflection peak of FBG and one of the interference dips of the MFFPI, strain and temperature can be simultaneously determined. The resolutions of this particular sensor in measuring strain and temperature are estimated to be ±8.4  μϵ and ±3.3°C, respectively, in the range from 0 to 1122 μϵ and from 23°C to 600°C.

  14. Strain and high-temperature discrimination using a Type II fiber Bragg grating and a miniature fiber Fabry-Perot interferometer.

    PubMed

    Jiang, Yajun; Yang, Dexing; Yuan, Yuan; Xu, Jian; Li, Dong; Zhao, Jianlin

    2016-08-10

    A novel method for simultaneous measurement of strain and high temperature using a Type II fiber Bragg grating (FBG) and a miniature fiber Fabry-Perot interferometer (MFFPI) is proposed. The MFFPI is produced by fusion splicing a short section of quartz capillary tube with two single-mode fibers, and then it is exposed by a focused femtosecond laser and a phase mask to inscribe a Type II FBG nearby. The reflection spectrum of this sensor is the superposition of the reflection spectrum of the FBG and the interference fringe of the MFFPI. This sensor shows perfect high-temperature and strain responses. Because of the different responses to the uniform variations of strain and temperature, by measuring the reflection peak of FBG and one of the interference dips of the MFFPI, strain and temperature can be simultaneously determined. The resolutions of this particular sensor in measuring strain and temperature are estimated to be ±8.4  μϵ and ±3.3°C, respectively, in the range from 0 to 1122 μϵ and from 23°C to 600°C. PMID:27534477

  15. Sub-hertz relative frequency stabilization of two-diode laser-pumped Nd:YAG lasers locked to a Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Day, Timothy; Gustafson, Eric K.; Byer, Robert L.

    1992-01-01

    Two-diode laser-pumped Nd:YAG lasers have been frequency stabilized to a commercial 6.327-GHz free spectral range Fabry-Perot interferometer yielding a best-case beatnote linewidth of 330 mHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 has been built, and when substituted in place of the commercial interferometer produced a robust and easily repeatable beatnote linewidth of 700 MHz.

  16. SUNLITE program. Sub-Hertz relative frequency stabilization of two diode laser pumped Nd:YAG lasers locked to a Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1990-01-01

    Two laser pumped Nd:YAG lasers were frequency stabilized to a commercial 6.327 GHz free spectral range Fabry-Perot interferometer yielding a best case beatnote linewidth of 330 MHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 was built, and when it was substituted in place of the commercial interferometer, it produced a robust and easily repeatable beatnote linewidth of 700 MHz.

  17. Triple-layer Fabry-Perot/SPP aluminum absorber in the visible and near-infrared region.

    PubMed

    Shu, Shiwei; Li, Yang Yang

    2015-03-15

    We report a theoretical study on a novel type of absorber that can achieve near perfect absorption in the visible and near-infrared regions by utilizing the Fabry-Perot and the surface plasmon polariton (SPP) effects. The absorber consists of an Al/dielectric/Al triple-layered structure with the top Al layer consisting of an array of holes. The absorption features can be easily controlled by tuning the structural parameters, particularly the porous features of the top Al layer. When the porous features in the top Al layer are significantly smaller than the wavelength, light absorption is enabled through the Fabry-Perot effect. On the other hand, when the porous features in the top layer are at the subwavelength scale, new absorption peaks emerge due to the SPP effect. Furthermore, when the top Al layer consists of an array of hollow rings, the electric field at the interface between the top Al layer and the middle dielectric layer is greatly enhanced due to the plasmonic effect, indicating that the absorber reported here may be suitable for novel applications, e.g., the surface-enhanced Raman spectroscopy (SERS) substrates.

  18. Design of high finesse, wideband Fabry-Perot filter based on chirped fiber Bragg grating by numerical method

    NASA Astrophysics Data System (ADS)

    Peng, Xindong; Roychoudhuri, Chandrasekhar

    2000-07-01

    The spectral characteristics of a Fabry-Perot spectrometer (filter) formed by a pair of identical linearly chirped fiber Bragg gratings in optical fiber are studied numerically using the characteristic matrix method. The results indicate that based on available techniques and materials, one can fabricate such filters with a finesse as high as 104 and contrast as high as 109 by inscribing a pair of identical linearly chirped fiber gratings. Achieving such superfinesse and contrast in a conventional Fabry-Perot (FP) is very difficult because of fabrication complexities in achieving superflatness at ultrahigh reflectivities simultaneously and keeping them aligned. Our numerical solution also indicates that the spectral characteristics of the fiber FP (FFP) filter can be approximated by that of a classical plane mirror FP (PFP) with a mirror separation of L + (Delta) L, where L is the length of any one of the two gratings and (Delta) L is the separation between the two gratings. This analogous characteristic enables one to estimate time domain and other behavior of an FFP from already established PFP analysis. Thus, miniature FFPs can be used not only to achieve ultralow, crosstalk in wavelength division multiplexing, but they can also be integrated into miniature, hybrid, spectral sensors (such as Brillouin and Raman sensors) where ultrahigh contrast with superresolution is required.

  19. Formation of Fabry-Perot cavity in one-dimensional and two-dimensional GaAs nanostructures

    NASA Astrophysics Data System (ADS)

    Arab, Shermin; Yao, Maoqing; Chi, ChunYung; Zhou, Chongwu; Dapkus, P. Daniel; Cronin, Stephen B.

    2014-09-01

    We report formation of an optical cavity and observation of Fabry-Perot resonance in GaAs nanowires and nanosheets grown by metal organic chemical vapor deposition (MOCVD) with selective area growth (SAG). These nanostructures are grown along the (111)B direction. The formation of an optical cavity in the nanowires and nanosheets are fundamentally different from each other. In nanowires the optical cavity is formed along the length of the nanowire with ends of the nanowire behaving as two parallel mirrors. In nanosheets, however, the three non-parallel edges of the GaAs nanosheets are involved in trapping of the light through total internal reflection, thus forming a 2D cavity. We show that through surface passivation and local field enhancement, both the photoluminescence intensity and hence Fabry-Perot peak intensity increases significantly. Transferring the GaAs nanowires and nanosheets to the gold substrate (instead of Si/SiO2 substrate) leads to substantial enhancement in the photoluminescence intensity by 5X (for nanowires) and 3.7X (for nanosheets) to infinite enhancement of the FP peaks intensities. In order to reduce the non-radiative recombination in these nanowires the surface states in the nanowires can be passivated by either an ionic liquid (EMIM-TFSI) or an AlGaAs surface layer. Both passivations methods lead to an enhancement of the optical response by up to 12X.

  20. Fiber Optic Fabry-Perot Current Sensor Integrated with Magnetic Fluid Using a Fiber Bragg Grating Demodulation.

    PubMed

    Xia, Ji; Wang, Qi; Liu, Xu; Luo, Hong

    2015-01-01

    An optical fiber current sensor based on Fabry-Perot interferometer using a fiber Bragg grating demodulation is proposed. Magnetic fluid is used as a sensitive medium in fiber optical Fabry-Perot (F-P) cavity for the optical characteristic of magnetic-controlled refractive index. A Fiber Bragg grating (FBG) is connected after the F-P interferometer which is used to reflect the optical power at the Bragg wavelength of the interference transmission spectrum. The corresponding reflective power of the FBG will change with different external current intensity, due to the shift on the interference spectrum of the F-P interferometer. The sensing probe has the advantages of convenient measurement for its demodulation, low cost and high current measurement accuracy on account of its sensing structure. Experimental results show that an optimal sensitivity of 0.8522 nw/A and measurement resolution of 0.001 A is obtained with a FBG at 1550 nm with 99% reflectivity. PMID:26184201

  1. Fiber Optic Fabry-Perot Current Sensor Integrated with Magnetic Fluid Using a Fiber Bragg Grating Demodulation

    PubMed Central

    Xia, Ji; Wang, Qi; Liu, Xu; Luo, Hong

    2015-01-01

    An optical fiber current sensor based on Fabry-Perot interferometer using a fiber Bragg grating demodulation is proposed. Magnetic fluid is used as a sensitive medium in fiber optical Fabry-Perot (F-P) cavity for the optical characteristic of magnetic-controlled refractive index. A Fiber Bragg grating (FBG) is connected after the F-P interferometer which is used to reflect the optical power at the Bragg wavelength of the interference transmission spectrum. The corresponding reflective power of the FBG will change with different external current intensity, due to the shift on the interference spectrum of the F-P interferometer. The sensing probe has the advantages of convenient measurement for its demodulation, low cost and high current measurement accuracy on account of its sensing structure. Experimental results show that an optimal sensitivity of 0.8522 nw/A and measurement resolution of 0.001 A is obtained with a FBG at 1550 nm with 99% reflectivity. PMID:26184201

  2. Simple air-gap fiber Fabry-Perot interferometers based on a fiber endface with Sn-microsphere overlay

    NASA Astrophysics Data System (ADS)

    Lee, Cheng-Ling; Hung, Cheng-Hung; Li, Chai-Ming; You, Yan-Wun

    2012-10-01

    This study presents a simple, cost-effective and sensitive air-gap fiber Fabry-Perot interferometer (AG-PPFI) which is based on a metal Tin (Sn)-overlaying fiber technique. An extremely small drop of metallic Sn was heated and then melted to shrink into a microsphere owing to the cohesion of the material. When a fiber was inserted into the melting Sn microsphere, an air gap was naturally formed between the fiber endface and the metal Sn during the cooling process. By carefully controlling the reaction time, various air-gaps can be formed as the Fabry-Perot interferometric cavities for the proposed AG-PPFIs. Measurements reveal that a smaller length of air-gap and heavier mass of Sn-microsphere are associated with higher sensitivity of temperature, but the former is dominated. A best temperature sensitivity of wavelength shift with +4.3 nm/°C is achieved when the air-gap is about 5 μm with mass of Sn-microsphere of about 10 μg. The variation of the wavelength shift is equivalent to sensitivity for a change in the cavity length of +14.83 nm/°C.

  3. Fabry-Perot interferometer-based remote sensing of SO2

    NASA Astrophysics Data System (ADS)

    Kuhn, Jonas; Bobrowski, Nicole; Lübcke, Peter; Pöhler, Denis; Tirpitz, Jan-Lukas; Vogel, Leif; Platt, Ulrich

    2015-04-01

    We studied SO2 degassing from volcanoes and monitored the corresponding SO2 fluxes. Besides the effect on climate and the hazardous effects at a local scale, the absolute magnitude of SO2 fluxes or ratios of SO2 with other volcanic gases can be an indicator for volcanic activity and even help to understand and model processes in the interior of volcanoes. Due to its characteristic absorption structure, high abundance in the volcanic plume and low atmospheric background, SO2 can be easily identified and quantified by remote sensing techniques. DOAS and FTIR became standard techniques for volcanic SO2 measurements. Along with the development of portable devices they offer the advantage of simultaneous measurements of multiple gas species. However, both techniques often need complex data evaluation and observations are usually limited to a single viewing direction. Spatially resolved measurements, which are for instance required to determine gas fluxes, frequently have to be obtained sequentially leading to a relatively low time resolution. A further, today nearly established method to determine SO2 emission fluxes is the "SO2 camera". The SO2 camera has the advantage of a high spatial and temporal resolution, but is very limited in spectral information using only two wavelength channels and thus being less selective. Cross-interferences with volcanic plume aerosol, the ozone background, and other trace gases frequently cause problems in SO2 camera measurements. Here we introduce a novel passive remote sensing method for SO2 measurements in the atmosphere using a Fabry-Perot interferometer (FPI) setup. The transmission profile of this FPI consists of periodic transmission peaks that match the periodic SO2 absorption bands in the UV. In principle, this method allows imaging of two-dimensional SO2 distributions similarly to SO2 cameras. Interferences of standard SO2 cameras are greatly reduced with the FPI method. In addition, this technique can also be applied to other

  4. A tunable electrochromic fabry-perot filter for adaptive optics applications.

    SciTech Connect

    Blaich, Jonathan David; Kammler, Daniel R.; Ambrosini, Andrea; Sweatt, William C.; Verley, Jason C.; Heller, Edwin J.; Yelton, William Graham

    2006-10-01

    The potential for electrochromic (EC) materials to be incorporated into a Fabry-Perot (FP) filter to allow modest amounts of tuning was evaluated by both experimental methods and modeling. A combination of chemical vapor deposition (CVD), physical vapor deposition (PVD), and electrochemical methods was used to produce an ECFP film stack consisting of an EC WO{sub 3}/Ta{sub 2}O{sub 5}/NiO{sub x}H{sub y} film stack (with indium-tin-oxide electrodes) sandwiched between two Si{sub 3}N{sub 4}/SiO{sub 2} dielectric reflector stacks. A process to produce a NiO{sub x}H{sub y} charge storage layer that freed the EC stack from dependence on atmospheric humidity and allowed construction of this complex EC-FP stack was developed. The refractive index (n) and extinction coefficient (k) for each layer in the EC-FP film stack was measured between 300 and 1700 nm. A prototype EC-FP filter was produced that had a transmission at 500 nm of 36%, and a FWHM of 10 nm. A general modeling approach that takes into account the desired pass band location, pass band width, required transmission and EC optical constants in order to estimate the maximum tuning from an EC-FP filter was developed. Modeling shows that minor thickness changes in the prototype stack developed in this project should yield a filter with a transmission at 600 nm of 33% and a FWHM of 9.6 nm, which could be tuned to 598 nm with a FWHM of 12.1 nm and a transmission of 16%. Additional modeling shows that if the EC WO{sub 3} absorption centers were optimized, then a shift from 600 nm to 598 nm could be made with a FWHM of 11.3 nm and a transmission of 20%. If (at 600 nm) the FWHM is decreased to 1 nm and transmission maintained at a reasonable level (e.g. 30%), only fractions of a nm of tuning would be possible with the film stack considered in this study. These tradeoffs may improve at other wavelengths or with EC materials different than those considered here. Finally, based on our limited investigation and material set

  5. All-fiber upconversion high spectral resolution wind lidar using a Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Shangguan, Mingjia; Xia, Haiyun; Wang, Chong; Qiu, Jiawei; Shentu, Guoliang; Zhang, Qiang; Dou, Xiankang; Pan, Jian-wei

    2016-08-01

    An all-fiber, micro-pulse and eye-safe high spectral resolution wind lidar (HSRWL) at 1550nm is proposed and demonstrated by using a pair of upconversion single-photon detectors and a fiber Fabry-Perot scanning interferometer (FFP-SI). In order to improve the optical detection efficiency, both the transmission spectrum and the reflection spectrum of the FFP-SI are used for spectral analyses of the aerosol backscatter and the reference laser pulse. The reference signal is tapped from the outgoing laser and served as a zero velocity indicator. The Doppler shift is retrieved from a frequency response function Q, which is defined as the ratio of difference of the transmitted signal and the reflected signal to their sum. Taking advantages of high signal-to-noise ratio of the detectors and high spectral resolution of the FFP-SI, the Q spectra of the aerosol backscatter are reconstructed along the line-of-sight (LOS) of the telescope. By applying a least squares fit procedure to the measured Q spectra, the center frequencies and the bandwidths are obtained simultaneously. And then the Doppler shifts are determined relative to the center frequency of the reference signal. To eliminate the influence of temperature fluctuations on the FFP-SI, the FFP-SI is cased in a chamber with temperature stability of 0.001 during the measurement. Continuous LOS wind observations are carried out on two days at Hefei (31.843 N, 117.265 E), China. In the meantime, LOS wind measurements from the HSRWL show good agreement with the results from an ultrasonic wind sensor (Vaisala windcap WMT52). Due to the computational expensive of the convolution operation of the Q function, an empirical method is adopted to evaluate the quality of the measurements. The standard deviation of the wind speed is 0.76 m/s at the 1.8 km. The standard deviation of the retrieved bandwidth variation is 2.07 MHz at the 1.8 km.

  6. A theoretical performance study of an external cavity fiber Fabry-Perot interferometer for displacement measurement

    NASA Astrophysics Data System (ADS)

    Arumugam, Kumar

    The objective of this research is to explore a mathematical model developed by Wilkinson and Pratt for the external cavity fiber-based Fabry-Perot interferometer (EFPI) and to create a Michelson interferometer setup to validate a frequency modulation component of this model. A laser diode with nominal wavelength 635 nm is modulated by oscillating the diode current of maximum amplitude 22.62 mA to create correspondingly varying wavelength. Experiments are included to evaluate a rotating vector representation of the modulation harmonics in the signal received at the photodetector as of a cube corner translated by a piezo-electric actuator is displaced. Wavelength modulation as a function of diode current, the coherence length of the laser, and characteristics of the modulation harmonics are evaluated. A real time DAQ system and two lock-in amplifiers are utilized for detecting three side-band harmonics of the signal. For short range displacements this interferometer setup is monitored using a capacitance displacement sensor. The capacitance displacement measurement differed from the Michelson interferometer by 160 nm. The piezoelectric stage actuated with a 15 V Ramp signal produced 2.54 mum displacement of the cube corner. The setup is tested with Ramp signals of 75 V to 1.5 V and with the Ramp periods of 1 to 20 seconds to find the resolution of the interferometer, modulation of the wavelength sensitivity and the coherence length of the laser as 10.53 nm, 1.786 nm·A-1 and >1 m respectively. The best quadrature signal achieved corresponded to modulating the laser at amplitude of 18.86 mA at 1 kHz frequency with a path length difference of 6.35 mm. The amplitude comparison of side-band harmonics with Bessel function curves is consistent with a modulation amplitude of 1.28 rad corresponding to amplitude ratios of 0.5 (second and first) , 0.15 (third and second) and 0.06 (third and first) in the first through third Bessel function values.

  7. Spectral imagery: Recent results with the SPIFI and their implications for cometary atmospheric studies. [servocontrolled polarimetric imaging Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Smith, W. H.

    1981-01-01

    Spectral polarimetric imaging of comets is considered using state-of-the-art methods and a servo-controlled polarimetric imaging Fabry-Perot interferometer is described. Related observational data are shown and sensitivity levels are given which indicate the range of objects which may be studied. Some proposed observational goals are indicated.

  8. Frequency stabilization based on high finesse glass-ceramic Fabry-Perot cavity for a 632.8-nm He-Ne laser

    NASA Astrophysics Data System (ADS)

    Fu, Tingting; Yang, Kaiyong; Tan, Zhongqi; Luo, Zhifu; Wu, Suyong

    2014-12-01

    A frequency stabilization technique for a 632.8nm He-Ne laser with a high finesse Fabry-Perot cavity is introduced in this paper. The resonant frequency of the cavity is taken as the frequency standard .In this system the Fabry-Perot cavity is composed of a glass-ceramic spacer, with thermal expansion coefficient smaller than 2×10-8/°C , which means an excellent thermal stabilization which greatly decreases the thermal impacts on the cavity length in the desired constant-temperature environment.The intra-cavity spherical mirror is specially designed, which makes the Fabry-cavity a sensor element in our subsequent experiments for a new practical optical accelerometer .Both cavity mirrors were custom made in our laboratory which have reflectivities greater than 99.995% at 632.8nm, so the Fabry-Perot cavity has a finesse of about 62830. The half-maximum transmission line width is about 55.48 KHz and the free spectral range is 3.5GHz .In the experimental setup, we adopt the frequency stabilization circuit with small dithering .With proper dithering voltage, the laser can be precisely locked to the Fabry-Perot cavity minimum reflection point. Theoretically the frequency stability can reach 10-10 order.

  9. Coherent coupling between a molecular vibration and Fabry-Perot optical cavity to give hybridized states in the strong coupling limit (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Long, James P.; Owrutsky, Jeff C.; Fears, Kenan P.; Dressick, Walter J.; Dunkelberger, Adam D.; Compton, Ryan; Spann, Bryan; Simpkins, Blake S.

    2015-09-01

    Coherent coupling between an optical-transition and confined optical mode, when sufficiently strong, gives rise to new modes separated by the vacuum Rabi splitting. Such systems have been investigated for electronic-state transitions, however, only very recently have vibrational transitions been considered. Here, we bring strong polaritonic-coupling in cavities from the visible into the infrared where a new range of static and dynamic vibrational processes await investigation. First, we experimentally and numerically describe coupling between a Fabry-Perot cavity and carbonyl stretch (~1730 cm 1) in poly-methylmethacrylate. As is requisite for "strong coupling", the measured vacuum Rabi splitting of 132 cm 1 is much larger than the full width of the cavity (34 cm-1) and the inhomogeneously broadened carbonyl-stretch (24 cm-1). Agreement with classical theories providea evidence that the mixed-states are relatively immune to inhomogeneous broadening. Next, we investigate strong and weak coupling regimes through examination of cavities loaded with varying concentrations of urethane. Rabi splittings increases from 0 to ~104 cm-1 with concentrations from 0-20 vol% and are in excellent agreement to an analytical description using no fitting parameters. Ultra-fast pump-probe measurements reveal transient absorption signals over a frequency range well-separated from the vibrational band as well as modifications of energy relaxation times. Finally, we demonstrate coupling to liquids using the C-O stretching band (~1985 cm-1) of Mo(CO)6 in an aqueous solution. Opening the field of polaritonic coupling to vibrational species promises to be a rich arena amenable to a wide variety of infrared-active bonds that can be studied statically and dynamically.

  10. Velocity Fields in H II Regions Using High Resolution Imaging Fabry-Perot Spectrometer

    NASA Astrophysics Data System (ADS)

    Seema, P.

    1996-05-01

    The thesis comprises of two parts: I. Instrumentation II. Observations, results and discussion. An imaging Fabry-Perot spectrometer (IFPS) is designed and constructed for the studies on kinematics of extended astronomical objects (Seema et al., 1992). IFPS comprises of a field aperture, collimating lens and a two dimensional imaging sensor called Imaging Photon Detector (IPD). It is the first time that IPD which uses a resistive anode for position determination is being used in the spectroscopic studies of astronomical objects. Observations were made on Orion and Trifid nebula covering a wide field of view using a 35cm Celestron-14 telescope (f/11 cassegrain) at Gurushikhar, Mt.Abu, India. Orion Nebula: Observations were made in [OIII] 5007A, line with a spectral resolution of 6 km/sec and spatial resolution of 4" covering a field of view of 10.5', to study (i) general velocity flow (ii) high velocity flow and (iii)random motions. Line profiles generated for about 2000 positions showed an asymmetric shape with (a)a narrow component 20 +- 3 km/sec and (b) a broad component 50 +- 3 km/sec. The two components could be interpreted in terms of the interaction of the ionized gas (from the trapezium stars) with the condensations present in the nebula, resulting in the secondary flows. The iso-velocity contour map generated for both the components showed velocity flow in agreement with the champagne flow model (Tenorio-Tagle 1982). A model emission line profile constructed assuming a champagne flow in [OIII] 5007A, line for a position 2' away from theta-1 C Ori showed a reasonably good agreement with the narrow component of the observed profile. Certain high velocity flow (~50 km/s) regions are observed to be superimposed on the main flow of the narrow component. These flows are either radiation pressure driven stellar winds or jets generated during the formation phase of Young stellar objects. The radial velocity was found to be low with no high velocity flow regions in

  11. Quantum-enhanced metrology based on Fabry-Perot interferometer by squeezed vacuum and non-Gaussian detection

    SciTech Connect

    Li, Wenfang; Du, Jinjin; Wen, Ruijuan; Li, Gang; Zhang, Tiancai

    2014-03-28

    We have investigated the transmission spectra of a Fabry-Perot interferometer (FPI) with squeezed vacuum state injection and non-Gaussian detection, including photon number resolving detection and parity detection. In order to show the suitability of the system, parallel studies were made of the performance of two other light sources: coherent state of light and Fock state of light either with classical mean intensity detection or with non-Gaussian detection. This shows that by using the squeezed vacuum state and non-Gaussian detection simultaneously, the resolution of the FPI can go far beyond the cavity standard bandwidth limit based on the current techniques. The sensitivity of the scheme has also been explored and it shows that the minimum detectable sensitivity is better than that of the other schemes.

  12. Microscopic theory of dipole-dipole interaction in ensembles of impurity atoms in a Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Kuraptsev, A. S.; Sokolov, I. M.

    2016-08-01

    We develop a consistent quantum theory of the collective effects that take place when electromagnetic radiation interacts with a dense ensemble of impurity centers embedded in a transparent dielectric and placed in a Fabry-Perot cavity. We have calculated the spontaneous decay dynamics of an excited impurity atom as a specific example of applying the developed general theory. We analyze the dependence of the decay rate on the density of impurity centers and the sample sizes as well as on the characteristic level shifts of impurity atoms caused by the internal fields of the dielectric. We show that a cavity can affect significantly the pattern of collective processes, in particular, the lifetimes of collective states.

  13. Optical pressure/acoustic sensor with precise Fabry-Perot cavity length control using angle polished fiber.

    PubMed

    Wang, Wenhui; Wu, Nan; Tian, Ye; Wang, Xingwei; Niezrecki, Christopher; Chen, Julie

    2009-09-14

    This paper presents a novel Fabry-Perot (FP) optical fiber pressure/acoustic sensor. It consists of two V-shaped grooves having different sized widths, a diaphragm on the surface of the larger V-groove, and a 45 degrees angle-polished fiber. The precision of FP cavity length is determined by the fabrication process of photolithography and anisotropic etching of a silicon crystal. Therefore, the cavity length can be controlled on the order of ten nm. Sensors were fabricated and tested. Test results indicate that the sensors' cavity lengths have been controlled precisely. The packaged sensor has demonstrated very good static and dynamic responses compared to a commercially available pressure sensor and a microphone. PMID:19770876

  14. Combined fringe and Fabry-Perot laser anemometer for three component velocity measurements in turbine stator cascade facility

    NASA Technical Reports Server (NTRS)

    Seasholtz, R. G.; Goldman, L. J.

    1986-01-01

    A laser anemometer is described that was developed for use in a 508 mm diameter annular turbine stator cascade facility. All three velocity components are measured through a single restricted optical port, both within the stator vane row and downstream of the vanes. The measurements are made through a cylindrical window in the casing that matches the tip radius of the cascade. The stator tested has a contoured hub endwall that results in a large radial flow near the hub. The anemometer uses a standard fringe configuration (LFA) with a fluorescent aerosol seed to measure the axial and circumferential velocity components. The radial component is measured with a confocal Fabry-Perot interferometer. The two configurations are combined in a single optical system and can operate simultaneously. Data are presented to illustrate the capabilities of the system.

  15. Differential Radiometers Using Fabry-Perot Interferometric Technique for Remote Sensing Determination of Various Atmospheric Trace Gases

    NASA Technical Reports Server (NTRS)

    Georgieva, E. M.; Heaps, W. S.; Wilson, E. L.

    2007-01-01

    New type of remote sensing instrument based upon the Fabry-Perot inte rferometric technique has been developed at NASA's Goddard Space Flight Center. Fabry-Perot interferometry (FPI) is a well known, powerful spectroscopic technique and one of its many applications is to be use d to measure greenhouse gases and also some harmful species in the at mosphere. With this technique, absorption of particular species is me asured and related to its concentration. A solid Fabry-Perot etalon is used as a frequency filter to restrict the measurement to particular absorption bands of the gas of interest. With adjusting the thicknes s of the etalon that separation (in frequency) of the transmitted fri nges can be made equal to the almost constant separation of the gas a bsorption lines. By adjusting the temperature of the etalon, which changes the index of refi-action of its material, the transmission fring es can be brought into nearly exact correspondence with absorption li nes of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosph ere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The instrument that we have dev eloped detects the absorption of various atmospheric trace gases in d irect or reflected sunlight. Our instrument employing Fabry-Perot interferometer makes use of two features to achieve high sensitivity. The first is high spectral resolution enabling one to match the width of an atmospheric absorption feature by the instrumental band pass. The second is high optical throughput enabled by using multiple spectral lines simultaneously. For any species that one wishes to measure, thi s first feature is available while the use of multiple spectral features can be employed only for species with suitable spectra and freedom from interfering species in the same wavelength region. We have deve loped an instrument for use as ground based

  16. Mirror Birefringence in a Fabry-Perot Cavity and the Detection of Vacuum Birefringence in a Magnetic Field

    NASA Technical Reports Server (NTRS)

    Chui, T. C. P.; Shao, M.; Redding, D.; Gursel, Y.; Boden, A.

    1995-01-01

    We discuss the effect of mirror birefringence in two optical schemes designed to detect the quantum-electrodynamics (QED) predictions of vacuum birefringence under the influence of a strong magnetic field, B. Both schemes make use of a high finesse Fabry-Perot cavity (F-P) to increase the average path length of the light in the magnetic field. The first scheme, which we called the frequency scheme, is based on measurement of the beat frequency of two orthogonal polarized laser beams in the cavity. We show that mirror birefringence contributes to the detection uncertainties in first order, resulting in a high susceptibility to small thermal disturbances. We estimate that an unreasonably high thermal stability of 10-9 K is required to resolve the effect to 0.1%. In the second scheme, which we called the polarization rotation scheme, laser polarized at 45 relative to the B field is injected into the cavity.

  17. Narrow-band Imagery with the Goddard Fabry-Perot: Probing the Epoch of Active Accretion for PMS Stars

    NASA Technical Reports Server (NTRS)

    Woodgate, Bruce E.; Grady, C.; Endres, M.; Williger, G.

    2006-01-01

    The STIS coronagraphic imaging sample of I'MS stars was surveyed with the Goddard Fabry-Perot (GFP) interferometer to determine what fraction of the stars drive jets, whether there is any difference in behavior for a group of intermediate-mass stars as compared with T Tauri stars, and to search for evolutionary effects. Compared to broad band imaging, the FGP achieves an emission-line nebulosity-to-star contrast gain of between 500 and 3000. To date, we have detected jets associated with classical T Tauri stars spanning a factor of 280 in mass accretion rate in approximately 50% of the STIS coronagraphic imaging sample. We also detected jets or Herbig-HARO knots associated with 5 Herbig Ae stars, all younger than 8 Myr, for a detection fraction which is smaller than the T Tauri survey.

  18. Note: An in situ method for measuring the non-linear response of a Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Bu, Wenhao; Liu, Mengke; Xie, Dizhou; Yan, Bo

    2016-09-01

    The transfer cavity is a very important frequency reference for laser stabilization and is widely used for applications such as precision measurements and laser cooling of ions or molecules. But the non-linear response of the piezoelectric ceramic transducer (PZT) in the Fabry-Perot cavity limits the performance of the laser stabilization. Thus, measuring and controlling such non-linearity is essential. Here we report an in situ, optical method to characterize this non-linearity by measuring the resonant signals of a dual-frequency laser. The differential measurement makes it insensitive to the laser and cavity drifts, while maintaining a very high sensitivity. It can be applied for various applications with PZTs, especially in an optical lab.

  19. Gas dynamics of a pulsed supersonic nozzle molecular source as observed with a Fabry--Perot cavity microwave spectrometer

    SciTech Connect

    Campbell, E.J.; Buxton, L.W.; Balle, T.J.; Keenan, M.R.; Flygare, W.H.

    1981-01-15

    The gas dynamics of a pulsed supersonic nozzle molecular source are investigated by using a pulsed Fabry--Perot cavity microwave spectrometer to obtain free induction decay signals from rotational two-level systems in the gas expansion. An equation is derived giving the time domain emission signal line shape as an integral over the active molecular distribution in the beam. The Doppler splitting phenomenon is discussed in detail. Experimental line shapes are deconvoluted to give molecular velocities, dephasing times, and density distributions. We find that the density distribution of active molecules from the the pulsed nozzle varies rapidly in time, starting with a depletion on the nozzle axis at short times after the nozzle is opened, and changing to on-axis concentration at longer times. Results obtained with the gas nozzle axis oriented at angles ranging from 0 /sup 0/ to 90 /sup 0/ with respect to the direction of propagation of the microwaves are reported.

  20. Cryogenic mechanisms for scanning and interchange of the Fabry-Perot interferometers in the ISO long wavelength spectrometer

    NASA Technical Reports Server (NTRS)

    Davis, G. R.; Furniss, I.; Patrick, T. J.; Sidey, R. C.; Towlson, W. A.

    1991-01-01

    The Infrared Space Observatory (ISO) is an ESA cornerstone mission for infrared astronomy. Schedules for launch in 1993, its four scientific instruments will provide unprecedented sensitivity and spectral resolution at wavelengths which are inaccessible using ground-based techniques. One of these, the Long Wavelength Spectrometer (LWS), will operate in the 45 to 180 micron region (Emery et. al., 1985) and features two Fabry-Perot interferometers mounted on an interchange mechanism. The entire payload module of the spacecraft, comprising the 60 cm telescope and the four focal plane instruments, is maintained at 2 to 4 K by an onboard supply of liquid helium. The mechanical design and testing of the cryogenic interferometer and interchange mechanisms are described.

  1. A Near IR Fabry-Perot Interferometer for Wide Field, Low Resolution Hyperspectral Imaging on the Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Barry, R. K.; Satyapal, S.; Greenhouse, M. A.; Barclay, R.; Amato, D.; Arritt, B.; Brown, G.; Harvey, V.; Holt, C.; Kuhn, J.

    2000-01-01

    We discuss work in progress on a near-infrared tunable bandpass filter for the Goddard baseline wide field camera concept of the Next Generation Space Telescope (NGST) Integrated Science Instrument Module (ISIM). This filter, the Demonstration Unit for Low Order Cryogenic Etalon (DULCE), is designed to demonstrate a high efficiency scanning Fabry-Perot etalon operating in interference orders 1 - 4 at 30K with a high stability DSP based servo control system. DULCE is currently the only available tunable filter for lower order cryogenic operation in the near infrared. In this application, scanning etalons will illuminate the focal plane arrays with a single order of interference to enable wide field lower resolution hyperspectral imaging over a wide range of redshifts. We discuss why tunable filters are an important instrument component in future space-based observatories.

  2. Wavelength modulation spectroscopy at 1530.32 nm for measurements of acetylene based on Fabry-Perot tunable filter

    NASA Astrophysics Data System (ADS)

    Yun-Long, Li; Bing-Chu, Yang; Xue-Mei, Xu

    2016-02-01

    Sensitive detection of acetylene (C2H2) is performed by absorption spectroscopy and wavelength modulation spectroscopy (WMS) based on Fiber Fabry-Perot tunable filter (FFP-TF) at 1530.32 nm. After being calibrated by Fiber Bragg Grating (FBG), FFP-TF is frequency-multiplexed and modulated at 20 Hz and 2.5 kHz respectively to achieve wavelength modulation. The linearity with 0.9907 fitting coefficient is obtained by measuring different concentrations in a 100 ppmv-400 ppmv range. Furthermore, the stability of the system is analyzed by detecting 50 ppmv and 100 ppmv standard gases for 2 h under room temperature and ambient pressure conditions respectively. The precision of 11 ppmv is achieved by calculating the standard deviation. Therefore, the measuring system of C2H2 detection can be applied in practical applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61172047 and 61071025).

  3. Amplification of the signal intensity of fluorescence-based fiber-optic biosensors using a Fabry-Perot resonator structure.

    PubMed

    Hsieh, Meng-Chang; Chiu, Yi-Hsin; Lin, Sheng-Fu; Chang, Jenq-Yang; Chang, Chia-Ou; Chiang, Huihua Kenny

    2015-01-01

    Fluorescent biosensors have been widely used in biomedical applications. To amplify the intensity of fluorescence signals, this study developed a novel structure for an evanescent wave fiber-optic biosensor by using a Fabry-Perot resonator structure. An excitation light was coupled into the optical fiber through a laser-drilled hole on the proximal end of the resonator. After entering the resonator, the excitation light was reflected back and forth inside the resonator, thereby amplifying the intensity of the light in the fiber. Subsequently, the light was used to excite the fluorescent molecules in the reactive region of the sensor. The experimental results showed that the biosensor signal was amplified eight-fold when the resonator reflector was formed using a 92% reflective coating. Furthermore, in a simulation, the biosensor signal could be amplified 20-fold by using a 99% reflector. PMID:25690548

  4. SnO2-MOF-Fabry-Perot humidity optical sensor system based on fast Fourier transform technique

    NASA Astrophysics Data System (ADS)

    Lopez-Aldaba, A.; Lopez-Torres, D.; Ascorbe, J.; Rota-Rodrigo, S.; Elosua, C.; Lopez-Amo, M.; Arregui, F. J.; Corres, J. M.; Auguste, J.-L.; Jamier, R.; Roy, P.

    2016-05-01

    In this paper, a new sensor system for relative humidity measurements based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Perot (FP) sensing head is presented and characterized. The interrogation of the sensing head is carried out by monitoring the Fast Fourier Transform phase variations of the FP interference frequency. This method is low-sensitive to signal amplitude variations and also avoids the necessity of tracking the evolution of peaks and valleys in the spectrum. The sensor is operated within a wide humidity range (20%-90% relative humidity) with a maximum sensitivity achieved of 0.14rad/%. The measurement method uses a commercial optical interrogator as the only active element, this compact solution allows real time analysis of the data.

  5. Long-term stability of a Fabry-Perot interferometer used for measurement of stellar Doppler shift

    NASA Technical Reports Server (NTRS)

    Mcmillan, R. S.; Smith, P. H.; Perry, M. L.; Moore, T. L.; Merline, W. J.

    1990-01-01

    The use of a fiber-optic-link CCD-detector Fabry-Perot interferometer (McMillan et al., 1985, 1986, and 1988) to obtain high-accuracy measurements of stellar Doppler shifts at KPNO is described in detail and illustrated with sample data. Particular attention is given to accuracy requirements and techniques for reducing errors, resolution (orders of 50 mA at wavelength 4300 A are separated by 640 mA), CCD sensitivity, observing and data-processing operations, and the control of environmental conditions. Standard-deviation data and statistics on seven solar-type stars are presented in tables, and the time evolution of the radial velocity of Beta Com is shown in a graph.

  6. Dual Fiber-Optic Fabry-Perot Interferometer Temperature Sensor with Low-Cost Light-Emitting Diode Light Source

    NASA Astrophysics Data System (ADS)

    Wang, Mu-Chun; Hsieh, Zhen-Ying; Tseng, Yuan-Tai; Tseng, Fan-Gang; Huang, Heng-Sheng; Wang, Jon-En; Taylor, Henry F.

    2008-04-01

    A dual fiber-optic Fabry-Perot interferometer (FFPI) sensor system with a low-coherence communication-system light-emitting diode (LED) as a light source is investigated to detect temperature variation signals. In this system, there are two FFPIs: the sensing and reference FFPIs. When the perturbation of interest, such as that of temperature, disturbs the sensing FFPI to produce a phase shift, the light reflected from the sensor is demodulated by the reference FFPI to extract the measurand. A low-power (sub-nW) optical signal is converted into an electrical signal and processed by a designed optical receiver. This setup is availably applied in biosensors to compensate the temperature variation in a sensing environment or sense the temperature effect in a certain measurement on an interior local site.

  7. A Fabry-Perot etalon-based notch filter for background cleaning in Brillouin microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Shao, Peng; Besner, Sebastien; Scarcelli, Giuliano; Yun, Seok-Hyun

    2016-03-01

    In Brillouin scattering imaging, rejection of background noise due to elastic scattering and reflections from optical components is crucial. This is because Brillouin signal is weak, and the signal frequency shift compared with source laser line is very small. Therefore the line of interest is very easy to be contaminated. Whereas physical blocking of undesired component in a dispersed spectrum is used, to filter out background optically provides better stability. Conventional optical filter techniques, such as dielectric-stack filters, holographic volume filters, Lyot fitlers etc. normally have a stopband-width (bandstop filter) or edge-width (edge filter) ranging from a few nanometers to tens of nanometers despite high rejection rate. They cannot be implemented in Brillouin imaging due to the small wavelength shift (< 1 pm). We report a Fabry-Perot etalon-based notch filter for background cleaning in Brillouin imaging. The notch filer takes advantage of multiple reflections of the light beam with a Fabry-Perot etalon to achieve high rejection with narrow bandwidth. The theoretical rejection rate is multiple time of the rejection of one reflection of the etalon. We demonstrated a laser line suppression of > 40 dB while with < 40% power loss with experiments. Width of the stopband at -30 dB rejection level is ~ 1 GHz. This method is not wavelength specific. One etalon may be implanted to a wide spectrum of laser wavelengths. Furthermore, it does not require heating as gaseous notch filters. Our method can also be implemented to Raman scattering, fluorescent imaging and other imaging techniques in which line of interest is close to the laser source.

  8. High Resolution Fabry-Perot Spectroscopy Of Comet Fragments 73P/ Schwassmann-Wachmann 3-B,C

    NASA Astrophysics Data System (ADS)

    Oliversen, Ronald J.; Mierkiewicz, E. J.; Morgenthaler, J. P.; Harris, W. M.; Kokorowski, M.; Kidder, A.; Schnackenberg, T.; Carpena Nunez, J.; Hall, T.; Haffner, L.

    2006-09-01

    In May 2006, comet 73P/Schwassmann-Wachmann 3 (SW3) made a spectacular close approach to the Earth. During its 1995 apparition, the comet fragmented into several pieces. One of the brighter components, SW3-B, fragmented into dozens of pieces during the 2006 apparition while another bright fragment, SW3-C did not. Understanding the difference between these two fragments will contribute significantly to our understanding of cometary interiors. We performed observations of SW3-B and SW3-C from Kitt Peak using the Fabry-Perot spectrometers at the McMath-Pierce (MMP) telescope from April 29 - May 10 and at the Wisconsin Hydrogen Alpha Mapper (WHαM) from May 1 - 6, 2006. This period is significant due to its proximity to perigee, overlap with complementary observations, and coincidence with the onset and decline-phase of a major outburst/fragmentation event from SW3-B. The MMP and WHAM Fabry-Perot spectrometers made high resolution measurements of [O I] and NH2 emissions near 6300 Å at δV = 5 km/s and 12 km/s with 4.5 arcmin and 1 degree fields of view, respectively. Many of the spectra separate the cometary and terrestrial [O I] lines and allow determination of water production rates. We report the preliminary analysis of these data, including discussion of the radial distribution of emissions, a comparison activity levels between the two fragments, and a comparison with complementary production rate measurements made over the same period. In addition, following the SW3-B May 9 outburst, H20+ measurements near 6200 Å were made to map the acceleration of water ions near the head and down the tail.

  9. Improvements in filtered Rayleigh scattering measurements using Fabry-Perot etalons for spectral filtering of pulsed, 532-nm Nd:YAG output

    NASA Astrophysics Data System (ADS)

    Sutton, Jeffrey A.; Patton, Randy A.

    2014-09-01

    In this manuscript, we investigate a new methodology for increasing the spectral purity of the second-harmonic output of an injection-seeded, frequency-doubled, Q-switched Nd:YAG laser operating near 532 nm. Specifically, tunable Fabry-Perot etalons (FPEs) are used as ultra-narrowband spectral filters, transmitting the desired single-mode output, while filtering out a significant portion of the broadband pedestal characteristic of injection-seeded lasers. A specific emphasis is placed on the design and optimization of the FPEs in the context of filtered Rayleigh scattering (FRS) measurements and how their utilization results in substantial increases in spectral purity, realizable attenuation of unwanted scattering, and applications in environments with high particulate levels. Experimental results show an increase in laser spectral purity of more than one order-of-magnitude (from 0.99997 to 0.999998) when using FPE filters, which led to a two-order-of-magnitude increase in achievable attenuation of laser light passing through a molecular iodine filter. The utility of the FPE-based spectral filtering of the pulsed Nd:YAG output for 2D FRS imaging was demonstrated in turbulent, isothermal gas-phase jets, seeded with varying levels of non-evaporating droplets with particle volume fractions ( F Vp) ranging from ~5 to >60 parts-per-million (ppm). After implementation of an optimized air-spaced FPE in the 532-nm output, no particle scattering was observed (based on visual and statistical analysis), even for the highest seed case ( F Vp ~ 60 ppm), and the gas-phase Rayleigh-Brillouin signals were collected without interference from the flowfield particulate. The current results suggest that the implementation of properly specified FPEs allows FRS to be applied in environments with high flowfield particulate levels; levels are well beyond what have been suitable for previous FRS measurements.

  10. High-resolution interrogation technique for fiber optic extrinsic Fabry-Perot interferometric sensors by the peak-to-peak method

    NASA Astrophysics Data System (ADS)

    Jiang, Yi

    2008-03-01

    An improved peak-to-peak method is developed for interrogating the absolute cavity length of fiber optic extrinsic Fabry-Perot interferometric (EFPI) sensors with high resolution. A fiber Fabry-Perot tunable filter (FFP-TF) is used to scan the optical spectrum of an EFPI, and the problems caused by the nonlinear performance and poor repeatability of the FFP-TF are removed by using a wavelength calibration technique. A linear fitting is used to calculate the wavelength spacing between two adjacent apexes in the optical spectrum, and the cavity length can be retrieved using this wavelength spacing. The experimental results show that the measuring resolution is improved from 25 to 1 μm, and a linear output is also obtained.

  11. Using four wavelength-multiplexed self-seeding Fabry-Perot lasers for 10 Gbps upstream traffic in TDM-PON.

    PubMed

    Yeh, Chien-Hung; Chow, Chi-Wai; Wang, Chia-Husan; Shih, Fu-Yuan; Wu, Yu-Fu; Chi, Sien

    2008-11-10

    In this paper, we propose and experimentally investigate a simple self-injection Fabry-Perot laser scheme on each optical network unit (ONU) for 10 Gbps TDM passive optical networks (PONs). Based on the proposed four wavelength-multiplexed 2.5 Gbps lasers, the 10 Gbps uplink traffic can be achieved at a cost-effective way. The network architecture and performance have also been analyzed and discussed. PMID:19581975

  12. A simple fiber-optic humidity sensor based on extrinsic Fabry-Perot cavity constructed by cellulose acetate butyrate film

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Huang, Wo-Bin; Huang, Xu-Guang; Yu, Chang-yuan

    2013-12-01

    A fiber-optic relative humidity sensor with an extrinsic micro Fabry-Perot cavity constructed with a thin layer of cellulose acetate butyrate coated on a fiber end is presented. Its operational principle is based on the relative-humidity-dependent wavelength shift of the interference fringes formed by Fresnel reflections from both interfaces of the thin film. Both the experimental and theoretical analyses are investigated in detail. The experimental data for relative humidity ranging from 8.8% to 88.1% are measured in the both humidification and dehumidification processes, which fits the linear equation very well with a value of R2 = 0.9946. As observed, it shows a high sensitivity of 0.307 nm/%RH with a high resolution of 0.06%. The time-dependent response of the sensor is estimated. The long term stability of the sensor is also addressed with high precision of ±0.03% over 100 min. The proposed relative humidity sensor has a simple, solid, and compact structure.

  13. Observations of the Solar Minimum Thermosphere Above Poker Flat, Alaska, with an All-Sky Imaging Fabry-Perot Spectrometer

    NASA Astrophysics Data System (ADS)

    Conde, M. G.; Anderson, C.; Andersen, C. S.

    2009-12-01

    The recent deep solar minimum conditions have provided an ideal opportunity to resolve how various external drivers perturb the state of Earth's thermosphere. Here, we present observations of thermospheric wind and temperature fields above Poker Flat, Alaska, during the 2007/08 and 2008/09 northern winters. These data were taken with an all-sky imaging Fabry-Perot spectrometer, that was recently upgraded to improve sensitivity and to allow interleaved observations of both the 6300A (red) and 5577A (green) emission in a single night. The multi-wavelength capability provides vertical resolution, whereas the observing cadence of 2-5 minutes allows determination of the ion-neutral coupling time constant. All-sky wind mapping resolves these responses horizontally, on scales down to 100 km or less. Even at solar minimum we often observed signatures of strong localized ion-neutral coupling; horizontal divergence and shear with magnitudes up to 0.0005 inverse seconds were not uncommon, even in the E-region. The quiescent conditions also allowed us to observe an approximately 3-week long cooling period in the F-region, following the stratospheric warming event of January/February 2009. The magnitude of this cooling was around 100K.

  14. Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe

    PubMed Central

    Tosi, Daniele; Saccomandi, Paola; Schena, Emiliano; Duraibabu, Dinesh Babu; Poeggel, Sven; Leen, Gabriel; Lewis, Elfed

    2016-01-01

    We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies. PMID:27092504

  15. Method of hybrid multiplexing for fiber-optic Fabry-Perot sensors utilizing frequency-shifted interferometry.

    PubMed

    Ou, Yiwen; Zhou, Ciming; Zheng, Angui; Cheng, Chunfu; Fan, Dian; Yin, Jiadi; Tian, Hui; Li, Mengmeng; Lu, Ying

    2014-12-10

    Experimental and theoretical research on hybrid multiplexing for fiber-optic Fabry-Perot (F-P) sensors based on frequency-shifted interferometry is presented. Four F-P sensors multiplexed in a hybrid configuration were experimentally investigated. The location of each multiplexed sensor was retrieved by performing the fast Fourier transform, and the reflection spectrum of each sensor was also obtained in spite of the spectral overlap, which was consistent with the results measured by an optical spectrum analyzer. With theoretical modeling, the maximum sensor number of a two-channel hybrid multiplexing system reaches 26 with crosstalk of less than -50  dB and a maximum frequency-domain signal-to-noise ratio (SNR) of ∼25  dB, when the source power is 2 mW and the sensor separation is optimal, i.e., 40 m. And the sensor number is almost twice that multiplexed by a serial system under the same conditions. An SNR improvement of 3.9 dB can be achieved by using a Hamming window in a noise-free system compared with a Hanning window. In addition, we applied the experimental multiplexing system to a strain sensing test. The cavity lengths and cavity-length shifts of the four F-P sensors were demodulated, which was consistent with the actual situation. It provides a new feasible method to multiplex F-P sensors at large scale. PMID:25608081

  16. An efficient hexagonal switched beam antenna structure based on Fabry-Perot cavity leaky-wave antenna

    NASA Astrophysics Data System (ADS)

    Aymen El Cafsi, Mohamed; Nedil, Mourad; Osman, Lotfi; Gharsallah, Ali

    2015-11-01

    A novel design of switched beam antenna (SBA) system based on Fabry-Perot cavity leaky-wave antenna (FPC LWA) is designed and fabricated for base station operating in the unlicensed ISM central frequency band at 5.8 GHz of the wireless local area network (WLAN) standard. The proposed SBA is designed with hexagonal shape of FPC LWA Arrays in order to get 360° of coverage. The single element of FPC LWA array is composed of a patch antenna and covered by a Partially Reflective Surface (PRS), which is composed of a Metal Strip Grating and printed on a high permittivity Superstrate. First, the Transmission Line Model of FPC LWA is introduced to analyse and calculate the far-field components in E- and H planes by using the Transverse Equivalent Network. This approach is then compared with other full wave's commercial software such as Ansoft HFSS and CST Microwave Studio. Second, a parametric study is performed to evaluate the effect of the angle formed by the two successive FPC LWA on the radiation efficiency of the activate sector. To examine the performance of the proposed SBA, experimental prototype was fabricated and measured. As a result, multiple orthogonal beams (six beams) of 10 dBi of gain with low Side Lobes Level and 360° of coverage are produced. This SBA structure is suitable for WLAN communication systems.

  17. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

    PubMed Central

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

    2014-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0–10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

  18. System and method for generating a displacement with ultra-high accuracy using a fabry-perot interferometer

    DOEpatents

    McIntyre, Timothy J.

    1994-01-01

    A system and method for generating a desired displacement of an object, i.e., a target, from a reference position with ultra-high accuracy utilizes a Fabry-Perot etalon having an expandable tube cavity for resolving, with an Iodine stabilized laser, displacements with high accuracy and for effecting (as an actuator) displacements of the target. A mechanical amplifier in the form of a micropositioning stage has a platform and a frame which are movable relative to one another, and the tube cavity of the etalon is connected between the platform and frame so that an adjustment in length of the cavity effects a corresponding, amplified movement of the frame relative to the cavity. Therefore, in order to provide a preselected magnitude of displacement of the stage frame relative to the platform, the etalon tube cavity is adjusted in length by a corresponding amount. The system and method are particularly well-suited for use when calibrating a high accuracy measuring device.

  19. Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry-Perot laser

    NASA Astrophysics Data System (ADS)

    Hisham, Hisham Kadhum; Abas, Ahmad Fauzi; Amouzad Mahdiraji, Ghafour; Mahdi, Mohd Adzir; Mahamd Adikan, Faisal Rafiq

    2015-04-01

    The effects of the external optical cavity parameters (external optical cavity length ( L ext), amplitude coupling ( C o) and anti-reflection coating (ARC) reflectivity coefficients) on the noise and modulation spectra of a fiber grating Fabry-Perot laser are numerically analyzed for designing a laser that operates in strong feedback regime (Regime V). Fiber Bragg grating (FBG) is used as a wavelength selective element to control the properties of the laser output by controlling the external optical feedback (OFB) level. The study is performed by modifying a set of rate equations that are solved by considering the effects of external OFB and ambient temperature ( T) variations. We proposed a model to calculate the temperature dependence (TD) of laser characteristics according to the TD of laser parameters. An accurate analytical expression for the TD of threshold carrier density ( N th,fe) has been derived. The TD of N th,fe was calculated according to the TD of laser cavity parameters instead of using well-known empirical Pankove relationship via the use of characteristics temperature ( T o) and current ( I o). Results show that the optimum external fiber length ( L ext) is 3.1 cm. Also, it is shown that ARC with reflectivity value of 1 × 10-2 is sufficient for the laser to operate at low noise, good modulation response, and low fabrication complexity.

  20. Dual hollow core fiber-based Fabry-Perot interferometer for measuring the thermo-optic coefficients of liquids.

    PubMed

    Lee, Cheng-Ling; Ho, Hsuan-Yu; Gu, Jheng-Hong; Yeh, Tung-Yuan; Tseng, Chung-Hao

    2015-02-15

    A microcavity fiber Fabry-Perot interferometer (MFFPI) that is based on dual hollow core fibers (HCFs) is developed for measuring the thermo-optic coefficients (TOCs) of liquids. The proposed MFFPI was fabricated by fusion-splicing a tiny segment of the main-HCF with a diameter D of 30 μm and another section of feeding-HCF with a diameter of 5 μm. Then, the main-HCF was filled with liquid by capillary action through the feeding-HCF by immersing the MFFPI in the liquid. The TOCs of the Cargille liquid (n(D)=1.3), deionized (DI) water, and ethanol were accurately determined from the shift of the interference wavelength, which was due to the temperature variation. Our experimental results were also compared with other published studies to investigate the effectiveness of the proposed sensing scheme. The major advantage is that the miniature MFFPI can achieve the measurement of the TOCs of the liquids with picoliter volume, and the measured liquids also can be sealed off and stored inside the HCF to prevent contamination.

  1. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement.

    PubMed

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S

    2013-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0-10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation.

  2. Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe.

    PubMed

    Tosi, Daniele; Saccomandi, Paola; Schena, Emiliano; Duraibabu, Dinesh Babu; Poeggel, Sven; Leen, Gabriel; Lewis, Elfed

    2016-04-15

    We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies.

  3. Optical Gain in MoS2 via Coupling with Nanostructured Substrate: Fabry-Perot Interference and Plasmonic Excitation.

    PubMed

    Jeong, Hye Yun; Kim, Un Jeong; Kim, Hyun; Han, Gang Hee; Lee, Hyangsook; Kim, Min Su; Jin, Youngjo; Ly, Thuc Hue; Lee, Si Young; Roh, Young-Geun; Joo, Won-Jae; Hwang, Sung Woo; Park, Yeonsang; Lee, Young Hee

    2016-09-27

    Despite the direct band gap of monolayer transition metal dichalcogenides (TMDs), their optical gain remains limited because of the poor light absorption in atomically thin, layered materials. Most approaches to improve the optical gain of TMDs mainly involve modulation of the active materials or multilayer stacking. Here, we report a method to enhance the optical absorption and emission in MoS2 simply through the design of a nanostructured substrate. The substrate consisted of a dielectric nanofilm spacer (TiO2) and metal film. The overall photoluminescence intensity from monolayer MoS2 on the nanostructured substrate was engineered based on the TiO2 thickness and amplified by Fabry-Perot interference. In addition, the neutral exciton emission was selectively amplified by plasmonic excitations from the local field originating from the surface roughness of the metal film with spacer thicknesses of less than 10 nm. We further demonstrate that the quality factor of the device can also be engineered by selecting a spacer material with a different refractive index.

  4. Nanoantenna-induced fringe splitting of Fabry-Perot interferometer: a model study of plasmonic/photonic coupling.

    PubMed

    Liu, Huanhuan; Erouel, Mohsen; Gerelli, Emmanuel; Harouri, Abdelmounaim; Benyattou, Taha; Orobtchouk, Régis; Milord, Laurent; Belarouci, Ali; Letartre, Xavier; Jamois, Cécile

    2015-11-30

    In this paper, we present a simple approach to study the coupling mechanisms between a plasmonic system consisting of bowtie nanoantennas and a photonic structure based on a Fabry-Perot interferometer. The nanoantenna array is represented by an equivalent homogeneous layer placed at the interferometer surface and yielding the effective dielectric function of the NA resonance. A phase matching model based on thin film interference is developed to describe the multi-layer interferences in the device and to analyze the fringe variations induced by the introduction of the plasmonic layer. The general model is validated by an experimental system consisting of a bowtie nanoantenna array and a porous-silicon-based interferometer. The optical response of this hybrid device exhibits both the enhancement induced by the nanoantenna resonance and the fringe pattern of the interferometer. Using the phase matching model, we demonstrate that strong coupling can occur in such a system, leading to fringe splitting. A study of the splitting strength and of the coupling behavior is given. The model study performed in this work enables to gain deeper understanding of the optical behavior of plasmonic/photonic hybrid devices.

  5. Dual hollow core fiber-based Fabry-Perot interferometer for measuring the thermo-optic coefficients of liquids.

    PubMed

    Lee, Cheng-Ling; Ho, Hsuan-Yu; Gu, Jheng-Hong; Yeh, Tung-Yuan; Tseng, Chung-Hao

    2015-02-15

    A microcavity fiber Fabry-Perot interferometer (MFFPI) that is based on dual hollow core fibers (HCFs) is developed for measuring the thermo-optic coefficients (TOCs) of liquids. The proposed MFFPI was fabricated by fusion-splicing a tiny segment of the main-HCF with a diameter D of 30 μm and another section of feeding-HCF with a diameter of 5 μm. Then, the main-HCF was filled with liquid by capillary action through the feeding-HCF by immersing the MFFPI in the liquid. The TOCs of the Cargille liquid (n(D)=1.3), deionized (DI) water, and ethanol were accurately determined from the shift of the interference wavelength, which was due to the temperature variation. Our experimental results were also compared with other published studies to investigate the effectiveness of the proposed sensing scheme. The major advantage is that the miniature MFFPI can achieve the measurement of the TOCs of the liquids with picoliter volume, and the measured liquids also can be sealed off and stored inside the HCF to prevent contamination. PMID:25680124

  6. Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe.

    PubMed

    Tosi, Daniele; Saccomandi, Paola; Schena, Emiliano; Duraibabu, Dinesh Babu; Poeggel, Sven; Leen, Gabriel; Lewis, Elfed

    2016-01-01

    We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies. PMID:27092504

  7. Fiber-optic gas pressure sensing with a laser-heated silicon-based Fabry-Perot interferometer.

    PubMed

    Liu, Guigen; Han, Ming

    2015-06-01

    We report a novel fiber-optic sensor for measurement of static gas pressure based on the natural convection of a heated silicon pillar attached to a fiber tip functioning as a Fabry-Perot interferometer (FPI). A visible laser beam is guided by the fiber to efficiently heat the silicon pillar, while an infrared whitelight source, also guided by the fiber, is used to measure the temperature of the FPI, which is influenced both by the laser power and the pressure through natural convection. We theoretically and experimentally show that, by monitoring the fringe shift caused by the laser heating, air pressure sensing with little temperature cross-sensitivity can be achieved. The pressure sensitivity can be easily tuned by adjusting the heating laser power. In our experiment, the sensor performance within the temperature range from 20°C to 50°C and the pressure range from 0 to 1400 psi has been characterized, showing an average sensitivity of -0.52  pm/psi. Compared to the passive version of the sensor, the pressure sensitivity was ∼15 times larger, and the temperature cross-sensitivity was ∼100 times smaller. PMID:26030532

  8. Investigation of miniature fiber optic surface-mountable Fabry-Perot pressure sensor built on 45° angled fiber

    NASA Astrophysics Data System (ADS)

    Bae, H.; Yu, M.

    2011-04-01

    We present a surface-mountable miniature Fabry-Perot (FP) pressure sensor that exploits the total internal reflection at a polished 45° angled fiber end face to swerve the optical axis by 90°. Optical analysis of the sensor system is performed based in ABCD method in terms of intensity of the beams reflected from each mirror and visibility of the sensor compared to conventional sensor system. One unique feature of the surface-mountable sensor is its embeddability with minimum intrusiveness to the system. By using the fiber as a waveguide, as well as an inherent mask for photolithography, a self-aligned FP cavity is constructed. A polymer-metal composite diaphragm is employed as a deflection diaphragm for pressure sensing which enables achieving higher sensitivity and low-cost fabrication over silicon diaphragm. The sensor exhibits a good linearity over the designed pressure range. Fiber Bragg grating is embedded in the vicinity of the pressure sensor to solve the problem of cross sensitivity between pressure and temperature by measuring the temperature of the system and compensating the temperature effect. This sensor is expected to impact many fronts where temperature effect should be considered to perform reliable and accurate pressure measurement with minimum intrusiveness.

  9. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement.

    PubMed

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S

    2013-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0-10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

  10. Resolution and sensitivity enhancements in strong grating based fiber Fabry-Perot interferometric sensor system utilizing multiple reflection beams

    NASA Astrophysics Data System (ADS)

    Niu, Siliang; Liao, Yi; Yao, Qiong; Hu, Yongming

    2012-06-01

    We investigate an asymmetric intensive fiber Bragg grating (FBG) defined Fabry-Perot (F-P) sensor system decoded by a multiple-path-matched Michelson interferometer. The interrogation of higher order reflection beams cannot only solve the problem of the degraded resolution induced by the spectral mismatch of the FBGs, but also amplify the effect of the fiber strain on the phase of the light. We demonstrate multiple reflection beams in the F-P cavity based on the concept of the FBG effective length for constructing respective interrogation interferometers, and present a cost function with optimized system parameters to improve noise properties. The performances of interrogating the second, third and fourth order reflection beams are compared in a strain sensing experiment arrangement. Under the condition of the same optical path length mismatch, the interrogation of the fourth order reflection beam can achieve 9.8 dB sensitivity enhancement and 3 dB resolution promotion compared with the result using the second order reflection beam.

  11. Trace Tropospheric Species Sensing-Fabry-Perot Interferometer (TTSS-FPI): spaceborne sensor concept studies for measuring tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Puschell, Jeffery J.; Hastings, C. T.; Chrien, Thomas; Larar, Allen M.; Cook, William B.; Mills, Carl S.; Flood, Michael A.; Skinner, Wilbert R.

    2005-01-01

    We present results of studies of instrument concepts for a spaceborne imaging Fabry-Perot interferometer to measure tropospheric ozone. Ozone is recognized as one of the most important trace constituents of the troposphere. Tropospheric ozone is responsible for acute and chronic human health problems and contributes toward destruction of plant and animal populations. Furthermore, it is a greenhouse gas and contributes toward radiative forcing and climate change. Tropospheric ozone levels have been increasing and will continue to do so as concentrations of precursor gases (oxides of nitrogen, methane, and other hydrocarbons) necessary for the photochemical formation of tropospheric ozone continue to rise. Space-based detection and monitoring of tropospheric ozone is critical for enhancing scientific understanding of creation and transport of this important trace gas and for providing data needed to help develop strategies for mitigating impacts of exposure to elevated concentrations of tropospheric ozone. Measurement concept details are discussed in a companion paper by Larar et al. Development of an airborne prototype instrument for this application is discussed by Cook et al. in another companion paper.

  12. Diffraction-limited Fabry-Perot cavity in the near concentric regime

    NASA Astrophysics Data System (ADS)

    Durak, K.; Nguyen, C. H.; Leong, V.; Straupe, S.; Kurtsiefer, C.

    2014-10-01

    Nearly concentric optical cavities can be used to prepare optical fields with a very small mode volume. We implement an anaclastic design of such a cavity that significantly simplifies mode matching to the fundamental cavity mode. The cavity is shown to have diffraction-limited performance for a mode volume of ≈ {{10}4}{{λ }3}. This is in sharp contrast with the behavior of cavities with plano-concave mirrors, where aberrations significantly decrease the coupling of the input mode to the fundamental mode of the cavity and increase the coupling to the higher-order modes. We estimate the related cavity quantum electrodynamics parameters and show that the proposed cavity design allows for strong coupling without a need for high finesse or small physical-cavity volume.

  13. Stratospheric temperature measurement with scanning Fabry-Perot interferometer for wind retrieval from mobile Rayleigh Doppler lidar.

    PubMed

    Xia, Haiyun; Dou, Xiankang; Shangguan, Mingjia; Zhao, Ruocan; Sun, Dongsong; Wang, Chong; Qiu, Jiawei; Shu, Zhifeng; Xue, Xianghui; Han, Yuli; Han, Yan

    2014-09-01

    Temperature detection remains challenging in the low stratosphere, where the Rayleigh integration lidar is perturbed by aerosol contamination and ozone absorption while the rotational Raman lidar is suffered from its low scattering cross section. To correct the impacts of temperature on the Rayleigh Doppler lidar, a high spectral resolution lidar (HSRL) based on cavity scanning Fabry-Perot Interferometer (FPI) is developed. By considering the effect of the laser spectral width, Doppler broadening of the molecular backscatter, divergence of the light beam and mirror defects of the FPI, a well-behaved transmission function is proved to show the principle of HSRL in detail. Analysis of the statistical error of the HSRL is carried out in the data processing. A temperature lidar using both HSRL and Rayleigh integration techniques is incorporated into the Rayleigh Doppler wind lidar. Simultaneous wind and temperature detection is carried out based on the combined system at Delhi (37.371°N, 97.374°E; 2850 m above the sea level) in Qinghai province, China. Lower Stratosphere temperature has been measured using HSRL between 18 and 50 km with temporal resolution of 2000 seconds. The statistical error of the derived temperatures is between 0.2 and 9.2 K. The temperature profile retrieved from the HSRL and wind profile from the Rayleigh Doppler lidar show good agreement with the radiosonde data. Specifically, the max temperature deviation between the HSRL and radiosonde is 4.7 K from 18 km to 36 km, and it is 2.7 K between the HSRL and Rayleigh integration lidar from 27 km to 34 km. PMID:25321553

  14. Observations of storm time midlatitude ion-neutral coupling using SuperDARN radars and NATION Fabry-Perot interferometers

    NASA Astrophysics Data System (ADS)

    Joshi, P. P.; H. Baker, J. B.; Ruohoniemi, J. M.; Makela, J. J.; Fisher, D. J.; Harding, B. J.; Frissell, N. A.; Thomas, E. G.

    2015-10-01

    Ion drag is known to play an important role in driving neutral thermosphere circulation at auroral latitudes, especially during the main phase of geomagnetic storms. During the recovery phase, the neutrals are known to drive the ions and generate ionospheric electric fields and currents via the disturbance dynamo mechanism. At midlatitudes, the precise interplay between ions and neutrals is less understood largely because of the paucity of measurements that have been available. In this work, we investigate ion-neutral coupling at middle latitudes using colocated ion drift velocity measurements obtained from Super Dual Auroral Radar Network radars and neutral wind velocity and temperature measurements obtained from the North American Thermosphere Ionosphere Observing Network (NATION) Fabry-Perot interferometers. We examine one recent storm period on 2-3 October 2013 during both the main phase and late recovery phase. By using ion-neutral momentum exchange theory and a time-lagged correlation analysis, we analyze the coupling time scales and dominant driving mechanisms. We observe that during the main phase the neutrals respond to the ion convection on a time scale of ˜84 min which is significantly faster than what would be expected from local ion drag momentum forcing alone. This suggests that other storm time influences are important for driving the neutrals during the main phase, such as Joule heating. During the late recovery phase, the neutrals are observed to drive the ion convection without any significant time delay, consistent with the so-called "neutral fly wheel effect" or disturbance dynamo persisting well into the late recovery phase.

  15. Stratospheric temperature measurement with scanning Fabry-Perot interferometer for wind retrieval from mobile Rayleigh Doppler lidar.

    PubMed

    Xia, Haiyun; Dou, Xiankang; Shangguan, Mingjia; Zhao, Ruocan; Sun, Dongsong; Wang, Chong; Qiu, Jiawei; Shu, Zhifeng; Xue, Xianghui; Han, Yuli; Han, Yan

    2014-09-01

    Temperature detection remains challenging in the low stratosphere, where the Rayleigh integration lidar is perturbed by aerosol contamination and ozone absorption while the rotational Raman lidar is suffered from its low scattering cross section. To correct the impacts of temperature on the Rayleigh Doppler lidar, a high spectral resolution lidar (HSRL) based on cavity scanning Fabry-Perot Interferometer (FPI) is developed. By considering the effect of the laser spectral width, Doppler broadening of the molecular backscatter, divergence of the light beam and mirror defects of the FPI, a well-behaved transmission function is proved to show the principle of HSRL in detail. Analysis of the statistical error of the HSRL is carried out in the data processing. A temperature lidar using both HSRL and Rayleigh integration techniques is incorporated into the Rayleigh Doppler wind lidar. Simultaneous wind and temperature detection is carried out based on the combined system at Delhi (37.371°N, 97.374°E; 2850 m above the sea level) in Qinghai province, China. Lower Stratosphere temperature has been measured using HSRL between 18 and 50 km with temporal resolution of 2000 seconds. The statistical error of the derived temperatures is between 0.2 and 9.2 K. The temperature profile retrieved from the HSRL and wind profile from the Rayleigh Doppler lidar show good agreement with the radiosonde data. Specifically, the max temperature deviation between the HSRL and radiosonde is 4.7 K from 18 km to 36 km, and it is 2.7 K between the HSRL and Rayleigh integration lidar from 27 km to 34 km.

  16. Feasibility of global tropospheric and total ozone monitoring using a double-etalon Fabry-Perot interferometer

    SciTech Connect

    Larar, A.M.; Drayson, S.R.

    1994-12-31

    Monitoring of the global distribution of tropospheric ozone (O{sub 3}) is desirable for enhanced scientific understanding as well as to potentially lessen the ill-health impacts associated with exposure to elevated concentrations in the lower atmosphere. Such a capability can be achieved using a satellite-based device making high spectral resolution measurements with high signal-to-noise ratios; this would enable observation in the pressure-broadened wings of strong O{sub 3} lines while minimizing the impact of undesirable signal contributions (i.e., from the terrestrial surface and interfering species). The Fabry-Perot interferometer (FPI) provides high spectral resolution and high throughput capabilities that are essential for this measurement task. Through proper selection of channel spectral regions, the FPI optimized for tropospheric O{sub 3} measurements can simultaneously observe a stratospheric component and thus the total O{sub 3} column abundance. A conceptual instrument design to achieve the desired measurement will be presented. It involves a double-etalon fixed-gap series configuration FPI along with an ultra-narrow bandpass filter to achieve single-order operation with an overall spectral resolution of approximately .068 cm{sup {minus}1}, sampling a narrow spectral region within the strong 9.6 {micro}m ozone infrared band from a nadir-viewing satellite configuration. A retrieval technique has been implemented and is demonstrated for a tropical atmosphere possessing enhanced tropospheric ozone amounts. An error analysis assessing the impact on retrieved O{sub 3} amounts of the most significant uncertainties associated with this particular measurement has been performed for several different types of atmospheres. Results show the proposed instrumentation to enable a good measurement of absolute ozone amounts and an even better determination of relative changes.

  17. Extrinsic Fabry-Perot interferometry for noncontact temperature control of nanoliter-volume enzymatic reactions in glass microchips.

    PubMed

    Easley, Christopher J; Legendre, Lindsay A; Roper, Michael G; Wavering, Thomas A; Ferrance, Jerome P; Landers, James P

    2005-02-15

    Optical fiber extrinsic Fabry-Perot interferometry (EFPI) was investigated as a noncontact temperature sensor and utilized for regulating the temperature of small-volume solutions in microchips. Interference pattern analysis determined the optical path lengths (OPL) associated with reflections from various surfaces on or in the microchip, in particular, from gold sputtered on the bottom of a microchannel. Since OPL is directly proportional to refractive index, which is dependent on solution temperature, the EFPI sensor was capable of noncontact monitoring of solution temperature simply from alterations in the measured path length. Calibration of the sensor against a thermocouple was performed while heating the microchip in a noncontact manner with an IR lamp. The combination of EFPI temperature sensor, IR-mediated heating, and air cooling allowed a fully noncontact system for small-volume temperature control in microchip structures, and its utility was illustrated by optimal digestion of DNA by a temperature-dependent restriction endonuclease in 320 nL. The functionality and simplicity of the microchip EFPI temperature sensor was enhanced by replacing the prebonding sputtered gold with a tunable, chemically plated semireflective silver coating created in situ after chip fabrication. This provided an 8-fold improvement in the lowest detectable temperature change (deltaT = 0.1 degrees C), facilitated primarily by enhanced reflection from both the bottom and top surfaces of the microchannel. This approach for controlling micro- and nanoscale reactions--with heating, cooling, and temperature control being carried out in a completely noncontact fashion--provides an accurate and sensitive method for executing chemical and biochemical reactions in microchips. PMID:15858983

  18. Long distance high performance remote strain sensing with a fiber Fabry-Perot by radio-frequency laser modulation

    NASA Astrophysics Data System (ADS)

    Chow, Jong H.; Littler, Ian C. M.; McClelland, David E.; Gray, Malcolm B.

    2006-05-01

    We use a radio-frequency (RF) diode laser modulation technique to interrogate a fiber Fabry-Perot (FFP), and demonstrate unprecedented remote sensitivity performance for measuring fiber dynamic strain. We present results for its experimental demonstration in a 5 km remote strain sensing system, where we have attained sub-picostrain/√Hz resolution in an acoustic signal band from 100 Hz to 100 kHz, with better than 300 femtostrain/√Hz sensitivity above 300 Hz. This is unprecedented in sensitivity and broadband performance, unparalleled over such a long interrogation distance. Strain signals are extracted interferometrically from the differential phase between the carrier and its RF sidebands. This elegant architecture is immune to intensity noise in the laser, as well as ambient acoustic and mechanical perturbations in the remote delivery fiber. The excellent frequency discrimination by the FFP also facilitates a superior signal-to-noise ratio, to effectively overcome the random phase noise due to Rayleigh backscatter in the long length of fiber. Furthermore, the interrogation length can be well beyond the coherence length of the laser source. We show that this performance is limited only by the frequency noise of the diode laser source, as all systemic noise sources in the delivery fiber are effectively transparent to the sensing architecture. This remote sensitivity is a seminal demonstration for a range of applications, such as sea floor acoustic sensing arrays, deep sea hydrophone arrays, and remote surveillance. We will discuss upscaling of this single element experiment to multi-element sensing arrays.

  19. Experimental Evaluation of White Light Fabry-Perot Interferometry Fiber-Optic Strain Gages when Measuring Small Strains

    NASA Technical Reports Server (NTRS)

    St.Cyr, William; Figueroa, Fernando; VanDyke, David; McVay, Greg; Mitchell, Mark

    2002-01-01

    An experimental study was conducted to evaluate whether fiber optic strain gages (FOSG) are "better" sensors than typical foil gages. A particularly attractive feature of FOSG was their specified resolution of 0.01% of full-scale (0.1 micro strain for 1000 micro strain full-scale). This feature would make FOSG practical tank level sensors, by measuring very small strains on the support structure of a tank. A specific application in mind was to measure liquid oxygen tank level, with support beams that were predicted to contract approximately 11 micro strain as the tank goes from empty to full. Among various fiber optic technologies currently available, Fabry-Perot Interferometry using white light was selected. This technology exhibits highly desirable feature such as absolute strain measurement, linearity over its full-scale, and temperature compensation. However, experiment results suggest that the resolution is 0.8 micro strain, at best, calibration from one sensor to another can be off by 2.4 - 11.2%, and that temperature compensation is not fully predictable, with errors of up to 3.5 micro strain over an 11C range. Hence, when compared with classic foil gages, FOSG possess less accuracy, similar resolution and repeatability (precision), and superior linearity over their entire operating range. They are immune to EMI and their signals suffer minimal degradation over long distances. It is also expected that drift with time will be minimal in FOSG whereas the gage factor of foil sensors changes over time when exposed to varying environmental conditions. In conclusion, FOSG are "better" than foil gages as long as the application allows calibration of individual units as installed for operation.

  20. Fabry-Perot Laser Ultrasonic Elastic Anisotropy Measurements on a Moving Paper Web

    SciTech Connect

    Walter, John Bradley; Telschow, Kenneth Louis; Gerhardstein, J. P.; Pufahl, B. M.; Habeger, C. C; Lafond, E. M.; Brodeur, P. H.

    1999-07-01

    On-line measurement of material properties is a goal of many manufacturers to improve production and quality. The elastic stiffness of paper is important for the paper industry. Currently, the elastic constants of paper are measured offline with contact ultrasonic methods [1-4]. Piezoelectric transducers are placed in contact with the paper surface to generate and detect plate wave modes, known as Lamb wave modes [5-7]. At low frequencies, where the wavelength of the elastic wave is larger than the paper thickness, two wave modes dominate in the paper, an anti-symmetric or flexural mode and a symmetric or thickness mode. Measurements of the phase velocities of these modes along both the machine direction (MD) and the perpendicular cross direction (CD) of the paper web provide an important parameter revealing the increased stiffness in the paper along the MD direction.

  1. Comparison between method of lines and time domain method in evaluating the large signal responses of Fabry-Perot semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Braverman, Ada L.

    1998-07-01

    An extensive comparison between two modeling methods: Method of Lines and Time Domain Method in analyzing the large signal responses of Fabry-Perot semiconductor lasers is presented. The methods are implemented in two numerical codes written in FORTRAN and using DIGITAL ALPHA workstations under VAX/VMS and UNIX operating systems. The comparison shows good agreement between the simulation results under specific conditions. A special accent is placed on the advantages and drawbacks of both methods by taking into account their numerical problems and the computational effort implied by simulations.

  2. Random Fabry-Perot resonator-based sub-kHz Brillouin fiber laser to improve spectral resolution in linewidth measurement.

    PubMed

    Xu, Yanping; Xiang, Dao; Ou, Zhonghua; Lu, Ping; Bao, Xiaoyi

    2015-05-01

    For the first time, we propose a novel Brillouin random fiber laser with a narrow linewidth of ∼860  Hz based on the bi-directionally pumped stimulated Brillouin scattering (SBS) in a 10-km-long optical fiber. A random fiber Fabry-Perot (FP) resonator is built up through the pump depletion effects of SBS at both ends of the fiber. A theoretical model is developed to reveal the physics behind the unique random FP resonator that enables narrow random lasing emission. The novel laser is successfully applied for linewidth characterization beyond 860 Hz of light source under test. PMID:25927748

  3. Active Q-switching of a fiber laser using a modulated fiber Fabry-Perot filter and a fiber Bragg grating

    NASA Astrophysics Data System (ADS)

    Martínez Manuel, Rodolfo; Kaboko, J. J. M.; Shlyagin, M. G.

    2016-02-01

    We propose and demonstrate a simple and robust actively Q-switched erbium-doped fiber ring cavity laser. The Q-switching is based on dynamic spectral overlapping of two filters, namely a fiber Bragg grating-based filter and a fiber Fabry-Perot tunable filter. Using 3.5 m of erbium-doped fiber and a pump power of only 60 mW, Q-switched pulses with a peak power of 9.7 W and a pulse duration of 500 ns were obtained. A pulse repetition rate can be continuously varied from a single shot to a few KHz.

  4. Combination of highly nonlinear fiber, an optical bandpass filter, and a Fabry-Perot filter to improve the signal-to-noise ratio of a supercontinuum continuous-wave optical source.

    PubMed

    Nan, Yinbo; Huo, Li; Lou, Caiyun

    2005-05-20

    We present a theoretical study of a supercontinuum (SC) continuous-wave (cw) optical source generation in highly nonlinear fiber and its noise properties through numerical simulations based on the nonlinear Schrödinger equation. Fluctuations of pump pulses generate substructures between the longitudinal modes that result in the generation of white noise and then in degradation of coherence and in a decrease of the modulation depths and the signal-to-noise ratio (SNR). A scheme for improvement of the SNR of a multiwavelength cw optical source based on a SC by use of the combination of a highly nonlinear fiber (HNLF), an optical bandpass filter, and a Fabry-Perot (FP) filter is presented. Numerical simulations show that the improvement in modulation depth is relative to the HNLF's length, the 3-dB bandwidth of the optical bandpass filter, and the reflection ratio of the FP filter and that the average improvement in modulation depth is 13.7 dB under specified conditions. PMID:15929296

  5. Combination of highly nonlinear fiber, an optical bandpass filter, and a Fabry-Perot filter to improve the signal-to-noise ratio of a supercontinuum continuous-wave optical source

    NASA Astrophysics Data System (ADS)

    Nan, Yinbo; Huo, Li; Lou, Caiyun

    2005-05-01

    We present a theoretical study of a supercontinuum (SC) continuous-wave (cw) optical source generation in highly nonlinear fiber and its noise properties through numerical simulations based on the nonlinear Schrödinger equation. Fluctuations of pump pulses generate substructures between the longitudinal modes that result in the generation of white noise and then in degradation of coherence and in a decrease of the modulation depths and the signal-to-noise ratio (SNR). A scheme for improvement of the SNR of a multiwavelength cw optical source based on a SC by use of the combination of a highly nonlinear fiber (HNLF), an optical bandpass filter, and a Fabry-Perot (FP) filter is presented. Numerical simulations show that the improvement in modulation depth is relative to the HNLF's length, the 3-dB bandwidth of the optical bandpass filter, and the reflection ratio of the FP filter and that the average improvement in modulation depth is 13.7 dB under specified conditions.

  6. Measurement of radiation-pressure-induced optomechanical dynamics in a suspended Fabry-Perot cavity

    SciTech Connect

    Corbitt, Thomas; Ottaway, David; Innerhofer, Edith; Pelc, Jason; Mavalvala, Nergis

    2006-08-15

    We report on experimental observation of radiation-pressure induced effects in a high-power optical cavity. These effects play an important role in next-generation gravitational wave detectors, as well as in quantum nondemolition interferometers. We measure the properties of an optical spring, created by coupling of an intense laser field to the pendulum mode of a suspended mirror, and also the parametric instability (PI) that arises from the coupling between acoustic modes of the cavity mirrors and the cavity optical mode. We measure an unprecedented optical rigidity of K=(3.08{+-}0.09)x10{sup 4} N/m, corresponding to an optical rigidity that is 6000 times stiffer than the mechanical stiffness, and PI strength R{approx_equal}3. We measure the unstable nature of the optical spring resonance, and demonstrate that the PI can be stabilized by feedback to the frequency of the laser source.

  7. Self-induced light trapping in nonlinear Fabry-Perot resonators

    NASA Astrophysics Data System (ADS)

    Pichugin, K. N.; Sadreev, A. F.

    2016-10-01

    In the framework of the coupled mode theory we consider light trapping between two off-channel resonators which serve as self-adjusted Fano mirrors due to the Kerr effect. By inserting an auxiliary nonlinear resonator between the mirrors we achieve self-tuning of phase shift between the mirrors. That allows for the light trapping for arbitrary distance between the mirrors.

  8. A simple technique for accurate and complete characterisation of a Fabry-Perot cavity.

    PubMed

    Locke, C R; Stuart, D; Ivanov, E N; Luiten, A N

    2009-11-23

    It has become a significant challenge to accurately characterise the properties of recently developed very high finesse optical resonators (F > 10(6)). A similar challenge is encountered when trying to measure the properties of cavities in which either the probing laser or the cavity length is intrinsically unstable. We demonstrate in this article the means by which the finesse, mode-matching, free spectral range, mirror transmissions and dispersion may be measured easily and accurately even when the laser or cavity has a relatively poor intrinsic frequency stability. PMID:19997438

  9. MWIR/LWIR filter based on Liquid-Crystal Fabry-Perot structure for tunable spectral imaging detection

    NASA Astrophysics Data System (ADS)

    Zhang, Huaidong; Muhammad, Afzal; Luo, Jun; Tong, Qing; Lei, Yu; Zhang, Xinyu; Sang, Hongshi; Xie, Changsheng

    2015-03-01

    An electrically tunable medium-wave infrared (MWIR)/long-wave infrared (LWIR) filter based on the key structure of Liquid-Crystal (LC) Fabry-Perot (FP), which works in the wavelength range from 2.5 μm to 12 μm, is designed and fabricated successfully in this paper. According to the optical interference principle of the FP cavity and electrically controlled birefringence of nematic LC molecules, the particular functions including spectral selection and spectral staring and spectral adjustment, can be realized by the developed MWIR/LWIR filter driven and controlled electrically. As to the LC-FP filter, both planar reflective mirrors are shaped by depositing a layer of aluminum (Al) film (∼60 nm) over one side of double-side polished Zinc Selenide (ZnSe) wafer (∼1 mm), and then polyimide (PI) layer with the thickness of ∼100 nm is coated directly on Al film. With typical sandwich architecture, the depth of the cavity with nematic LC molecules sealed in is ∼7.5 μm. To make sure the LC molecules parallel aligned and twist regularly under voltage driving signal applied on Al film, which also acts as electrode, the V-grooves are formed in PI layer with the depth of ∼90 nm and the width of ∼350 nm at average by strong rubbing. The typical transmission spectrum in MWIR&LWIR wavelength range and several spectral images in MWIR wavelength range based on the fabricated LC-FP filter, have been obtained through applying a voltage driving-signal with different root-means-square (RMS) value over the electrodes of LC-FP filter in the selected voltage range from 0VRMS to 19.8VRMS. The testing result demonstrates a prospect of realization smart spectral imaging and further integrating the LC-FP filter with infrared focal plane arrays (FPAs) to achieve the purpose infrared multispectral imaging. The developed MWIR&LWIR LC-FP filters show some obvious advantages such as wide working wavelength range, electrically tunable spectral selection, ultra-compact, low cost, being

  10. Electrically tunable infrared filter based on the liquid crystal Fabry-Perot structure for spectral imaging detection.

    PubMed

    Zhang, Huaidong; Muhammmad, Afzal; Luo, Jun; Tong, Qing; Lei, Yu; Zhang, Xinyu; Sang, Hongshi; Xie, Changsheng

    2014-09-01

    An electrically tunable infrared (IR) filter based on the liquid crystal (LC) Fabry-Perot (FP) key structure, which works in the wavelength range from 5.5 to 12 μm, is designed and fabricated successfully. Both planar reflective mirrors with a very high reflectivity of ∼95%, which are shaped by depositing a layer of aluminum (Al) film over one side of a double-sided polished zinc selenide wafer, are coupled into a dual-mirror FP cavity. The LC materials are filled into the FP cavity with a thickness of ∼7.5  μm for constructing the LC-FP filter, which is a typical type of sandwich architecture. The top and bottom mirrors of the FP cavity are further coated by an alignment layer with a thickness of ∼100  nm over Al film. The formed alignment layer is rubbed strongly to shape relatively deep V-grooves to anchor LC molecules effectively. Common optical tests show some particular properties; for instance, the existing three transmission peaks in the measured wavelength range, the minimum full width at half-maximum being ∼120  nm, and the maximum adjustment extent of the imaging wavelength being ∼500  nm through applying the voltage driving signal with a root mean square (RMS) value ranging from 0 to ∼19.8  V. The experiment results are consistent with the simulation, according to our model setup. The spectral images obtained in the long-wavelength IR range, through the LC-FP device driven by the voltage signal with a different RMS value, demonstrates the prospect of the realization of smart spectral imaging and further integrating the LC-FP filter with IR focal plane arrays. The developed LC-FP filters show some advantages, such as electrically tunable imaging wavelength, very high structural and photoelectronic response stability, small size and low power consumption, and a very high filling factor of more than 95% compared with common MEMS-FP spectral imaging approaches. PMID:25321356

  11. Thermospheric winds and temperatures above Mawson, Antarctica, observed with an all-sky imaging, Fabry-Perot spectrometer

    NASA Astrophysics Data System (ADS)

    Anderson, C.; Conde, M.; Dyson, P.; Davies, T.; Kosch, M. J.

    2009-05-01

    A new all-sky imaging Fabry-Perot spectrometer has been installed at Mawson station (67°36' S, 62°52' E), Antarctica. This instrument is capable of recording independent spectra from many tens of locations across the sky simultaneously. Useful operation began in March 2007, with spectra recorded on a total of 186 nights. Initial analysis has focused on the large-scale daily and average behavior of winds and temperatures derived from observations of the 630.0 nm airglow line of atomic oxygen, originating from a broad layer centered around 240 km altitude, in the ionospheric F-region. The 1993 Horizontal Wind Model (HWM93), NRLMSISE-00 atmospheric model, and the Coupled Thermosphere/Ionosphere Plasmasphere (CTIP) model were used for comparison. During the geomagnetically quiet period studied, observed winds and temperatures were generally well modelled, although temperatures were consistently higher than NRLMSISE-00 predicted, by up to 100 K. CTIP temperatures better matched our data, particularly later in the night, but predicted zonal winds which were offset from those observed by 70-180 ms-1 westward. During periods of increased activity both winds and temperatures showed much greater variability over time-scales of less than an hour. For the active night presented here, a period of 45 min saw wind speeds decrease by around 180 ms-1, and temperatures increase by approximately 100 K. Active-period winds were poorly modelled by HWM93 and CTIP, although observed median temperatures were in better agreement with NRLMSISE-00 during such periods. Average behavior was found to be generally consistent with previous studies of thermospheric winds above Mawson. The collected data set was representative of quiet geomagnetic and solar conditions. Geographic eastward winds in the afternoon/evening generally continued until around local midnight, when winds turned equatorward. Geographic meridional and zonal winds in the afternoon were approximately 50 ms-1 weaker than

  12. Submillimeter spectroscopy of the Carina Nebula: Observations, operations and upgrades of the South Pole Imaging Fabry-Perot Interferometer

    NASA Astrophysics Data System (ADS)

    Oberst, Thomas Edward

    2009-06-01

    We present the results of a ~ 250 arcmin 2 mapping of the 205 μm [NII] fine- structure line emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Telescope and Remote Observatory (AST/RO) at South Pole. New upgrades and modifications to the SPIFI instrument are discussed, and full details of SPIFI-AST/RO integration and calibration are provided. At the time of these observations, SPIFI had a spectral resolving power of ~ 4250, a FWHM beam size of ~ 54'', and a noise equivalent power (NEP) referred to the front end of the receiver of ~ 2.5 × 10 -15 W Hz -1/2 (~ 1.4 times the background limit). These data constitute the first ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the Cosmic Background Explorer (COBE) Far Infrared Absolute Spectrophotometer (FIRAS) and the Kuiper Airborne Observatory (KAO) in the early 1990s. We supplement the 205 μm data with new reductions of far-infrared fine- structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 m [NII], 146 μm [OI], and 158 μm [CII]; the 146 μm [OI] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum and CO maps. The 122/205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158/205 [CII]/[NII] line ratio is used to probe the fraction of C + arising from photodissociation regions (PDRs). The [OI] and [CII] lines are used to construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49. This is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept

  13. Active cancellation of residual amplitude modulation in a frequency-modulation based Fabry-Perot interferometer.

    PubMed

    Yu, Yinan; Wang, Yicheng; Pratt, Jon R

    2016-03-01

    Residual amplitude modulation (RAM) is one of the most common noise sources known to degrade the sensitivity of frequency modulation spectroscopy. RAM can arise as a result of the temperature dependent birefringence of the modulator crystal, which causes the orientation of the crystal's optical axis to shift with respect to the polarization of the incident light with temperature. In the fiber-based optical interferometer used on the National Institute of Standards and Technology calculable capacitor, RAM degrades the measured laser frequency stability and correlates with the environmental temperature fluctuations. We have demonstrated a simple approach that cancels out excessive RAM due to polarization mismatch between the light and the optical axis of the crystal. The approach allows us to measure the frequency noise of a heterodyne beat between two lasers individually locked to different resonant modes of a cavity with an accuracy better than 0.5 ppm, which meets the requirement to further determine the longitudinal mode number of the cavity length. Also, this approach has substantially mitigated the temperature dependency of the measurements of the cavity length and consequently the capacitance. PMID:27036752

  14. Active cancellation of residual amplitude modulation in a frequency-modulation based Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Yu, Yinan; Wang, Yicheng; Pratt, Jon R.

    2016-03-01

    Residual amplitude modulation (RAM) is one of the most common noise sources known to degrade the sensitivity of frequency modulation spectroscopy. RAM can arise as a result of the temperature dependent birefringence of the modulator crystal, which causes the orientation of the crystal's optical axis to shift with respect to the polarization of the incident light with temperature. In the fiber-based optical interferometer used on the National Institute of Standards and Technology calculable capacitor, RAM degrades the measured laser frequency stability and correlates with the environmental temperature fluctuations. We have demonstrated a simple approach that cancels out excessive RAM due to polarization mismatch between the light and the optical axis of the crystal. The approach allows us to measure the frequency noise of a heterodyne beat between two lasers individually locked to different resonant modes of a cavity with an accuracy better than 0.5 ppm, which meets the requirement to further determine the longitudinal mode number of the cavity length. Also, this approach has substantially mitigated the temperature dependency of the measurements of the cavity length and consequently the capacitance.

  15. Cognitive fiber Bragg grating sensors system based on fiber Fabry-Perot tunable filter technology

    NASA Astrophysics Data System (ADS)

    Zhang, Hongtao; Wang, Pengfei; Zou, Jilin; Xie, Jing; Cui, Hong-Liang

    2011-05-01

    The wavelength demodulation based on a Fiber Fabry-Pérot Tunable Filter (FFP-TF) is a common method for multiplexing Fiber Bragg Grating (FBG) sensors. But this method cannot be used to detect high frequency signals due to the limitation by the highest scanning rate that the FFP-TF can achieve. To overcome this disadvantage, in this paper we present a scheme of cognitive sensors network based on FFP-TF technology. By perceiving the sensing environment, system can automatically switch into monitoring signals in two modes to obtain better measurement results: multi measurement points, low frequency (<1 KHz) signal, and few measurement points but high frequency (~50 KHz) signals. This cognitive sensors network can be realized in current technology and satisfy current most industrial requirements.

  16. Smooth, low-damage, definition of InGaAlAs asymmetric Fabry-Perot optical transmission modulators by Cl{sub 2}+Ar reactive-ion-beam etching

    SciTech Connect

    Vawter, G.A.; Fritz, I.J.; Drummond, T.J.; Lee, S.R.; Hafich, M.J.; Howard, A.J.; Briggs, R.D.; Casalnuovo, S.A.; Griego, L.

    1996-02-01

    Chlorine-argon-based reactive-ion-beam etching was used successfully to etch novel InGaAlAs (1.32 {mu}m-wavelength Fabry-Perot resonator transmission) modulators. Resulting etch is very smooth, anisotropic, and has low etch-induced (sidewall) damage. Use of this simple chemistry eliminates difficulties with polymer formation encountered in hydrocarbon-based etches.

  17. Hydrogen-doping stabilized metallic VO{sub 2} (R) thin films and their application to suppress Fabry-Perot resonances in the terahertz regime

    SciTech Connect

    Zhao, Yong; Pan, Xuan; Bernussi, Ayrton A.; Fan, Zhaoyang; Karaoglan-Bebek, Gulten; Holtz, Mark

    2014-06-16

    We demonstrate that catalyst-assisted hydrogen spillover doping of VO{sub 2} thin films significantly alters the metal-insulator transition characteristics and stabilizes the metallic rutile phase at room temperature. With hydrogen inserted into the VO{sub 2} lattice, high resolution X-ray diffraction reveals expansion of the V-V chain separation when compared to the VO{sub 2}(R) phase. The donated free electrons, possibly from O-H bond formation, stabilize the VO{sub 2}(R) to low temperatures. By controlling the amount of dopants to obtain mixed insulating and metallic phases, VO{sub 2} resistivity can be continuously tuned until a critical condition is achieved that suppresses Fabry-Perot resonances. Our results demonstrate that hydrogen spillover is an effective technique to tune the electrical and optical properties of VO{sub 2} thin films.

  18. MEMS Fabry-Perot interferometer-based spectrometer demonstrator for 7.5 μm to 9.5 μm wavelength range

    NASA Astrophysics Data System (ADS)

    Mäkynen, Jussi H.; Tuohiniemi, Mikko; Näsilä, Antti; Mannila, Rami; Antila, Jarkko E.

    2014-03-01

    VTT Technical research centre of Finland has developed a MEMS Fabry-Perot interferometer (FPI) for the wavelength range from 7.5 μm to 9.5 μm. The device consists of two Distributed Bragg Reflectors (DBR) manufactured with MEMS processing techniques. The full width half maximum of the transmission peak is 150nm. This transmission peak can be tuned from 7.5 μm to 9.5 μm by applying a control voltage from 0 V to 30 V. A laboratory demonstrator has been put together to show the use of this module as a part of a spectral measurement setup. Several gas samples have been measured with the setup and compared against measurement results found in literature.

  19. Realistic loss estimation due to the mirror surfaces in a 10 meters-long high finesse Fabry-Perot filter-cavity.

    PubMed

    Straniero, Nicolas; Degallaix, Jérôme; Flaminio, Raffaele; Pinard, Laurent; Cagnoli, Gianpietro

    2015-08-10

    In order to benefit over the entire frequency range from the injection of squeezed vacuum light at the output of laser gravitational wave detectors, a small bandwidth high finesse cavity is required. In this paper, we investigate the light losses due to the flatness and the roughness of realistic mirrors in a 10 meters-long Fabry-Perot filter cavity. Using measurements of commercial super-polished mirrors, we were able to estimate the cavity round trip losses separating the loss contribution from low and high spatial frequencies. By careful tuning of the cavity g-factor and the incident position of the light on the mirrors, round trip losses due to imperfect mirror surfaces as low as 3 ppm can be achieved in the simulations. PMID:26367993

  20. Performance of a Distributed Simultaneous Strain and Temperature Sensor Based on a Fabry-Perot Laser Diode and a Dual-Stage FBG Optical Demultiplexer

    PubMed Central

    Kim, Suhwan; Kwon, Hyungwoo; Yang, Injae; Lee, Seungho; Kim, Jeehyun; Kang, Shinwon

    2013-01-01

    A simultaneous strain and temperature measurement method using a Fabry-Perot laser diode (FP-LD) and a dual-stage fiber Bragg grating (FBG) optical demultiplexer was applied to a distributed sensor system based on Brillouin optical time domain reflectometry (BOTDR). By using a Kalman filter, we improved the performance of the FP-LD based OTDR, and decreased the noise using the dual-stage FBG optical demultiplexer. Applying the two developed components to the BOTDR system and using a temperature compensating algorithm, we successfully demonstrated the simultaneous measurement of strain and temperature distributions under various experimental conditions. The observed errors in the temperature and strain measured using the developed sensing system were 0.6 °C and 50 με, and the spatial resolution was 1 m, respectively. PMID:24284773

  1. University of Michigan ground-based circle-to-line Fabry-Perot interferometer and its applications in mesosphere and lower thermosphere dynamics studies

    SciTech Connect

    Wang, J.; Wu, J.; Hays, P.B.

    1994-12-31

    An advanced Fabry-Perot interferometer with an innovative focal plane detection technique called the Circle-to-Line Interferometer Optical (CLIO) system and high quantum efficiency CCD has been developed and field tested. During the field test at Ann Arbor, Michigan, 9 interference orders were collected simultaneously for the OH(7,3) P{sub 1}(3). A signal-to-noise ratio (SNR) of 10-100 was achieved with 1-minute integration. Compared with conventional FPI, the CLIO-FPI is more sensitive and capable of collecting airglow data at much higher temporal resolution. The first operational CLIO-FPI will be deployed at the Polar Cap Observatory (PCO) at Resolute, Northwest Territories, Canada (74{degree}54{prime}N, 94{degree}54{prime}W), in 1994. This new instrument is expected to enhance the ability to study the Earth`s mesosphere and lower thermosphere.

  2. Simple locking of infrared and ultraviolet diode lasers to a visible laser using a LabVIEW proportional-integral-derivative controller on a Fabry-Perot signal

    NASA Astrophysics Data System (ADS)

    Kwolek, J. M.; Wells, J. E.; Goodman, D. S.; Smith, W. W.

    2016-05-01

    Simultaneous laser locking of infrared (IR) and ultraviolet lasers to a visible stabilized reference laser is demonstrated via a Fabry-Perot (FP) cavity. LabVIEW is used to analyze the input, and an internal proportional-integral-derivative algorithm converts the FP signal to an analog locking feedback signal. The locking program stabilized both lasers to a long term stability of better than 9 MHz, with a custom-built IR laser undergoing significant improvement in frequency stabilization. The results of this study demonstrate the viability of a simple, computer-controlled, non-temperature-stabilized FP locking scheme for our applications, laser cooling of Ca+ ions, and its use in other applications with similar modest frequency stabilization requirements.

  3. Subkilohertz linewidth reduction of a DFB diode laser using self-injection locking with a fiber Bragg grating Fabry-Perot cavity.

    PubMed

    Wei, Fang; Yang, Fei; Zhang, Xi; Xu, Dan; Ding, Meng; Zhang, Li; Chen, Dijun; Cai, Haiwen; Fang, Zujie; Xijia, Gu

    2016-07-25

    A simple and low-cost 1550 nm semiconductor laser with subkilohertz intrinsic linewidth is experimentally demonstrated. A commercial distributed feedback diode laser is self-injection locked to the resonance transmission peaks of a fiber Bragg grating Fabry-Perot cavity through a polarization-maintaining fiber ring with the optical path length of 4 m, with the laser frequency noise suppressed by over 70 dB in the Fourier frequency band from 5 Hz and 1 kHz. The laser features an intrinsic Lorentzian linewidth of 125 Hz as well as a relative intensity noise of <-142 dBc/Hz above 2 MHz, and provides over 0.8 nm quasi-continuous tunability, which is suitable for advanced applications requiring a narrow linewidth laser with ultralow frequency noise.

  4. Multi-physics simulation and fabrication of a compact 128 × 128 micro-electro-mechanical system Fabry-Perot cavity tunable filter array for infrared hyperspectral imager.

    PubMed

    Meng, Qinghua; Chen, Sihai; Lai, Jianjun; Huang, Ying; Sun, Zhenjun

    2015-08-01

    This paper demonstrates the design and fabrication of a 128×128 micro-electro-mechanical systems Fabry-Perot (F-P) cavity filter array, which can be applied for the hyperspectral imager. To obtain better mechanical performance of the filters, F-P cavity supporting structures are analyzed by multi-physics finite element modeling. The simulation results indicate that Z-arm is the key component of the structure. The F-P cavity array with Z-arm structures was also fabricated. The experimental results show excellent parallelism of the bridge deck, which agree with the simulation results. A conclusion is drawn that Z-arm supporting structures are important to hyperspectral imaging system, which can achieve a large tuning range and high fill factor compared to straight arm structures. The filter arrays have the potential to replace the traditional dispersive element.

  5. Simultaneous measurement of temperature and refractive index using focused ion beam milled Fabry-Perot cavities in optical fiber micro-tips.

    PubMed

    André, Ricardo M; Warren-Smith, Stephen C; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M I; Latifi, H; Marques, Manuel B; Bartelt, Hartmut; Frazão, Orlando

    2016-06-27

    Optical fiber micro-tips are promising devices for sensing applications in small volume and difficult to access locations, such as biological and biomedical settings. The tapered fiber tips are prepared by dynamic chemical etching, reducing the size from 125 μm to just a few μm. Focused ion beam milling is then used to create cavity structures on the tapered fiber tips. Two different Fabry-Perot micro-cavities have been prepared and characterized: a solid silica cavity created by milling two thin slots and a gap cavity. A third multi-cavity structure is fabricated by combining the concepts of solid silica cavity and gap cavity. This micro-tip structure is analyzed using a fast Fourier transform method to demultiplex the signals of each cavity. Simultaneous measurement of temperature and external refractive index is then demonstrated, presenting sensitivities of - 15.8 pm/K and -1316 nm/RIU, respectively.

  6. Ground-Based Fabry-Perot Interferometry of the Terrestrial Nightglow with a Bare Charge-Coupled Device: Remote Field Site Deployment

    NASA Technical Reports Server (NTRS)

    Niciejewski, Rick; Killeen, Timothy L.; Turnbull, Matthew

    1994-01-01

    The application of Fabry-Perot interferometers (FPIs) to the study of upper atmosphere thermodynamics has largely been restricted by the very low light levels in the terrestrial airglow as well as the limited range in wavelength of photomultiplier tube (PMT) technology. During the past decade, the development of the scientific grade charge-coupled device (CCD) has progressed to the stage in which this detector has become the logical replacement for the PMT. Small fast microcomputers have made it possible to "upgrade" our remote field sites with bare CCDs and not only retain the previous capabilities of the existing FPls but expand the data coverage in both temporal and wavelength domains. The problems encountered and the solutions applied to the deployment of a bare CCD, with data acquisition and image reduction techniques, are discussed. Sample geophysical data determined from the FPI fringe profiles are shown for our stations at Peach Mountain, Michigan, and Watson Lake, Yukon Territory.

  7. In situ and air index measurements: influence of the deposition parameters on the shift of TiO2/SiO2 Fabry-Perot filters.

    PubMed

    Schmitt, B; Borgogno, J P; Albrand, G; Pelletier, E

    1986-11-01

    We measure the refractive index of thin films of TiO2 and SiO2 for given deposition parameters. Two complementary methods are used. The first is a postdeposition technique which uses the measurements of reflectance and transmittance in air. The second, in contrast, makes use of in situ measurements (under vacuum and during the actual deposition of the layer). The differences between the values deduced from the two methods can be explained by the amount of atmospheric moisture adsorbed by films. One tries to minimize these shifts for the two materials by choosing deposition parameters. The difficulties come from the absorption losses which must be as small as possible. We use the measured refractive indices of individual layers to give good numerical prediction of the wavelength shift (observed during the admittance of air after deposition in the vacuum chamber) of the transmittance peak of multidielectric Fabry-Perot filters.

  8. Simple locking of infrared and ultraviolet diode lasers to a visible laser using a LabVIEW proportional-integral-derivative controller on a Fabry-Perot signal.

    PubMed

    Kwolek, J M; Wells, J E; Goodman, D S; Smith, W W

    2016-05-01

    Simultaneous laser locking of infrared (IR) and ultraviolet lasers to a visible stabilized reference laser is demonstrated via a Fabry-Perot (FP) cavity. LabVIEW is used to analyze the input, and an internal proportional-integral-derivative algorithm converts the FP signal to an analog locking feedback signal. The locking program stabilized both lasers to a long term stability of better than 9 MHz, with a custom-built IR laser undergoing significant improvement in frequency stabilization. The results of this study demonstrate the viability of a simple, computer-controlled, non-temperature-stabilized FP locking scheme for our applications, laser cooling of Ca(+) ions, and its use in other applications with similar modest frequency stabilization requirements.

  9. Subkilohertz linewidth reduction of a DFB diode laser using self-injection locking with a fiber Bragg grating Fabry-Perot cavity.

    PubMed

    Wei, Fang; Yang, Fei; Zhang, Xi; Xu, Dan; Ding, Meng; Zhang, Li; Chen, Dijun; Cai, Haiwen; Fang, Zujie; Xijia, Gu

    2016-07-25

    A simple and low-cost 1550 nm semiconductor laser with subkilohertz intrinsic linewidth is experimentally demonstrated. A commercial distributed feedback diode laser is self-injection locked to the resonance transmission peaks of a fiber Bragg grating Fabry-Perot cavity through a polarization-maintaining fiber ring with the optical path length of 4 m, with the laser frequency noise suppressed by over 70 dB in the Fourier frequency band from 5 Hz and 1 kHz. The laser features an intrinsic Lorentzian linewidth of 125 Hz as well as a relative intensity noise of <-142 dBc/Hz above 2 MHz, and provides over 0.8 nm quasi-continuous tunability, which is suitable for advanced applications requiring a narrow linewidth laser with ultralow frequency noise. PMID:27464187

  10. Simultaneous measurement of temperature and refractive index using focused ion beam milled Fabry-Perot cavities in optical fiber micro-tips.

    PubMed

    André, Ricardo M; Warren-Smith, Stephen C; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M I; Latifi, H; Marques, Manuel B; Bartelt, Hartmut; Frazão, Orlando

    2016-06-27

    Optical fiber micro-tips are promising devices for sensing applications in small volume and difficult to access locations, such as biological and biomedical settings. The tapered fiber tips are prepared by dynamic chemical etching, reducing the size from 125 μm to just a few μm. Focused ion beam milling is then used to create cavity structures on the tapered fiber tips. Two different Fabry-Perot micro-cavities have been prepared and characterized: a solid silica cavity created by milling two thin slots and a gap cavity. A third multi-cavity structure is fabricated by combining the concepts of solid silica cavity and gap cavity. This micro-tip structure is analyzed using a fast Fourier transform method to demultiplex the signals of each cavity. Simultaneous measurement of temperature and external refractive index is then demonstrated, presenting sensitivities of - 15.8 pm/K and -1316 nm/RIU, respectively. PMID:27410566

  11. Ultra-low sensitivity to temperature low-cost optical fiber Fabry-Perot micro pressure sensor with a chitosan diaphragm

    NASA Astrophysics Data System (ADS)

    Wang, Wenhua; Li, Sidong; Wen, Lili

    2013-11-01

    In this paper, a low-cost CDEFPI (chitosan diaphragm-based extrinsic Fabry-Perot interferometer) micro pressure sensor with high sensitivity and ultra-low temperature dependence is proposed. The chitosan diaphragm is achieved through crosslinking method via glutaraldehyde which reduces extremely the water swelling property of chitosan and improves greatly the performance of sensor. A vent hole leaving during laser heating fusion bonding process guarantees the ultra-low temperature sensitivity of the sensor. The CDEFPI pressure sensor with a sensitivity of 25.65 nm/kPa (176.86 nm/psi), a resolution of 7.8 Pa (0.001 psi), temperature sensitivity of 0.015 nm/°C, and a thermal induced pressure measurement error limited within 0.0005 kPa/°C (0.00007 psi/°C) has been demonstrated.

  12. Cost-effective colorless WDM-PON delivering up/down-stream data and broadcast services on a single wavelength using mutually injected Fabry-Perot laser diodes.

    PubMed

    Ji, Ho-Chul; Yamashita, Ikuo; Kitayama, Ken-Ichi

    2008-03-31

    We propose and demonstrate for the first time a cost-effective and colorless wavelength-division-multiplexed passive optical network which can provide a full-duplex 155-Mb/s up/downstream data and broadcast signals on a single wavelength using light-injected optical sources and bidirectional transmission in a single fiber. The optical sources for downstream and upstream baseband data are Fabry-Perot laser diode (FPLD) at the central office and a reflective semiconductor optical amplifier (RSOA) at each optical network unit, respectively. The broadband light source (BLS) for the downstream is implemented by using mutually injected FPLDs. The transmission experiment shows that the error-free operation for baseband data and a high-quality broadcast signal with 3-dB CNR margin can be obtained. PMID:18542550

  13. Microfluidic refractive index sensor based on an all-silica in-line Fabry-Perot interferometer fabricated with microstructured fibers.

    PubMed

    Tian, Jiajun; Lu, Yujie; Zhang, Qi; Han, Ming

    2013-03-11

    We report a microfluidic fiber-optic refractive index (RI) sensor based on an in-line Fabry-Perot (FP) interferometer, which is formed by a silica tube sandwiched by two microstructured fibers (MFs). The sensor reported here can be fabricated at low cost, possess a robust structure, and has microfluidic capability. The micro-sized holes in the MFs naturally function as microfluidic channels through which liquid samples can be efficiently and conveniently delivered into and out of the FP cavity by a pressure/vacuum pump system for high-performance RI measurement. Due to the microfluidic capability enabled by the MFs, only sub microliter sample is required. We also experimentally study and demonstrate the superior performances of the sensor in terms of high RI sensitivity, good measurement repeatability, and low temperature cross-sensitivity. PMID:23482235

  14. A New Remote Sensing Filter Radiometer Employing a Fabry-Perot Etalon and a CCD Camera for Column Measurements of Methane in the Earth Atmosphere

    NASA Technical Reports Server (NTRS)

    Georgieva, E. M.; Huang, W.; Heaps, W. S.

    2012-01-01

    A portable remote sensing system for precision column measurements of methane has been developed, built and tested at NASA GSFC. The sensor covers the spectral range from 1.636 micrometers to 1.646 micrometers, employs an air-gapped Fabry-Perot filter and a CCD camera and has a potential to operate from a variety of platforms. The detector is an XS-1.7-320 camera unit from Xenics Infrared solutions which combines an uncooled InGaAs detector array working up to 1.7 micrometers. Custom software was developed in addition to the graphical user basic interface X-Control provided by the company to help save and process the data. The technique and setup can be used to measure other trace gases in the atmosphere with minimal changes of the etalon and the prefilter. In this paper we describe the calibration of the system using several different approaches.

  15. Ultraviolet Rayleigh-Mie lidar with Mie-scattering correction by Fabry-Perot etalons for temperature profiling of the troposphere.

    PubMed

    Hua, Dengxin; Uchida, Masaru; Kobayashi, Takao

    2005-03-01

    A Rayleigh-Mie-scattering lidar system at an eye-safe 355-nm ultraviolet wavelength that is based on a high-spectral-resolution lidar technique is demonstrated for measuring the vertical temperature profile of the troposphere. Two Rayleigh signals, which determine the atmospheric temperature, are filtered with two Fabry-Perot etalon filters. The filters are located on the same side of the wings of the Rayleigh-scattering spectrum and are optically constructed with a dual-pass optical layout. This configuration achieves a high rejection rate for Mie scattering and reasonable transmission for Rayleigh scattering. The Mie signal is detected with a third Fabry-Perot etalon filter, which is centered at the laser frequency. The filter parameters were optimized by numerical calculation; the results showed a Mie rejection of approximately -45 dB, and Rayleigh transmittance greater than 1% could be achieved for the two Rayleigh channels. A Mie correction method is demonstrated that uses an independent measure of the aerosol scattering to correct the temperature measurements that have been influenced by the aerosols and clouds. Simulations and preliminary experiments have demonstrated that the performance of the dual-pass etalon and Mie correction method is highly effective in practical applications. Simulation results have shown that the temperature errors that are due to noise are less than 1 K up to a height of 4 km for daytime measurement for 300 W m(-2) sr(-1) microm(-1) sky brightness with a lidar system that uses 200 mJ of laser energy, a 3.5-min integration time, and a 25-cm telescope.

  16. All-glass extrinsic Fabry-Perot interferometer thermo-optic coefficient sensor based on a capillary bridged two fiber ends.

    PubMed

    Cao, Zhitao; Jiang, Lan; Wang, Sumei; Wang, Mengmeng; Liu, Da; Wang, Peng; Zhang, Fei; Lu, Yongfeng

    2015-03-20

    An all-glass extrinsic Fabry-Perot interferometer (EFPI) is demonstrated for thermal-optic coefficient (TOC) of water, glycerol, and their mixture (volume ratio of 1:1). The compensation for the thermal expansion of Fabry-Perot (FP) cavity is realized by assembling a glass capillary and optical fibers through a CO2 laser welding. The thermal responses of EFPIs are tested in air at different cavity lengths of 578.6 μm, 911.7 μm, and 1520.3 μm, respectively. The corresponding refractive index errors induced by thermal expansion of FP cavity are negligible, which are demonstrated to be 4.33×10-6  RIU/°C, 4.13×10-6  RIU/°C, and 3.45×10-6  RIU/°C when temperature increases from 20.03°C to 60.78°C. The thermal-optic coefficients of water, glycerol, and their mixture are measured to be -1.5×10-4  RIU/°C, -2.3×10-4  RIU/°C, and -2.0×10-4  RIU/°C, respectively. Our study suggests a potential use of this sensor for TOC measurements of liquids with the advantages of low costs and robustness.

  17. All-glass extrinsic Fabry-Perot interferometer thermo-optic coefficient sensor based on a capillary bridged two fiber ends.

    PubMed

    Cao, Zhitao; Jiang, Lan; Wang, Sumei; Wang, Mengmeng; Liu, Da; Wang, Peng; Zhang, Fei; Lu, Yongfeng

    2015-03-20

    An all-glass extrinsic Fabry-Perot interferometer (EFPI) is demonstrated for thermal-optic coefficient (TOC) of water, glycerol, and their mixture (volume ratio of 1:1). The compensation for the thermal expansion of Fabry-Perot (FP) cavity is realized by assembling a glass capillary and optical fibers through a CO2 laser welding. The thermal responses of EFPIs are tested in air at different cavity lengths of 578.6 μm, 911.7 μm, and 1520.3 μm, respectively. The corresponding refractive index errors induced by thermal expansion of FP cavity are negligible, which are demonstrated to be 4.33×10-6  RIU/°C, 4.13×10-6  RIU/°C, and 3.45×10-6  RIU/°C when temperature increases from 20.03°C to 60.78°C. The thermal-optic coefficients of water, glycerol, and their mixture are measured to be -1.5×10-4  RIU/°C, -2.3×10-4  RIU/°C, and -2.0×10-4  RIU/°C, respectively. Our study suggests a potential use of this sensor for TOC measurements of liquids with the advantages of low costs and robustness. PMID:25968523

  18. Experimental study into single-longitudinal-mode Tm,Ho:YVO4 lasers

    NASA Astrophysics Data System (ADS)

    Dai, Tong-Yu; Han, Liu; Yao, Bao-Quan; Ju, You-Lun; Yu, Kuai-Kuai; Wang, Yue-Zhu

    2015-11-01

    The single-longitudinal-mode (SLM) Tm,Ho:YVO4 lasers were achieved by microchip configuration and double Fabry-Perot structure at room temperature. In the case of the microchip configuration laser, the maximum SLM power up to 17 mW was obtained on 2052.4 nm at 15 °C. In order to improve the output power of the SLM laser, it was implemented that the configuration of double Fabry-Perot etalons was used into the study of Tm,Ho:YVO4 lasers. Utilizing such configuration, the laser generated up to 95 mW output power in SLM at the wavelength of 2051.3 nm. With the angle of the Fabry-Perot etalons varied, the wavelength of the SLM laser could be turned from 2050.4 nm to 2051.3 nm, corresponding to a turning frequency of -64 GHz.

  19. Evaluation of an integrated Fourier-transform spectrometer utilizing a lateral effect position sensitive detector with a multi-channel Fabry Perot interferometer

    NASA Astrophysics Data System (ADS)

    Andersson, H. A.; Manuilskiy, A.; Thungström, G.; Nilsson, H.-E.

    2008-04-01

    The basis of this paper is the evaluation of an integrated multi-channel Fourier-transform (FT) spectrometer based on a multi-channel wedge Fabry-Perot interferometer and a one-dimensional lateral effect position sensitive detector (PSD). The use of a PSD for an interferogram readout allows for a simple scanning mechanism with no requirement for any position reference. The use of a wedge-shaped interferometer makes it possible to integrate it directly onto the PSD surface, thus producing a very compact spectrometer. The capabilities of the spectrometer are demonstrated by absorption spectral measurements using a reference sample. In addition, spectral measurements on 532 nm DPSS and 632.8 nm He-Ne lasers are presented. The resolution of the spectrometer is approximately 5 nm. The evaluated spectrometer set-up can be used in applications where compact and low cost spectrometers are required, such as in process control and in education. Further, it is shown that there are deteriorations in very high accuracy position measurements, which are caused by changes in incident light intensity. A model describing the above-mentioned nonlinearities was developed based on analysing the equivalent circuit for PSDs and parameters such as leakage current and serial resistance. Additionally, a method is proposed to assist in the reduction of the nonlinearity caused by this effect.

  20. A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Rakhman, A.; Hafez, M.; Nanda, S.; Benmokhtar, F.; Camsonne, A.; Cates, G. D.; Dalton, M. M.; Franklin, G. B.; Friend, M.; Michaels, R. W.; Nelyubin, V.; Parno, D. S.; Paschke, K. D.; Quinn, B. P.; Souder, P. A.; Tobias, W. A.

    2016-06-01

    A high-finesse Fabry-Perot cavity with a frequency-doubled continuous wave green laser (532 nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton polarimetry. The infrared (1064 nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO3 crystal. The maximum achieved green power at 5 W infrared pump power is 1.74 W with a total conversion efficiency of 34.8%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7 kW with a corresponding enhancement of 3800. The polarization transfer function has been measured in order to determine the intra-cavity circular laser polarization within a measurement uncertainty of 0.7%. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0% precision in polarization measurements of an electron beam with energy and current of 1.06 GeV and 50 μA.