Design of a Fabry-Perot interferometer based on silicon wafer for dielectric gas sensing applicationsPublished: 13 November 2018 by SPIE-Intl Soc Optical Eng in Infrared Sensors, Devices, and Applications VIII
In this work a design and analysis of a Fabry-Perot interferometer (FPI) based on a silicon wafer for possible application in a SF6 gas sensor used in electric power systems is presented. The sensor design is based on cross correlation spectroscopy principle with an FPI, which acts an optical modulator. Hence, due to characteristics of the FPI transmission spectrum, it can be used detect molecules with very well defined ro-vibrational lines such as those produced by diatomic and linear molecules. The design of the FPI depends mainly of the SF6 absorption wavelength peaks and of the optimum thickness of the silicon wafer. For this reason, in order to measure this absorption peaks a HITRAN database was used. The optimum thickness of the silicon wafer was calculated and simulated transmission spectrum. Finally, we demonstrated by using analytical simulations that a silicon wafer can be implemented as a FPI and used in a SF6 gas sensor.
Erbium Ring Fiber Laser Cavity Based on Tip Modal Interferometer and Its Tunable Multi-Wavelength Response for Refractiv...Published: 10 August 2018 by MDPI in Applied Sciences
A tunable multi-wavelength fiber laser is proposed and demonstrated based on two main elements: an erbium-doped fiber ring cavity and compact intermodal fiber structure. The modal fiber interferometer is fabricated using the cost-effective arc splice technique between conventional single-mode fiber and microfiber. This optical fiber structure acts as a wavelength filter, operated in reflection mode. When the refractive index and temperature variations are applied over the fiber filter, the ring laser cavity provides several quad-wavelength laser spectra. The multi-wavelength spectra are tuned into the C-band with a resolution of 0.05 nm. In addition, the spectra are symmetric with minimal power difference between the lasing modes involved, and the average of the side mode suppression ratio is close to 37 dB. This laser offers low-cost implementation, low wavelength drift, and high power stability, as well as an effect of easy controllability regarding tuned multi-wavelength.
Switchable multi-wavelength laser based on a core-offset Mach-Zehnder interferometer with non-zero dispersion-shifted fi...Published: 01 August 2018 by Elsevier BV in Optics & Laser Technology
In this paper, a switchable multi-wavelength erbium-doped fiber ring laser, based on a core-offset Mach-Zehnder interferometer (MZI) with non-zero dispersion shifted fiber (NZ-DSF), is proposed and experimentally demonstrated. Here, the core-offset MZI was implemented by fusion splicing a segment of a NZ-DSF between two single-mode fiber sections. In the proposed ring cavity design, the core-offset MZI is acting as a wavelength selective filter and it is optimized in order to achieve a single-mode suppression ratio (SMSR) of about of 56 dB. In addition, the laser is capable of emitting a single, double, or triple line, which can be switched from 1546 to 1564 nm by controlling its polarization states. Finally, this laser fiber offers a high output power stability at room temperature, compactness, robustness and low implementation cost.
A fiber optic laser arrangement for temperature sensing applications is presented. The multi-wavelength spectrum has a SMSR of 40dB and moreover, the temperature generated tunable multi-wavelength effect, here, a sensitivity of 20pm/°C is achieved.
An analysis of the effects of the evolution of the polarization states on an Erbium doped fiber is presented; this it to optimize the development tunable fiber laser systems. In this research, we study the polarization state effects of the pumping source for linear and Circular Polarization, as well as the effect produced by the evolution of the polarization state along the experimental setup in an erbium-doped fiber.
A laser temperature sensor based on a core-offset aluminum coated Mach-Zehnder interferometer is presented. The experimental results shown a temperature sensitivity of 28 pm/°C and a signal to noise ratio of 45 dB.
Supercontinuum generation was achieved with numerous setups of optical fibers which include SMF-28, high-Numerical Aperture and dispersion-shifted fiber. Supercontinuum flatness was studied by modifying the configurations and inducing fiber losses.
We report the implementation of the RK4IP method for studying the propagation of a hyperbolic secant pulse into 10 km of standard fiber. The results describe the appearance of chaotic phenomena in the spectral broadening.
An angular deflection laser sensor in ring configuration is presented, based on a wavelength selective filter (WSF), which was manufactured by splicing a segment of thin core fiber (Thin-Core Fiber, TCF) between two segments of single-mode fiber SMF-28 (Single-Mode Fiber). A spectral shift of the thin core fiber modal interferometer TCFMI (Thin-Core Fiber Modal Interferometer) was obtained at different angles of deflection in steps of 17.86 µrad.
We propose and demonstrate a fibre optic system based on bi-tapered silica fibre that can simultaneously measure strain and fibre curvature. Both modalities on the signal can be extracted with no measurable crosstalk between them. The experimental signal has a pure phase modulation when strain is applied to the tapered fibre optic section of the sensor and the signal shows only intensity modulation when an un-tapered fibre section is bent. High sensitivity is achieved from the experimental results for strain and bending losses and the estimation of measurement errors is 0.2 and 0.1%, respectively. This system offers low-cost, compactness and it can be adapted for structural health monitoring.
A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF) span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.
In this paper a temperature sensing setup based on a Photonic Crystal Fiber (PCF) Mach-Zehnder Interferometer (MZI), coated with aluminum is proposed. Here, this interferometer is fabricated through the concatenation of two sections of Single Mode Fiber (SMF) with a segment of PCF between them. The SMF-PCF joint acts as beam splitter causing the excitement of PCF’s, both cladding and fundamental core modes. In the PCF-SMF union, the cladding modes couple again to the core of the SMF, and interfere with the fundamental core mode, this interaction results in an interference pattern spectrum. Moreover, the MZI was coated with aluminum, using the evaporation technique. By adding a thin metal layer to the PCF section, the general thermal coefficient of the structure changes, enhancing the sensitivity of the device. Experimental results show that a visibility of 13 dBm can be obtained and a sensitivity of 250 pm/°C. Finally, the proposed structure is simple, cost effective and easy to fabricate. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Multi-parameter fiber optic sensing setup based on spectral-overlap using Fabry-Perot interferometersPublished: 22 February 2017 by SPIE-Intl Soc Optical Eng in Physics and Simulation of Optoelectronic Devices XXV
In this work, multi-parameter fiber optic sensing setup is demonstrated by the simultaneous analyses of curvature and transversal load. The experimental arrangement operates by using two compact all fiber Fabry-Perot interferometers. Using a 2x1 optical fiber coupler the reflected interference patterns provided by each interferometer are combined, consequently new interference spectrum is obtained. Overlapping interference spectra is generated, and when curvature and load are simultaneously applied, intensity and phase variations are independently observed. The load information is obtained through a wavelength shifting generated by one interferometer, meanwhile the curvature data were analyzed using the intensity modulation provided by the other interferometer. The load analysis presents sensitivity around 0.1nm/N and moreover the experimented curvature shows a resolution of 0.4*10-3cm-1. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
In this experimental manuscript, a switchable Erbium-doped fiber ring laser based on an all-fiber Fabry-Perot filter was demonstrated. The filter is composed by several air micro-cavities formed into a section of a single-mode fiber splice joints with special hollow-core photonic crystal fiber. These micro-cavities are formed by air and silica, which produces several reflections generated at each silica-air-silica interfaces. Using this experimental setup we obtain a very high stable triple-laser emission at 1529.450nm, 1549.100nm and 1555.350nm with a linewidth of 0.2nm and a side-mode suppression ratio of 32dB, 37dB and 29dB respectively. These laser emission show a maximal peak power fluctuation around 0.4dB, 1.5dB and 2.6dB, with 0.025nm of wavelength oscillations. These results were observed after monitoring the laser cavity during an hour by recording the data each three minutes. By appropriately adjusting of transversal load applied over the Fabry-Perot filter between 0g and 550g, the ring laser cavity can be operated in double- wavelength, triple- wavelength, or quadruple- wavelength states. For this analysis, the all-fiber Fabry-Perot filter was set between a metal layer (below) and a thin glass layer (above) where transversal load was applied, here uniform load distribution over all the Fabry-Perot filter structure is achieved, as a result, the air intra-cavities that conform the filter are affected and the gain-losses profile is modified into the laser arrangement. The lasing emissions obtained in this work have a side-mode suppression ratio greater than 30dB. This ring laser cavity design offers a compact, simple and low-cost implementation and can be used in different applications where a very stable double, triple or quadruple laser lines are required. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A torsion experimental sensing setup based on a Mach-Zehnder interferometer (MZI) with photonics crystal fiber is presented. The MZI was fabricated by fusion splicing a piece of photonic crystal fiber (PCF) between two segments of a single-mode fiber (SMF). Here, a spectral MZI fringe shifting is induced by applying torsion over the SMF-PCF-SMF. As a result a torsion sensitivity of 35.79 pm/ and a high visibility of 10 dB were achieved. Finally, it is shown that the sensing arrangement is compact and robust. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mn0.75Zn0.25Fe2O4 nanoparticles were used to characterize magnetic fields using an all-fiber Fabry–Perot interferometer. The 20-nm nanoparticles were fabricated with citrate and displayed a coercive field of approximately 10 mT. The nanoparticles were dispersed in oleic acid to prepare a magnetic fluid to fill a Fabry–Perot structure fabricated by arc splicing with conventional single-mode and hollow core photonic crystal fibers. This device provided sensitivity and resolution of 0.11 dB/mT and 0.09 mT, respectively. Thermal analysis indicated that the magnetic measurements are weakly depending on temperature (0.7 pm/°C and 7 × 10−3 dB/°C). This device offers low-cost fabrication, simple implementation and may be used in several industrial applications.
Generation of supercontinuum light in micro-structured fiber and polarization study at different wavelengthsPublished: 07 October 2016 by SPIE-Intl Soc Optical Eng in Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications X
In this work, we study the changes of polarization at different wavelengths in a supercontinuum source generated through a microchip laser in the IR spectrum. We use a microchip laser pulsed as pumped source, 1064 nm of wavelength, and a photonic crystal fiber by generated a supercontinuum spectrum. We twist the fiber to the purpose to induce birefringence and study the changes of the state of polarization, and through bandpass filters we observe a single wavelength of the broad spectrum obtained. Besides, ellipticity study for different filters and its relation with the supercontinuum results is discussed. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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.
Switchable and multi-wavelength linear fiber laser based on Fabry–Perot and Mach–Zehnder interferometersPublished: 01 September 2016 by Elsevier BV in Optics Communications
Highlights•A switchable and multi-wavelength EDF laser arrangement based on FPI and MZI cavities is analyzed.•The FPI is composed by two air-microcavities.•Single, double, triple and quadruple laser emissions with a SNR of 30dB are presented.•The laser is stable at wavelength and power at room temperature. AbstractIn 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.
In this work, we study a 215-m-long figure-of-eight fiber laser including a double-clad erbium-ytterbium fiber and a nonlinear optical loop mirror based on nonlinear polarization evolution. For proper adjustments, self-starting passive mode-locking is obtained. Measurements show that the mode-locked pulses actually are noise-like pulses, by analyzing the autocorrelation, scope traces and the very broad and flat spectrum extending over a record bandwidth of more than 200 nm, beyond the 1750 nm upper wavelength limit of the optical spectrum analyzer. Noise-like pulsing was observed for moderate and high pump power preserving the same behavior, reaching pulse energies as high as 300 nJ, with pulse durations of a few tens of ns and a coherence length in the order of 1 ps. Stable fundamental mode locking as well as harmonic mode locking up to the 6th order were observed. The bandwidth was further extended to more than 450 nm when a 100-m piece of highly nonlinear fiber was inserted at the laser output. The enhanced performances obtained compared to other similar schemes could be related to the absence of a polarizer in the present setup, so that the state of polarization along the cavity is no longer restricted.
A Core-Offset Mach Zehnder Interferometer Based on A Non-Zero Dispersion-Shifted Fiber and Its Torsion Sensing Applicati...Published: 10 June 2016 by MDPI in Sensors
In this paper, an all-fiber Mach-Zehnder interferometer (MZI) based on a non-zero dispersion-shifted fiber (NZ-DSF) is presented. The MZI was implemented by core-offset fusion splicing one section of a NZ-DSF fiber between two pieces of single mode fibers (SMFs). Here, the NZ-DSF core and cladding were used as the arms of the MZI, while the core-offset sections acted as optical fiber couplers. Thus, a MZI interference spectrum with a fringe contrast (FC) of about 20 dB was observed. Moreover, its response spectrum was experimentally characterized to the torsion parameter and a sensitivity of 0.070 nm/° was achieved. Finally, these MZIs can be implemented in a compact size and low cost.
Numerical analysis of the supercontinuum spectrum generation in a couple of photonic crystal fibers with different struc...Published: 14 March 2016 by SPIE-Intl Soc Optical Eng in Physics, Simulation, and Photonic Engineering of Photovoltaic Devices V
In this work, we performed a numerical analysis of the supercontinuum spectrum generation in a couple of photonic crystal fibers with different structure. The proposed configuration initially has an input pulse with hyperbolic secant profile to generate noise-like pulses as output signal, by the Runge-Kutta method (RK4IP). By using the same configuration, now these noise-like pulses are used as pump for supercontinuum generation obtaining a broad and good flatness spectrum. The numerical analysis presented here demonstrates the potential of noise-like pulses from a passively mode-locked fiber laser for broadband spectrum generation combining two different photonic crystal fibers. Besides this paper helps to understand the phenomena of supercontinuum generation which is mainly related to Raman self-frequency shift. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Polarization study of a supercontinuum light source for different wavelengths through a photonic crystal fiberPublished: 04 March 2016 by SPIE-Intl Soc Optical Eng in Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XV
In this work we show the changes of polarization at different wavelengths in the end of a photonic crystal fiber (PCF) by means bandpass filters in a supercontinuum light source. A linear and circular polarization was introduced in a piece of PCF, showing the changes of the polarization for each wavelength of each one of the filters from 450 to 700nm. We used a microchip laser as pumping source with wavelength of 532nm and short pulses of 650ps with repetition rate of 5kHz. We obtained a continuous spectrum in the visible spectral region, showing a comparison of the polarization state at the fiber input with respect to polarization state in the fiber output for different wavelengths by rotating the axes of the PCF. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Analytical Modelling of a Refractive Index Sensor Based on an Intrinsic Micro Fabry-Perot InterferometerPublished: 15 October 2015 by MDPI in Sensors
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.
In this work, a refractive index sensor setup based on a biconically tapered fiber (BTF) concatenated to an intrinsic all-fiber micro Fabry-Perot interferometer (MFPI) is presented. Here, the power of the MFPI spectral fringes decreases as the refractive index interacts with theevanescent field of the BTF segment. Furthermore, it is demonstrated that the RI sensitivity can be enhanced by bending the BTF segment.Finally, it is shown that by using this sensing arrangement, at ~1.53 µm wavelength, it is possible to detect refractive index changeswithin the measurement range of 1.3 to 1.7 RIU, with a sensitivity of 39.92 dB/RIU and a RI resolution of 2.5 x 10
Modified All-Fiber Fabry–Perot Interferometer and Its Refractive Index, Load, and Temperature AnalysesPublished: 01 June 2015 by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Photonics Journal
We show the sensing of load by means mechanically induced long-period fiber grating (MLPFG) made by applying pressure by means a screw to a pair of grooved plates over single-mode fiber. We used a torquemeter in order to obtain precision in the adjustment screw and thus establish an equilibrium pressure applied to a specific region of the optical fiber to form the long-period grating mechanically induced fiber. The increase the torque to screw, the resonance wavelength of MLPFG increases its depth over 16 dB. We use a detector to observe the changes amplitude according to the fiber pressure.
A tunable multi-wavelength erbium doped fiber laser based on a Mach–Zehnder interferometer and photonic crystal fiberPublished: 18 November 2013 by IOP Publishing in Laser Physics
Highly sensitive curvature and displacement sensing setup based on an all fiber micro Fabry–Perot interferometerPublished: 01 November 2013 by Elsevier BV in Optics Communications
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.