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.
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.
Reconfiguration of the multiwavelength operation of optical fiber ring lasers by the modifiable intra-cavity induced los...Published: 16 February 2018 by IOP Publishing in Laser Physics
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.
In-fiber Mach–Zehnder interferometer based on a Nd-doped double-clad fiber for switchable single and dual-wavelength EDF...Published: 31 March 2017 by IOP Publishing in Laser Physics
We present an experimental study of a novel Mach–Zehnder in-fiber interferometer and its application for single and dual-wavelength operation of a ring cavity fiber laser. The proposed in-fiber interferometer, consisting of a segment of Nd-doped fiber spliced between two segments of standard single mode fibers, exhibits a wavelength periodical transmission spectrum with a period of 2.8 nm and a fringe contrast of ~0.8 dB. The Mach–Zehnder interferometer (MZI) is used as a spectral filter to obtain switchable single and dual-wavelength operation of an Er-doped fiber laser (EDFL). Laser emission with laser lines spectral width less than 0.22 nm and wavelength separation of 2.8 nm corresponding to transmission spectrum wavelength period of the MZI is obtained. The stability of the dual-wavelength operation of the EDFL is also discussed. The use of the proposed in-fiber MZI as a reliable, spectral filter to achieve stable single and dual-wavelength laser generation in a ring cavity fiber laser is experimentally demonstrated.
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.
We propose the use of a figure eight fiber laser cavity in fundamental and harmonic mode-locking noise-like pulsing regimes, with output pulse energies as high as 302.8 nJ, as an improved supercontinuum source. The absence of a polarizer in the laser setup, so that the state of polarization along the cavity is not restricted, allows enhanced performances compared to other similar schemes. Noise-like pulses with durations of a few tens of ns were generated and a coherence length in the order of ps. For proper adjustments, self-starting passive mode-locking is obtained and a supercontinuum spectrum is observed at the laser output. We observe that the spectrum flatness is significantly improved in the harmonic mode-locking regime of the fiber laser. These results were achieved without the need to insert any high-nonlinearity propagation medium in the setup or at the laser output.
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.
Tunable wavelength erbium doped fiber linear cavity laser based on mechanically induced long-period fiber gratingsPublished: 07 September 2016 by SPIE-Intl Soc Optical Eng in Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications X
Tunable wavelength erbium doped fiber linear cavity laser, based on mechanically induced long-period fiber gratings (MLPFG) is presented. The laser was tuned applying pressure over the MLPFG, in order to monitor this, pressure is applied over a plate with periodic grooves that has a short length, this pressure is controlled by a digital torque tester as a result tunable effect is observed. The grooves have a period of 620µm and the maximal pressure without breakpoint fiber is around 0.80lb-in2. Furthermore, the MLPFG used can be erased, reconfigured and exhibit a transmission spectra with termal stability, similar to high cost photoinduced long period gratings. In this work, by pressure increment distributed over the MLPFG from 0.40 lb-in2 to 0. 70 lb-in 2, tuned operation range of 14nm was observed and single line emission was tuned in the C telecommunication band. According to the stability analysis the signal to noise ratio was 29 dB and minimal wavelength oscillations of 0.29nm. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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.
A tunable wavelength erbium doped fiber ring laser based on mechanically induced long-period fiber gratingsPublished: 26 August 2015 by SPIE-Intl Soc Optical Eng in Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications IX
A tunable wavelength erbium doped fiber ring laser, based on mechanically induced long-period fiber gratings (MLPFG) is presented. The laser was tuned applying pressure over the MLPFG, in order to control this, pressure is applied over a plate with periodic grooves that has a short length, this pressure is applied by a digital torque tester, as a result tunable effect is observed. The grooves have a period of 630μm and the maximal pressure without breakpoint fiber is around 0.80lb-in2. Furthermore, the MLPFG used can be erased, reconfigured and exhibit a transmission spectra with thermal stability, similar to high cost photoinduced long period gratings. In this work, by pressure increment distributed over the MLPFG from 0.20 lb-in2 to 0.50 lb-inμ, tuned operation range of 10nm was observed and single line emission was tuned between C and L telecommunications bands. According to the stability analysis the signal to noise ratio and linewidth observed were 35dB and 0.2nm respectively. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fabrication and characterization of a non-zero dispersion-shifted mechanically-induced long-period grating for optical f...Published: 25 August 2015 by SPIE-Intl Soc Optical Eng in Laser Beam Shaping XVI
We present the fabrication and characterization of a mechanically induced long period grating (MLPG) using a grating period of 400 μm and 1m of NZ-DSF. Pressure is gradually applied up to 120 Lb at different angles like 0, 30, 45 and 60 degrees. An attenuation band is observed centered at a wavelength around 1064nm using a fiber position of 30 degrees with respect to the grating´s metal plate and a maximum pressure of 145 Lb. The loss band presents a maximum depth of 22dB and a bandwidth of approximately 10nm. Torsion and curvature characterizations did not change the output spectrum of the optical grating. However, temperature characterization depicted a small shifting which could be insignificant for some applications. Still, there is 16dB attenuation as temperature increases in a range from room temperature up to 450°C. These preliminary studies show that this 1064 nm centered wavelength MILPG might be used in a low linear dynamic range with temperature (75-300)°C as a temperature sensor. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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.