In this letter, symmetric and asymmetric core-offset Mach-Zehnder interferometer (MZI) torsion sensors based on a single mode fiber (SMF) are presented. Here, three different MZIs were implemented and their interference patterns and torsion characteristics have been experimentally investigated. In our devices, the maximum torsion sensitivities are 6x10-3, 12x10-3, and 23x10-3 nm/°, with the possibility to discriminate between clockwise and anticlockwise rotation. Finally, these interferometers only employ SMF and can be fabricated at low cost.
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.
In this letter, a highly sensitive curvature sensor arrangement based on an abrupt tapered fiber (ATF) concatenated with an all-fiber micro Fabry-Pérot interferometer (MFPI) is presented. Here, as the ATF is bent, the MFPI spectral fringes contrast decreases. In addition, the curvature sensitivity is considerably enhanced due to the use of the ATF. Finally, it is shown that with this arrangement, at 1530-nm wavelength, it is possible to detect curvature changes with a sensitivity of 11.27 dB/m -1 and a curvature resolution of 8.87 × 10 -3 m -1 within the measurement range of 0 - 3.5 m -1 .
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.
A compact high temperature fiber sensor where the sensor head consists of a short fattened long period fiber grating (F-LPFG) of at least 2 mm in length and background loss of −5 dBm is reported. On purpose two different F-LPFGs were used to measure temperature variations, taking advantage of their broad spectrum and the slope characteristics of the erbium light source. This approach affected the spectrum gain as the linear band shifting took place. The measured sensitivity of the long period fiber gratings were about 72 pm/°C in a range from 25 to 500 °C. Here, the temperature rate of the experiment was 0.17 °C/s and the temperature response time was within 3 s. Moreover, temperature changes were detected with an InGaAs photodetector, where a sensitivity of 0.05 mV/°C was achieved.
In this work we present the results obtained to couple a filter Optical fiber to Erbium doper fiber laser, with this setup we eliminate noise ASE.