We present the fabrication and characterization of a micro-displacement sensor using Mach-Zehnder
interferometer in conventional optical fiber SMF28-e. The Mach-Zehnder interferometer uses a
configuration of two long-period gratings (LPG) in series mechanically induced. The Mach-Zehnder
interferometers were made to operate in the region of 1300 nm. As a result the interferometers were
obtained with transmission bands with a bandwidth of 2 nm, extinction ratio of 12 dB and insertion loss of
2 to 3 dB. The characterization of the interferometer was found to be measured displacements up to 500
μm with a resolution of 7 microns, which envisions potential applications of micro-displacement sensor in
the measurement of micro-deformations.
We present the temperature response of a mechanically-induced long-period fiber grating (MLPFG) made in photonic
crystal fiber (PCF) with and without the coating polymer. In both cases, we found a wavelength shift to shorter
wavelengths and a critical decrease of the attenuation peaks. A maximum wavelength shift of 6 nm at 1060 nm was
obtained when the temperature changed from 20 to 80 °C in PCF without the polymer. Whereas, the depth of the
attenuation peaks were dramatically reduced from 12 to almost 2 dB at 1060 nm when the temperature increase from 20
to 100 °C in both experiments. These results are important to consider when MLPFG are applied in a medium with room
We demonstrate the minimization of background loss for arc-induced long-period fiber gratings in standard fiber by Taguchi's optimization method. We use Taguchi's method to determine the optimum values for parameters like electric-arc power, arc duration, and tensile strain applied over the fiber during the inscription process. With these optimal parameters, we minimize the background loss resulting from the geometrical deformations of the fiber. The experimental results show that background loss can be reduced from more than 1 dB to less than 0.3 dB at rejection bands with isolation >15 dB.