A positioning fiber-optic vibration sensor based on M-Z interference principle

The heat transfer enhancement of gas flow in narrow-channel with a pair of embedded half-delta longitudinal vortices generators is studied by using the M-Z interference method, and the M-Z interference images focusing on the temperature field of heat convection are taken on the cases whether the vortices generators are embedded.

Using Mach-Zehnder interferometer to quantitatively measure the refractive index of air and its theoretical discussion;

The results show that triplexer chips with high tolerance and improved spectral response can be fabricated by using two-mode couplers and Mach-Zehnder interferometer.

Detection of shift of reflective wavelength of FBG sensor demodulation system using M-Z interferometer;

According to XPM principle,the intensity of accessorial light can be altered by feedback control and the phase of the light signal from the M-Z interferometer can be modulated in a phase-locked way,thus the system phasic-difference can be locked at the point of the highest sensitivity.

A kind of M-Z interferometer is designed,which consists of 2×2 coupler and 3×3 coupler and is successfully applied to the demodulation of the designed fiber Bragg grating(FBG) voltage sensors.

By tracking phase drift and distributing key at suitable times,the quantum key distribution based on double M-Z interferometer was performed over a fiber length of 80 km with a quantum bit-error rate of 6%,and it had been working stably for several days.

Quantum Key Distribution (QKD) system based on the two asymmetric Mach-Zehnder optical fiber interferometers is easily influenced by the external environmental interference, which causes phase excursion.