Experimental study of a novel Mach-Zehnder interferometer

This paper shows a novel all-fiber Mach-Zehnder interferometer, and introduces two times of total reflection in the two output ports of the interferometer. It can obtain a higher extinction ratio. In the elimination of environmental interference situation, the peak wavelength difference of the interferometer is 3.24 nm and the extinction ratio is 25.2 dB. Compared with conventional single-pass Mach-Zehnder interferometer, the extinction ratio is increased by 7.2 dB. The system can make use of piezoelectric (PZT) to control the arm length difference of the interferometer, so as to achieve the tuning phase. Experiments prove that this device has advantages of simple structure, easy to realize high sensitivity and extinction ratio, ease of tuning, etc., so it has a broad application value in optical fiber communications and fiber-optic sensors.