Brillouin optical time domain analyzer based on few-mode fiber mode multiplexing

The invention discloses a Brillouin optical time domain analyzer based on few-mode optical fiber mode multiplexing. The analyzer comprises a narrow linewidth laser, a first optical fiber coupler, an optical pulse modulation unit, an erbium-doped optical fiber amplifier, a band-pass filter, a second optical fiber coupler, three optical fiber circulators, a first optical fiber mode multiplexer, a few-mode sensing optical fiber, a second optical fiber mode multiplexer, a third optical fiber coupler, an optical fiber scrambler, a microwave frequency sweeping unit, three photoelectric detectors and a digital signal processing unit. According to the optical time domain reflectometer, simultaneous measurement of multiple parameters can be realized, and the common problem of temperature and strain cross sensitivity in engineering application of a distributed optical fiber sensing technology can be solved. 本发明公开了一种基于少模光纤模式复用的布里渊光时域分析仪，其特征在于，包括窄线宽激光器、第一光纤耦合器、光脉冲调制单元、掺铒光纤放大器、带通滤波器、第二光纤耦合器、三个光纤环形器、第一光纤模式复用器、少模传感光纤、第二光纤模式