Sensor based on laser

A sensor based on laser, comprising a pump source, a common section, and a reference section and a detection section which are connected to the two ends of the common section in parallel, wherein the common section is provided with a gain medium, and the detection section is provided with a sensing element capable of causing an optical path difference;

• wherein one end of each of the reference section and the detection section is connected to the common section though a first polarization splitting unit, another end of each of the reference section and the detection section is connected to the common section though a second polarization splitting unit;
• the common section and the reference section constitute a first laser resonator transmitting a first linearly polarized light, and the common section and the detection section constitute a second laser resonator transmitting a second linearly polarized light;
• the common section is provided with an output unit or each of the reference section and the detection section is provided with the output unit, the output unit is connected to a photoelectric detector through a light uniting unit, lasers are output from the output unit, and are united and transmitted to the photoelectric detector;
• a polarization rotation unit configured for the consistency of the polarization states of the first linearly polarized light and the second linearly polarized light, is disposed between the light uniting unit and the output unit.