Michelson interference optical fiber temperature sensor for detecting contrast change of fringes

A Michelson interference optical fiber temperature sensor for detecting a contrast change of interference fringes, comprising:

• a light source, an optical fiber coupler, a coarse wavelength division multiplexer, a first photodetector, a second photodetector, a processing circuit, a display device, a first optical fiber, a second optical fiber, and a semiconductor;
• wherein the light source, the optical fiber coupler and the coarse wavelength division multiplexer are connected sequentially in that order, the coarse wavelength division multiplexer is connected to the first photodetector and the second photodetector individually, the first photodetector and the second photodetector are connected to the processing circuit, and the processing circuit is connected to the display device;
• wherein the optical fiber coupler is further connected to the first optical fiber and the second optical fiber, and an end of one of the first optical fiber and the second optical fiber facing away from the optical fiber coupler is connected to the semiconductor;
• wherein the light source is configured to transmit optical signals;
• wherein the optical fiber coupler is configured to couple and distribute the optical signals transmitted by the light source and optical signals returned by the first optical fiber and the second optical fiber;
• wherein the coarse wavelength division multiplexer is configured to demultiplex the optical signals returned by the first optical fiber and the second optical fiber to obtain a broadband optical signal and a narrowband optical signal;
• wherein the first photodetector and the second photodetector are respectively configured to receive the broadband optical signal and the narrowband optical signal obtained by the demultiplexing of the coarse wavelength division multiplexer;
• wherein the processing circuit is configured to process the broadband optical signal and the narrowband optical signal received by the first photodetector and the second photodetector, detect a contrast change of the interference fringes, and demodulate, based on the contrast change of the interference fringes, to obtain a temperature detection result;
• wherein the display device is configured to display the temperature detection result obtained by the demodulating;
• and
• wherein the processing circuit is specifically configured to perform amplification processing on the broadband optical signal and the narrowband optical signal received by the first photodetector and the second photodetector, make the narrowband optical signal of the second photodetector after the amplification processing divide by the broadband optical signal of the first photodetector after the amplification processing to obtain phase information and phase change information of the interference fringes, to thereby obtain information of the contrast change of the interference fringes, and obtain a change of ambient temperature based on the information of the contrast change of the interference fringes.