Optical time-domain reflectometer, and method for eliminating interference fading

An optical time-domain reflectometer, characterized in that the optical time-domain reflectometer is connected with a sensing optical fiber, comprising:

• a laser device, a frequency-division multiplexing modulator, a circulator and a signal processing device, and the frequency-division multiplexing modulator comprises a first modulator, a second modulator, a first attenuator and a second attenuator;
• wherein the laser device is configured to generate a coherent light source, and the coherent light source passes sequentially through the first modulator and the first attenuator, so as to obtain a first optical pulse signal;
• the coherent light source sequentially passes through the first modulator and the second modulator, so as to obtain a second optical pulse signal;
• the coherent light source sequentially passes through the second attenuator and the second modulator, so as to obtain a third optical pulse signal;
• and
• the circulator is configured to transmit the first optical pulse signal, the second optical pulse signal, and the third optical pulse signal to the sensing optical fiber, and the sensing optical fiber is configured to generate corresponding reflected optical signals according to the first optical pulse signal, the second optical pulse signal, and the third optical pulse signal, and transmit the reflected optical signals to the signal processing device through the circulator for processing.