Method for detecting influence on laser from back-reflection light of laser and detection device

A detection device, comprising a dual-channel optical coupler, a first optical power meter, a second optical power meter, an adjustable reflector, and a processor, wherein a first left port, a second left port, a first right port, and a second right port are disposed on the dual-channel optical coupler, the first left port is connected to a laser, the first optical power meter is connected to the first right port, the adjustable reflector is located in front of the second right port, the second optical power meter is connected to the second left port, and the processor is connected to the first optical power meter, the second optical power meter, and the adjustable reflector, respectively;

• the dual-channel optical coupler is configured to:
• receive, by using the first left port, light input by the laser, split the input light into first detection light and second detection light, output the first detection light to the first optical power meter by using the first right port, and output the second detection light to the adjustable reflector by using the second right port, wherein power of the first detection light and power of the input light satisfy a first predetermined relationship;
• the adjustable reflector reflects a part of the second detection light to the second right port;
• the dual-channel optical coupler is further configured to:
• receive, by using the second right port, a part of the second detection light reflected by the adjustable reflector, split the part of the second detection light reflected by the adjustable reflector into first back-reflection light and second back-reflection light, return the first back-reflection light to the laser by using the first left port, and send the second back-reflection light to the first optical power meter by using the second port, wherein power of the second back-reflection light and power of the part of the first detection light reflected by the adjustable reflector satisfy a second predetermined relationship;
• and
• detect the power of the first detection light by using the first optical power meter, and detect the power of the second back-reflection light by using the second optical power meter;
• the processor is configured to:
• calculate the power of the input light of the laser according to the power of the first detection light, calculate power of the first back-reflection light according to the power of the second back-reflection light, and establish and output a power corresponding relationship between the power of the first back-reflection light and the power of the input light of the laser;
• and
• the processor is further configured to control the adjustable reflector to rotate for N−1 times, to enable the adjustable reflector to be located at N different reflection angles to reflect a part of the first detection light, so as to output N power corresponding relationships, wherein N is natural number greater than or equal to 2.