Grating filter

Fiber Bragg grating filter is an important device for communication link detection in the field of optical communication. The principle is equivalent to a band-pass filter, which completely reflects the light from 1643.5nm to 1656.5nm (the return ratio is more than 99.5%), and all other wavelengths pass through. When used in the field of communication, it can separate the communication light (c + L band) from the detection light, prevent the detection light from passing, thus affecting the communication signal, and detect the return light at the control end. All the indexes of fiber Bragg grating are stronger than the coating method.