Weak optical fiber Bragg grating used as matched optical filter

From two aspects analyze the advantage of weak optical fiber Bragg grating used as filter to filter the ASE noise of optical amplifier before the signal is detected. Firstly, we calculated the temporal response of the weak optical Bragg grating filter, the matched Bragg grating filter and the commonly used F-P filter. We find that the reflected pulse of weak optical Bragg grating closely resembles the triangular shape characteristic of a perfectly matched filter. It almost has no intersymbol interference. Whereas the pulse from a F-P transmission filter has a long decaying tail. This will lead to errors in detection. Secondly, we simulate the transmission process in computer. Calculating the power SNR(signal-to-noise ratio) Of Output signal with the same input signal filtered by the optical fiber Bragg grating, matched filter, F-P filter. Analyzing the improvement of the SNR after filtered by them. We find it also has advantage over F-P filter. Taking the two reasons into account, the weak optical fiber Bragg grating is superior to the widely used F-P filter. The weak optical fiber grating can be approximate used as a matched filter.