Noise Analysis of a Flat Optical Frequency Comb in O-U Band Based on a Brillouin Laser Cavity

Abstract Optical frequency comb (OFC) have great potential as an excellent multi-wavelength light source in the field of communications.The communication system can have a transmission rate in the order of a hundred Tbit s -1 by combining the OFC light source with wavelength-division-multiplexing (WDM) and space-division-multiplexing (SDM) technologies which is of significant application value in 5G/6G communications Internet of Things and au tonomous driving.For an optical communication system that integrates wavelength division multiplexing and spatial division multiplexing technologies its transmission capacity depends on the number of channels in both WDM and SDM the modulation symbol rate of the system and the signal-to-noise ratio (SNR) of the light source.Through an optical system based on a Brillouin laser cavity with dispersion-engineered highly nonlinear fluorotellurite fiber we can obtain a flat OFC with a wide range of adjustable repetition frequency spectral coverage of the entire O-U band and a standard deviation of the comb intensity of less than 5 dB in the O-U band.This paper calculates the linewidth and frequency noise of the comb teeth across different bands of the optical frequency comb and establishes a Brillouin