Research On High-performance Optical Frequency Comb Generation Technology

Optical frequency comb(OFC), whose spectrum likes a comb with equally spaced and discrete lights, is a stable kind of light comparable to the laser light. OFC is the core technology in the connection of microwave frequency standard and optical frequency standard. And it has important application values in many areas, such as laser technology, high-speed optical communication and microwave phonics and so on. Thus, how to obtain a high-performance OFC with wide bandwidth,fine flatness, tunable center wavelength and line spacing is always the pursuing goal of many scholars.By the use of EAM with excellent broadening performances and FM with high modulation depth, an OFC generation scheme based EAM and FM is proposed. Working principle of the scheme is introduced and the theory model is also established. By using the optical simulation software, the influences of light wavelength, light power, light width, frequency of RF driven signal and frequency offset of FM on the performance of OFC are also studied. Using multiple light sources and electro-absorption modulator with the feature of short- time window, an ultra-wide and flat OFC generation scheme based on EAMs and FM is proposed. The sub-OFCs with same bandwidth generated at the wavelength of every light source expand the bandwidth of OFC to ~THz range. The introduction of the second EAM can reduce the value of power difference between spectral lines to optimize the spectrum flatness. Working principle of the scheme is introduced and the theory model is also established. In the case of with a single light source and multiple light sources, tunability of the center frequency and line spacing generated OFC is studied respectively.Also, the bandwidth limit of the generated ultra-wide OFC with multiple light sources is studied.Using the frequency-shifted function of the frequency shifter, an OFC generation scheme based on the optical path of frequency-shifted loop is proposed. First, working principle of the scheme is introduced and the theory model is also established. By the simulation of this scheme with optical simulation software, the generation of ultra-wide and flat OFC based on the optical path of the loop frequency shift is implemented. Besides, the effects of light wavelength, light power, light width,the amount of frequency shift and length of erbium-doped fiber on OFC are study.