Double-repetition-frequency optical frequency comb light source

The invention provides a double-repetition-frequency optical frequency comb light source. A first pumping source and a second pumping source excite a doped fiber to generate laser through a wavelength division multiplexer 1 and a wavelength division multiplexer 2 respectively. A first circulator and a second circulator are used for controlling the transmission direction of femtosecond laser to form two mutually independent annular resonant cavities. By adopting the combination of the two circulators and utilizing the one-way transmission characteristic of the circulators, two mutually independent annular resonant cavities are formed in one mode-locked fiber laser, and the cavity lengths of the two resonant cavities are tuned by using piezoelectric ceramics respectively, so that femtosecond laser pulse output with double repetition frequencies is realized, the problem that two mode-locked fiber lasers are needed in the prior art is solved, the size is small, the control system is relatively simple, and the fre