Simple Optical Frequency Comb Generation Based on the Optoelectronic Oscillator

Abstract

The simple optical frequency comb (OFC) with tunable free spectra range (FSR) based on the optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. Thanks to the gain switching effect when the big microwave signal, which is generated by the OEO, is directly modulated to the laser, no optical modulator or microwave source are employed in the system. The FSR can be tuned from 4.33GHz to 7.1GHz by simply changing the bias current of the laser. There are at least 9 combs within the 10-dB power fluctuation. When FSR is 5.4GHz, the phase noise of basic microwave signal reaches to −122dBc/Hz@10kHz.