Flat Self-Oscillating Parametric Optical Frequency Comb Based on a Dual-Mode Microcavity Laser

A highly coherent and flat optical frequency comb (OFC) based on an optoelectronic oscillator (OEO) is presented using a dual-mode microcavity laser. In this scheme, the microcavity laser is applied as a light source and a photonic microwave filter simultaneously. The dual-mode is phase-locked in the self-injection OEO configuration. Meanwhile, a 10-tones OFC with a frequency spacing of 28.8 GHz is generated without an external microwave source. The generated OFC is further broadened through a parametric frequency mixer by the dispersion compensation and nonlinear expansion technique. Forty-three optical tones with a 5-dB power variation spanning over 10 nm are obtained.