Robust Optical Frequency Comb Generation by Using a Three-Stage Optical Nonlinear Dynamic

In this article, we propose and investigate a novel scheme to generate optical frequency combs (OFCs) by using a three-stage generator, which is based on optical injection-induced dynamics cascaded by subharmonic electro-optic modulation and the four-wave mixing (FWM) effect. A primary seed OFC is rooted from the nonlinear dynamics in the optically injected semiconductor laser, and its performance is improved using a two-stage booster based on subharmonic electro-optic modulation and the FWM effect. The comb spacing can be easily tuned by adjusting that of the primary seed OFC or through electro-optic modulation by the use of subharmonics with different orders. Moreover, it becomes stabilized because the phase relationship between the comb teeth can be fixed in the process of subharmonic electro-optic modulation. Its optical spectrum continues to be broadened in the following FWM process. Finally, robust OFCs with a comb spacing of 4 GHz and a comb teeth number of 23 and a comb spacing of 5 GHz and a comb teeth number of 21 are experimentally demonstrated.

Automated summary

This article proposes a novel scheme for generating optical frequency combs using a three-stage generator, involving optical injection-induced dynamics, subharmonic electro-optic modulation, and four-wave mixing. The comb characteristics can be easily adjusted by tuning the seed OFC spacing and subharmonic electro-optic modulation, leading to stable comb generation. Additionally, the optical spectrum can be broadened through the FWM process, demonstrating robust OFCs with specific comb spacing and teeth numbers in experiments.