Numerical modeling of dynamics and frequency noise of InGaAsP/InP laser and its dependence on optical feedback and non-radiative recombination

Abstract This article highlights the important roles of the non-radiative recombination (NRR) rate and optical feedback (OFB) in improving the dynamics and frequency noise (FN) of laser diodes (LDs). We categorize the dynamics of lasers based on bifurcation diagrams of photon numbers. Our findings show that a lower NRR rate stabilizes the laser output and promotes continuous wave mode. In regions with strong OFB, reducing the NRR rate shifts the operation from chaotic to stable modes, aligning the FN with the characteristics of solitary lasers. In the chaotic region, the FN increases by more than twelve orders of magnitude compared to the solitary laser noise level. In contrast, under weak OFB, as the NRR rate increases, low-frequency FN rises significantly. Under very strong OFB, FN drops dramatically to levels four orders of magnitude lower than those observed in solitary lasers as the injection current increases. By carefully engineering the NRR rate and manipulating the OFB strength, we can effectively stabilize LD performance and advance laser technology.