Influence of Radiative and Non-Radiative Recombination Lifetimes and Feedback Strength on the States and Relative Intensity Noise of Laser Diode

Abstract

A systematic treatment of the influence of the optical feedback (OFB) and the ratio of the radiative and the non-radiative recombination lifetime (τr/τnr) on the relative intensity noise (RIN) and the system dynamics of a semiconductor laser (SL) is presented. We found that the ratio τr/τnr causes a significant change in the intensity of noise, states, and route to chaos of such a system. Laser transit from a continuous wave (CW) to a periodic oscillation (PO) becomes faster in terms of the OFB strength by increasing the ratio τr/τnr. The route to chaos was identified in three distinct operating regions, namely, PO, period doubling (PD), and sub-harmonics (SH), which are dependent on the ratio τr/τnr, and injection current. In the route to chaos regime, the ratio τr/τnr triggers a slight shift in the frequency with reference to the frequency of the solitary laser. At upmost levels of the current, the highest value of the ratio τr/τnr stabilizes the laser and stimulates it to operate in CW or PO. In the strong OFB region, when the ratio τr/τnr increases, the chaotic operation changed to CW or PO operation and RIN is suppressed close to the quantum noise level.

Keywords

• semiconductor lasers
• radiative and non-radiative recombination
• optical feedback
• intensity noise
• chaos
• bifurcation diagram