Experimental Investigation on the Mode Characteristics of an Excited-State Quantum Dot Laser under Concave Mirror Optical Feedback

Abstract

In this paper, we experimentally investigated the mode configuration of an excited-state quantum dot laser (ESQDL) under concave mirror optical feedback, and the influences of the feedback strength on the mode characteristics were analyzed. The results showed that after introducing concave mirror optical feedback, some longitudinal modes of the excited-state (ES) existing in a free-running ESQDL could be suppressed. When the feedback strength increased to a certain extent, the ground-state (GS) emission occurred and co-existed with the ES emission. By further increasing the feedback strength, all the longitudinal modes of the ES emission were suppressed, and only the longitudinal modes of the GS emission could be observed. As a result, the emission-state switching from the ES to GS emission was realized. When the ESQDL was biased at a larger current, the feedback strength required to achieve emission-state switching was stronger.

Theorems for Arcs of Different Circles Having Same Arc-Angles with Application in Concave and Convex Structures

“…For two concave mirrors (Zheng et al, 2023) with arcs A 1 E 1 B 1 and A 2 E 2 B 2 having same arc angles created from different size objects, the arc length can be calculated using Arc and Chord Length theorem (Figure 3).…”

Preface for Special Issue: Advancements in Semiconductor Lasers

“…Further expanding on the study of nonlinear dynamics of semiconductor lasers and their applications, Zhao et al experimentally investigated the nonlinear dynamics of an inter-band cascade laser under variable-aperture optical feedback, revealing various dynamical states [7]. Additionally, the mode configuration of an excited-state quantum dot laser (ESQDL) under concave mirror optical feedback demonstrating the selective excitation of longitudinal modes was explored [8]. Bian et al proposed a simple method using mutually coupled free-running VCSELs to generate broadband polarization chaos [9], while the locking map of a semiconductor laser under the injection of a frequency comb was studied [10].…”