1.55 $\boldsymbol{\mu} \mathbf{m}$ Quantum Dot Lasers with Increased Modal Gain Based on Improved Gain Material with High Size Homogeneity

The optical C-band, centered around 1.55 μm, is essential for fiber-optic communications as it minimizes fiber attenuation and offers optimal signal transmission [1]. The InP-based technologies have driven advancements in long-wavelength lasers, with the InAs/InP quantum dot (QD) system emerging as a promising candidate for 1.55 μm emission, due to its low lattice-mismatch (3.2%), improved temperature stability, and high modulation bandwidth [2], [3]. However, the full potential of this material system has not been fully realized. Significant progress has been made in addressing QD morphological challenges, such as shape, size, and uniformity. However, maintaining reduced inhomogeneous broadening in stacked QD layers, which form the active region of lasers, remains a critical challenge [4]. This study focuses on optimizing InAs QDs to achieve narrower spectral linewidths in stacked QD layers for improved laser performance.