Linearly Polarized Broadband Emission and Multi-Wavelength Lasing in Solution-Processed Quantum Dots.

A miniature laser with linear polarization is a long sought-after component of photonic integrated circuits. In particular, for multi-wavelength polarization lasers, it supports simultaneous access to multiple, widely varying laser wavelengths in a small spatial region, which is of great significance for advancing applications such as optical computing, optical storage, and optical sensing. However, there is a trade-off between the size of small-scale lasers and laser performance, and multi-wavelength co-gain of laser media and multi-cavity micromachining in the process of laser miniaturization remain as significant challenges. Herein, room-temperature linearly polarized multi-wavelength lasers in the visible and near-infrared wavelength ranges are demonstrated, by fabricating random cavities scattered with silica in an Er-doped Cs 2 Ag 0.4 Na 0.6 In 0.98 Bi 0.02 Cl 6 double-perovskite quantum dots (QDs) gain membrane. By regulating the local symmetry and enabling effective energy transfer in nanocrystals, multi-wavelength lasers with ultra-low thresholds are achieved at room temperature. The maximum degree of polarization reaches 0.89. With their advantages in terms of miniaturization, ultra-low power consumption, and adaptability for integration, these lasers offer a prospective light source for future photonic integrated circuits aimed at high-capacity optical applications. This article is protected by copyright. All rights reserved.