Carrier density non-pinning at stripe edges and widened lateral far field due to longitudinal temperature variation in broad-area high power diode lasers

Khamari, S. K., Arslan, S., Zink, C., Sweeney, S. J. and Crump, P. (2023) Carrier density non-pinning at stripe edges and widened lateral far field due to longitudinal temperature variation in broad-area high power diode lasers. Applied Physics Letters, 122(21), 211101. (doi: 10.1063/5.0149986)

Abstract

Broad area lasers operating at high power with improved beam quality are needed in many applications. In typical high-power diode lasers with asymmetric facet coating, it is observed that the carrier density fails to completely pin above threshold with significant levels of lateral carrier accumulation (LCA) at the front facet stripe edges. Systematic experimental data are presented to quantify such non-pinning and its effect on lateral far field in multiple diode lasers with varying longitudinal temperature variation (LTV) using spontaneous emission imaging. LTV is quantified and correlated with the carrier accumulation and its dependence on facet reflectivity and cavity length. Results of measurements under continuous wave (CW) and quasi-CW conditions are used to regulate the level of heating and, hence, to isolate the contribution of LTV and optical field profile. Conventional long resonator asymmetric-coated devices show a twofold increase in LCA from threshold to 10 A current at the front stripe edge, but LCA varies less than 20% for lower facet asymmetry or short resonators. Similarly, strong temperature driven far field broadening is observed for conventional long-resonator asymmetric-coated devices (3°–4° variation with temperature at 10 A), which is strongly reduced for lower facet asymmetry or short resonators (<1° at 10 A).

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sweeney, Professor Stephen

Creator Roles

Sweeney, S.: Funding acquisition, Supervision, Writing – review and editing

• Authors: Khamari, S. K., Arslan, S., Zink, C., Sweeney, S. J., and Crump, P.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Applied Physics Letters
• Publisher: AIP Publishing
• ISSN: 0003-6951
• ISSN (Online): 1077-3118
• Published Online: 24 May 2023
• Copyright Holders: Copyright © 2023 AIP Publishing
• First Published: First published in Applied Physics Letters 122(21):211101
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher