Multi-Section Waveguide Method for Facet Temperature Reduction and Improved Reliability of High-Power Laser Diodes Kaveh Ebadi 1 , Yuxian Liu 2,3 , Ali Kaan Sünnetçioğlu 1 , Sinan Gündoğdu 1 , Serdar Şengül 1 , Yuliang Zhao 2,3 , Yu Lan 2,3 , Guowen Yang 2,3,4 , Abdullah Demir 1,* 1 Bilkent University, UNAM - Institute of Materials Science and Nanotechnology, Ankara, Turkey, 06800 2 State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an, China, 710119 3 University of Chinese Academy of Sciences, Beijing, China, 100049 4 Dogain Laser Technology (Suzhou) Co., Ltd., Suzhou, China, 215123 ABSTRACT Catastrophic optical mirror damage (COMD) limits the output power and reliability of lasers diodes (LDs). Laser self- heating together with facet absorption of output power cause the facet to reach a critical temperature (T c), resulting in COMD and irreversible device failure. The self-heating of the laser contributes significantly to the facet temperature, but it has not been addressed so far. We implement a multi-section waveguide method where the heat is separated from reaching the output facet by exploiting an electrically isolated window. The laser waveguide is divided into two electrically isolated laser and transparent window sections. The laser section is pumped at high current levels to achieve laser output, and the passive waveguide is biased at low injection currents to obtain a transparent waveguide with negligible heat generation. Using this design, we demonstrate facet temperatures lower than the junction temperature of the laser even at high output power operation. While standard LDs show COMD failures, the multi-section waveguide LDs are COMD-free. Our technique and results provide a pathway for high-reliability LDs, which would find diverse applications in semiconductor lasers. 1. INTRODUCTION GaAs-based high-power LDs have evolved drastically to be used in industrial applications [1, 2 ]. Although they have the highest electro-optical conversion efficiency and record output power levels [3,4,5], the primary problem limiting the reliable output power of LDs is still COMD at the output facet, which has been studied extensively [6, 7]. COMD limits the performance of the LDs and directly affects fiber and solid-state lasers that rely on high-power LDs as pump sources. Therefore, a method for solving COMD in LDs directly improves the performance, reliability and cost of modern high- power fiber, direct-diode and solid-state lasers. In general, heat adversely affects the electronic and optoelectronic device performance and lifetime. In LDs, self-heating contributes the most to laser facet heating, causing the facet to reach a critical temperature (Tc), resulting in a feedback mechanism resulting in COMD and device failure [7]. Many attempts have been reported in the literature to address this issue, such as the current blocking layer near the output facet [8], non-absorbing mirror (NAM) [9], ultra-high vacuum (UHV) passivation [10], passivation of air-exposed surface states [11] and quantum well intermixing [12, 13, 14]. * abdulllah.demir@unam.bilkent.edu.tr Semiconductor Lasers and Laser Dynamics X, edited by Marc Sciamanna, Krassimir Panajotov, Sven Höfling, Proc. of SPIE Vol. 12141, 1214104 © 2022 SPIE · 0277-786X · doi: 10.1117/12.2621651 Proc. of SPIE Vol. 12141 1214104-1 Downloaded From: https://www.spiedigitallibrary.org/conference-proceedings-of-spie on 20 Feb 2023 Terms of Use: https://www.spiedigitallibrary.org/terms-of-use