Proton implantation in just above active region for improvement of power conversion efficiency of VCSELs

Abstract

Improving the power conversion efficiency of vertical cavity surfaceemitting lasers (VCSELs) by three-dimensionally control of the carrier concentration, which is the main mechanism of the electrical resistance and optical absorption has been investigated using the proton implantation technique just above the active region. The fabricated VCSELs showed improved power conversion efficiency of approximately 3 points without serious deterioration of threshold current and operating voltage. Improvement of slope efficiency from 0.5 W/A to 0.6 W/A is the main cause and these improved the output power by 1.2 times. Co., Ltd. and the Tsurugi-Photonics Foundation. Part of the device fabrication process was supported by SHI-ATEX Co., Ltd. and Ricoh Co., Ltd.