Putting the active

摘要

PURPOSE: To enable a semiconductor laser element to be protected against COD and enhanced in output power by a method wherein a current non-injection region on an active layer adjacent to a projection end face of a double hetero structure cleaved in the lengthwise direction of a resonator and a semiconductor layer larger than the active layer in band gap are provided. ;CONSTITUTION: An n-GaAs buffer layer 2, an n-AlGaAs lower clad layer 3, a GaAs lower light confinement layer 4, an active layer 5, a GaAs upper light trapping layer 6, a P-AlGaAs upper clad layer 7, and a P⁺⁺-GaAs cap layer 8 are successively laminated on an n-GaAs substrate 1. The cap layer 8 and the upper clad layer 7 are etched for the formation of a ridge mesa, a part of the cap layer 8 on the top of the ridge mesa is removed as long as the length of a resonator so as to serve as a current non-injection region 8a, and an SiO_x layer 9, an electrode contact window 9a, and an AlO_x layer 10 are formed. Therefore, when an InGaP layer 11 larger in band gap than the active layer 5 is grown on a cleavage end face, a semiconductor laser element high in power output and reliability can be obtained preventing COD.;COPYRIGHT: (C)1997,JPO