| 摘要 |
PURPOSE:To obtain a high output from a semiconductor laser element at a low threshold current by forming a mesa type stripe having a wavy grating on a P-type InP substrate, and forming an N-type InP current constriction layer and a P-type InP current constriction layer at both sides of the stripe. CONSTITUTION:When a semiconductor laser element having a DH structure which has internal current constriction layers 12, 13 on a substrate 10 with a mesa and an optical guide layer 14, an active layer 15 and a clad layer 16 in a stripelike groove is formed, the substrate 10 is formed of a P-type InP substrate, and a wavy grating 10a of suitable pitch and depth is formed on the stripe. Further, the top of the mesa is covered with a dielectric film 11 made of SiO2, the N-type and P-type current constriction layers 12, 13 of the thickness durable even if sufficiently high voltage is applied to the both sides thereof are selectively formed, stripelike shallow grooves are formed, and SiO2 or the like 11 is removed by etching. Then, the DH structure is formed by a second LPE. Thus, the layers 12, 13 become PNP junction structure to improve its breakdown strength, and a high voltage can be applied to operate at a high output. |
