N-TYPE MODULATION-DOPED MULTI QUANTUM WELL SEMICONDUCTOR LASER DEVICE

摘要

An n-type modulation dope multiple quantum well semiconductor laser having amultiple quantum well structure comprising a heterojunction structure of awell layer and a barrier layer, wherein the well layer is made of a nondopedsemiconductor material, the barrier layer is made of a semiconductor materialmodulation-doped with an n-type dopant, a low-reflectance film is formed onthe front edge face, a high-reflectance film is formed on the back edge face,the cavity length is 800 µm or more, and the mirror loss (.alpha.m)expressed by .alpha.m=(1/2L)ln(1/(Rf.Rr)) (where L is the cavity length (cm),Rf is the reflectance of the front edge face, and Rr is the reflectance of theback edge face) is 15 cm-1 or less. The output of the laser is high comparedwith conventional nondoped MQW semiconductor lasers, and the industrial valueof the laser used as, e.g., a 1480-nm laser for EDFA excitation is high.