JPS6477188A - Semiconductor laser - Google Patents

Abstract

PURPOSE:To produce a semiconductor laser which stably performs fundamental transverse mode oscillation and can perform oscillation of large output with low noise, by forming an optical waveguide of a structure which has a waveguide layer between an active layer and a second clad layer. CONSTITUTION:A buffer layer 202 of n type GaAs, a first clad layer 203 of n type AlxGa1-xAs, an active layer 204 of AlyGa1-yAs (x>y), a waveguide layer 205 of AluGa1-uAs, a second clad layer 206 of p type AlzGa1-zAs (z>y), and a contact layer 207 of p type GaAs are formed in turn on a substrate 201 of n type GaAs so that a desired structure is produced. Moreover, the width of an index waveguide is approximately equal to the current injection width, in the vicinity of the end surfaces of a resonator, to form an index waveguide mechanism. As a result, a single transverse mode oscillation can be stably performed, and the laser beam with very small astigmatic difference is emitted.