Semiconductor diode laser and method of manufacturing same

Abstract

A diode laser present in an gas or vacuum atmosphere. The semiconductor body of the diode laser comprises two end faces which bound the resonant cavity within which radiation is generated in an active region. The active region forms part of an active layer situated between two cladding layers on a substrate. At least one end face is coated with a covering layer. The covering layer comprises at least two sub-layers of a first dielectricum with a first refractive index and of a second dielectricum with a second refractive index, respectively, and the optical thicknesses and refractive indices of the sub-layers are chosen such that the maximum intensity of the field strength of the generated radiation in the semiconductor body and the covering layer lies outside the end face, and preferably such that the intensity of the field strength of the generated radiation is approximately a minimum adjacent the end face. Preferably, the covering layer comprises two or three sub-layers of dielectric materials such as Al.sub.2 O.sub.3, Si.sub.3 N.sub.4, and SiO.sub.2, on an exit face. A very thin intermediate layer of Si or Al is preferably present between the semiconductor body and the covering layer. The invention also relates to a method of manufacturing such a diode laser.