Semiconductor laser with non-absorbing mirror facet

Claim 1

A semiconductor laser comprising: a body of material having a pair of opposed mirror facets which are reflective of light, at least one of which is partially transmissive of light, said body including: a substrate having first and second opposed surfaces with a pair of substantially parallel channels with a mesa therebetween, in said first surface and extending between said facets; a first confinement layer overlying said first surface and the surfaces of said channels and said mesa; a guide layer overlying said first confinement layer and tapering in thickness in the lateral direction; an active layer overlying a portion of the guide layer and extending towards but not contacting at least one of said facets, thereby forming a first region in the body where said active layer overlies the guide layer and a second region where said active layer does not overlie said guide layer; a second confinement layer overlying said active layer in said first region; a confinement region overlying said guide layer in said second region; and first and second electrical contacts overlying said second confinement layer and said second surface respectively; wherein the lateral tapers of the guide layer in the first and second regions are different; and wherein said active layer has a larger refractive index than said guide layer, said first and second confinement layers and said confinement region.