Double heterostructure laser for direct coupling to an optical fiber

Claim 1

A laser having a semiconductor substrate and a double heterostructure on a surface of said substrate, said structure comprising; a first confining layer of semiconductor material on said surface of said substrate, an active layer of semiconductor material on said first confining layer and a second confining layer on said active layer, said first confining layer being of the same conductivity type as said substrate; said second confining layer being of the opposite conductivity type as said first confining layer and said active layer being of the same conductivity type as one of said confining layers to form a p-n junction between said active layer and one of said confining layers; a cleaved end surface on said structure, said end surface extending normal to the plane of said active layer; a reflecting surface extending through said second confining layer and said active layer and inclined relative to the plane of said active layer to form a resonant cavity between said end surface and a further surface at said substrate surface; a hole through said substrate to said first confining layer, said hole aligned with said reflecting surface for emission of light therethrough; and electrical contact means for applying a forward bias to said active layer.