Double heterojunction semiconductor laser having improved high-frequency characteristics

Claim 1

A semiconductor laser comprising a semiconductor body having a substrate of a first conductivity type and a layer structure provided thereon, said layer structure comprising successively at least a first passive layer of the first conductivity type, a second passive layer of the second opposite conductivity type and an active layer having a strip-shaped active region and being located between said first and second passive layers and having a pn junction which at a sufficiently high current strength in the forward direction generates coherent electro-magnetic radiation in the strip-shaped active region of the active layer, the first and second passive layers having a lower refractive index for the generated radiation and a larger band gap that that of the active layer, a current-limiting blocking layer which has a strip-shaped interruption at the area of the active region, and connection conductors electrically connected to the second passive layer and the substrate, characterized in that a high resistance region having a disturbed crystal structure extends outside and on either side of the strip-shaped active region from the side of the semiconductor body located opposite the substrate at least throughout the thickness of the blocking layer.