Abstract: A method of making an (In,Ga)(As,P) inverted rib waveguide laser in which a lateral waveguiding effect is provided by an inverted rib formed in intermediate index material spacing the active layer from the substrate which accommodates the rib in a channel in the substrate includes forming the channel with {111}B or {011} plane side walls, thereby permitting the use of a thinner intermediate index material layer than is possible when using a channel with {111}A plane sides.

Abstract: A method of making a channel substrate buried heterostructure InP/(In,Ga)(As,P) laser avoids the need to use two separate stages of epitaxial growth by using a channel in a (100) surface substrate 1 extending in the [011] direction with {111}B sides. This allows the channel to be made before the growth of an (In,Ga)(As,P) blocking layer 3 which can be grown under conditions which do not require the use of a mask to prevent nucleation on the channel sides. The same technique is also applicable to the manufacture of a terraced substrate laser incorporating a blocking layer.

Abstract: In the manufacture of an InP/(In,Ga) (As,P) buried rib laser, the sides of the laser are profiled to have surfaces extending in {111} A planes down to the junction between the active and lower confining layers, and to have surfaces extending in other planes beneath this junction. In the subsequent epitaxial regrowth nucleation above this junction between the surfaces is discriminated against in favor of growth beneath this junction so that the regrowth up the sides of the rib is automatically temporarily arrested in the vicinity of this junction.