Abstract: Formation of an optical modulator in an optical rib waveguide configuration in an epitaxial semiconductor layer is facilitated by using an electrode cladding (electrically conducting-optically transparent) layer for contacting the rib portion of the epitaxial layer. The electrode cladding layer is essentially a polycrystalline compound semiconductive material of suitably low refractive index and is advantageously characterized by a relatively high (0.4 to 1.0 volt or more) heterojunction potential barrier height at the epitaxial layer. The electrode cladding layer results in relatively low optical waveguide cladding loss as well as good electrode contact, thereby facilitating the application of a modulating electric field into the epitaxial rib waveguide during operation. The electrode cladding layer can also serve as a mask for controllably forming the rib portion with a predetermined rib height in the epitaxial layer.

Abstract: Described is a double heterostructure junction laser in which the active region tapers to zero thickness within the structure, causing light to couple into an adjacent, underlying passive waveguide layer. Also described is a laser device in which the passive waveguide layer terminates in a region of increased thickness adjacent a laser output face. In addition, LPE and MBE techniques for fabricating the tapers are described.

Abstract: Described is a double heterostructure (DH) junction laser in which the intermediate layer in which light is guided is composed of an active and a passive zone which are disposed in tandem along the direction of light propagation. The active zone is thin and has a relatively narrow bandgap, and the passive zone is thicker and has a wider bandgap. The transition in thickness and bandgap between zones is relatively gradual. Also described is a monolithic integrated circuit including a DH laser and a DH modulator which have such an intermediate layer in common. In addition, described is an LPE growth technique for fabricating the intermediate layer in which two solutions, used to grow simultaneously zones of different composition, are placed on opposite sides of a partition which bifurcates one of the wells of the growth apparatus. The passive zone grows under the partition.

Abstract: Described is a double heterostructure junction laser in which the active region tapers to zero thickness within the structure, causing light to couple into an adjacent, underlying passive waveguide layer. Also described is a laser device in which the passive waveguide layer terminates in a region of increased thickness adjacent a laser output face. In addition, LPE and MBE techniques for fabricating the tapers are described.

Abstract: An optically nonlinear liquid thin film in a thin film optical waveguide is utilized in order to produce optical parametric interactions such as second harmonic generation. Optimization (tuning) of parametric output by "phase matching" is achieved by means of an electric field which is set up in the liquid film, the field having a spatial periodicity along the propagation direction of the optical waves in the thin film. Alternative or further optimization of parametric output is achieved by varying the thickness of the liquid film in situ.