Abstract: A ring-type laser including a traveling wave cavity which incorporates at least first and second straight cavity sections and at least one curved cavity section. Corresponding first ends of the straight cavity sections are interconnected at a first light-emitting facet, and second ends of the straight sections are interconnected by the curved waveguide. Additional curved and straight sections can be linked to provide various ring configurations.

Abstract: A semiconductor ring-type optical device having an optical cavity with at least one partially transmitting facet which serves as an emergence region for light propagating within the optical cavity has the upper surface of the cavity coated with a conductive layer which is divided into at least two segments so as to provide two separate electrodes to allow application of separate voltages to the two segments. When different voltages are applied, one segment of the laser will carry a lower current density than the other, resulting in a lower gain under the electrode having the lower voltage and causing the generated laser wavelength to experience a shift to shorter wavelengths. Accordingly, variations in the voltage applied to the two electrodes allows tuning of the laser output wavelength.

Abstract: A ring-type laser including a traveling wave cavity which incorporates at least first and second straight cavity sections and at least one curved cavity section. Corresponding first ends of the straight cavity sections are interconnected at a first light-emitting facet, and second ends of the straight sections are interconnected by the curved waveguide. Additional curved and straight sections can be linked to provide various ring configurations.