Patent ID: 7567595

Claim:
A laser source comprising a laser diode and a controller, wherein: the laser diode is configured as a semiconductor heterostructure comprising an anode, a cathode, and an active waveguide layer formed between P and N type semiconductor layers defining a P-N junction; the laser diode comprises a wavelength selective section, a phase matching section, and a gain section, each defined within the semiconductor heterostructure; the wavelength selective section comprises a P+ type current confinement layer formed over the P type semiconductor layer and first and second sets of interdigital heater electrodes formed over the current confinement layer; individual electrode digits of the first and second sets of interdigital heater electrodes alternate in succession along a direction of optical propagation defined by the active waveguide layer; and the controller is connected to the cathode and the first and second sets of interdigital heater electrodes such that the first set of interdigital heater electrodes is positively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the P+-type current confinement layer transports electrical current between adjacent electrode digits of the first and second sets of interdigital heater electrodes along the direction of optical propagation defined by the active waveguide layer.