Abstract: The present invention relates generally to semiconductor lasers and laser projection systems. According to one embodiment of the present invention, a projected laser image is generated utilizing an output beam of the semiconductor laser. A gain current control signal is generated by a laser feedback loop to control the gain section of the semiconductor laser. Wavelength fluctuations of the semiconductor laser are narrowed by incorporating a wavelength recovery operation in a drive current of the semiconductor laser and by initiating the wavelength recovery operations as a function of the gain current control signal or an optical intensity error signal. Additional embodiments are disclosed and claimed.

Abstract: A method for aligning a beam spot with a waveguide portion of a wavelength conversion device includes scanning a beam spot over the input face of the wavelength conversion device while measuring the output intensity of the device such that an output intensity for each of a plurality of fast scan lines is generated. A first alignment set point is then determined based on the output intensity of each fast scan line. A second scan of the beam spot is then performed over the fast scan line containing the first alignment set point while measuring the output intensity for each point along the fast scan line. A second alignment set point is then determined based on the output intensities measured during the second scan. The beam spot is then aligned with the waveguide portion using the first alignment set point and the second alignment set point.

Abstract: The present invention relates generally to semiconductor lasers and laser scanning systems and, more particularly, to schemes for controlling wavelength in semiconductor lasers. According to one embodiment of the present invention, a method of minimizing laser wavelength variations in a semiconductor laser is provided. According to the method, one or more of the laser drive currents is configured to comprise a drive portion and a wavelength recovery portion. The wavelength recovery portion of the drive current comprises a recovery amplitude IR that is distinct from the drive amplitude ID and a recovery duration tR that is less than the drive duration tD. The recovery amplitude IR and duration tR are sufficient to recover carrier density distribution distorted by gain compression effects prior to recovery. Additional embodiments are disclosed and claimed.

Abstract: Methods of controlling semiconductor lasers are provided where the semiconductor laser generates a wavelength-modulated output beam ?MOD that is directed towards the input face of a wavelength conversion device. The intensity of a wavelength-converted output ?CONV of the device is monitored as the output beam of the laser is modulated and as the position of the modulated output beam ?MOD on the input face of the wavelength conversion device is varied. A maximum value of the monitored intensity is correlated with optimum coordinates representing the position of the modulated output beam ?MOD on the input face of the wavelength conversion device. The optical package is operated in the data projection mode by directing an intensity-modulated laser beam from the semiconductor laser to the wavelength conversion device using the optimum positional coordinates. Additional embodiments are disclosed and claimed. Laser controllers and projections systems are also provided.

Abstract: The present invention relates to relates generally to semiconductor lasers and, more particularly, to schemes for measuring and controlling the temperature of semiconductor lasers and schemes for wavelength stabilization of semiconductor lasers. According to one embodiment of the present invention, a method of driving a temperature control mechanism in a semiconductor laser is provided. According to the method, signals representing an operating temperature of the semiconductor laser and ambient temperature are generated and a target laser operating temperature that is a function of the ambient temperature signal is established. A temperature control mechanism of the semiconductor laser is then driven to increase a degree of correlation between the operating temperature signal and the target laser operating temperature. Additional embodiments are disclosed and claimed.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser scanning systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser is configured for optical emission of encoded data. At least one parameter of the optical emission is a function of a drive current IGAIN injected into the gain section of the semiconductor laser and one or more additional drive currents I/VPHASE, I/VDBR. Mode selection in the semiconductor laser is altered by perturbing at least one of the additional drive currents I/VPHASE, I/VDBR with a perturbation signal I/VPTRB to alter mode selection in the semiconductor laser such that a plurality of different emission modes are selected in the semiconductor laser over a target emission period.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser scanning systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser is configured for optical emission of encoded data. At least one parameter of the optical emission is a function of a drive current IGAIN injected into the gain section of the semiconductor laser and one or more additional drive currents I/VPHASE, I/VDBR. Mode selection in the semiconductor laser is altered by perturbing at least one of the additional drive currents I/VPHASE, I/VDBR with a perturbation signal I/VPTRB to alter mode selection in the semiconductor laser such that a plurality of different emission modes are selected in the semiconductor laser over a target emission period.

Abstract: The present invention relates generally to semiconductor lasers and laser scanning systems and, more particularly, to schemes for controlling wavelength in semiconductor lasers. According to one embodiment of the present invention, a method of minimizing laser wavelength variations in a semiconductor laser is provided. According to the method, one or more of the laser drive currents is configured to comprise a drive portion and a wavelength recovery portion. The wavelength recovery portion of the drive current comprises a recovery amplitude IR that is distinct from the drive amplitude ID and a recovery duration tR that is less than the drive duration tD. The recovery amplitude IR and duration tR are sufficient to recover carrier density distribution distorted by gain compression effects prior to recovery. Additional embodiments are disclosed and claimed.

Abstract: The present invention relates to relates generally to semiconductor lasers and, more particularly, to schemes for measuring and controlling the temperature of semiconductor lasers and schemes for wavelength stabilization of semiconductor lasers. According to one embodiment of the present invention, a method of driving a temperature control mechanism in a semiconductor laser is provided. According to the method, signals representing an operating temperature of the semiconductor laser and ambient temperature are generated and a target laser operating temperature that is a function of the ambient temperature signal is established. A temperature control mechanism of the semiconductor laser is then driven to increase a degree of correlation between the operating temperature signal and the target laser operating temperature. Additional embodiments are disclosed and claimed.

Abstract: The present invention relates to methods for modulating a semiconductor laser and wavelength matching to a wavelength converter using monolithic micro-heaters integrated in the semiconductor laser. The present invention also relates to wavelength matching and stabilization in laser sources in general, without regard to whether the laser is modulated or whether second harmonic generation is utilized in the laser source. According to one embodiment of the present invention, a method of compensating for thermally induced patterning effects in a semiconductor laser is provided where the laser's heating element driving current IH is set to a relatively high magnitude when the laser's driving current ID is at a relatively low magnitude. Additional embodiments are disclosed and claimed.