Abstract: A GRINSCH laser having an asymmetric configuration wherein the optical confinement is weighted more to the n-doped multilayer section than to the p-doped multilayer section. The GRINSCH laser can emit laser light at a wavelength ?=976 nm over a broad area with a beam power of 11.4 W at a 12 A bias current at a temperature of 20° C. Fabry-Perot and distributed Bragg reflector GRINSCH laser configurations are disclosed.

Abstract: Metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size. Additional embodiments of the present disclosure relate to the respective geometries and orientations of adjacent pairs of contact pads. Still further embodiments are disclosed and claimed.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.

Abstract: In accordance with one embodiment of the present disclosure, a process of manufacturing a semiconductor laser diode comprising a gain section, a QWI output window, and QWI waveguide areas is provided. The QWI waveguide areas are fabricated using quantum well intermixing and define a QWI waveguide portion in the QWI output window of the laser diode. The QWI output window is transparent to the lasing wavelength ?L. The QWI waveguide portion in the QWI output window is characterized by an energy bandgap that is larger than an energy bandgap of the gain section such that the band gap wavelength ?QWI in the QWI waveguide portion and the QWI output window is shorter than the lasing wavelength ?L. The QWI output window is characterized by a photoluminescent wavelength ?PL. The manufacturing process comprises a ?PL screening protocol that determines laser diode reliability based on a comparison of the lasing wavelength ?L and the photoluminescent wavelength ?PL of the QWI output window.

Abstract: An optical package is provided comprising a laser diode and a wavelength conversion device. The laser diode and the wavelength conversion device define an external laser cavity and the wavelength conversion device is tilted relative to the output face of the laser diode to define a tilt angle ? that is less than approximately 85°. The input face of the wavelength conversion device comprises a pair of tapered facets and a microlens. The pair of tapered facets and the microlens are defined on the input face such that they share respective portions of the facial waveguide region on the input face, with the tapered facets occupying peripheral portions of the facial waveguide region on the input face and the microlens occupying an interior portion of the facial waveguide region on the input face. Each of the pair of tapered facets define a facet angle ? within the facial waveguide region that is less than the facet angle ? and is greater than approximately 45°. Additional embodiments are disclosed and claimed.

Abstract: In accordance with one embodiment of the present disclosure, a method of evaluating the operating characteristics of a Distributed Bragg Reflector (DBR) laser diode is provided. According to the method, a diagnostic electrical current is injected into the wavelength tuning section of the DBR laser to generate amplified spontaneous emission of light in the wavelength tuning section. Light emitted from the wavelength tuning section is absorbed by the gain section and photo current generated by the light absorbed in the gain section is measured. The photo current measured in the gain section can be correlated with an evaluation of the operating characteristics of the DBR laser diode. For example, the measured photo current can be correlated with a substandard operating characteristic when it departs from a given photo current metric by more than an acceptable amount. Additional embodiments are disclosed and claimed.

Abstract: In accordance with one embodiment of the present disclosure, a process of manufacturing a semiconductor laser diode comprising a gain section, a QWI output window, and QWI waveguide areas is provided. The QWI waveguide areas are fabricated using quantum well intermixing and define a QWI waveguide portion in the QWI output window of the laser diode. The QWI output window is transparent to the lasing wavelength ?L. The QWI waveguide portion in the QWI output window is characterized by an energy bandgap that is larger than an energy bandgap of the gain section such that the band gap wavelength ?QWI in the QWI waveguide portion and the QWI output window is shorter than the lasing wavelength ?L. The QWI output window is characterized by a photoluminescent wavelength ?PL. The manufacturing process comprises a ?PL screening protocol that determines laser diode reliability based on a comparison of the lasing wavelength ?L and the photoluminescent wavelength ?PL of the QWI output window.

Abstract: An optical package is provided comprising a laser diode and a wavelength conversion device. The laser diode and the wavelength conversion device define an external laser cavity and the wavelength conversion device is tilted relative to the output face of the laser diode to define a tilt angle ? that is less than approximately 85°. The input face of the wavelength conversion device comprises a pair of tapered facets and a microlens. The pair of tapered facets and the microlens are defined on the input face such that they share respective portions of the facial waveguide region on the input face, with the tapered facets occupying peripheral portions of the facial waveguide region on the input face and the microlens occupying an interior portion of the facial waveguide region on the input face. Each of the pair of tapered facets define a facet angle ? within the facial waveguide region that is less than the facet angle ? and is greater than approximately 45°. Additional embodiments are disclosed and claimed.

Abstract: An external cavity laser source is provided comprising an external laser cavity, a tunable distributed Bragg reflector (DBR), a DBR tuning element, an output reflector, a semiconductor optical amplifier (SOA), a frequency-selective optical coupler/reflector, and a wavelength conversion device. The tunable DBR, the DBR tuning element, the SOA, and the output reflector are configured to generate a fundamental laser signal characterized by a fundamental bandwidth that is narrower than the QPM bandwidth of the wavelength conversion device and can be tuned to a fundamental center wavelength within the QPM bandwidth. The frequency-selective optical coupler/reflector is configured for substantially non-reflective two-way transmission of optical signals at the fundamental center wavelength and is further configured for substantially complete reflection of wavelength-converted optical signals generated by the wavelength conversion device.

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 gain current 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: Metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size. Additional embodiments of the present disclosure relate to the respective geometries and orientations of adjacent pairs of contact pads. Still further embodiments are disclosed and claimed.

Abstract: In accordance with one embodiment of the present disclosure, a method of evaluating the operating characteristics of a DBR laser diode is provided. According to the method, a diagnostic electrical current is injected into the wavelength tuning section of the DBR laser to generate amplified spontaneous emission of light in the wavelength tuning section. Light emitted from the wavelength tuning section is absorbed by the gain section and photo current generated by the light absorbed in the gain section is measured. The photo current measured in the gain section can be correlated with an evaluation of the operating characteristics of the DBR laser diode. For example, the measured photo current can be correlated with a substandard operating characteristic when it departs from a given photo current metric by more than an acceptable amount.

Abstract: The present invention relates generally to semiconductor lasers and laser projection systems. According to one embodiment of the present invention, a method of correcting output power variations in a semiconductor laser is provided. According to the method, an output power feedback loop is utilized to generate optical intensity feedback signals representing actual output power of the laser source for discrete portions V1, Vi, . . . Vj of the image signal. Error signals E1, Ei, . . . Ej are generated representing the degree to which actual projected output power varies from a target projected output power for the discrete portions V1, Vi, . . . Vj of the image signal. These error signals E1, Ei, . . . Ej are utilized to apply corrected control signals G1?, Gi?, . . . Gj? to the gain section of the semiconductor laser for projection of compatible discrete portions V1?, Vi?, . . . Vj? of the image signal.

Abstract: The present invention relates generally to semiconductor lasers and laser projection systems. According to one embodiment of the present invention, a method of correcting output power variations in a semiconductor laser is provided. According to the method, an output power feedback loop is utilized to generate optical intensity feedback signals representing actual output power of the laser source for discrete portions V1, Vi, . . . Vj of the image signal. Error signals E1, Ei, . . . Ej are generated representing the degree to which actual projected output power varies from a target projected output power for the discrete portions V1, Vi, . . . Vj of the image signal. These error signals E1, Ei, . . . Ej are utilized to apply corrected control signals G1?, Gi?, . . . Gj? to the gain section of the semiconductor laser for projection of compatible discrete portions V1?, Vi?, . . . Vj? of the image signal.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.

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: Methods of controlling semiconductor lasers are provided where, the time-averaged optical spectrum of the semiconductor laser is broadened by modulating the drive current at a relatively high frequency. Generally, the frequency of the drive current modulation is high enough to induce wavelength chirping within the data periods encoded in the gain current signal. Laser controllers and projections systems operating according to the disclosed methodology are also provided.

Abstract: A semiconductor laser source is provided wherein the wavelength selective section of the laser diode comprises a P+ type current confinement 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 of the laser diode. The first set of interdigital heater electrodes are positively or negatively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the relative bias is either less than the forward bias turn-on voltage of the P-N junction or has an absolute value less than the reverse break-down voltage of the P-N junction.

Abstract: A semiconductor laser source is provided wherein the wavelength selective section of the laser diode comprises a P+ type current confinement 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 of the laser diode. The first set of interdigital heater electrodes are positively or negatively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the relative bias is either less than the forward bias turn-on voltage of the P-N junction or has an absolute value less than the reverse break-down voltage of the P-N junction.

Abstract: According to one embodiment of the present invention, a programmable light source comprises one or more semiconductor lasers, a wavelength conversion device, and a laser controller. The controller is programmed to operate the semiconductor laser using a modulated feedback control signal. The wavelength control signal is adjusted based on the results of a comparison of a detected intensity signal with a feedback signal to align the lasing wavelength with the conversion efficiency peak of the wavelength conversion device. Laser controllers and projections systems operating according to the control concepts of the present invention are also provided.