Abstract: Methods are disclosed for forming Group III--arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

Abstract: A optical medium, such as an angled distributed reflector, e.g., an angular grating, or .alpha.-DFB laser diode or a waveguide wavelength selective filter, has a mean optical axis defining an optical cavity for substantially confined light propagation within the device. An angular grating is provided in at least a portion of the optical cavity forming a grating region permitting light to propagate along the optical cavity in two coupled waves or modes incident along the angular grating, a first incident propagating wave substantially parallel with respect to the mean optical axis and a second incident propagating wave at an angle with respect to the mean optical axis.

Abstract: III-V arsenide-nitride semiconductor are disclosed. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V materials varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V material can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

Abstract: An optical amplifier system includes a fiber amplifier doped with rare earth dopant provided in its fiber core. A plurality of fiber lasers have their light outputs optically coupled together for launching into the fiber amplifier for optically pumping the amplifier. Each of the fiber lasers have a rare earth dopant provided in its fiber core for stimulated lasing emission with the rare earth dopant of the fiber amplifier being different from the rear earth dopant of the fiber lasers. A reflector may be provided in each of the coupling fibers for reflecting a portion of the respective light outputs back into the fiber lasers to control their wavelength of operation, the wavelength of operation of the reflectors chosen to be within a high absorption region of the absorption band of the fiber amplifier. Where the pump source is a semiconductor laser source, the source may include a flared gain section to increase the output intensity of the light output of the source.

Abstract: Apparatus is provided for an improved stabilized laser source comprising a laser source having a light beam output and an electrical input. An optical waveguide, such as an optical fiber, having an input end is optically coupled to the laser source to receive the light beam. A reflector in the optical fiber, such as fiber grating, reflects a portion of the light beam output back into the laser source. The reflector is provided at a distance from the laser source permitting the laser source to switch between states of coherence and coherence collapse of operation. The electrical input of a drive signal for the laser source includes a modulated signal with variations in amplitude to the electrical input to control the variation in switching between the states of coherence and coherence collapse of the laser source so that continuous laser operation remains kink-free.

Abstract: A device and method for fabricating a high power laser diode device with an output emission with a nearly circular mode profile for efficient coupling into an optical fiber. A vertical taper waveguide and a window tolerance region are formed in a base structure of the device employing successive etching steps. Further regowth completes the device structure. The resultant laser device has a vertical and lateral tapered waveguide that adiabatically transforms the highly elliptical mode profile in an active gain section of the device into a substantially circular mode profile in a passive waveguide section of the device.

Abstract: An external cavity, continuously tunable wavelength source comprising a coherent light source having an external cavity including a reflector, such as a mirror or right-angle prism, for reflecting a selected wavelength from a diffraction grating back into the coherent light source. The wavelength is selected by simultaneous rotation and linear translation of the reflector about a pivot point such that the optical path length of the external cavity is substantially identical to a numerical integer of half wavelengths at a plurality of tunable wavelengths about a central wavelength of a tunable bandwidth for the source such that cavity phase error is zero at the central wavelength and is maximally flat on either side of the center wavelength within the tunable bandwidth. The location of said pivot axis is chosen to set the cavity phase error equal to zero and its first and second derivatives substantially equal to zero at exactly one wavelength.

Abstract: A system and method for operating a high power laser diode device with high efficiency coupling of a laser diode bar. The laser diode bar and a micro-cylinder lens are vertically oriented in a device package, such that the array axis of the laser bar and the longitudinal axis of the micro-cylinder lens are aligned substantially parallel to a gravity vector. In the two different embodiments disclosed, either initial collimation of the fast-axis divergence or, alternatively, initial collimation of both the fast-axis and slow-axis divergences take place before beam reformatting via a beam array turning mirror. Additionally, the vertical orientation of these components is combined with methods of compensating for the bending or "smile" of the laser diode bar to provide for optimal output beam coupling, resulting in a uniform far field intensity distribution.

Abstract: A fiber Bragg grating is used to stabilize the intensity and frequency fluctuations of a diode laser. The diode laser is connected with an opto-mechanical apparatus to the fiber which contains the grating. The grating is formed in the guided-mode region of the optical fiber. The wavelength of maximum grating reflectivity is selected to lie near the maximum of the diode laser gain bandwidth. The magnitude and bandwidth of the grating reflectivity stabilizes the diode laser output without appreciably reducing the optical output power from the end of the fiber. The bandwidth of the optical spectrum of the diode laser is selected depending on the distance of the grating from the diode laser.

Abstract: Apparatus for stabilizing multiple laser sources having distinguishable optical characteristics, e.g., in polarization field or operational wavelength, comprises a plurality of semiconductor laser sources having respective lasing cavities capable of lasing within a narrow bandwidth of wavelengths and providing spectral outputs at their respective laser exit facets having different optical characteristics from one another. The spectral output beams of the sources may be coupled to respective optical fibers and the beams combined via a beam combiner, e.g., a polarizing beam combiner or a WDM combiner. The beam combiner combines the beam outputs forming a single beam which is launched into an output optical fiber. At least one feedback fiber grating is provided in at least one of the optical fibers with the number thereof depending upon distinguishable optical characteristics of the multiple laser sources.

Abstract: A beam reconfiguring device comprises a single prism element that reconfigures a beam input, such as from a semiconductor laser or bar array, having aperture images with major axis aligned abreast along a single axis, into an output comprising multiple segments of the input image with a major axis of each segment aligned perpendicular along the same single axis. The etendue, the aperture-times-divergence product of a beam, in orthogonal directions of the output beam will be more nearly equal than the etendue in orthogonal directions of the input beam. The input beams and reconfigured beams are provided as adjacent inputs to a hypotenuse front edge surface of the prism element. The reconfigured beams are more conducive for converging into a single substantially symmetrical spot for input to an optical handling device or medium such as an optical fiber. An optical handling system is disclosed for achieving straight in-line, beam input/output that is more adaptable for optically aligned delivery applications.

Abstract: As to a first feature, a semiconductor optoelectronic device includes a resonator having an optical cavity between opposite end facets, a larger portion of a length of the resonator cavity comprising a single mode confining region for propagation of light and a smaller portion of a length of the resonator cavity comprising a tapered region for permitting propagation of light with a diverging phase front to a first of the end facets, which first facet is the light beam output. The tapered region provides a sufficiently large aperture to prevent catastrophic optical mirror damage (COD) at the first end facet while reducing the amount of required astigmatism correction while the single mode confining region provides spatial filtering to maintain diffraction-limited beam at the output. This structure therefore, more readily lends itself for incorporation into existing device packages designed for linear stripe laser diodes devices.

Abstract: A method is disclosed for curing epoxy adhesive between the slider head and load/gimbal suspension assemblies of a disk drive access actuator employing a concentrated pulsed heat source rather than conventional, broadly applied heat source as employed in the past, such as oven heating or UV exposure. The laser source power is delivered via an optical fiber to the slider air-bearing surface (ABS) of the slider head assembly so that with this approach, the time for curing can be minimized and accurately controlled without causing damage to the assembly, and the overall curing step in the manufacturing process is reduced in time of application. Apparatus in the form of a fixture, such as an anvil element, provides a convenient gauge and support for alignment of the laser output beam with the slider ABS to which the heat for curing is to be applied as well as provide for its heat sinking.

Abstract: In a double-clad optical fiber comprising a core having an index of refraction n.sub.1, an inner cladding surrounding the core and having an index of refraction n.sub.2, and a first outer cladding surrounding the inner cladding and having an index of refraction n.sub.3 (wherein n.sub.1 >n.sub.2 >n.sub.3), the softness of the first outer cladding often renders it difficult to perform polishing or other mechanical operations on the end of the fiber. To reduce such difficulties it is advantageous to remove the first outer cladding from a limited end portion of the fiber, replacing it with a second outer cladding having an index of refraction n.sub.4 (wherein n.sub.2 >n.sub.4) and a hardness which is greater than that of the first outer cladding.

Abstract: An optical transmission link has both a transmitter module and a receiver module operable under uncooled conditions, i.e., without the need of costly cooling equipment, such as thermoelectric coolers. The optical transmission system includes both a semiconductor laser diode source and an optical receiver module that are both designed to operate uncooled under high frequencies (e.g., GHz range) over a wide temperature range without significant changes in signal bandwidth and at temperatures in excess of 125.degree. C. Compensation is provided to reduce the effect of photodiode noise and amplifier noise. In addition, temperature compensation can be provided that provides for overall reduction in receiver noise across the bandwidth of the receiver module through maintenance of a temperature environment optimizing receiver performance.

Abstract: Two approaches are provided for achieving an optical amplifier system capable of producing high peak power, high energy pulse outputs while suppressing scattering noise. The first approach relates to an optical amplifier system which has at least one laser diode pulsed or cw pumped double clad fiber amplifier utilized for receiving a high frequency modulated injected signal pulse of short duration from the laser diode, via the fiber core, for amplification by coupling pump light into the inner cladding of the fiber. The average signal power is sufficient to saturate the gain of the fiber so as to minimize significant onset and buildup of forward and backward scattering noise. The duty cycle of the injected signal source pulse is chosen to allow adequate gain recovery in the fiber amplifier between pulses.

Abstract: A surface of a compound III-V semiconductor device is passivated and protected, respectively, by treatment with a sulfur-containing or selenium-containing passivation film on the surface followed by the deposit of a GaN, GaP, InGaP, GaAsP, ZnS or ZnSe protection layer. Prior to passivation and deposition of the protective layer, previously formed contact metalizations may be protected with a liftoff film or layer. A low temperature MOCVD process is used to deposit the protection layer so that the integrity of the previously deposited contact metalization is maintained. The preferred range for MOCVD deposition of the protection layer is in the range of about 300.degree. C. to about 450.degree. C. This processing temperature range is within a temperature range where stable contact metalization exists.

Abstract: An optical fiber amplifier having a doped fiber, through which an input signal propagates, is bi-directionally pumped in a manner that provides for a desired composite absorption profile such as, in one case, a uniform degree of local pump energy absorbed along at least a substantial length of the fiber. Co-propagating and a counter-propagating pump sources are prescribed to have their wavelengths selected relative to the peak absorption wavelength of the amplifier to provide for a uniform composite absorption profile across the length of the fiber thereby improving the overall inversion efficiency of the amplifier as well as providing for reduced amplifier noise figure.

Abstract: An apparatus for pumping an optical gain medium, such as a fiber gain medium, comprises a pump source having a plurality of different spatially separate or multiple wavelengths or wavelength bands which are all coupled into the fiber gain medium and provide at least one or more wavelengths to fall within the absorption band of fiber gain medium producing gain despite wavelength shifts in the pump source multiple wavelengths due to changes in the operating temperature of the pump source. At least one or more of the pump wavelengths will overlap the gain spectrum of the fiber gain medium sufficiently to continually provide high input power for pumping of the fiber gain medium.

Abstract: A laser system is provided for supplying high power, stable light intensity via an aperture limited delivery system to an application requiring continuous light output intensity in spite of the laser source being subjected optical feedback noise caused by external system and delivery system perturbations that cause fluctuation in laser source power intensity. Non-stable light intensity in the output is due to environmental temperature changes, and phase and amplitude changes caused by system induced perturbations such as by movement of the aperture limited delivery system and optical artifacts of the optical elements, comprising the aperture limited delivery system, introducing noise into the feedback in the laser system changing the output intensity pattern of the delivered power beam. This can be substantially remedied by the employing a monolithic, multiple, independent single mode laser source which is substantially unaffected by this noise.