Abstract: A system and method for implementing a next generation laser-like light source with Free Electron Lasers (FELs) are provided whereby the construction of a Free Electron Laser (FEL) is customized through the use of individual modules having specified characteristics. Such individual modules include conventional lasers, electron guns, linear accelerators, magnetic bunch compressors and permanent magnet, hybrid, and electromagnetic, undulators or a combination of these undulators. These individual modules are arranged to exploit the occurring fundamental and nonlinear harmonics generated in each SP HG FEL to be used themselves as a light source, or alternatively to be a coherent seed for another module, such as, in high-gain harmonic generation (HGHG). An efficient method for producing shorter wavelengths of a synchrotron light source is provided. A three step process including imprinting, upconverting or wavelength shifting and reinforcing or strengthening of the electron beam microbunching is provided.

Abstract: A semiconductor laser (100) comprises, in succession, a first reflector (102), a first optically active region (104), which can emit light of a first wavelength (&lgr;1), a second reflector (107), a second optically active region (110), which can emit light of a second wavelength (&lgr;2), which is shorter than the first wavelength (&lgr;1), and a third reflector (112), wherein the two optically active regions (110, 112) are able to emit their light on a common optical axis (118) in a common emission direction (119).

Abstract: A projection lithography system exposes a photo sensitive material on a surface of a semiconductor substrate that includes surface height variations between a high level and a low level. The system comprises an illumination source projecting illumination within a narrow wavelength band centered about a nominal wavelength on an optic path towards the substrate during an exposure period. A wavelength modulation system within the optic path comprises means for chromatically separating the narrow wavelength band into at least two sub-bands, the first sub-band being smaller than the narrow wavelength band and centered about a first sub-band wavelength and the second sub-band being smaller than the narrow wavelength band and centered about a second sub-band wavelength and means for passing each of the first sub-band and the second sub-band during distinct time periods within the exposure period.

Abstract: A laser apparatus capable of emitting laser beams of a plurality of different wavelengths includes: a solid-state laser medium which emits light of a plurality of different peak wavelengths; a resonance optical system which resonates the emitted light of the plurality of different peak wavelengths and converts respective light to oscillate the laser beams of the plurality of different wavelengths; and a ¼ wave plate for a wide band, which is placed in the resonance optical system and has a property of providing a uniform phase difference to the light of the plurality of different peak wavelengths to be converted.

Abstract: An ultra-broadband, variable and multiple wavelength, waveform shaping apparatus is disclosed that excels with the ability to yield light pulses shaped in waveform, variable and multiple in wavelength over an ultra-broad bandwidth, the pulses being as short as in the order of pico-seconds or less, or even in the order of femto-seconds.

Abstract: An alignment system for co-aligning multiple laser beams to a single spatial reference point in real time. The alignment system includes a beam sampler for sampling the multiple pulsed laser beams. The sampled laser beams are directed onto a quadrant photo detector or quad cell. The output signals from the quad cell are directed to a detector signal integration circuit which develops error signals for driving tip-tilt mirrors in the beam path of the multiple lasers. The system includes a gate, reset and pulse ID generator for generating pulse trigger signals for each of the multiple lasers and signals for correlating the detector signals with the laser that produced the signal. Accordingly, a system is provided for a time multiplexed, multiple laser system which automatically co-aligns the output beams from each of the lasers to a single spatial reference point in real time.

Abstract: An arrangement for tuning a micro-electro-mechanical (MEM) laser center wavelength to exactly match the passband of its associated filter. A dither wavelength locked feedback loop dynamically adjusts the position of the MEM element, and hence the laser, wavelength, to keep it nominally centered at the filter passband peak. The dither wavelength locked feedback loop compensates for many internal variables of the laser, filter, and the MEM with a single mechanism that stabilizes the laser and locks the wavelength to any desired value.

Abstract: An etching control layer with a composition different from that of a compound semiconductor substrate is deposited over the surface of the substrate. Then, a first multilayer structure, made up of multiple semiconductor layers including a first active layer with a composition different from that of the etching control layer, is defined over the etching control layer. A first semiconductor laser structure is formed out of the first multilayer structure on a first region of the substrate by selectively etching and patterning the first multilayer structure. A second multilayer structure, made up of multiple semiconductor layers including a second active layer, is defined over the surface of the substrate as well as over the first semiconductor laser structure. A second semiconductor laser structure is formed out of the second multilayer structure on a second region of the substrate by selectively etching and patterning the second multilayer structure.

Abstract: YAG laser can simultaneously emit a plurality of laser beams having different wavelengths from each other. By simultaneously irradiating the laser beams having different wavelengths from each other to a same region of a non-single crystal semiconductor film, an interference influence is suppressed to obtain a more uniform laser beam. For example, by simultaneously generating second and third harmonics of YAG laser to irradiate the same region through suitable optical system, a laser beam having higher uniformity and having an energy in which interference is highly suppressed is obtained.

Abstract: A multi-wavelength laser device includes at least two of a blue laser diode, a red laser diode, and an infrared laser diode, which are arranged in the same direction on the same base. One laser light emission point is arranged behind another in increasing order of wavelengths of the laser diodes.

Abstract: Extremely advanced technology for scrambling an optical signal based on quantum mechanical fluctuation is used to provide a highly reliable optical communication method which can invalidate illicit activities such as wire-tapping, a system, and a laser oscillator which is used in the method and system. A transmitter side generates laser light, simultaneously oscillated at a plurality of wavelengths, the total number of generated photons being constant, and transmits a signal light comprising data which has been added to the light of the plurality of wavelengths; and at a receiving side, light, simultaneously oscillated at the plurality of wavelengths, is selected from the signal light, and the data is demodulated.

Abstract: A programmable multiwavelength modelocked laser system. Embodiments of the system can use a computer, gratings, optical spectrum analyzer and SLM(spatial light modulator) inside of a laser cavity to control output amplitudes and phase of each of the wavelength channels of a multiple wavelength laser system. The programmable control allows for wavelength intensity(amplitude) levels of up to approximately 16 channels to be controlled and evened out. An InGaAsP SOA based modelocked multiwavelength ring laser is stabilized using a programmable liquid crystal spatial light modulator in a feedback control loop. The system produces 16 independent modelocked RZ wavelength channels at 10 GHz with 0.44 dB flatness and 25 psec pulses.

Abstract: Provided are a semiconductor laser device capable of increasing an emission angle of a laser beam, an astigmatic correction plate used therefor and a method of arranging the astigmatic correction plate. In order to correct the astigmatism of a laser beam emitted from a first laser light source or a second laser light source, the astigmatic correction plate is arranged so as to intersect diagonally an optical center line (an optical axis) of the laser beam, and the astigmatic correction plate, the first light source and the second light source are arranged so that an optical axis of the first laser light source coincides with a center line (CL) of an effective diameter of an aperture and a distance from the second laser light source to the astigmatic correction plate in a direction parallel to the optical axis is shorter than a distance from the first laser light source to the astigmatic correction plate.

Abstract: A semiconductor laser device comprises: a first light-emitting element having a first laser part, an insulating layer, and an ohmic electrode layer; and a second light-emitting element having a second laser part, an insulating layer, and an ohmic electrode layer. The first laser part has a ridge waveguide, and is formed by stacking thin films of group-III nitride compound semiconductors (for example, GaN-based semiconductors). The second laser part has a ridge waveguide, and is formed by stacking thin films of group III-V compound semiconductors (such as GaAs). The first laser part and the second laser part are integrally bonded to each other by the interposition of an adhesive metal layer which is formed between the ohmic electrode layers. This provides the semiconductor laser device with a small distance between the light-emitting spots of the laser parts.

Abstract: A failure analysis system and method for multi-layer semiconductor devices, including a molecular fluorine laser system for producing a 157 nm beam and an imaging system for imaging the beam onto the semiconductor device. The laser beam etches away one or more top (passivation) layers to expose layers disposed underneath. Circuitry formed in exposed layers can then be tested.

Abstract: A multiple wavelength surface-emitting laser device equipped with a substrate and a plurality of surface-emitting lasers formed on the substrate by a continuous manufacturing process is provided. Each surface-emitting laser includes a bottom reflection layer on the substrate, that is doped with impurities of one type and composed of alternating semiconductor material layers having different refractive indexes; an active layer that is formed on the bottom reflection layer; an intermediate layer that is doped with impurities of the other type on the active layer; a top electrode that is formed on the intermediate layer to have a window through which light is emitted; and a dielectric reflection layer where dielectric materials with different refractive indexes are alternately layered on the intermediate layer and/or the top electrode to a thickness suitable for a desired resonance wavelength, and the resonance wavelength is controlled by adjusting the thickness of the dielectric reflection layer.

Abstract: The present invention has applications in the field of color displays, including computer monitors, video games, television, and other applications that may require a variety of light wavelengths. In one aspect of the invention, a light generator can generate light having selected proportions of red, green, and blue wavelengths from a single source of blue light. In a specific embodiment, the light generator includes a blue laser for generating a first beam of blue light. In another aspect of the invention, beamsplitters are used to split the beam of blue light into separate beams to generate light having a single color in each beam. In one such embodiment, upconversion lasers are used to generate each of the single colors.

Abstract: A multi-wavelength laser array where each element can be individually heated for fine tuning. The wavelength of the array can be coarsely tuned by selecting one laser of a particular wavelength for the array, and then applying a heating current to fine-tune the wavelength. The lasers can be phase shifted DFBs for high single-mode yield. The heating can be performed monolithic to the device by passing current longitudinally through the p-type stripe, while the injection current passes vertically through the stripe. Alternatively an adjacent laser to the one selected can be activated, though not fiber coupled, such that the thermal load is sufficient to tune the selected laser. Thin film heaters placed on top or adjacent to the cavity can also be used. To minimize continuous power consumption, the on-chip heater can be used initially to tune the laser while the TE cooler responds on a slower time scale.

Abstract: The preferably highly antireflection coated facet of a laser chip is imaged by an optical system onto a reflector, as a result of which the adjustment tolerance is substantially increased by the cat's eye effect and, since the optical system is provided with a high longitudinal chromatic aberration, the wavelength can be tuned by shifting given parts of the total system relative to other parts of the total system. In this way a tunable semiconductor laser light source which is free from mode jumps and has at most two adjustable degrees of freedom can be produced.

Abstract: A multiple wavelength laser is tunable in output beam frequency, number of output channels, spacing and power. The multiple wavelength laser system is made of two coupled stages of laser amplifiers, where the first stage comprises a series of optical gain mediums pumped with small power to operate near or above laser threshold, for stable operation. The second stage boosts the output of the first stage to high powers. As the optical gain mediums in the first stage are isolated by a de-multiplexing filter the can be separately powered, attenuated or otherwise modulated to provide an agile wavelength provisioning function, effective use of the pump power and direct-modulated laser signals.

Abstract: A multi-wavelength surface emitting laser for emitting light having different wavelengths includes a lower reflector, an active layer and an upper reflector which are integrally formed above one substrate. The multi-wavelength surface emitting laser is manufactured by forming a first surface emitting laser, partially removing a first upper reflector, a first active layer, and a first lower reflection layer by etching. A protection film is formed on the outer surface of the first surface emitting laser. A second surface emitting laser is formed by removing a second lower reflector, a second active layer, and a second upper reflection layer formed on the protection film by etching. The protection film is removed and first and second upper electrodes are formed on upper surfaces of the first and second upper reflection layers, respectively, and a lower electrode is formed on a bottom surface of the substrate.

Abstract: The present invention provides a light wavelength conversion module in which an output light amount of a light wavelength conversion element increases monotonically as a driving current of a semiconductor laser increases. The light wavelength conversion module includes the semiconductor laser having an external resonator provided with a narrow band-pass filter, and the light wavelength conversion element for converting a laser beam emitted from the semiconductor laser to a second harmonic wave. A semiconductor laser, which emits a laser beam including a plurality of longitudinal mode spectra within an acceptable wavelength band of the light wavelength conversion element, is used in the light wavelength conversion module.

Abstract: A multiple spectral line Raman laser having adjustable relative power output between different spectral lines is provided. The laser includes a lasing cavity, first and second reflectors optically coupled to a back end of the cavity that reflects substantially all light having wavelengths of &lgr;1 and &lgr;2, respectively, and a tunable reflector assembly optically coupled to a front end of the cavity that reflects a selected proportion of said light having wavelengths of &lgr;1 and &lgr;2 in response to a single source of strain to control relative power output of light at these wavelengths. The lasing cavity may be a linear length of gain fiber, and the tunable reflector may include a single fiber Bragg grating (FBG) having a trapezoidal reflection profile, or a pair of fiber Bragg gratings mounted on either side of a flexible substrate such that when the substrate is bent, one FBG stretches while the other is compressed.

Abstract: The invention relates to an High Repetition Rate UV Excimer Laser which includes a source of a laser beam and one or more windows which include magnesium fluoride. Another aspect of the invention relates to an excimer laser which includes a source of a laser beam, one or more windows which include magnesium fluoride and a source for annealing the one or more windows. Another aspect of the invention relates to a method of producing a predetermined narrow width laser beam.

Abstract: The optical system includes a stack of lensed, AR-coated laser diode bars and optics to brighten the stack's output. A spatial filter forces each bar to lase in one or a few high-order modes having two strong emission lobes. Radiation in the first lobe is passed to a collimating optic to form a filtered image of each of the lensed diode bars on an associated grating, whose angle then determines the lasing wavelength of that bar. Radiation in the second lobe is directed into an output path where another collimating optic produces an array of spatially separated, collimated beams. The wavelengths set for each beam allow them to be spectrally combined into a single, multi-wavelength, collimated output beam possessing substantially the same cross section and divergence as an individual input beam.

Abstract: This invention provides a means for generating multiple wavelengths in an integrated manner using a resonant cavity containing dispersion shifted non-linear medium and coupled to a pulsed laser source. The dispersion shifted non-linear medium is seeded by at least some of the desired wavelengths. The laser source emits radiation at a particular wavelength and is pulsed in a manner synchronously related to the round trip time of the resonant cavity. By means of wave mixing, such as four wave mixing, the dispersion shifted non-linear medium produces a set of discrete wavelengths. The reflective elements of the resonant cavity are designed to contain the radiation of the laser sources within the resonant cavity and to transmit an equal amount of each of the generated set of wavelengths.

Abstract: A wavelength tunable laser includes a distributed feedback (DFB) array with first and second DFB laser diodes that generate first and second beams of light in first and second wavelength ranges. A microelectromechanical (MEMS) optical element selectively couples one of the first and second beams of light from the DFB laser array into an optical waveguide. The MEMS optical element includes a collimating lens and a thermal or electrostatic MEMS actuator for moving the collimating lens to select the one of the first and second beams of light. A focusing lens is located between the collimating lens and the optical waveguide. Alternately, the MEMS optical element includes a fixed collimating lens that collimates the first and second beams of light, a mirror, and a MEMS actuator for tilting the mirror to select the one of the first and second beams of light.

Abstract: An object of the present invention is to provide a semiconductor laser device which is capable of selectively emitting two kinds of laser light of light emitting characteristics differing in wavelength, light emission point, beam shape, light emission power, longitudinal mode and so on, by switching the direction of the voltage applied to the device. There is provided the semiconductor laser device including first and second laser units, each unit having a ridge type structure and each unit comprising a multilayer structure body made of at least an n-type semiconductor layer, an active layer and a p-type semiconductor layer deposited in this order, and a p-side electrode and an n-side electrode, wherein the p-side electrode and the n-side electrode of the first laser unit and the n-side electrode and the p-side electrode of the second laser unit are electrically connected, respectively.

Abstract: A multi-channel light source generator has a pumping laser source for generating a pumping laser having a predetermined wavelength, a multi-channel light source generating device for generating multi-channel light sources using the pumping laser, a light separating device for separating the pumping laser and the multi-channel light sources, a demultiplexing device for separating the multi-channel light sources into a plurality of individual light sources, an intensity adjusting device for adjusting an intensity of the individual light sources, and a multiplexing device for combining the individual light sources outputted from the intensity adjusting device.

Abstract: A photodetector has a spatially varying absorption spectrum formed in a monolithic InGaAsP structure whose quantum well active structure has modified effective bandgap properties. A waveguide couples light to the quantum well active structure. The spatially varying absorption spectrum allows wavelength-division demultiplexing. The effective bandgap properties can be modified by rapid thermal annealing to cause the diffusion of defects from one or two InP defect layers into the quantum well active structure.

Abstract: A laser heterostructure having an active layer, a lateral waveguide terminating in an output aperture, and a gain section with a current drive electrode. A rear surface distributed Bragg grating with a tuning current electrode is formed on a surface of said laser heterostructure. The laser also includes a front surface distributed Bragg grating with a tuning current electrode on a surface of the laser heterostructure. The front surface distributed Bragg grating is closer to the output aperture than the rear surface distributed Bragg grating, There is a space between the rear surface distributed Bragg grating and the front surface distributed Bragg grating. A current drive electrode is formed on the space. Operation is best when the front surface distributed Bragg grating has adequate reflectivity at the Bragg wavelength with minimal scattering loss at other wavelengths, particularly at the wavelength of the rear surface Bragg grating.

Abstract: A fiber-optic laser source capable of emitting multiple useful wavelengths at the same time, including multiple ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define a first set of possible lasing wavelengths corresponding to ITU grid lasing wavelengths, and a resonant filter for defining a subset of the first set of wavelengths. The arrangement is enclosed in a ring resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator may also comprise in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in a set of single cavity longitudinal modes.

Abstract: The invention features a displacement and dispersion measuring interferometry system having a Helium-Neon laser light source. The light source can be a Helium-Neon laser that includes an intracavity doubling crystal and an intracavity etalon to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. Alternatively, the light source can be a single-mode Helium-Neon laser that directs a single-frequency input beam into a resonant external cavity enclosing a doubling crystal to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. In addition to dispersion measurements, the inherent wavelength stability of the Helium-Neon source permits high-accuracy displacement measurements.

Abstract: In a laser apparatus, a solid-state laser medium emits light of a plurality of peak wavelengths by light from an exciting light source, and a rotatable reflection mirror rotatable on or parallel to a resonance optical axis of the laser medium is disposed changeably between a first and second positions by driving of a rotating unit.

Abstract: An optical wavelength conversion device includes: two or more non-linear optical crystals each having approximately identical phase matching conditions for a fundamental wave light and a second harmonic wave light; and a phase adjusting section inserted between the adjacent non-linear optical crystals, wherein the phase adjusting section a dispersion characteristic which is different from that of the non-linear optical crystals, and the phase adjusting section is formed so as to allow at least one of a refractive index or a length thereof to be modulated.

Abstract: An external-resonator laser system having multiple laser elements is configured to permit each laser to undergo individual amplification notwithstanding optical beam combination. In this way, overall output power may be scaled in a desired fashion, depending on the selected characteristics of the optical amplifier elements. To achieve additional power, each of the amplifiers may implemented as a phased array. Viewed more generally, a phased-array configuration affords beam combining in two stages, with each contributing input source itself composed of multiple sources whose outputs have been combined. If each phased-array source emits at a different wavelength, this design offers a multi-wavelength output whose power level may be scaled in accordance with the number and character of the devices forming each phased array.

Abstract: Two semiconductor laser light sources for outputting light of two properly selected wavelengths are employed as excitation light sources. That is, as excitation light sources, there are used a first semiconductor laser excitation light source for exciting ion from a base level to a laser low level or an energy level higher than the laser low level and a second semiconductor laser excitation light source having a wavelength different from that of the first excitation light source for exciting ion from a laser low level to a laser high level. For example, an amplification fiber uses a fluoro zircon ate glass as a base material. Two multiple wavelength couplers are disposed at the input side of the amplification fiber. The multiple wavelength couplers are connected to the first excitation light source and the second excitation light source, respectively.

Abstract: A directly modulatable laser comprising an active medium inside a laser cavity formed by a resonator mirror and an out-coupling mirror, and a pump light source exciting the active medium. It is characterized in that the active medium generates radiation of two wavelengths (&lgr;1 and &lgr;2) and the resonator mirror is constructed as a controllable reflector by which the reflectivity is controllable for each of the two wavelengths (&lgr;1 and &lgr;2) and the controllable reflector is connected with a control unit, wherein the reflection factor is controlled in such a way that the inversion density of the electrons which is generated in the active medium is constant and the light output of one of the wavelengths ((&lgr;1) is controllable between a minimum value and a maximum value according to an applied control signal, wherein the control of the two wavelengths ((&lgr;1 and &lgr;2) is carried out in push-pull.

Abstract: A MEMS-based selectable laser output optical device (10) includes a laser source (12) having a laser output 14. A MEMS switch (16) is optically coupled to the laser source (12) for selectively coupling the laser output (14) from the laser source (12) in one of two directions (141) or (142). The MEMS switch (16) has a mirror (160) that is slidable or otherwise movable from a first position (161), where the mirror (160) is laying flat or in another non-obstructing position to provide a non-obstructing linear exit optical path (141). A second position (162) where the mirror (160) is in its upright vertically aligned direction, obstructs the linear optical path to re-direct the optical path in a non-linear direction.

Abstract: Multiwavelength modelocked laser systems and methods for reducing intensity fluctuations and amplitude noise in each of the wavelength channels as well as manipulating the interwavelength phase coherence properties. The systems and methods can include lens, semiconductor optical amplifier, grating, cylindrical lens, rod lens and an approximately 7 nm MQW saturable absorber between mirrors for providing a laser cavity resonator for hybridly modelocked operation. Additional systems and methods can include two different positions for the saturable absorber inside the laser resonator which enables direction of the interwavelength phase coherence properties. Up to approximately 300 MHz optical pulse trains in each of up to approximately three channels can be generated. Combining gain flattening and noise suppression within the optical cavity of the modelocked laser can result in generating up to approximately 123 wavelength channels, each having up to approximately 6 Giga Hertz optical pulse trains.

Abstract: A resonating cavity system of a tunable multi-wavelength semiconductor laser. The system has a laser, a collimating lens, a grating, a slit plate, and adjustable mirrors. The laser has two ends. The first end is coupled to the cavity, and the second end outputs the laser beam. The grating is located in the lasing path between the first end of the semiconductor laser and the plate, and the plate is located before the adjustable mirrors. Each adjustable mirror is aligned to the corresponding slit of the plate. Lasing paths extend from the first end of the laser, through the grating, the lens, a plurality of the slits of the plate, to the adjustable mirrors. Each mirror can be adjusted independently to ensure each beam is reflected accurately back to each resonating path. Thereby, a feature of equal lasing gains of all the resonating paths is guaranteed.

Abstract: An external cavity diode laser and method of generating laser light comprising: generating light from a Fabry-Perot diode laser source; collimating light from the source with an intracavity optical element; reflecting light via a feedback mirror; and employing a diffraction grating to receive light from the optical element, diffract received light to the mirror in a non-zero order, receive reflected light from the mirror, and direct reflected light back towards the optical element and Fabry-Perot diode laser to complete an external cavity, the diffraction grating additionally directing a portion of the received light from the optical element toward a target.

Abstract: A multi-aperture fiber laser system that includes a fiber amplifier laser engine having a tunable master oscillator, a wavelength selective beam router optically connected to the laser engine, and a plurality of beam directors optically connected to the wavelength selective beam router. The tunable master oscillator outputs a first optical signal selectively tuned to at least one specific wavelength. The wavelength selective beam router receives a plurality of second optical signals that have the same at least one wavelength of the first optical signal. The wavelength selective beam router then routes each second optical signal to one of the beam director assemblies based the wavelength of the second optical signals. Thus, the multi-aperture fiber laser system enables a single high power fiber amplifier laser engine to supply laser power to more than one beam director in a highly flexible and efficient manner.

Abstract: Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod.

Abstract: A resonating cavity system of a tunable multi-wavelength semiconductor laser. The system has a laser, a collimating lens, a grating, a slit plate, and adjustable mirrors. The laser has two ends. The first end is coupled to the cavity, and the second end outputs the laser beam. The grating is located in the lasing path between the first end of the semiconductor laser and the plate, and the plate is located before the adjustable mirrors. Each adjustable mirror is aligned to the corresponding slit of the plate. Lasing paths extend from the first end of the laser, through the grating, the lens, a plurality of the slits of the plate, to the adjustable mirrors. Each mirror can be adjusted independently to ensure each beam is reflected accurately back to each resonating path. Thereby, a feature of equal lasing gains of all the resonating paths is guaranteed.

Abstract: A wavelength conversion device that converts a wavelength by second harmonic-wave generation and generates a laser beam, includes: a substrate having a plurality of electrodes; a semiconductor laser device mounted on the substrate and electrically connected to the plurality of electrodes; and a nonlinear optical element having an optical waveguide for guiding a laser beam emitted from the semiconductor laser device and for converting a wavelength of the laser beam. Here, the nonlinear optical element is mounted on the substrate so that the optical waveguide in the nonlinear optical element is located away from the center line of the substrate. Thereby, a small wavelength conversion device provided with a semiconductor laser device and a nonlinear optical element, which are mounted on the substrate in an integrated manner, can be obtained, and therefore an optical pickup unit in the optical disk employing this wavelength conversion device can be miniaturized.

Abstract: A wavelength selectable light source is comprised of a two-dimensional (2-D) array of variable wavelength vertical-cavity surface-emitting lasers (VCSELs), wherein light beams emitted from the VCSELs are coupled into an output optical fiber. The light beams emitted from the VCSELs are collimated via a 2-D array of micro-lenses, the collimated light beams impinge upon a first fixed-position mirror that points each of the collimated light beams toward a second movable mirror located at a common focal point in a common area, and the second movable mirror redirects the collimated light beams into a lens coupled to the output optical fiber. By moving the second movable mirror, different ones of the collimated light beams can be directed into the output optical fiber, so that the second movable mirror performs a wavelength selection function.

Abstract: The present invention is directed to a system and method which utilize an incoherently beam combined (IBC) laser. The IBC laser includes a plurality of emitters with each of the emitters possessing a partially reflective surface on their front facet. The partially reflective surface causes resonant wavelengths to be defined. In certain embodiments, the system and method arrange the external cavity and emitter spacings of the IBC laser such that the center feedback wavelength provided to each emitter is an etalon resonant wavelength. In other embodiments, the range of feedback wavelengths is adapted so that it is greater than the free spectral range (the separation in wavelength space between adjacent etalon resonant wavelengths).

Abstract: Embodiments of the present invention are directed to method of fabrication of a broadband emitter array. Embodiments of the present invention may grown a first set of emitters possessing a first quantum well characteristic (e.g., quantum well thickness or composition). A portion of the first set of emitters is removed by etching. In place of the removed emitters, a second set of emitters is regrown with said second set of emitters possessing a different quantum well characteristic. By fabricating the emitters sets in this manner, a unitary emitter array may be fabricated that possesses an increased bandwidth, e.g., the first and second sets of emitters may be associated with different center wavelengths. Embodiments of the present invention may utilize emitter arrays fabricated in this manner in, for example, incoherently beam combined (IBC) lasers and in Raman amplifier systems.

Abstract: A method for selecting free spectral ranges (FSR) of intra-cavity optics to optimize reliability of the channel switching mechanism and corresponding apparatus. In particular, the optimal relationship between the FSR of the internal etalon and the FSR of the laser cavity is derived. For the external cavity diode lasers (ECDL) the optimal relationship between the FSR of the internal etalon and the FSR of the gain chip is also derived. Equations are derived for selecting free spectral ranges of various optical cavities so as to create a locally commensurate condition under which the relative position of the lasing mode with respect to the transmission peak of the laser's tunable filter (e.g., etalon plus channel selector) does not change when the laser hops between adjacent channels.