Abstract: An optical device (10) includes a broad area laser (72) for lasing at a first wavelength (64), a multimode active-doped tapered waveguide laser (6); and a multimode passive planar mode transformer (118) coupling and tapering from the broad area laser (72) to the multimode active-doped tapered waveguide laser (6).

Abstract: Selectively oxidized vertical cavity lasers emitting near 1300 nm using InGaAsN quantum wells are reported for the first time which operate continuous wave below, at and above room temperature. The lasers employ two n-type Al0.94Ga0.06As/GaAs distributed Bragg reflectors each with a selectively oxidized current aperture adjacent to the active region, and the top output mirror contains a tunnel junction to inject holes into the active region. Continuous wave single mode lasing is observed up to 55° C.

Abstract: A diode-pumped solid-state laser oscillator optically pumps a laser medium. The oscillator has at least one pumping light source that emits light in a predetermined wavelength band, and a laser medium that absorbs light in the wavelength band. In the wavelength band, the optical absorption index of the laser medium increases with an increase in wavelength, and the optical radiation energy of the light source decreases with an increase in wavelength. Thus, with respect to wavelength changes, an increase in the optical absorption index is cancelled out by a decrease in the radiation energy, making the stability of the laser output less dependent on the temperature of the optical pumping medium or laser medium.

Abstract: A diode laser arrangement is disclosed wherein a radiation source is designed which can be scaled with respect to power such that different types of cooling can be applied and the configuration of the radiation field is suitable for adapting to different tasks in a simple manner. For this purpose, every diode laser is connected to a thermal contact surface of a separate, heat-spreading carrier which is fastened to a cooling surface of a common cooling element so as to be electrically insulated. The carriers are arranged adjacently in such a way that the line-shaped emission regions of the diode lasers are adjacent in series and the p-n junction planes extend parallel to the thermal contact surfaces. The diode laser arrangement is particularly suitable as a pump light source.

Abstract: A “Folded Cavity Surface Emitting Laser” (FCSEL) sum frequency generating device capable of generating a second harmonic at room temperatures with high efficiency and output power, while having a small size, low energy consumption, and a low manufacturing cost. A FCSEL sum frequency generating semiconductor diode laser has a multilayered structure that comprises a mode discriminating polyhedral shaped prism waveguide, which is located at one end of two light emitting diodes, a partial photon reflecting mirror, which is located at the opposite end of the two light emitting diodes, and a phase-matching sum-frequency generating superlattice, which is located between the polyhedral shaped prism waveguide and the partial photon reflecting mirror.

Abstract: A compressive strain GRIN-SCH-MQW active layer and a tensile strain GRIN-SCH-MQW active layer are laminated, and there are provided a diffraction grating formed in the vicinity of the compressive strain GRIN-SCH-MQW active layer and a diffraction grating formed in the vicinity of the tensile strain GRIN-SCH-MQW active layer, between the radiation end face and the reflection end face of the laser beam. A laser beam obtained by polarization-multiplexing a laser beam in the TE mode generated in the compressive strain GRIN-SCH-MQW active layer and a laser beam in the TE mode generated in the tensile strain GRIN-SCH-MQW active layer, and having a plurality of oscillation longitudinal modes of not larger than a predetermined output value is output by the wavelength selection characteristic of the diffraction gratings.

Abstract: A solid-state laser having an active medium for generating a laser beam is described. The laser includes a resonator, and a plurality of crystal wafers disposed in the resonator and are optically coupled to one another and form a common beam path for the laser beam. A pumping light source is provided for generating a pumping light beam whose optical axis is collinear with respect to an optical axis of the laser beam. The pumping light source is disposed upstream of the resonator. At least one lens functioning as an imaging element is provided for focusing the pumping light beam emerging from one of the crystal wafers onto another one of the crystal wafers disposed downstream.

Abstract: The present invention provides a laser machining apparatus in a simple structure which can properly carry out laser machining by irradiating a laser beam easily at a predetermined energy density to a machining-target site in a predetermined range, and in addition, which can be downsized and can be kept with easy maintenance and has enhanced durability. The apparatus includes: a semiconductor stack 1 comprising a plurality of semiconductor laser elements; and a controller for controlling emission of the laser beam emitted from each of the semiconductor laser elements. The semiconductor stack 1 is divided into a plurality of blocks B11, B12, B13, B14 in correspondence with the machining-target site of a work piece. The controller controls the irradiation of the laser beam from each of the blocks B11, B12, B13, B14 to be changeable in terms of time.

Abstract: A vertical cavity organic laser device, that includes: an organic laser cavity including: a bottom dielectric stack for receiving and transmitting pump beam light and being reflective to laser light over a predetermined range of wavelengths; an organic active region for receiving transmitted pump beam light from the bottom dielectric stack and for emitting the laser light; a top dielectric stack for reflecting transmitted pump beam light and laser light from the organic active region back into the organic active region, wherein a combination of the bottom and the top dielectric stacks and the organic active region produces the laser light; the device further including an external pump beam light source for optically pumping light to the organic laser cavity; and a positioner for locating the organic laser cavity in a spaced relationship to the external pump beam light source.

Abstract: A semiconductor laser element includes: a semiconductor laser region in which at least one laser emission portion including an active layer for emitting light is provided; a multimode interference region including a first wave-guiding layer, one end of the first wave-guiding layer being optically coupled to the active layer of the at least one laser emission portion; and an output waveguide region including a second wave-guiding layer, the second wave-guiding layer being optically coupled to another end of the first wave-guiding layer, wherein the active layer of the at least one laser emission portion, the first wave-guiding layer, and the second wave-guiding layer are integrally formed.

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 semiconductor laser device having two active-layer stripe structures includes an n-InP substrate, an n-InP clad layer, a lower GRIN-SCH layer, an active layer, an upper GRIN-SCH layer, a p-InP clad layer, and a p-InGaAsP contact layer grown in this order, in a side cross section cut along one of the stripe structure. A high-reflection film is disposed on a reflection-side end surface, and a low-reflection film is disposed on an emission-side end surface. A p-side electrode is disposed on only a part of the upper surface of the p-InGaAsP contact layer so that a current non-injection area is formed on an area absent the p-side electrode.

Abstract: The SG-DFB laser diode of the present invention has a high output optical efficiency in comparison with a conventional wavelength tunable laser provided with Bragg reflection ends at the both ends of the gain region for the wavelength tuning as a structure capable of connecting an optical fiber directly without losing the optical wave generated at the gain region. And also, the present invention can be manufactured by the manufacturing process of a conventional wavelength tunable laser diode without reinvesting a new equipment. Further, the SG-DFB laser diode of the present invention can control a broadband wavelength with a simple circuit construction in comparison with a conventional wavelength tunable laser diode since it can vary the wavelength in continuous/incontinuous by the change of current of the each region of the phase control regions.

Abstract: A solid-state laser device, comprising a first resonator arranged on a first optical axis, a second resonator arranged on a second optical axis, a first light emitter for entering an excitation light to the first resonator, a second light emitter for entering an excitation light to the second resonator, and further comprising a separated optical axis portion serving as a part of the first optical axis, a separated optical axis portion serving as a part of the second optical axis, a common optical axis portion where the first optical axis and the second optical axis are superimposed, a first solid-state laser medium arranged on the separated optical axis portion of the first optical axis, a second solid-state laser medium arranged on the separated optical portion of the second optical axis, and an optical member for wavelength conversion and wavelength switching means arranged on the common optical axis portion, wherein the optical member for wavelength conversion comprises a plurality of optical crystals for

Abstract: Co-doping the gain medium of a diode-pumped infrared laser to make the laser resistant to long-term degradation from high-intensity internal infrared radiation is disclosed. Co-doping the gain medium with ions such as Cr3+ and Ce3+ that make the gain medium resistant to external ionizing radiation solves problems of long-term degradation of the gain medium.

Abstract: A solid-state laser device, comprising a first resonator arranged on a first optical axis, a second resonator arranged on a second optical axis, a first light emitter for entering an excitation light to the first resonator, a second light emitter for entering an excitation light to the second resonator, a common optical axis portion commonly used by the first optical axis and the second optical axis, a wavelength separating plate for separating the first optical axis from the second optical axis so that the common optical axis portion can be commonly used by the optical axes, an output portion provided on the common optical axis portion, a first solid-state laser medium arranged on a separated optical axis of the first optical axis, a second solid-state laser medium arranged on a separated optical axis of the second optical axis, and an optical crystal for wavelength conversion arranged on the common optical axis portion.

Abstract: An apparatus and method for achieving ultrahigh-power output from a solid-state laser. The solid-state laser of the subject invention uses multiple disk-shaped laser gain media (subapertures) placed adjacent to each other to fill an optical aperture of an AMA module. In one preferred embodiment each of the laser gain media is provided with optical coatings for operation in the active mirror configuration. Furthermore, each of the laser gain media is hydrostatic pressure-clamped to a rigid, cooled substrate, which allows it to maintain a prescribed shape even when experiencing significant thermal load. A cooling medium can be provided to a heat exchanger internal to the substrate and/or flowed through the passages on the substrate surface, thereby directly cooling the laser gain medium.

Abstract: A single core 35, 50 or a plurality of cores arranged in rings 21, 28, 29 around a central core 20, 27, or in an array 42, are provided with either or both of (a) a modal discrimination characteristic, including gain, index of refraction and cross sectional area, which is greatest in the center of the core or the array, and lowers outwardly therefrom, and (b) an oblong cross section, thereby to provide either or both of (c) a bright laser beam of the fundamental in-phase supermode, and/or (d) a linearly polarized output beam.

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: 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: Illumination unit for an apparatus, particularly for the implementation of diaphanoscopic examinations at a human, animal or botanical examination subject, has a monolithic semiconductor laser diode bar with driveable laser diodes that emit radiation as well as at least one optical arrangement for collimating and/or focusing the emitted laser radiation. The laser diode bar and the optical arrangement are mounted at a common carrier, and the laser diode bar is connected to pin-like terminal elements at the carrier for diode drive, that are in turn connected or connectable to terminals provided at a carrier plate accepting the carrier. A radiation-transparent covering that encapsulates the carrier.

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: An improved laser system and method of operation provides signal continuity and safety in the event of accidental interruption of the laser beam. At the transmitting end, a main laser generates a beam, which is surrounded by a low powered guard beam generated by a pulsed laser. At the receiver, a leas system includes a main lens for receiving the main laser beam and a surrounding annular segmented set of lenses acting as a set of parallel receivers for the surrounding guard beam. A trigger circuit is connected to the parallel receivers. In operation, the guard beam insulates the main laser beam and detects interruptions. When the guard beam is interrupted at any point along the length of the beam, one or more of the parallel receivers will be blocked, and a signal will be generated by the trigger circuit to activate a return laser to alter the performance of the main laser, including shutdown of the beam. Upon shutdown, the current stream of bits or packets to the main laser is buffered.

Abstract: A depletion enhancement layer having a striped opening on the upper surface of a ridge portion, a low carrier concentration layer and an n-type current blocking layer are successively formed on a p-type cladding layer having the ridge portion. The low carrier concentration layer has a lower carrier concentration than the n-type current blocking layer. The band gap of the depletion enhancement layer is set to an intermediate level between the band gaps of the p-type cladding layer and the low carrier concentration layer. Alternatively, a first current blocking layer having a low carrier concentration and a second current blocking layer of the opposite conduction type are formed on an n-type depletion enhancement layer, and a p-type contact layer is formed on the second current blocking layer of the opposite conduction type and another p-type contact layer.

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 present invention is directed to a method and system for conditioning the output signals of an array of surface-emitting lasers with an array of edge-receiving optical devices. Both the array of surface-emitting lasers and the array of edge-receiving optical devices are mounted on an optical bench substrate. The array of edge-receiving optical devices may also be monolithically fabricated on the optical bench substrate. The array of surface-emitting lasers and the array of edge-receiving optical devices are aligned by alignment features and slots, which are fabricated on the optical bench substrate so as to optically couple the array of surface-emitting lasers to the array of edge-receiving optical devices.

Abstract: The medical laser unit (1) includes at least one laser body (3) being made of laser material (4). A first type of a pump light source (11) is designed and arranged to continuously excite the laser material (4) and to generate continuous laser radiation (7). A second type of a pump light source (16) is designed and arranged to excite the laser material (4) by pulses and to generate pulsed laser radiation (7). A transmitting unit is designed and arranged to transmit the continuous laser radiation (7) and the pulsed laser radiation (7) to a surgical application site. More particularly, the medical laser unit (1) has two modes of operation, a first mode for cutting with continuous laser radiation (7) and a second mode for fragmenting with pulsed laser radiation (7) of short time and high power laser pulses.

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: There is disclosed an improved laser device (10), comprising a semiconductor laser diode. The invention provides laser device (10) comprising: at least two lasing regions (12,14); an interference region (16) into which an output of each lasing region (12,14) is coupled; and an output region (118) extending from the interference region (116) to an output (20) of the device (10).

Abstract: This invention provides a tunable laser in which a plurality of gain elements (e.g., semiconductor diodes) with a plurality of gain spectra are optically coupled to a splitting-combining means (e.g., a wavelength router or fiber-optic coupler) in parallel, and the splitting-combining means is in optical communication with a wavelength-selecting means (e.g., a diffraction grating optically coupled to a movable mirror). The tunable laser of the present invention further comprising an optical fiber, optically coupling the splitting-combining means to the wavelength-selecting means. The use of a plurality of distinct gain spectra greatly enhances the tuning range of the tunable laser in the present invention.

Abstract: An up-conversion laser unit in which a semiconductor laser of high output power can be used as a pump light source and the wavelength of up-converted laser light is suitable for display. The light of infrared wavelength is generated by the pump light source, the generated light being inputted into a Pr3+ up-conversion laser to up-convert there into red light by Pr3+ ion. The up-converted red light is inputted into, as a pump light source, a Tm3+ up-conversion laser, there being up-converted into blue light by the Tm3+ ion. Thereby, efficient up-conversion into blue light is made possible.

Abstract: There is provided an optical system for reducing faint interference observed when laser annealing is performed to a semiconductor film. The faint interference conventionally observed can be reduced by irradiating the semiconductor film with a laser beam by the use of an optical system using a mirror of the present invention. The optical system for transforming the shape of the laser beam on an irradiation surface into a linear or rectangular shape is used. The optical system may include an optical system serving to convert the laser beam into a parallel light with respect to a traveling direction of the laser beam. When the laser beam having passed through the optical system is irradiated to the semiconductor film through the mirror of the present invention, the conventionally observed faint interference can be reduced. Besides, the optical system which has been difficult to adjust can be simplified.

Abstract: Disclosed is a surface-emitting laser device which eliminates an absorption loss of a p-type doped layer and reduces a scattering loss in a mirror layer and a carrier loss due to a current induction, comprising a first conductive type of semiconductor substrate; a bottom mirror layer formed on the semiconductor substrate and composed of a first conductive type of semiconductor layer; an active layer formed on the bottom mirror layer; an electron leakage barrier layer formed on the active layer and having an energy gap larger than the active layer; a current induction layer formed on the electron leakage barrier layer and a second conductive type of semiconductor layer; a current extension layer formed on the current induction layer and composed of the second conductive type of semiconductor layer; and a top mirror layer formed on the current extension layer, wherein the top mirror layer includes undoped center portion and its both end having the second conductive type of dopant diffusion region.

Abstract: An optical resonator has an axial mode frequency tuning rate with respect to temperature matching the peak gain frequency tuning rate, so that mode hops are eliminated. The resonator contains a composite cavity consisting of a gain medium and free space. Preferably, the resonator is a single-frequency solid state laser containing a solid state gain medium defining a physical path length Lg. The optical cavity is defined by a high reflector and output coupler surrounding the gain medium and defining a physical cavity path length Lo. The high reflector and output coupler are mounted on a substrate so that Lo is temperature insensitive. Preferably, the substrate is a thermally insensitive material having a negligible coefficient of thermal expansion; for example, it may be Invar™, Super-Invar™, ULE™ Glass, Zerodur™, and fused silica. Alternately, the substrate is a thermally isolated material that is temperature controlled and insulated from the gain medium.

Abstract: A new class of coupled-resonator vertical-cavity semiconductor lasers has been developed. These lasers have multiple resonant cavities containing regions of active laser media, resulting in a multi-terminal laser component with a wide range of novel properties.

Abstract: A solid-state laser oscillator comprising solid-state laser rods disposed coaxially in series with each other, radiating light when excited, and amplifying the light through stimulated emission. A solid-state laser rod exciting device excites any number of solid-state laser rods with a 90° optical rotator disposed coaxially and arranged between the rods. The rotator rotates a component of the light generated in the axial direction while heat lens compensating devices are disposed coaxially with the solid-state laser rods. A reflecting device and a partial reflection device are disposed coaxially and arranged, outside of the solid-state laser rods and heat lens compensating devices, for propagating the axially generated component of the light. An exciting source driving device drives the exciting sources included in the solid-state laser rod exciting device.

Abstract: The invention is directed to optical devices comprising a solid-state structured glass substrate having at least one waveguide incorporated therein, particularly waveguides and lasers incorporating such structure. The invention is also directed to methods for modifying such devices and their properties. The waveguides and lasers of the invention provide advantageous high power and increased slope efficiency and find use, for example, in telecommunications applications.

Abstract: The present invention provides a multiple wavelength semiconductor laser device array having approximately the same optical output levels of inducing kink and COD. The multiple wavelength semiconductor laser device array has the same construction as that of a conventional two-wavelength semiconductor laser device array except the thickness of the reflection films at the light emitting end faces. The thickness of the reflection films deposited on the light emitting end faces of the two-wavelength semiconductor laser device array is determined so as to have a lower reflectivity at a light emitting end face of a 650 nm band semiconductor laser device consisting of an AlGaInP type four-element compound semiconductor which may induce kink and COD more easily, than a reflectivity at a light emitting end face of a 780 nm band semiconductor laser device consisting of an AlGaAs type three-element compound semiconductor.

Abstract: A laser structure of the present invention is composed of microparticles cyclically arrayed so as to have a face centered cubic lattice structure or a closest-packed hexagonal lattice structure. Bragg reflection occurs from such regularly arrayed microparticles. The laser structure causes laser oscillation with a luminous material such as a pigment or an organic electroluminescence material taken as a laser medium. The laser structure has an advantageous that it is small in both size and weight and can be easily produced, and is applicable to a variety of application fields such as a light emitting device, an image display unit, and an optical amplifier.

Abstract: In a laser-diode-pumped laser apparatus, a solid-state laser crystal doped with at least one rare-earth element including at least Pr3+ is pumped with a laser diode, and emits laser light. In the first aspect, the laser diode has an active layer made of one of an InGaN, InGaNAs, and GaNAs materials, and an optical wavelength conversion element converts the solid-state laser light into ultraviolet laser light by wavelength conversion. In the second aspect, the solid-state laser crystal is codoped with Pr3+ and at least one of Er3+, Ho3+, Dy3+, Eu3+, Sm3+, Pm3+, and Nd3+. In the third aspect, instead of the solid-state laser crystal, an optical fiber codoped with Pr3+ and at least one of Er3+, Ho3+, Dy3+, Eu3+, Sm3+, Pm3+, and Nd3+ is pumped with a GaN-based compound laser diode.

Abstract: One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as “nanowires”, include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

Abstract: An optical modulator and a semiconductor laser device including the optical modulator, both reducing variations in the refractive index of an optical modulator or making variations negative without an increase in loss or a decrease in extinction ratio, as well as an optical communications system increasing an interval of distance at which modulated light is transmitted, by use of the optical modulator and the semiconductor laser device including the optical modulator. The optical modulator includes a semiconductor substrate of a first conductivity type; a light absorption layer on the semiconductor substrate and having a multiple quantum well structure, the multiple quantum well structure including a first well layer and second well layers. The peak wavelength of the absorption spectrum of the second well layers is shorter than the peak wavelength of the absorption spectrum of the first well layers A semiconductor cladding layer of the second conductivity type is on the light absorption layer.

Abstract: The invention provides an optical fiber amplifier which assures stable operation of a pump light source and efficiently makes use of residual pump power to achieve improvement in conversion efficiency. The optical fiber amplifier includes a rare earth doped fiber. Pump light from a pump light source is introduced into one end of the rare earth doped fiber by way of a first optical coupler, and residual pump light originating from the pump light and arriving at the other end of the rare earth doped fiber is applied to the other rare earth doped fiber amplifier or the loss compensation of a dispersion compensating fiber by Raman amplification.

Abstract: According to this method, in order to fabricate active elements which comprise at least one doped part comprising a doping capable of absorbing a pump beam and at least one undoped part, and which have opposed faces of the same geometrical shape, a process of preparing an elongate active rod (5), which has a cross section identical to said geometrical shape, said process comprising at least one step of cutting and one step of joining at least one doped block (6) and at least one undoped block (7, 8), and a process of forming a plurality of active elements from the active rod (5), said formation process comprising at least one step of transverse cutting along the active rod (5) and the step of collectively treating surfaces of the active elements, are carried out in succession.

Abstract: A laser diode array assembly includes a laser diode array and a memory device integrally packaged with the array. The memory device includes operational information concerning the array. The memory device is accessible by a host external operating system which determines the manner in which the array is to be powered based on the operational information. The memory device may have the capability to be written to such that tie external operating system can record in the memory device significant events such as extreme operational conditions, operational faults, and the on-time or shot-count of the array. The assembly may include sensors to which the operating system is coupled. The assembly may further include a processing means to monitor the sensors and provide real-time updates to the external operating system such that laser diode array is continuously powered in an optimal manner.

Abstract: A sub-nanosecond passively Q-switched microchip laser is disclosed. It combines an optically pumped, passively Q-switched, high-frequency, microchip laser producing short pulses with an optically end-pumped amplifier producing high small-signal gain while pumped at low power. The microchip laser for emitting pulsed laser radiation is a monolithic body comprising two reflective elements defining an optical resonator for laser radiation, a laser gain medium, e.g., Nd:YAG, and a saturable absorber medium, e.g., Cr4+:YAG placed inside said resonator. The optical amplifier stage for amplifying the laser radiation comprises an amplifying medium, e.g., Nd:YVO4. The microchip laser and the amplifier are optically end-pumped, preferably by high-brightness diodes. This entirely passive laser system directly produces &mgr;J pulses at repetition rates of about 45 kHz.

Abstract: A light source for an exposure device associated with an optical lithographic system is disclosed. The light source includes a structural body having slots for receiving a plurality of laser elements. The laser elements are modular. Thus, they can be removed and installed separately, which facilitates ease of maintenance. The laser elements have a semiconductor laser that pumps a solid-state laser that is subjected to nonlinear optical crystals that convert the laser beam to smaller wavelength light to produce polarized UV laser light for use in optical lithography. The laser light from each laser element is linearly polarized. The laser elements are located in the structural body in different orientations so as to orient their respective directions of polarization different from each other so as to prevent dissimilar line widths of linear features of lithographically produced substrates that use laser light sources.

Abstract: A fiber laser or fiber amplifier uses resonant pumping of the gain medium by providing a pump resonator that establishes a resonator cavity at the pump wavelength which includes the pumped gain medium. The pump resonator may be of a distributed feedback (DFB) or a distributed Bragg reflector (DBR) type construction, and may be combined with signal reflection apparatus of either DFB or DBR type construction that provides oscillation of the desired laser output wavelength. If used without a signal reflection apparatus, the invention may be operated as a resonant pumped fiber amplifier. Multiple resonators may also be pumped by a single pump source by locating each in a different branch of a multiple branch directional coupler. If the resonators are constructed to couple their outputs away from the coupler, a plurality of different laser outputs each having a different wavelength and equal output powers is provided.

Abstract: According to the invention, the active element for a laser source comprises an elongate rod comprising a doped matrix capable of absorbing a pump beam in order to amplify laser radiation propagating longitudinally, at least one input face for the pump beam, a first reflection face for the pump beam which is inclined with respect to the longitudinal axis of the rod and at least one interacting second reflection face, at least one of the input face and second reflection face being equally inclined.