Abstract: Apparatus and method for achieving improved performance in a solid-state laser. The solid-state laser apparatus preferably uses a laser gain medium in the shape of a disk wherein optical pump radiation is injected into the peripheral edge of the disk. In the preferred embodiment the laser gain medium is provided with optical coatings for operation in the active mirror configuration. Furthermore, the laser gain medium is 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. Sources of optical pump radiation are placed around the perimeter of the gain medium. Tapered ducts may be disposed between the sources and the gain medium for the purpose of concentrating optical pump radiation.

Abstract: An integrated optically pumped vertical cavity surface emitting laser (VCSEL) is formed by integrating an electrically pumped in-plane semiconductor laser and a vertical cavity surface emitting laser together with a beam steering element formed with the in-plane semiconductor laser. The in-plane semiconductor laser can be a number of different types of in-plane lasers including an edge emitting laser, an in-plane surface emitting laser, or a folded cavity surface emitting laser. The in-plane semiconductor laser optically pumps the VCSEL to cause it to lase. The in-plane semiconductor laser is designed to emit photons of relatively short wavelengths while the VCSEL is designed to emit photons of relatively long wavelengths. The in-plane semiconductor laser and the VCSEL can be coupled together in a number of ways including atomic bonding, wafer bonding, metal bonding, epoxy glue or other well know semiconductor bonding techniques. The beam steering element can be an optical grating or a mirrored surface.

Abstract: A laser crystal is formed on a substrate in a solid-state laser device. The laser crystal oscillates laser beam from a second end face when an excitation beam is projected to a first end face. An excitation beam emission element emitting the excitation beam is provided for the solid-state laser device. A waveguide path is formed on the substrate. The excitation beam is transmitted through the waveguide path. The waveguide path has a first end portion on which the excitation beam emitted by the excitation beam emission element impinges and a second end portion which opposes the first end face of the laser crystal. The excitation beam is emitted from the second end portion.

Abstract: A pulsed, solid laser having a solid-state gain-medium and Q-switch is optically-pumped by a diode-laser array controlled to deliver pump-light pulses to the gain-medium. The Q-switch and the diode-laser array are cooperatively controlled by a controller such that laser output-pulses produced in response to pump-light pulses have the same energy independent of the time-interval between laser output-pulses. Pump-light pulses may be provided by the controller operating a switchable current supply which supplies current-pulses to the diode-laser array for causing pump-light pulses to be delivered to the gain-medium. A controller may also be arranged to drive the diode-laser to provide continuous pump-light output and to operate a light modulator located between the diode-laser array and the gain-medium to cause pump-light pulses to be delivered to the gain medium.

Abstract: A diode pumped solid state laser for producing a high aspect ratio beam comprises a diode pumping array (1) on a diode array mount (3) and optical means for imaging a pump light beam onto a substantially asymmetrical spot with a smooth intensity profile. The pump light beam is pumping a laser medium (4). Both the pump and the lasing mode have strong asymmetries. In combination with the right choice of laser medium (4), this results in high power laser performance. The axis of the pump light beam is adjustable by a simple adjusting means (110) to a defined plane or direction relative to a mounting frame (111) of a diode array pumping device (103). The adjusting means (110) compensates small tolerances on mounting of the diode array (1) and/or at least one optical element (2). The adjusting means include at least one wedged window (127). Because of this adjustment the axis of the light beam lies in a defined plane relative to the mounting frame (111) of the pumping device (103).

Abstract: According to the invention, a high power diode pumped solid state laser is provided. The laser includes a first and second reflective surfaces which form an optical resonator cavity. A laser medium, particularly a Nd doped laser medium for example: a Nd:YAG, a Nd:YLF, or a Nd:YVO4 crystal is provided within the laser cavity. A fundamental frequency laser beam propagates from the front and back ends of the laser medium. The first reflective surface is highly reflective for fundamental beam. The second reflective surface is at least partially reflective for fundamental beam. The laser medium is end pumped by at least one diode pumping apparatus for example, a laser diode, or diode array, or fiber coupled laser diodes, whose wavelength matches at least one laser medium absorption band. The diode pumping apparatus is located adjacent either the front end or the back end of the laser medium, or both. The optical resonator cavity is configured to provide a laser beam diameter in the laser medium from about 0.

Abstract: Phase masks which can be used to make both linear and curved gratings of single or multiple submicron pitches, with or without any abrupt quarter-wavelength shifts (or gradually varying finer phase shifts) simultaneously on the wafer/substrate. The phase masks are made using direct write electron or ion-beam lithography of two times the required submicron pitches of linear and curved gratings on commercially available &pgr; phase-shifting material on a quartz substrate and wet or dry etching of the &pgr; phase-shifting material. The phase masks can be used in connection with making multi-wavelength laser diode chips. The laser diodes have a ridge structure with metal shoulders on either side of the ridge. The laser diode chip, with different wavelength lasers, is bonded and interfaced to a novel microwave substrate that allows for high signal-to-noise ratio and low crosstalk. The substrate is packaged in a low loss rugged housing for WDM applications.

Abstract: An optically pumped monolithic VCSEL (vertical cavity surface emitting laser) architecture is disclosed. The laser structure comprises at least one signal VCSEL, at least one pump laser, and transition regions between the signal VCSELs and the pump lasers The signal VCSEL is laterally optically pumped by the pump laser, which can be electrically or optically pumped. The signal VCSEL, the pump laser and the transition region all are monolithically integrated onto a common substrate. The signal VCSEL can be disposed outside or inside the pump laser cavity (extra-cavity or intra-cavity pumping). The cavity of the pump laser can takes various forms, such as a concave cavity, a confocal cavity, or a cylindrical or ellipsoidal form of cavity. Several signal VCSEL can be disposed in the focus or focal area of the cavity of the pump laser.

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 zirconate 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 solid state modulated ultraviolet laser comprises a laser diode for generating modulated optical energy, a waveguide upconversion laser for converting a portion of the modulated optical energy to upconversion optical energy, and a waveguide sum frequency generator for combining the modulated optical energy and the upconversion optical energy to generate a modulated ultraviolet signal.

Abstract: A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.

Abstract: A light source including at least one laser diode module and a heat pipe having a heat absorbing portion and a heat radiating portion. The laser diode module includes a metal substrate mounting a laser diode chip and an optical component, and a peltier device thermally connected with the metal substrate. The heat absorbing portion of the heat pipe is thermally connected with the peltier device. The light source preferably includes a plurality of densely placed laser diode modules, each of which has an output of at least 100 mW. The light source also preferably includes a plurality of heat pipes having heat radiating fins on the heat radiating portions thereof.

Abstract: A window is formed at a portion in a reflecting surface that surrounds a slab type solid-state laser oscillating medium, filler strips, and a flow tube. A laser diode is disposed outside the region surrounded by the reflecting surface. Excitation light emitted from the laser diode is injected into the region surrounded by the reflecting surface through a condenser lens and the window.

Abstract: A semiconductor laser array is arranged on the side of a solid state laser element, and an optical resonator to an excitation light is constructed by applying a high reflection coating to an oscillation wavelength of the semiconductor laser array is applied to an end face of the semiconductor laser array positioned on the opposite side to the solid state laser element and a side of the solid state laser element positioned on the opposite side to the semiconductor laser array. The solid state laser element is arranged on the inside of the optical resonator, and the solid state laser element is excited optically by the excitation light.

Abstract: In order to improve a laser radiation source comprising an array of N individual slave laser diodes in a predetermined surface area, a slave power supply for the slave laser diodes, a master laser diode for generating a master laser radiation, a master power supply for the master laser diode, an optical coupling device, with which the master laser radiation can be coupled into the individual slave laser diodes in order to operate them at the frequency of the master laser diode in a phase-locked manner, and an optical transformation device which combines the slave laser radiation of the individual slave laser diodes to form a coherent total laser radiation field with essentially plane wave fronts, in such a manner that it is possible as a result of the adjustability of the power supply networks to adjust the slave laser diodes relative to one another and thus operate them in a stable manner in relation to one another it is suggested that the slave power supply have a separate power supply network for each slav

Abstract: An optical device has a mount including a mount surface with a longitudinal axis. A diode source has a first diode emitter producing a first beam, a second diode emitter producing a second beam and a third diode emitter producing a third beam. The diode source is mounted above the mount surface at an angle &thgr; relative to the longitudinal axis of the mount. A prism array has a first prism face, a second prism face and a third prism face. The prism array has an angled surface cut at the angle &thgr; relative to a longitudinal axis of the prism array. The first, second and third beams are incident on the first, second and third prism faces respectively. Optical path lengths between the first, second and third diode emitters relative to the first, second and third prism faces are equal.

Abstract: Method and apparatus are disclosed for beam dividing and shaping, in which the beams from laser diode array are divided in a plurality of sections along the slow axis and the sections of beams are then recombined along their fast axis so that the Lagrange invariant of the resulting beam increased approximately by n-fold in fast axis and reduced approximately by n-fold in slow axis. With the inclusion of above apparatus in diode laser modules, the main objectives of constructing high-efficiency solid state lasers can be achieved.

Abstract: An inspection apparatus includes a laser system. The laser system has a high reflector and an output coupler that define an oscillator cavity which produces an output beam. A gain medium and a mode locking device are positioned in the oscillator cavity. A diode pump source produces a pump beam that is incident on the gain medium. An output beam directing apparatus directs the output beam to the surface of the article. A surface flaw at the surface of the article produces scattered light from at least a portion of the output beam incident on the surface flaw. A detector is positioned to detect the scattered light.

Abstract: A passive mode-locked linear-resonator fiber laser using polarization-maintaining fibers and a saturable absorber to produce ultra short pulses and a long-term reliable operation with reduced maintenance. Such a fiber laser can be configured to produce tunable pulse repetition rate and tunable laser wavelength.

Abstract: A diamond coating formed on a WC—Co substrate prepared through a process including employing a plasma and a variety of interactions from a multiple laser system demonstrates exceptional adhesion and indicates a durable cubic diamond structure. The coating on the WC—Co substrate is typically between 25 and 40 &mgr;m thick and has an average crystal size of between 10 and 20 &mgr;m. Various methods of confirming the cubic diamond structure of the coatings have been employed. The adhesion of the diamond coating to the substrate is very strong. An electron microprobe analysis shows tungsten and cobalt atoms incorporated into the film and a layer depleted in cobalt exists at the diamond-WC—Co interface. Particulates of WC—Co—C alloy are spread over the top surface, apparently formed by condensation from the vapor phase of metal-containing molecules. Carbon is confirmed as being the main component of the surface layer.

Abstract: A laser system for operation at elevated temperatures with minimal cooling requirements. The laser system comprises a laser media having first and second optical ends and an input port. The laser system further comprises at least one high-temperature laser diode which optically communicates with the laser media and is operative to generate a source beam of light which is transmitted into the input port of the laser media. Optically communicating with the first optical end of the laser media is at least one reflector, while optically communicating with the second optical end of the laser media is at least one optical coupler. The laser media, the reflector and the optical coupler are configured to form a laser resonator operative to generate a laser beam which is transmitted through the optical coupler.

Abstract: A laser structure may be used to fabricate a plastic laser and achieve electrically-driven lasing action. The structure comprises an LED, a waveguide laser, and a substrate disposed between them. The substrate has a first and a second side. Light emitted from the LED is received by the substrate at the first side and concentrated as it is guided with the body of the substrate to the second side, where it is received by the laser. Concentration of the light across the substrate improves the efficiency of the device and leads to lower threshold powers.

Abstract: A multistage optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources for pumping a single fiber laser pump source. A second level of redundancy deals with redundancy of a plurality of fiber laser pump sources for pumping a plurality of serially connected injection signal fiber amplifiers forming the multistage amplifier system. If one of fiber pump sources should fail, increased pumping power is available from the remaining fiber pump sources via their respectively connected amplifier stages. A third level of redundancy deals with redundancy in the employment of multiple single mode laser emitters on the same chip or bar sufficiently segmented and/or electrical isolated so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar.

Abstract: A side-pumped, diode-pumped solid state laser device includes an elongated housing having an elongated cavity defined therein and further having an elongated opening defined between the cavity and the exterior of the housing. A solid state rod is disposed within the cavity and is preferably surrounded by a cooling fluid. A cover seal sealably covering the opening and thereby encloses the cavity. The cover seal is formed of a material that is at least substantially transparent to pumping radiation at a predetermined pumping wavelength. A diode array emits the pumping radiation that traverses the cover seal and the opening to be absorbed by the rod to excite laser active species within the rod. The laser device further includes a resonator including the rod disposed therein for generating a laser beam.

Abstract: The present invention has the following objectives:

Abstract: A passively cooled solid-state laser system for producing high-output power is set forth. The system includes an optics bench assembly containing a laser head assembly which generates a high-power laser beam. A laser medium heat sink assembly is positioned in thermal communication with the laser medium for conductively dissipating waste heat and controlling the temperature of the laser medium. A diode array heat sink assembly is positioned in thermal communication with the laser diode array assembly for conductively dissipating waste heat and controlling the temperature of the laser diode array assembly. The heat sink assemblies include heat exchangers with extending surfaces in intimate contact with phase change material. When the laser system is operating, the phase change material transitions from solid to liquid phase.

Abstract: Using a thin disk laser gain element with an undoped cap layer enables the scaling of lasers to extremely high average output power values. Ordinarily, the power scaling of such thin disk lasers is limited by the deleterious effects of amplified spontaneous emission. By using an undoped cap layer diffusion bonded to the thin disk, the onset of amplified spontaneous emission does not occur as readily as if no cap layer is used, and much larger transverse thin disks can be effectively used as laser gain elements. This invention can be used as a high average power laser for material processing applications as well as for weapon and air defense applications.

Abstract: Modulated integrated optically pumped vertical cavity surface emitting lasers are formed by integrating an electrically pumped semiconductor laser and a vertical cavity surface emitting laser (VCSEL) together with a means of direct modulation of the electrically pumped semiconductor laser. In the preferred embodiments, the electrically pumped semiconductor laser is a type of folded cavity surface emitting laser (FCSEL). In a number of embodiments, the FCSEL is partitioned into two sections by a gap in material layers. In these embodiments, one section of the FCSEL is biased so as to maintain the generation of photons at a constant power level to pump the optically pumped VCSEL while the second section of the FCSEL is used for modulation and causes the optically pumped VCSEL to be modulated above the threshold. In another embodiment, an electric-absorption modulator is sandwiched between an electrically pumped FCSEL and an optically pumped VCSEL.

Abstract: A single mode surface emitting laser and its manufacturing method are provided. The surface emitting laser which has a characteristic of single transverse mode radiation in the broad region using reflectivity distribution of a reflector layer with an antiguide clad is provided.

Abstract: The invention offers a low-noise, compact, high-efficiency light generating device and an irradiation method thereof for use in medical applications. A fundamental harmonic laser head 106 is composed of a quasi-continuous wave oscillation mode laser diode (QCW-LD) 101, a laser crystal 103, a rear mirror 104 and an output mirror 105. The QCW-LD 101 is driven by an LD power source 102 capable of modulating the pulse waveform in time. A beam adjusting portion 108 comprises a wave plate, a polarizer, a lens and an isolator. A wavelength converting portion 112 is an optical parametric oscillator (OPO) comprising a non-linear optical crystal 109, an OPO input mirror and an OPO output mirror 111.

Abstract: A method for the self-calibration of a tunable, diode pumped solid state laser in which the frequency or the wavelength of the laser radiation of the fundamental frequency and/or doubled frequency is changed by of changing the optical cavity length by means of a piezo-actuator or Brewster window over the total amplification bandwidth of the laser-active material. According to the method, the performance curves during the tuning of an etalon or corresponding optical elements arranged in the cavity are recorded and stored and a tuning function for the respective optical element or optical elements is generated (derived) from these curves by a microcontroller or computer. An optimum working point for the optical element or optical elements for maximum suppression of side modes is adjusted by a digital or analog regulator with the help of a learning curve (learning characteristic).

Abstract: Thermally induced distortion of the optical wavefront caused by heating of the laser media by waste heat from the excitation process and absorption of laser radiation creates optical phase errors. A system generates an error signal derived from the optical phase errors. The error signal is fed back to the power supplies driving semiconductor diodes that excite the lasing liquid thereby introducing an electrically controllable wedge into the optical cavity to correct the optical phase errors.

Abstract: Modulated integrated optically pumped vertical cavity surface emitting lasers are formed by integrating an electrically pumped semiconductor laser and a vertical cavity surface emitting laser (VCSEL) together with a means of direct modulation of the electrically pumped semiconductor laser. In the preferred embodiments, the electrically pumped semiconductor laser is a type of folded cavity surface emitting laser (FCSEL). In a number of embodiments, the FCSEL is partitioned into two sections by a gap in material layers. In these embodiments, one section of the FCSEL is biased so as to maintain the generation of photons at a constant power level to pump the optically pumped VCSEL while the second section of the FCSEL is used for modulation and causes the optically pumped VCSEL to be modulated above the threshold. In another embodiment, an electric-absorption modulator is sandwiched between an electrically pumped FCSEL and an optically pumped VCSEL.

Abstract: An active mirror amplifier (AMA) laser module incorporating an optically transparent, rigid substrate having a plurality of cooling passages has one surface thereof disposed against a laser gain medium disk. The substrate also has a plurality of microchannels disposed near or at an outer surface thereof which is in contact with an outer surface of the disk. A cooling medium is circulated through the flow passages and the cooling microchannels to help keep the disk cool during use of the laser. This allows the laser module to operate at significantly increased power without overheating. In one preferred embodiment the disk is attached to the substrate using a pressure differential between a front surface of the disk and the pressure of the coolant. This eliminates attachment-induced thermal stresses of prior art designs and allows the laser to operate at increased power without fracturing the substrate.

Abstract: The invention is directed to an optically pumped surface-emitting semiconductor laser device having at least one radiation-generating quantum well structure and at least one pump radiation source for optically pumping the quantum well structure, whereby the pump radiation source comprises an edge-emitting semiconductor structure. The radiation-generating quantum well structure and the edge-emitting semiconductor structure are epitaxially grown on a common substrate. A very efficient and uniform optical pumping of the radiation-generating quantum well structure is advantageously possible with this monolithically produced semiconductor laser device. Methods for manufacturing inventive semiconductor laser devices are also specified.

Abstract: The invention is a frequency stabilized passive Q-switch laser, which has the advantages of small volume, simple structure, no need for high power voltage, etc. It has been a long time that timing jitter in conventional lasers is so large that they can not be applied to fields such as distance measurement. This invention utilizes an optical external modulation method to stabilize the repetition rate of the passive Q-switch, and thus to decrease its timing jitter. At the same time, the repetition rate of the Q-switch laser can be controlled by the same technology to meet various application needs.

Abstract: A diode-pumped gas laser includes a source of optical diode-pumping light and a gas cell having a first optical window for receiving the diode-pumping light. The gas cell contains a laser gas including a lasing gas comprised of at least one absorbing and lasing atomic or molecular gas. The lasing gas has an optical absorption band which is at least partially overlapped by the bandwidth of the diode-pumping light. The gas laser also includes a gas laser resonator for providing an output laser beam which is emitted from the gas cell via a second optical window. The output laser beam has one or more laser wavelengths. The gas laser may also include diode optics for directing the diode-pumping light through the first optical window and a heat power regulation system for regulating the temperature of the source of optical diode-pumping light.

Abstract: A laser diode pump for fiber amplifiers, such as erbium-doped fiber amplifiers (EDFAs), reduces spurious reflections in the signal frequencies by providing a laser pump system that is dissipative at these signal frequencies. Reflections from the pump system are reduced, or eliminated by using an output facet that is currently coated to be reflective at pump frequencies, but anti-reflective, or transmissive, at the signal frequencies. In one embodiment, material layers of aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) are used.

Abstract: A laser device includes a laser rod; a radial array of diode laser pumping devices, wherein each diode laser has a solid connection to the laser rod to maximize laser energy transfer. The diode laser radial array is serially connected via coatings and/or fingers and/or spheres. Cooling of the laser rod and the diode laser radial array is accomplished via a common fluid channel outside the laser rod, wherein a cooling fluid flows past the laser rod and the diode laser radial array. Innovative methods for creating the coating embodiments are disclosed. Various flat diode laser embodiment are also disclosed.

Abstract: A laser diode package couples laser diode outputs into a plurality of fibers, and these are bundled and brought to an output face that produces a divergent composite beam from the fiber ends. The beam end pumps a solid-state laser across a gap, and the divergence allows a wide tolerance in alignment of the pump and crystal. Preferably, one cavity mirror is a focusing mirror that reconcentrates residual pump light in the desired mode. In a preferred embodiment, the output face of the package is at a short stub or ferrule that provides a simple and effective pump beam centering alignment. The solid-state laser may be a rod or crystal and is preferably sufficiently short, in relation to pump beam diameter and divergence in the rod, that the pump beam within the rod lies in the TEMoo mode volume of the laser cavity. A concave mirror then refocuses residual pump light back into that mode. The rod preferably has a high index at the pump wavelength, but need not have high absorption.

Abstract: The present invention is directed to a novel wavelength division multiplexed (WDM) lightwave communication system having allocated wide bands of wavelengths within which the respective optical pump light employed to amplify the optical signals must stay. As the temperature of the pump laser varies, its lasing wavelength is allowed to wander anywhere within its allocated wavelength band. Preferably, the pump lasers are wavelength stabilized within its respective allocated wavelength band by means of a fiber Bragg grating having an appropriately wide spectral width. Extending the lasing wavelength range of the pump laser advantageously, in turn, may be used to extend the temperature range over which the pump laser can be operated or locked.

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: In an up-conversion laser using Tm, blue light having a wavelength of 450 nm and blue light having a wavelength of 480 nm are outputted simultaneously. A high output is enabled with a high efficiency, and a green up-conversion laser is also realized by a similar means. A hybrid fiber laser apparatus includes a light source which outputs light near a wavelength A, and comprises a means for reflecting light near the wavelength A, which is provided at another end of the optical fiber, thereby to form an optical resonator for the wavelength A. In this hybrid fiber laser apparatus, an up-conversion fiber is provided in the optical resonator for the wavelength A, and optical resonator structures for a wavelength B constructed by reflection means and for a wavelength B are respectively provided at two positions at both ends of the up-conversion fiber.

Abstract: A sub-mount, an LD bar and a light guide duct are mounted on an LD package main body of a semiconductor laser, and an outgoing section of the LD bar is inserted into the light guide duct. A gold metallized insulating plate is fused on one side of the LD package main body, and the LD bar and the gold metallizing are wire-bonded. The light guide duct transmits the excitation light directly up to a laser medium, and a reflector surrounds the periphery of the laser medium. Upon flowing of a current from the LD package main body to the cathode electrode, the LD excitation light is emitted and the laser medium is excited, to thereby make laser oscillation possible. With the above structure, there is provided an LD excitation solid-state laser device which is easy in assembling, low in the costs, high in efficiency and high in reliability.

Abstract: Optical detection apparatus comprises a solid state laser having an intracavity optical waveguide that supports a lasing filament and operates in one of two states: (1) in a first state, the filament is fixed in one of two orientations, and (2) in a second state, the filament may be induced to switch or oscillate between the two orientations, or it may be suppressed altogether. At least one feature is located on the output facet off-center with respect to the waveguide cross-section in order to provide a preferred orientation for the filament. In one embodiment, a single feature is located off-center and optical radiation of one intensity is injected through the facet feature, thereby causing the laser to operate in one of its states, whereas injected radiation of another intensity causes the laser to operate in the other of its states. The injected radiation may be radiation emitted by the laser that is reflected by an object (e.g.

Abstract: A semiconductor laser pumped solid state laser includes a solid laser medium, a semiconductor laser which radiates a pumping laser beam for pumping the solid laser medium, and a light entrance optical system which converges the pumping laser beam in the solid laser medium. The semiconductor laser is disposed with its beam radiating axis inclined to the optical axis of the light entrance optical system so that the pumping laser beam travelling from the semiconductor laser to the solid laser medium and a laser beam reflected at the pumping light inlet side end face of the solid laser medium travel different optical paths. A light-shielding plate which intercepts the laser beam reflected at the pumping light inlet side end face of the solid laser medium is provided between the semiconductor laser and the solid laser medium.

Abstract: A laser diode assembly includes a laser diode having an emitting surface and a reflective surface opposing the emitting surface. Between the emitting and reflective surfaces, the laser diode has first and second surfaces to which a first heat sink and second heat sink are attached, respectively, via a solder bond. A spacer element is disposed between the first and second heat sinks and is below the laser diode. The spacer element has a width that is chosen to provide optimum spacing between the first and second heat sinks. The spacer element has a height that is chosen to place the emitting surface of the laser diodes at a position that is substantially flush with the upper surfaces of the heat sinks. A substrate is positioned below the first and second heat sinks and is attached to these two components usually via a solder bond. The substrate is preferably of a nonconductive material so that electrical current flows only through the heat sinks and the laser diode.

Abstract: The invention provides an efficient, compact means of generating blue laser light at a wavelength near ˜493+/−3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near ˜986+/−6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the ˜490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from ˜980 to ˜992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm).

Abstract: A vertical cavity surface emitting laser diode (VCSEL), includes top and bottom electrically non-conductive mirrors defining a first laser cavity containing a laser medium and designed to resonate at a first wavelength. A second laser cavity is designed to resonate at a second wavelength less than the first wavelength. The second laser cavity is optically coupled to the first laser cavity so as to pump the laser medium and create laser action in the first laser cavity. The second laser cavity is normally provided by a VCSEL stacked below the first laser cavity.

Abstract: In a wavelength multiplexing light source used in an optical wavelength division multiplexing (WDM) transmission system and the like, at least three semiconductor lasers of single longitudinal mode have oscillation frequencies outside of their pull-in range at a normal injection locking without a modulation side band, an output light of a first semiconductor laser is injected in one way into a second semiconductor laser having an oscillation frequency adjacent to that of the first o semiconductor laser through a first one-way optical injection means to generate a modulation side band. The output light of the second semiconductor laser is then injected in one way into a third semiconductor laser having an oscillation frequency adjacent to that of the second semiconductor laser through a second one-way optical injection means to generate the modulation side band for an injection locking.