Abstract: A ring laser (10) incorporates a laser rod (R) with end faces (R.sub.1, R.sub.2). The first face (R.sub.1) is coated for high reflectivity at the laser wavelength and the second (R.sub.2) for high transmission at this wavelength. The first face (R.sub.1) provides one cavity end mirror, and a concave mirror (M.sub.1) spaced apart from the rod (R) provides the other. A rhombic prism (P) between the rod (R) and mirror (M.sub.1) defines differing (figure of eight) forward and return paths (14 to 17, 18 to 21) for cavity radiation passing from one end mirror (R.sub.1 or M.sub.1) to the other and returning. The prism (P) presents Brewster's angle refracting surfaces. The second rod face (R.sub.2) is tilted to produce an optical path in two planes. A magnetic field (B) along the rod axis (R.sub.a) produces Faraday rotation of polarization. This counteracts rotation arising from non-coplanar optics for one direction of propagation around the laser cavity (10) but not the other.

Abstract: A signal light is coupled by a light coupler/splitter (31) with a 0.98 micron first pumping light (.lambda..sub.1) generated by a first pumping light source (21), and the coupled light is launched into an Er-doped optical fiber (1). The signal light is optically amplified in the Er-doped optical fiber. A 1.48 micron second pumping light (.lambda..sub.2) generated by second pumping light source (22) is launched into the Er-doped optical fiber (1) with a light coupler/splitter (32). This 1.48 micron pumping light contributes boost the amplified signal.

Abstract: A solid state tunable laser resonator having a laser element, an excitation light source for outputting a pumping light, and elements for selecting a wavelength of the pumping light and directing the wavelength of the pumping light onto the laser element at a first point thereof on a first axis substantially parallel to an axis of oscillation light emitted by the laser element. The laser resonator may also include elements for directing the pumping light onto the laser element at a second additional point thereof. The laser resonator can be used as a laser light source having a wide tunable range with a narrow line width.

Abstract: A solid-state laser device which employs a bi-cylindrical lens as a focusing lens for focusing excitation light emitted from a semiconductor laser to pump a laser medium. Further, the radius of curvature of each cylindrical surface of the bi-cylindrical lens is selected such that a region of the laser medium to be pumped by a horizontal component of the pumping light and another region of the laser medium to be pumped by a vertical component of the pumping light are contained in a predetermined region of the laser medium. Thereby, output laser light which excels in transverse mode characteristics can be efficiently obtained without increasing the number of surfaces of lenses composing the focusing lens system. Moreover, there is provided a solid-state laser device which can be relatively small-sized and easily regulated.

Abstract: A laser light source in which a couple of light beams whose shapes are re-formed and whose polarizing planes are made perpendicular to each other are synthesized by a beam splitter and then the synthesized light is incident on an optical guide through a predetermined optical system, thereby generating the synthesized light having a short spot diameter and an improved power density.

Abstract: An end pumped solid-state laser is comprised of a resonator formed of a pair of mirrors and a laser rod disposed between the pair of mirrors, an exciting light source for generating a pumping light which excites the laser rod and a converging optical element for converging the pumping light from the exciting light source so that the converged pumping light is irradiated on an end face of the laser rod. The wavelength of the light generated from the exciting light source is widened in band and/or a converging optical element having a large wavelength dispersion is employed, whereby heat generation in the optical axis direction of the laser rod is uniformed so as to generate a laser beam of large power.

Abstract: A laser system and method for producing a laser emission at a wavelength of substantially 2.8 microns and having a quantum efficiency of at least unity and a slope efficiency of about 36%. In a preferred embodiment of the invention, the laser system comprises a laser cavity defined by first and second reflective elements with one of the reflective elements operating as an output coupler; a crystal disposed in the laser cavity and having a GSGG host material doped with a preselected percent concentration of erbium, the GSGG host material and preselected percent concentration of erbium being selected so as to provide a quantum efficiency of at least unity by the .sup.4 I.sub.13/2 +.sup.4 I.sub.13/2 .fwdarw..sup.4 I.sub.9/2 +.sup.4 I.sub.15/2 upconversion process and a slope efficiency of about 36% when the crystal is resonantly pumped; and a resonant pump laser for directly pumping the .sup.4 I.sub.

Abstract: The 1.06.mu. Nd transition in a co-doped Cr,Nd:Gd.sub.3 Sc.sub.2 Ga.sub.3 sub.12 (Cr,Nd:GSGG) gain element is obtained by diode pumping Cr.sup.3+ at 670 nm and produces efficient, low threshold laser operation. Although co-doped Cr,Nd:GSGG was developed for more efficient flashlamp pumping, it has the desirable property of having an extraordinarily broad absorption to allow for efficient diode pumping relative to the Nd:YAG laser. The consequent broad bandwidth tolerance of the Cr,Nd:GSGG for the diode pumping radiation allows diode pumping of the 1.06.mu. transition without regard to the wavelength of the visible diodes which has the potential for reducing the cost of the semiconductor pump and also demonstrates the extended versatility of these diodes which previously had been restricted to pump the Cr.sup.3+ tunable vibronic lasers. CW and long pulse diode pumping provided pump power levels as high as 300 mW cw and 1 W pulsed. The lowest threshold power was measured at 938 .mu.

Abstract: There is disclosed a new superfluorescent source comprising a long fiber doped with a lasing material presenting three-level transitions, such as Erbium. Due to the ground state signal absorption present in three-level systems, the source of the present invention can achieve backward signal quantum efficiencies well in excess of the limit of 0.5 exhibited by four-level systems. The source can be used in a Sagnac interferometer which may comprise an optical isolator because of possible high feedback.

Abstract: Apparatus and method for scaling solid-state devices to higher power using multiple sources each of which are separately collimated, followed by focusing of the pump radiation into gain medium colinear to laser mode using a moderated focus. A modularized system is also described.

Abstract: A laser apparatus and method is disclosed comprising a first lasant material which is located in an optical cavity and which produces laser radiation of a first wavelength, and a second lasant material which is pumped by radiation from the first lasant material, which absorbs laser radiation at the first wavelength in an amount generally comparable to the Optimum Output Coupling, which functions as the output coupler for the optical cavity and which lases at a second wavelength. The first lasant material and the second lasant material are preferably selected to have minimal losses such that there is a net gain in the cavity.

Abstract: A laser-diode or laser diode array end-pumped solid-state laser package for optical communications and the like mounted on a common thermally conductive, low thermal expansion base that is temperature stabilized with a thermo-electric cooler. The laser package includes a heat sink, a thermo-electric cooler mounted on the heat sink, a base having a base plate portion mounted on the thermo-electric cooler and a block portion mounted on the base plate portion and optical elements mounted on the base plate and block. The laser active medium and collimating and focusing lenses are mounted with their optically axes collinear in a v-groove formed in a top surface of the block. A laser diode pump is mounted to the base plate and supported so that its laser emission is aligned with the length of the groove.

Abstract: A method and apparatus for injecting a pump beam into a multi-pass amplifier to achieve a high degree of pump-input beam overlap.

Abstract: An end-pumped laser oscillator having an amplifier including a solid-state gain medium. Pump beams, which are generated by two groups of laser diode bars placed between the optical elements defining the optical resonator, are directed onto opposite end surfaces of the solid-state gain medium, which intersect the optical axis of the optical resonator. The laser diode bars of each group are circumferentially distributed about the optical axis in a uniform pattern and at the same distance along the optical axis from the gain medium. One group of diode bars is located to one side of the gain medium and the other group is located to the other side of the gain medium. Pump beam energy is thereby effectively and efficiently directed onto both end surfaces of the solid-state gain medium from a plurality of laser diode bars allowing the output power produced by the gain medium to be scaled to the thermal limits of the gain medium.

Abstract: A printing device employs a semiconductor laser source for producing a laser beam, and a semiconductor-laser-pumped solid-state laser. The solid-state laser includes an optical resonator, such as a nonlinear optical element for effecting wavelength conversion, and a solid-state laser material disposed therein. The solid-state laser material is optically pumped by the laser beam from the semiconductor laser source and produces a laser beam to be applied onto a photosensitive sheet of paper. Responsive to print data, the intensity of the laser beam from the semiconductor laser source is varied between a first intensity level and a second intensity level. The photosensitive sheet of paper is insensitive to the laser beam when the laser beam from the semiconductor laser source is at the first intensity level, whereas it is sensitive to the laser beam when the laser beam from the semiconductor laser source is at the second intensity level.

Abstract: A laser source for pumping an optical device which requires for its operation a significant amount of light power, the source comprising a semiconductor array (11) for providing a plurality of spaced apart light beams at different wavelengths, an optical assembly (14, 15, 16) for focussing the light beams into an optical waveguide (19), the optical waveguide (19) being coupled to the optical device.

Abstract: A semiconductor-laser-pumped, solid-state laser includes a semiconductor pumping laser emitting pumping light, a solid-state laser medium arranged to be excited by the pumping light, and a laser resonator structure for emitting laser light from the solid-state laser medium. The solid-state laser medium is plate shaped having a thickness less than the broadening width of the pumping light in the solid-state laser medium. The semiconductor laser is arranged close to the face of the solid-state laser medium, and the laser resonator structure has optical axis coinciding with that of the pumping light.

Abstract: The invention relates to laser systems of the type comprising optical fiber amplifiers. A laser system comprises a first laser 1 and a second laser 2. The second laser 2 is pumped at a first wavelength .lambda..sub.1 and caused to lase at a second wavelength .lambda..sub.2. The first laser 1 has absorption bands .lambda..sub.1 and .lambda..sub.2. The output .lambda..sub.2 of laser 2 and the remnant pump at .lambda..sub.1 are coupled and both are used to pump the first laser 1, thus causing laser 1 to lase at a third wavelength .lambda..sub.3.

Abstract: An optical assembly is disclosed herein along with a method of operation for use in a dye lasing arrangement, for example a dye laser oscillator or a dye amplifier, in which a continuous stream of dye is caused to flow through a given zone in a cooperating dye chamber while the zone is being illuminated by light from a pumping beam which is directed into the given zone. This in turn causes the dye therein to lase and thereby produce a new dye beam in the case of a dye laser oscillator or amplify a dye beam in the case of a dye amplifier. The optical assembly so disclosed is designed to alter the pump beam such that the beam enters the dye chamber with a different cross-sectional configuration, preferably one having a more uniform intensity profile, than its initially produced cross-sectional configuration.

Abstract: A high power TEM.sub.00 mode Nd:YLF solid state laser includes at least two pumped Nd:YLF solid state rods in series within a laser resonator. A spherical lens may be incorporated within the resonator as required for establishing, in concert with the rods and resonator end mirrors, a large intracavity beam diameter at the position of the rods. A cylindrical lens may be provided to compensate for astigmatic thermal focusing of the Nd:YLF rods, or else the rods may be used in pairs, in which case the rods are rotated by 90.degree. about the laser axis with respect to each other, and a half-wave plate is inserted between the rods of each pair to maintain oscillation at a single wavelength.

Abstract: An optical, low-noise amplifier of the active-fiber type, which fiber contains a laser light emitting substance, adapted to be connected to an optical telecommunication fiber and receiving light therefrom at the transmission wavelength. The active fiber is also fed from a light source at a pumping wavelength and has a length corresponding to a partial absorption of the pumping light. Downstream of active fiber, there is a selective mirror device which reflects the light at the pumping wavelength and is transparent to the transmission wavelength light. Preferably, the mirror device consists of an optical demultiplexer adapted to separate the transmission wavelength and the pumping wavelength on two output fibers. A mirror which reflects the pumping wavelength is present at the end of the fiber carrying the pumping wavelength.

Abstract: Solid state and dye lasers are described which are tunable over a wide spectral region, are operable at high repetition rate, are uniformly narrow in spectral width over the tuning range, and produce a spatially uniform, single longitudinal mode beam. In one embodiment having a simple grazing-incidence cavity, the laser comprises: (a) a longitudinal pump beam with a KiloHertz (KHz) repetition rate; (b) a resonating cavity comprising a first fixed mirror, a diffraction grating, and a second rotatable mirror; and (c) an active solid state or dye medium within the cavity. In this embodiment, (i) the pump beam is passed through the fixed mirror and directed at the active medium; (ii) the emission from the active medium strikes the grating near a grazing angle; (iii) the rotatable mirror is placed at a first order diffraction position from the grating and reflects the desired wavelength radiation back into the cavity; and (iv) the output is derived from the grating at the zeroeth diffraction order.

Abstract: In a solid-state laser device comprising, as a solid-state laser medium, a nonlinear optical crystal, such as Nd.sub.x Y.sub.1-x Al.sub.3 (BO.sub.3).sub.4, which generates a primary laser beam of a fundamental wavelength and which can convert the primary laser beam into a subsidiary laser beam of a harmonic wavelength, a pair of optical elements is brought into contact with both ends of the solid-state laser medium to form a resonator for the primary laser beam. The optical elements may be composed of optical thin films or reflectors attached to the ends of the medium. At least one of the ends of the medium has a spherical surface convex outwards of the medium so as to reflect the primary laser beam into the medium.

Abstract: A laser-diode-pumped solid-state laser including a solid-state laser rod doped with a rare-earth material such as neodymium, a semiconductor laser for emitting a laser beam to pump said solid-state laser rod to oscillate a beam, and a resonator including a bulk single crystal of organic nonlinear optical material for converting the wavelength of the beam which is oscillated by said solid-state laser rod. The organic nonlinear optical material is preferably PRA, MNA, NPP, NPAN, MAP, m-NA, or the like. The semiconductor laser may comprise a single-transverse-mode, or a single-longitudinal-mode semiconductor laser.

Abstract: Solid state and dye lasers are described which are tunable over a wide spectral region, are operable at high repetition rate, are uniformly narrow in spectral width over the tuning range, and produce a spatially uniform, single longitudinal mode beam. In one embodiment having a simple grazing-incidence cavity, the laser comprises: (a) a longitudinal pump beam with a KiloHertz (KHz) repetition rate; (b) a resonating cavity comprising a first fixed mirror, a diffraction grating, and a second rotatable mirror; and (c) an active solid state or dye medium within the cavity. In this embodiment, (i) the pump beam is passed through the fixed mirror and directed at the active medium; (ii) the emission from the active medium strikes the grating near a grazing angle; (iii) the rotatable mirror is placed at a first order diffraction position from the grating and reflects the desired wavelength radiation back into the cavity; and (iv) the output is derived from the grating at the zeroeth diffraction order.

Abstract: An optically pumped solid laser that uses a corner cube or rectangular prism as its solid laser medium, containing end faces through which a semiconductor pumping light beam is applied to the medium. The solid laser medium contains at least one kind of coating formed on at least a part of an end face, such that the end face acts as a resonator and/or output mirror. Optical fibers may be connected to the end faces for inputting or outputting light beams. Non-linear crystals in waveguide form may be coupled to the outputting end face of the medium, specifically crystals of either SHG, THG, FHG, or parameteric; and KTP, .beta.-BaB.sub.2 O.sub.4, KNbP.sub.3, or MgO doped LiNbO.sub.3.

Abstract: Device for coherent addition of laser beams including several optical amplifiers in parallel pumped by a beam coming from a master laser. The beams emitted by these amplifiers are transmitted to a non-linear material and play the role of pump beams. The non-linear material also receives a signal beam derived from the master laser. The various beams of the amplifiers are therefore added in the non-linear material along the direction of the signal beam.

Abstract: Four-wave mixing is used to produce a steered optical phase conjugate wave. First and second pump waves are combined with a probe wave in a nonlinear medium within an optical conjugate, producing an optical phase conjugate wave. The magnitude of the wave vectors corresponding to the first and second pump waves are different, causing the optical phase conjugate wave to define a non-zero angle .theta..sub.0 relative to the probe wave. In a first embodiment, the wavelengths of the first and second pump waves are controlled to vary the angle, while in a second embodiment, the intensities of the two pump waves are modified.

Abstract: A laser system and method for producing a laser emission at a wavelength of ubstantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser system comprises a crystal having a host material doped with erbium; a laser cavity defined by first and second reflective elements at opposing ends of the crystal to form a reflective path therebetween; and resonant pumping means for directly pumping the .sup.4 I.sub.11/2 upper laser state of the erbium with a pump beam at a preselected wavelength to cause the erbium-doped crystal to produce a laser emission corresponding to the .sup.4 I.sub.11/2 .fwdarw..sup.4 I.sub.13/2 laser transition having a wavelength of substantially 2.8 microns, a portion of the laser emission at substantially 2.8 microns being outputted from one of the first and second reflective elements.

Abstract: A laser medium for use in a slab laser having a light absorbing member provided in a region, wich is deviated from a zigzag path to be followed by a laser beam to be extracted therefrom and thus the laser beam does not pass through. Thereby, parasitic oscillation can be effectively suppressed, and laser oscillation and light amplification can be performed for a long period of time.

Abstract: A room temperature laser system for producing a CW Laser emission at substantially 2.7 microns is disclosed. In a preferred embodiment, the laser system comprises a laser diode source for producing a CW pump beam at a preselected wavelength; and a fiber laser doped with erbium activator ions to produce an output CW laser emission at a wavelength in the range of 2.71-2.78 microns when the fiber laser is pumped by the CW pump beam.

Abstract: Apparatus and method for scaling solid-state devices to higher power using multiple sources each of which are separately collimated, followed by focusing of the pump radiation into gain medium colinear to laser mode using a moderated focus. A modularized system is also described.

Abstract: A laser system for producing pulsed, longitudinal mode optical energy over a widely tunable range of wavelengths. The system includes an optical cavity and a solid-state gain medium. The optical cavity comprises first, second, and third optical element means. The first optical element means reflects energy received along a first reflective optical axis and directs the energy toward the second optical element means, which diffracts the optical energy into at least two orders of interference. The energy diffracted according to a first order of interference is reflected back toward the second optical element means by a third optical element means, thereby creating a resonant optical cavity. Another portion of the optical energy diffracted by the second optical element means is produced as an output beam.

Abstract: A laser system includes a first laser (66) and a second laser (68) optically coupled to the first laser (66), characterized in that the first laser (66) is arranged to respond to pumping by producing a first laser output and retaining for a time period a net gain for second laser output radiation, and the second laser (68) is adapted to be pumped by the first laser output and to respond within the time period by producing a second laser output optically coupled to the first laser (66) to effect injection control thereof. The first laser (66) may be an excimer laser and the second laser (68) may be a dye laser. The lasers may be coupled by a common laser mirror (20).

Abstract: A solid-state laser device includes a neodymium laser pump source capable outputting a pump beam of about 1.1 .mu.m wavelength, and a holmium laser being pumped by said 1.1 .mu.m pump beam to generate an output laser beam of about 3 .mu.m wavelength.

Abstract: A solid-state laser of improved amplitude stability is obtained by substantially eliminating spatial hole burning in the lasant material and maintaining the optical cavity of the laser at a temperature which results in substantially noise-free generation of output radiation.

Abstract: A large number of semiconductor laser sources coupled with tapered fibers provide a high energy density output for the purpose of longitudinal pumping of a solid state gain medium in an unstable resonator. Each semiconductor laser source generates a beam of radiation at the pump wavelength having characteristic lateral and transverse widths. A plurality of light transmitting fibers, each fiber having an input end and an output end, is coupled with the semiconductor laser sources for delivering the light from a remote location to pump the gain medium. The input end of each fiber has a cross-section substantially matching the transverse and lateral widths of the beams generated by the corresponding semiconductor laser source, and is coupled to receive the beam of radiation generated by a corresponding semiconductor laser source. The output ends of the light transmitting fibers are bundled to deliver the beams coupled into the fibers as a composite light source having a high energy density.

Abstract: An aquatic exercise device is provided having a housing with a convex front wall and a concave rear wall, a top surface and a bottom surface. The front wall and rear wall have attached thereto preferably a harness to permit the towing of the device. The housing has a first interior cavity, a second interior cavity, and a water inlet valve, with both the second interior cavity and the water inlet valve having closures. The water inlet valve depends downwardly from the bottom of the housing. The second interior cavity has a compartment having a wall with an aperture therethrough, through which aperture is inserted a hose member having two ends. One end extends through the aperture into the first interior cavity while the other end has air passage therethrough regulated from an air flow control valve. The top of the housing has fixed thereto a flag pole with a preferably brightly colored flag.

Abstract: A laser and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser comprises laser diode means for emitting a pump beam at a preselected wavelength; a crystal; and a laser cavity defined by first and second reflective elements at opposing ends of the crystal to form a reflective path therebetween; the crystal having a preselected host material doped with a predetermined percent concentration of erbium activator ions sufficient to produce a laser emission at substantially 2.8 microns when the crystal is pumped by the laser diode means, a portion of the laser emission at substantially 2.8 microns being outputted from one of the first and second reflective elements at a slope efficiency of at least 5 percent, but preferably 10 percent, when the crystal is pumped by the pump beam.

Abstract: A full color upconversion laser pumped by a single wavelength infrared laser source is disclosed. The pump energy excites a rare earth doped crystal and can simultaneously lead to laser emission at several wavelengths. The laser includes a crystal of YLiF.sub.4 :Er 5% fabricated in a monolithic structure which incorporates the laser mirrors as dielectric coatings on spherical surfaces of the crysal rod; the mirrors are optically reflecting at one or more of the desired output wavelengths. The laser rod is mounted in a helium cryostat that permits the operating temperature to be varied between 15.degree. and 120.degree. K. The pump energy is supplied through one of the mirrors specifically designed to be simultaneously highly reflecting at the laser wavelength and highly transmitting at the pump wavelength. To achieve optimum efficiency a lens is used in the pump path to focus the pump beam in such a manner as to provide a match of the laser mode size and pumped region of the crystal.

Abstract: This invention is a rare earth doped optical amplifier with increased gain and lowered pump thresholds. The amplifying scheme is based on a 3 level lasing system rather than the more prevalent 4 level lasing system. Additionally, the transmission mode of the optical fiber at the pump wavelength has a radius which is substantially equal to or greater than the radius of the distribution profile of the rare earth ions in the fiber amplifier core. With the inventive amplifier, a gain of 37 dB and a saturation power of 11.3 dBm has been obtained with only 54 mW of launch power at .lambda.=1.49 .mu.m.

Abstract: A modular interchangeable laser instrumentation system for applications in industrial processing, medical surgery and treatment, dental treatment, metrology, military applications, forensic investigation, micromachining, optical storage, spectroscopy, research and many other related applications. The system principally comprises a handheld stylus with interchangeable modules to produce various selected laser-radiation beams for any particular work as needed. Each module and the combined modular stylus is adapted to produce a particular type of laser beam for the intended project in hand, and as the modular section of one stylus is replaced by the modular section of another stylus, the generated laser beam assumes a different optical and spectral character, so as to be compatible with the work under process and characterized by the type of material and thickness thereof, texture, or human anatomical tissue of one kind or another, requiring different focus intensities and modal formats.

Abstract: A Ho:YLF crystal including Tm as sensitizers for the activator Ho, is optically pumped with a semiconductor diode laser array to generate 2.1 .mu.m radiation with a pump power to output power of efficiency as high as 68%. The prior-art dual sensitizer system of Er and Tm requires cooling, such as by LN.sub.2, but by using Tm alone and decreasing the concentrations of Tm and Ho, and decreasing the length of the laser rod to about 1 cm, it has been demonstrated that laser operation can be obtained from a temperature of 77.degree. K. with an efficiency as high as 68% up to ambient room temperature with an efficiency at that temperature as high as 9%.

Abstract: The output of a single semiconductor light source is used to optically pump two solid state lasers which are arranged in series and produce laser radiation at two different frequencies. Single longitudinal and single transverse mode operation can be achieved in both lasers.

Abstract: In a three-mirror optical resonator, solid state laser, the gain member is a thin slab, such as Nd:glass, disposed at Brewsters angle to minimize insertion loss. The gain slab is disposed at a beam waist in a confocal arm of the optical resonator. Optical pumping radiation from a laser diode source is focused through one of the concave mirrors of the confocal arm of the resonator into the gain slab. The second arm of the resonator is defined between a planar mirror and one of the confocal mirrors. An acousto-optic mode-locking modulator is disposed in the collimated beam region of the resonator proximate the planar mirror. Additional pumping diodes pump collinearly through the other confocal mirror for higher power operation. The slab is rotated and translated to average thermally induced stress and de-focusing effects.

Abstract: In a laser, the laser gain member is optically pumped by a semiconductive source of pumping radiation having an elongated output beam aperture such as that provided by a single-wide stripe diode or diode array. The elongated beam of optical pumping radiation is twice reflected from a concave surface at non-normal angles of incidence and then focused onto the laser gain material for pumping same. The reflections serve to differentially focus rays diverging in the vertical plane from rays diverging in the horizontal plane to shape the pumping beam for improved pumping efficiency in the pumped mode volume of the laser gain material. In a preferred embodiment, a magnifying lens is disposed inbetween the source and the reflectors for decreasing the divergence of the pumping beam.

Abstract: An optically pumped solid-state laser oscillating device which includes an optical resonator for outputting a laser beam of a predetermined wavelength. The optical resonator has a predetermined optical absorption band and is excited in response to a semiconductor laser beam having a wavelength falling within the optical absorption band. A plurality of excitation light sources are provided for emitting a plurality of semiconductor laser beams having different wavelengths and applying those laser beams to the optical resonator. At least one of the plurality of the semiconductor laser beams has a wavelength falling within the predetermined optical absorption band regardless of the change of an ambient temperature. Hence, a stable laser output is obtainable regardless of the change of the ambient temperature without need for employment of a complicated temperature controlling mechanism.

Abstract: Apparatus for providing self-organized, phase-matched harmonic generated radiation which includes a single-mode fiber doped with ytterbium or ytterbium-aluminum which is placed in a laser cavity having a mode-locking and a Q-switching apparatus.

Abstract: To alleviate the adverse thermal effects of the pumping power and to increase the efficiency of the laser, a solid state laser rod is formed of a polygonal cross-section having flat, internally reflecting side surfaces extending parallel to the rod axis. A light beam applied to one end surface describes an angluar helical path within the rod to a second end surface. By passing the light beam through diverse areas of the rod, compensation for radial temperature gradients is obtained. A plurality of laser beams may traverse the rod.

Abstract: A miniaturized Q-switch is added to the resonant cavity of a compact laser diode pumped solid state laser to produce short high peak power pulses. Q-switching the compact diode pumped solid state lasers takes advantage of the relatively high gain and short cavity length to provide a desirable combination of pulsewidth and pulse energy. Nd:YAG or Nd:YLF are useful solid state laser materials for Q-switching, or other longer lifetime rare earth ions such as erbium or holmium for greater energy storage. The Q-switch is formed of a material such as TeO.sub.2, SF.sub.10, or LiNbO.sub.3 with an acoustooptic figure of merit substantially greater than fused silica. Pulsewidths of 10-50 ns are achieved at pulse energies of 10-20 microjoules. TEMOO output is easily produced by the compact laser pumped solid state resonator. Applications include materials processing, link blowing in semiconductor memories, marking and scribing, and optical time domain reflectometry.