Abstract: A laser gain medium and laser system include a host material, a plurality of quantum dots dispersed throughout the host material, and a plurality of laser active ions surrounding each of the quantum dots. The laser active ions are disposed in close proximity to the quantum dots such that energy absorbed by the quantum dots is transferred to the ions, thereby exciting the ions to produce laser output. In an illustrative embodiment, each quantum dot is surrounded by an external shell doped with the laser active ions.

Abstract: A method for making a microchip laser includes preparing a laser-cavity chip assembly comprising a gain media, a first substantially flat surface, and a second substantially flat surface parallel to the first substantially flat surface. The method also includes forming a first reflective film on the first substantially flat surface to form a first cavity mirror, forming a second reflective film on the second substantially flat surface to form a second cavity mirror, and patterning at least one of the first reflective film or the second reflective film by removing at least a portion of the reflective film in the outer portion to form a center reflective portion in the one of the first reflective film or the second reflective film. The first cavity mirror and the second cavity mirror can suppress higher order transverse modes and produce a single TEM00 mode in the lasing light.

Abstract: Designs of fiber-coupled solid state microcavity light emitters based on microdisk cavities, photonic crystal cavities and other microcavity configurations to provide efficient optical coupling.

Abstract: There is provided a mode locked laser device including: a cavity, the cavity having a semiconductor saturable absorbing mirror and a negative dispersion mirror that controls group velocity dispersion within the cavity, disposed in a straight line; a solid-state laser medium, disposed in the cavity and outputting oscillating light due to excitation light being incident thereon; an excitation unit that causes the excitation light to be incident on the solid-state laser medium; and a cavity holder, the light incident face of the semiconductor saturable absorbing mirror attached to one end of the cavity holder, the negative dispersion mirror attached to the other end of the cavity holder, and the cavity holder integrally supporting the semiconductor saturable absorbing mirror and the negative dispersion mirror.

Abstract: A laser comprises an end pump light source and a gain medium having a first end, a second end, and four sides comprising a first, a second, a third, and a fourth side. The end pump light source is optically coupled to the first end and pumps the gain medium. The first side and the third side are tapered inwardly from the first end to the first end to the second end at a taper angle ? relative to a longitudinal lasing axis and have a polished finish capable of reflecting light inside the gain medium. The second side and the fourth side are substantially parallel to the longitudinal lasing axis have a ground blasted finish. The first side is also tilted inwardly at a slant angle ? from the fourth side to the second side. A laser beam R0 exits the second end of the gain medium.

Abstract: A laser system includes a first laser diode configured to generate first light in a first direction along an optical path; a laser resonator having a gain medium, anisotropic saturable absorber, and a wavelength selective outcoupler positioned in the optical path upon which the first light impinges a first side thereof so as to pump the gain medium (first light from the first laser diode is absorbed in the gain medium), a second laser diode configured to generate second light in a second direction along the optical path toward a second side of the resonator, passes through the wavelength selective outcoupler unimpeded and is absorbed by the saturable absorber element, wherein the second light has a polarization corresponding to the orientation of the saturable absorber; the wavelength selective outcoupler is configured to only allow third light of a predetermined wavelength to have feedback in the laser resonator, achieve gain in the resonator, and be emitted from the laser resonator.

Abstract: Method of manufacturing a laser medium with a material having a surface and a dopant in the material distributed whereby the material has a spatially variant optical flux density profile uses tailored non-uniform gain profiles within a Yb:YAG laser component (rod, slab, disc, etc.) achieved by a spatial material modification in the spatially masked pre-forms. High temperature-assisted reduction leads to the coordinate-dependent gain profiles, which are controlled by the topology of the deposited solid masks. The gain profiles are obtained by reducing the charge state of the laser-active trivalent Yb3+ ions into inactive divalent Yb2+ ions. This valence conversion process is driven by mass transport of ions and oxygen vacancies. These processes, in turn, affect the dopant distribution throughout the surface and bulk laser crystal. By reducing proportionally more Yb3+ ions at the unmasked areas of component, than in the masked areas, the coordinate-dependent or spatially-controlled gain profiles are achieved.

Abstract: A polycrystalline transparent ceramic article including lutetium is presented. The article includes an oxide with a formula of ABO3, having type A lattice sites and type B lattice sites. The lattice site A may further comprise a plurality of elements, in addition to lutetium. Type B lattice site includes aluminum. An imaging device, a laser assembly, and a scintillator including the lutetium-based article is provided. A method of making the above article is also provided.

Abstract: A device is provided for igniting a fuel-air mixture in a combustion chamber of an internal combustion engine with the aid of electromagnetic radiation, in particular light. The device includes at least two laser radiation sources, each having an optical resonator. The resonators are spatially oriented with respect to one another in such a way that modes of the laser radiation sources are coupled to one another and are able to generate time-shifted pulses of the electromagnetic radiation.

Abstract: A planar waveguide laser device forms a waveguide by a plate-like laser medium having birefringence and clad attached to at least one of the surfaces of the laser medium perpendicular to its thickness direction, amplifies laser light by a gain produced by excitation light incident on the laser medium, and performs laser oscillation. The laser medium is formed of a material having an optic axis on a cross section perpendicular to the light axis, which is the laser travelling direction. The clad is formed of a material having a refractive index in a range between refractive indexes of two polarized lights that travel along the light axis in the laser medium and have oscillation surfaces that are orthogonal to each other. The planar waveguide laser device readily oscillates linearly polarized laser light.

Abstract: A laser structure is provided in which an influence caused by a concave-convex structure on laser characteristics is reduced when the Epitaxial Lateral Overgrowth (ELO) technique is applied to a photonic-crystal surface emitting laser. A height of the mask structure is set such that a reflection peak wavelength of 0-th order diffracted light and a reflection peak wavelength of first-order diffracted light differ from each other for light that enters a concave-convex periodic structure, which is constituted by a first layer and a mask structure, from a photonic crystal. Further, reflection intensity of the 0-th order diffracted light from the concave-convex periodic structure is larger than reflection intensity of the first-order diffracted light from the concave-convex periodic structure at an oscillation wavelength ?.

Abstract: Current may be passed through an n-doped semiconductor region, a recessed metal semiconductor alloy portion, and a p-doped semiconductor region so that the diffusion of majority charge carriers in the doped semiconductor regions transfers heat from or into the semiconductor waveguide through Peltier-Seebeck effect. Further, a temperature control device may be configured to include a metal semiconductor alloy region located in proximity to an optoelectronic device, a first semiconductor region having a p-type doping, and a second semiconductor region having an n-type doping. The temperature of the optoelectronic device may thus be controlled to stabilize the performance of the optoelectronic device.

Abstract: A laser system employing amplification via a single exciton regime and to optical gain media having single exciton amplification is provided.

Abstract: A laser gain medium. The novel laser gain medium includes a host material, a plurality of quantum dots dispersed throughout the host material, and a plurality of laser active ions surrounding each of the quantum dots. The laser active ions are disposed in close proximity to the quantum dots such that energy absorbed by the quantum dots is non-radiatively transferred to the ions via a Forster resonant energy transfer, thereby exciting the ions to produce laser output. In an illustrative embodiment, each quantum dot is surrounded by an external shell doped with the laser active ions.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln—X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm?1 and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: A material having a surface and a dopant in the material distributed whereby the material has a spatially variant optical flux density profile. In accordance with the invention, tailored non-uniform gain profiles within a Yb:YAG laser component (rod, slab, disc, etc.) are achieved by a spatial material modification in the spatially masked pre-forms. High temperature-assisted reduction leads to the coordinate-dependent gain profiles, which are controlled by the topology of the deposited solid masks. The gain profiles are obtained by reducing the charge state of the laser-active trivalent Yb3+ ions into inactive divalent Yb2+ ions. This valence conversion process is driven by mass transport of ions and oxygen vacancies. These processes, in turn, affect the dopant distribution throughout the surface and bulk laser crystal.

Abstract: A laser configuration producing up to 100's of Watts of output is provided, based on a solid-state gain medium, a source of pump energy which is detuned from the maximum absorption wavelength for the gain medium, and optics arranged to deliver the pump energy through an end of the gain medium to propagate along the length of the gain medium. The length of the gain medium and the doping concentration in the gain medium are sufficient the absorption length is on the order of 10's of millimeters, and more than ? of the length, and that 90 percent or more of the pump energy is absorbed within two or fewer passes of the gain medium. A pump energy source that supplies 100 Watts to 1000 Watts or more.

Abstract: A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.

Abstract: The present application is directed to an apparatus and method for the automated compensation of dispersion over a broad wavelength range for coherent optical pulses. In one embodiment, the present application discloses an automatic dispersion compensating optical apparatus configured to change chirp introduced into an optical signal by an optical system in optical communication with the dispersion compensating optical apparatus and includes at least one wavelength-tunable source of coherent optical pulses configured to output at least one optical signal, at least one dispersion compensation device configured to receive the optical signal from the coherent source, and at least one controller in communication with the dispersion compensation device and configured to adjust chirp introduced into the optical signal by the dispersion compensation device as the wavelength of the optical signal is varied.

Abstract: The present invention provides a composite laser element that solves the problems encountered with a conventional laser medium composed of an Nd:YAG single crystal or polycrystal, and exhibits excellent performance as a laser medium. The invention relates to a laser element in which two or more crystal materials are joined, wherein (1) at least one of the crystal materials is a transparent crystal material capable of laser oscillation, including a laser active element in a matrix crystal, and (2) the transparent crystal material capable of laser oscillation and/or a second crystal body joined thereto is a polycrystal.

Abstract: A laser comprises an end pump light source and a gain medium having a first end, a second end, and four sides comprising a first, a second, a third, and a fourth side. The end pump light source is optically coupled to the first end and pumps the gain medium. The first side and the third side are tapered inwardly from the first end to the first end to the second end at a taper angle ? relative to a longitudinal lasing axis and have a polished finish capable of reflecting light inside the gain medium. The second side and the fourth side are substantially parallel to the longitudinal lasing axis have a ground blasted finish. The first side is also tilted inwardly at a slant angle ? from the fourth side to the second side. A laser beam R0 exits the second end of the gain medium.

Abstract: An edge-emitter semiconductor laser crystal having a receptacle for sample material which can influence the crystal's laser operation. There may be separate zones of laser action within the crystal, creating respective sensing zones in the receptacle. Detection may be achieved by providing photo-diode regions within the crystal, for example.

Abstract: A semiconductor laser device having a smooth cleavage plane is provided. The provided laser device includes a current injection ridge and force distribution ridges formed adjacent to the current injection ridge, which protrudes from an upper surface of a mesa structure. The mesa structure is formed of multi-semiconductor material layers including a laser resonance layer and cladding layers disposed above and below the resonance layer. The current injection ridge and the force distribution ridges distribute a scribing force when cleaving the laser device so that the smooth cleavage planes are obtained. Defects are prevented in the current injection ridge due to the distribution of force when bonding flip chips.

Abstract: By using a ceramics laser medium such as Nd:YAG ceramics or Yb:YAG ceramics, division of a lateral mode pattern to a local mode is suppressed so that single frequency, linear polarization oscillation are achieved in TEM00 mode. A laser oscillator comprising a laser light source for oscillating the pumping light, and a laser medium of Nd:YAG ceramics or Yb:YAG ceramics having an average grain size of 5 ?m or less upon which the pumping light impinges is provided. The laser medium may have a first surface having a first dielectric multilayer film, and a second surface having a second dielectric multilayer film.

Abstract: Optical microcavity arrangements and approaches facilitate a variety of applications. According to an example embodiment of the present invention, an optical microcavity arrangement includes a microcrystal structure having a plurality of optical cavities therein to facilitate the control of light. Emitters such as colloidal quantum dots are optically coupled to the optical cavities by attaching or otherwise arranging a material, which includes the emitters, to the optical microcavity arrangement. In many applications, the emitters couple photons of a wavelength in a range of wavelengths selectively passed by the optical cavities, and are amenable to operation at relatively high temperatures (e.g., at about room temperature or higher), which is useful for a variety of applications.

Abstract: A nitride semiconductor laser element comprises a substrate, a nitride semiconductor layer that is laminated on the substrate and that has a ridge on its surface, and an electrode that is electrically connected with the nitride semiconductor layer, wherein there is provided an insulating protective film produced by forming a monocrystalline first film or a first film containing hexagonal crystals, and extending from the side faces of the ridge to the nitride semiconductor layer on both sides of the ridge, and a second film containing a polycrystalline or amorphous substance, from the nitride semiconductor layer side, in this order.

Abstract: A Thulium laser (15) is used to directly drive a ZnGeP2 optical parametric oscillator (30) with a nominal 2 ?m output to generate the 3-5 micron wavelengths. In one embodiment, the ZGP OPO is configured as a linear resonator and in another embodiment the ZGP OPO is configured as a ring resonator. The ring resonator prevents optical feedback to the Thulium laser (15) and eliminates the need for an optical isolator (24). Moreover, the Thulium laser pump (15) is implemented as a Tm:YAlO3 laser in which YAlO is the host for the Thulium YAlO is particularly beneficial as it is a mechanically hard optical material allowing high thermal loading without fracture as well as natural birefringence that can minimize thermal birefringence losses. A longer wavelength transition at 1.99 microns is selected to minimize nonlinear crystal loss. More particularly, a high power, high efficiency Tm:YAlO3 laser repetitively Q-switched at 10 kHz is used to drive a ZnGeP2 OPO.

Abstract: A laser amplification system is disclosed that enables reliable operation over large ambient temperature operating window, as well as a significant reduction of laser temperature sensitivity typically associated with diode pumped lasers. The techniques employed by the system effectively eliminate damaging gain hot spots and lower ASE and ESA thresholds, thereby increasing laser peak and average power levels. Additionally, the techniques allow for thermal programming of active gain medium material to minimize thermally induced aberrations. In one particular example embodiment, a variable dopant concentration multi-pass laser amplifier is provided having a customized active ion concentration profile, tailoring the combination of laser absorption and gain distribution using a ceramic YAG host.

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: A polycrystalline transparent ceramic article including lutetium is presented. The article includes an oxide with a formula of ABO3, having type A lattice sites and type B lattice sites. The lattice site A may further comprise a plurality of elements, in addition to lutetium. Type B lattice site includes aluminum. An imaging device, a laser assembly, and a scintillator including the lutetium-based article is provided. A method of making the above article is also provided.

Abstract: The present disclosure relates to a self-powered, random scattering laser generating device comprising a housing comprises an opening and an inner chamber, at least one quantum dot positioned inside the inner chamber, a high-energy emitting source positioned within the inner chamber and in radioactive communication with the at least one quantum dot, and a first lasing medium. The present disclosure also relates to a method comprising providing at least one quantum dot, contacting the at least one quantum dot with a high-energy emitting source whereby randomly scattered light is produced, partially coherently amplifying the randomly scattered light emitted from the at least one quantum dot, and generating a random scattering laser.

Abstract: The invention relates to a waveguide laser or amplifier material comprising a silica glass host material, one or more rare earth elements in total concentration CRE at. %, one or more network modifier elements selected from the group of tri- or penta-valent atoms of the periodic table of the elements in total concentration CNME at. %, wherein the ratio of atomic concentrations of the modifier elements to that of the rare earth elements CNWCRE is larger than or equal to 1, and wherein the total atomic concentration of rare earth and the tri-valent network modifiers, such as aluminium and/or boron, is substantially equal to the atomic concentration of the penta-valent network modifier, such as phosphorous. Such materials exhibit reduced risk of photo darkening.

Abstract: A semiconductor laser having an n-cladding layer, an optical guide layer, an active layer, an optical guide layer, and a p-cladding layer above an InP substrate, in which the active layer has a layer constituted with Be-containing group II-VI compound semiconductor mixed crystals, and at least one of layers of the n-cladding layer, the optical guide layer, and the p-cladding layer has a layer constituted with elements identical with those of the Be-containing group II-VI compound semiconductor mixed crystals of the active layer, and the layer is constituted with a superlattice structure comprising, as a well layer, mixed crystals of a Be compositions with the fluctuation of the composition being within ±30% compared with the Be composition of the group II-VI compound semiconductor mixed crystals of the active layer, whereby the device characteristics of the semiconductor laser comprising the Be-containing group II-VI compound semiconductor matched with the InP substrate.

Abstract: A light emitting device with a ?-cavity including a first spacer of single crystal dielectric material and an active area including single crystal erbium dielectric material positioned on the first spacer. The erbium dielectric material and the single crystal dielectric material of the first spacer are substantially crystal lattice matched at their juncture. A second spacer of single crystal dielectric material is positioned on the active area. The erbium dielectric material and the single crystal dielectric material of the second spacer are substantially crystal lattice matched at the second surface. The high-? erbium dielectric provides a high gain ?-cavity that emits increased amounts of light in either spontaneous or stimulated modes of operation.

Abstract: A laser rod is provided having a tailored gain profile such that the quality of the output beam is enhanced. The laser rod has a concentration of active substitutional ions that is relatively high at the center of the rod and decreases to the surface of the rod. The laser rod further has a concentration of pre-active laser ions that is relatively high at the surface of the rod and decreases to the center of the rod. Methods are disclosed for creating a layer of inactive laser species in the near surface region of a laser rod using substitutional dopant ions and for creating a laser rod with a tailored gain profile such that the quality of the output beam is enhanced.

Abstract: A laser amplification system is disclosed that enables reliable operation over large ambient temperature operating window, as well as a significant reduction of laser temperature sensitivity typically associated with diode pumped lasers. The techniques employed by the system effectively eliminate damaging gain hot spots and lower ASE and ESA thresholds, thereby increasing laser peak and average power levels. Additionally, the techniques allow for thermal programming of active gain medium material to minimize thermally induced aberrations. In one particular example embodiment, a variable dopant concentration multi-pass laser amplifier is provided having a customized active ion concentration profile, tailoring the combination of laser absorption and gain distribution using a ceramic YAG host.

Abstract: The invention relates to laser materials and specifically to single crystal active media for solid state lasers operating in the middle-infrared (Mid-IR) 4-5 ?m range of optical spectrum, wherein a cross section of stimulated emission and laser wavelength is shifted to the range of atmospheric transparency with a single crystal orthorhombic structure with space group D242h-Fddd. The material contains Lead, Gallium, Sulfur and is doped with Dysprosium according to general formula: Pb1?3xDy2xGa2S4, where 0.0001<x<0.05. Lasers operating in this matter and in this spectral range are advantageous for lidar applications, free space communication, environmental monitoring, and other purposes.

Abstract: The present invention intends to provide a surface-emitting laser light source using a two-dimensional photonic crystal in which the efficiency of extracting light in a direction perpendicular to the surface is high. In a laser light source provided with a two-dimensional photonic crystal layer created from a plate-shaped matrix body in which a large number of holes are periodically arranged and an active layer arranged on one side of the two-dimensional photonic crystal layer, the holes are created to be columnar with a predetermined cross-sectional shape such as a circular shape, and the main axis of each of the columnar holes is tilted to a surface of the matrix body. When provided with this two-dimensional photonic crystal layer, the surface-emitting laser source using a two-dimensional photonic crystal has a Q? value (i.e.

Abstract: Lasers capable of lasing at least two wavelengths are provided having a lasing medium which is capable of lasing at a first wavelength and at a second wavelength. An output coupler is positioned along a longitudinal axis at a first end of the lasing medium and a first mirror, movable beam block shutter and second mirror are positioned sequentially along the longitudinal axis of the lasing medium at a second end of the lasing medium. The first mirror is highly reflective at a first wavelength, and the second mirror is highly reflective at a second wavelength while being transparent at the first wavelength. The beam block shutter is movable between a first position along the longitudinal axis of the lasing medium and between the first and second mirrors and a second position away from the longitudinal axis of the lasing medium.

Abstract: Provided are a laser apparatus into which a large current can be injected and a production method which enables easy production of the apparatus. A laser apparatus includes a light-emitting region on a substrate, and a periodic refractive index structure containing an i-type material provided at a periphery of the light-emitting region. Another laser apparatus includes a light-emitting region between a first electrode and a second electrode on a substrate, wherein at least one of the first and the second electrodes includes a periodic refractive index structure.

Abstract: One objective of the present invention is to provide a laser device which is capable of scanning beams of a laser light of high output power at a high speed without using mechanical scanning mechanisms. A plurality of the upper electrodes 33 is linearly arranged in the photonic crystal laser provided with an active layer 21 and a two-dimensional photonic crystal layer 23 which are held between upper electrodes 33 and a lower electrode 27. A current is introduced from one upper electrode 33 or the plurality of the upper electrodes 33 disposed adjacently. Therefore, the active layer 21 generates light and the light is intensified by diffraction in the two-dimensional photonic crystal layer 23, so that a stronger laser light is emitted to the outside from around the upper electrodes 33 into which a current is introduced. When the current-injected upper electrodes are sequentially switched, a laser light scan is performed in the direction of the array of the upper electrodes.

Abstract: Two-dimensional photonic crystal surface-emitting laser comprising a two-dimensional photonic crystal, having media different in refractive index arrayed in a two-dimensional cycle, disposed in the vicinity of an active layer that emits light by the injection of carriers, wherein the two-dimensional photonic crystal consists of square lattices having equal lattice constants in perpendicular directions, and a basic lattice consisting of a square with one medium as a vertex has an asymmetric refractive index distribution with respect to either one of the two diagonals of the basic lattice to thereby emit light in a constant polarizing direction.

Abstract: The present invention provides a composite laser element that solves the problems encountered with a conventional laser medium composed of an Nd:YAG single crystal or polycrystal, and exhibits excellent performance as a laser medium. The invention relates to a laser element in which two or more crystal materials are joined, wherein (1) at least one of the crystal materials is a transparent crystal material capable of laser oscillation, including a laser active element in a matrix crystal, and (2) the transparent crystal material capable of laser oscillation and/or a second crystal body joined thereto is a polycrystal.

Abstract: A laser medium includes a single crystal of chromium-doped LiScl-xInxGe1-ySiyO4, where 0?x?1 and 0?y?1. Preferably, x and y are not both 0. A laser, such as a tunable near infrared laser, can contain the laser medium.

Abstract: A method is described to improve and produce purer Cr4+-doped laser materials and lasers with reduced co-incorporation of chromium in any other valence states, such as Cr3+, Cr2+, Cr5+, and Cr6+. The method includes: 1) certain crystals of olivine structure with large cation (Ca) in octahedral sites such as Cr4+:Ca2GeO4, Cr4+:Ca2SiO4, Cr4+:Ca2GexSi1-xO4 (where 0<x<1), and/or 2) high-temperature solution growth techniques that enable the growth of the crystals below the temperature of polymorphic transitions by using low melting point solvent based on oxide, fluoride and/or chloride compounds. Purer Cr4+-doped laser materials are characterized by a relatively high concentration of Cr4+-lasing ion in crystalline host that makes these materials suitable for compact high power (thin disk/wedge) NIR laser applications.

Abstract: A zig-zag laser has the ability to generate a high power beam while effectively removing heat without degrading the beam quality. The laser has a series of gaps interposed between the thin slabs, the gain medium, and between the thin slabs and the quartz windows to receive coolant and cool the cell assembly. The coolant flows transversely relative to the path of the laser and the flow of the coolant is in the opposite direction on each side of the thin slab to minimize the temperature gradient. The gaps in conjunction with the inner channel portions in the secondary manifold flow the coolant through the cell assembly in a laminar manner therein not degrading the laser beam quality. A transparent quartz/quartz interface between the secondary manifold and the cell assembly allow the fluorescence to move away from the cell assembly and minimizes heat in the cell assembly.

Abstract: Solid-state lasers pumped by incoherent or partially coherent, monochromatic light sources such as high power VCSEL arrays. Efficient and uniform injection of pumping energy into gain medium is achieved through spectral match of the pump source with the gain medium absorption and multi-bounce reflections of unabsorbed pump light in a diffusing pump chamber. One preferred embodiment of the diffusing pump chamber is a hollow cylinder coaxially surrounding the gain medium. One or more transparent windows, slit-shaped or otherwise, for transmission of pump light are evenly distributed around the perimeter of the chamber and are parallel to the axis. Another preferred embodiment of the diffusing pump chamber is a highly reflecting compound parabolic concentrator. A 2-D VCSEL array is employed as the pump source and the gain medium is located at the focusing point of the chamber.

Abstract: To provide a laser processing apparatus compatible with increase in the output of the pumping light source without increasing the reflectance of the output mirror.

Abstract: A laser rod is provided having a tailored gain profile such that the quality of the output beam is enhanced. The laser rod has a concentration of active substitutional ions that is relatively high at the center of the rod and decreases to the surface of the rod. The laser rod further has a concentration of pre-active laser ions that is relatively high at the surface of the rod and decreases to the center of the rod. Methods are disclosed for creating a layer of inactive laser species in the near surface region of a laser rod using substitutional dopant ions and for creating a laser rod with a tailored gain profile such that the quality of the output beam is enhanced.