Abstract: Power scalable, rectangular, multi-mode, self-imaging, waveguide technologies are used with various combination of large aperture configurations, 20, 50, 80, 322, 324, 326, 328, 330, 332, 334, 336, 338, Gaussian 360 and super-Gaussian 350 beam profiles, thermal management configurations 100, flared 240 and tapered 161 waveguide shapes, axial or zig-zag light propagation paths, diffractive wall couplers 304, 306, 308, 310, 312, 314, 316, 318, 320 and phase controller 200, flexibility 210, phased arrays 450, 490, beam combiners 530, 530?, and separators 344, 430, and other features to generate, transport, and deliver high power laser beams.

Abstract: The invention is in the field of distributed Raman amplification for digital and analog transmission applications and other applications, e.g., instrumentation and imaging applications, including HFC-CATV applications. In particular, the invention uses a high power broadband source of amplified spontaneous emission (ASE) as the Raman pump source for improved system performance. The invention also includes methods for constructing such a high-power broadband Raman pump.

Abstract: A solid state zig-zag slab laser amplifier in which depolarization occurring at total internal reflection from opposed lateral faces of the amplifier slab is controlled by selecting a complex evanescent coating that provides a selected phase retardance that results in minimization of depolarization. Without use of the complex coating, small changes in incidence angles can result in phase retardance changes large enough to increase depolarization significantly, especially when the amplifier is operated at higher powers. Appropriate selection of the complex evanescent coating allows a desired phase retardance angle to be maintained relatively constant over a small range of angles of incidence, at a given wavelength, and therefore permits minimization of depolarization and birefringence effects.

Abstract: A system for generating a powerful laser beam includes a first laser element and at least one additional laser element having a rear laser mirror, an output mirror that is 100% reflective at normal incidence and <5% reflective at an input beam angle, and laser material between the rear laser mirror and the output mirror. The system includes an injector, a reference laser beam source, an amplifier and phase conjugater, and a combiner.

Abstract: Using lateral physical modulation, the optical properties of VCSELs can be stabilized and controlled by spatially varying the characteristics of the device material. This results in stabilization of the linewidth, the numerical aperture, the near and far field, as a function of bias and temperature. A VCSEL includes a substrate, an active region sandwiched between an upper and lower distributed Bragg reflector (DBRs), and electrical contacts. A light emission property e.g. the index of refraction, may be varied by patterning or texturing the surface of the substrate prior to growth of the epitaxial DBR layers or at least one layer of either the upper or lower DBRs, or by inserting a non-planar layer.

Abstract: An optical bandwidth source for generating amplified spontaneous emission (ASE) across a selected wavelength range, the optical bandwidth source including a waveguide having a first end and a second end, and comprising a plurality of separate wavelength gain subsections arranged in a serial configuration between the first end and the second end so as to collectively form an active waveguide between the first end and the second end; wherein each of the wavelength gain subsections is configured to produce ASE across a wavelength range which is less than, but contained within, the selected wavelength range, whereby the plurality of separate wavelength gain subsections collectively produce ASE across the selected wavelength range.

Abstract: A fluorescent member includes a plurality of particles dispersed in a medium. Each particle includes a core and a coating layer covering the core. The core is formed of a semiconductor which absorbs excitation light and emits light of a wavelength different from that of the excitation light. Each particle is made to have a particle size for causing Mie scattering with respect to the excitation light. Thus, a fluorescent member excellent in light conversion efficiency can be obtained.

Abstract: A pump fiber is stripped of its cladding over the last section. This can occur by etching a coating off. The sheath is preferably etched off wedge-shaped. As a result thereof, the remaining pump power is eliminated into the environment. How much stray pump light still proceeds via the fiber core to the fiber exit can be monitored over a length of the fiber completely stripped of the protective sheath.

Abstract: A laser includes a deformable tube holding an electrode assembly that includes conformable spacers. The spacers are deformed by compression of the tube into good surface contact with the electrodes and the tube walls, thereby providing the necessary path for heat removal from the plasma in order to maintain the required operating temperature for adequate performance of the laser.

Abstract: By tapering the diameter of a flanged barrel laser rod over its length, the maximum trapped path length of a barrel mode can be dramatically reduced, thereby reducing the ability of the trapped spontaneous emission to negatively impact laser performance through amplified spontaneous emission (ASE). Laser rods with polished barrels and flanged end caps have found increasing application in diode array end-pumped laser systems. The polished barrel of the rod serves to confine diode array pump light within the rod. In systems utilizing an end-pumping geometry and such polished barrel laser rods, the pump light that is introduced into one or both ends of the laser rod, is ducted down the length of the rod via the total internal reflections (TIRs) that occur when the light strikes the rod's barrel. A disadvantage of using polished barrel laser rods is that such rods are very susceptible to barrel mode paths that can trap spontaneous emission over long path lengths.

Abstract: This invention relates to the field of lasers and in particular to the pump sources used in lasers. Many existing lasers use linear flashlamps in order to create population inversion in the gain medium of the laser. Such pump sources suffer from a number of drawbacks particularly when pumping dye lasers including explosive damage, long optical pulse length and inappropriate spectral emission. This invention provides a pump source for a laser which exploits the surface discharge phenomenon. A dielectric material (1) which is in contract with a gas (9) has electrical energy discharged across its surface in order to provide an electromagnetic emission which is then used to pump the gain medium. By varying the dielectric material or the cover gas used (amongst other variables) the surface emission can be used to pump the laser gain medium.

Abstract: The inventive module of a light-pumped laser comprises light pump sources, a solid-state active element which is embodied in the form of a plate and provided with a couple of first opposite side faces, the distance therebetween defining the width of the active element for passing a pump radiation therethrough from the pump sources to the active element; a couple of second opposite side faces. The distance therebetween defining the thickness of the active element. which faces are embodied in the plane-parallel manner in order to direct a beam of formed laser radiation in such a way that it enables said beam to pass along the length of the active element in a zigzag manner, undergoing a total internal reflection from the couple of second side faces; a couple of end faces, the distance therebetween defining the length of the active element, and also heal-spreading devices which have a thermal contact with each second face in order So remove beat from the active element.

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

Abstract: A solid-state laser device consists of a gain medium in the shape of a polyhedron. A beam enters the gain medium at one surface of the polyhedron and is reflected internally at one or more surfaces with each reflection occurring in approximate the same plane as the plane of incidence of the incident beam. The beam enters and exits the gain medium at different locations. Pump radiation enters the polyhedron through one or more faces. The laser device may be used as the gain medium for a laser oscillator or a laser amplifier. In one variation, the polyhedron contains an internal core section in which there is no gain material. In another variation, the gain medium further includes one or more surfaces oriented to achieve a 90 degree internal reflection of the beam.

Abstract: Normal incidence stack architecture coupled with the development of diode array pumping enables the power/energy per disk to be increased, a reduction in beam distortions by orders of magnitude, a beam propagation no longer restricted to only one direction of polarization, and the laser becomes so much more amendable to robust packaging.

Abstract: In a solid state, optically end-pumped laser, the laser gain medium has a tapered diameter to minimize the maximum path length of barrelling amplified stimulated emission (ASE), and a roughened surface region at one end to scatter barrelling ASE out of the gain medium; thereby minimizing the negative effective of barrelling ASE's, and inhibiting the trapping of rays with a large longitudinal component, but disallowing a cyclic, i.e. repeated, pass path with specular reflections.

Abstract: A laser device employs a laser slab having an ionic layer and a nonionic layer, joined through an optical-quality interface. The laser slab has a trapezoidal cross-section in a direction perpendicular to the optical-quality interface. Thermal conductivity away from the ionic layer is enhanced through the thinness of the ionic layer and through the use of a heatsink attached to the ionic layer. Optical power input through the nonionic layer and into the ionic layer is further increased through the use of the trapezoidal cross section.

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

Abstract: A novel laser apparatus is disclosed which pertains to laser resonator geometries possessing circular symmetry, such as in the case of disk or spherical lasers. The disclosed invention utilizes multi-layer dielectric (MLD) thin film reflectors of many layer pairs of very small refractive index difference, the MLD deposited on a surface of revolution, thereby forming an optical cavity. These dielectric reflectors are disposed in such a way as to allow selection of preferred low order modes and suppression of parasitic modes while allowing a high cavity Q factor for preferred modes. The invention disclosed, in its preferred embodiments, is seen as particularly useful in applications requiring high efficiency in the production and coupling of coherent radiation. This is accomplished in a cavity design that is relatively compact and economical.

Abstract: A stable resonator for solid-state lasers which exhibit a thermally induced lensing effect, includes a laser rod, a rear mirror and a semi-reflecting output mirror. The invention is characterized in that the rear mirror has an extremely asymmetrical configuration, allowing the laser rod to move totally or almost totally toward the side of the output mirror. The laser rod is curved in a convex manner on one end in order to achieve a refractive effect, and a convex rear mirror is provided. As a result of the extreme asymmetry, the resonator has a beam quality as a function of the pump power with a comparably flat maximum even at relatively short resonator lengths in contrast to the state of the art. The effects of the thermal lens have practically no influence on processing results. Starting pulse behavior lies below the detection limit.

Abstract: A waveguide device in the form of either a solid-state laser or amplifier is divided into separate pumping and output mode control sections along at least one direction of the device by leaving a portion of a core of the device unclad or by depositing appropriate coatings on different sections of the core or by contacting/bonding materials with different refractive indices to different sections of the core or by a combination of these approaches. The core has a pump input surface for receiving pumping radiation at a pumping wavelength and one or more output surfaces for emitting a laser beam at an output wavelength. When used as an amplifier, the core also has a laser input surface which may be the same as one of the output surfaces.

Abstract: A stray light cutting structure for an optical device provided with an optical component through which a predetermined light beam travels in parallel to the optical axis of the optical device is provided. The structure is for cutting stray light, which travels at an angle to the optical axis of the optical device to enter the optical component through one end face thereof, and includes at least one notch formed on one side face of the optical component.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: The inventive rod includes a gain medium having first and second equal length portions sharing a common optical axis and an optical rotator disposed between said first and second portions which optical rotator compensates for birefringence. In an exemplary case, the optical rotator includes first and second waveplates optically coupled to one another and oriented with respect to one another by a predetermined angle, where the first waveplate receives a polarized beam having a first state, and the second waveplate produces the polarized beam having a second state, the first and second states differing from one another by 90°. Multiple rotators can be employed to compensate strongly birefringent rods, each rotator compensating a section of a rod constructed from a plurality of equal length optical gain elements.

Abstract: In a longitudinal flexible composite optical medium (3) for use in a laser device, the longitudinal flexible composite optical medium includes a laser beam guide portion (1) containing a laser active material (11) and an excitation beam guide portion (2) for distributing and introducing an excitation beam into the laser beam guide portion. The laser beam guide portion and the excitation beam guide portion are uncoaxially arranged in parallel to each other and integrally coupled with each other. By winding or folding the composite optical medium, a laser structure of a predetermined shape is obtained.

Abstract: Laser type source of coherent luminous radiation including a resonant cavity, an amplification medium placed in the resonant cavity and a dynamic photosensitive material which is placed in the resonant cavity to form a self-adapting spectral and/or spatial filter, characterized in that the cavity is a ring laser cavity and in that the dynamic photosensitive material is placed at the intersection of two beams.

Abstract: A hybrid slab laser is made using a slab of active laser material, for instance Yb:YAG, capped by a nonactive material, for instance undoped YAG or sapphire. The two materials are bonded together, for instance by diffusion bonding. The composite slab is then cut and polished to serve as a laser gain module. The slab can be Brewster-cut or flat-flat and antireflection coated on the ends. Alternatively, the nonactive material can be sandwiched between two active regions. The slab is pumped from the top face like a disk laser or from the end like a longitudinally pumped slab. The slab could also be side-pumped using close coupled diodes. The preferred pumping mechanism depends on the pump source used. The slab generates or amplifies a laser beam that is longitudinally coupled into the device through the end (possibly Brewster-cut) surfaces. The laser beam bounces via total internal reflection within the slab passing one or more times through the active part(s) of the medium.

Abstract: A system for supplying Iodine gas to a laser cavity includes a cartridge for generating Iodine gas and delivery piping for transporting Iodine gas from the cartridge to the laser cavity. The cartridge includes a hollow, cylindrical casing having an open end. The casing contains a solid preheat material, a solid mixture containing Iodine, and a purge material. An ignitor squib is disposed in the casing near the open end to initiate a burn front. The burn front travels through the preheat material to generate hot gas for preheating the delivery piping, preventing Iodine gas condensation in the piping. Next, the burn front travels through the mixture containing Iodine to generate Iodine gas which flows through the preheated delivery piping to the laser cavity. The burn front then passes through the purge material generating a purge gas to remove any traces of corrosive Iodine gas from the delivery piping.

Abstract: An optical pumping module for a laser including an amplifying medium forming a bar with a circular base, at least one light source for optical pumping of the amplifying medium, and a reflector that surrounds the amplifying medium to send the light, along several passes, towards the amplifying medium and forming a cylinder with a polygonal base. The light source is placed in front of one edge of this cylinder on the opposite side of this edge from the amplifying medium. The optical pumping module may be particularly applicable to laser cutting and welding.

Abstract: A laser system and method having an output laser beam uses an gain medium with one or more output beam transverse profile tailoring (OBTPT) longitudinal strips to tailor the transverse profile of the output laser beam to a desirable shape such as having a symmetrical profile transverse to the direction of propagation of the output laser beam. The laser system has two reflector systems on opposite ends in the long z-axis dimension of the gain medium to form a resonator that outputs the output laser beam following the same long z-axis dimension. In some embodiments the gain medium has a narrow y-axis dimension and a wide x-axis dimension. In these embodiments the OBTPT longitudinal strips have lengths running the long z-axis dimension, widths running the wide x-axis dimension and thicknesses running the narrow y-axis dimension of the gain medium. The widths of the OBTPT longitudinal strips are generally chosen with respect to coupling width of the output laser beam.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

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

Abstract: A concentrator including a volume of at least partially transmissive material and a plurality of facets disposed at at least one surface thereof. Each of the facets is disposed at a position dependent angle relative to the surface effective to cause an internal reflection of energy applied to the layer whereby the density of the applied energy varies as a function of position. In the illustrative implementation, the volume is an active medium, i.e., a slab. The slab has substantially parallel, planar upper and lower surfaces and first and second edges therebetween. A plurality of cladding layers are disposed on the upper and lower surfaces of the slab. The facets are provided in the cladding layers on the upper and lower surfaces of the slab and angled as a function of distance relative to the first or the second edge. The facets provide a Fresnel reflecting surface or a binary optic surface.

Abstract: In a distributed feedback semiconductor laser having at least an active layer and a diffraction grating on a semiconductor substrate and so constructed that a current is injected uniformly over an axial direction of a resonator, a bandgap wavelength of the active layer in the neighborhood of a light outputting end or a backward end opposite to the light outputting end, is shorter than that in the other region of the active layer along the axial direction of the resonator.

Abstract: A concentrator including a volume of at least partially transmissive material and a plurality of facets disposed at at least one surface thereof. Each of the facets is disposed at a position dependent angle relative to the surface effective to cause an internal reflection of energy applied to the layer whereby the density of the applied energy varies as a function of position. In the illustrative implementation, the volume is an active medium, i.e., a slab. The slab has substantially parallel, planar upper and lower surfaces and first and second edges therebetween. A plurality of cladding layers are disposed on the upper and lower surfaces of the slab. The facets are provided in the cladding layers on the upper and lower surfaces of the slab and angled as a function of distance relative to the first or the second edge. The facets provide a Fresnel reflecting surface or a binary optic surface.

Abstract: A waveguide device in the form of either a solid-state laser or amplifier is divided into separate pumping and output mode control sections along at least one direction of the device by leaving a portion of a core of the device unclad or by depositing appropriate coatings on different sections of the core or by contacting/bonding materials with different refractive indices to different sections of the core or by a combination of these approaches. The core has a pump input surface for receiving pumping radiation at a pumping wavelength and one or more output surfaces for emitting a laser beam at an output wavelength. When used as an amplifier, the core also has a laser input surface which may be the same as one of the output surfaces.

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

Abstract: A microlaser assembly is provided that includes a microresonator, such as a side pumped microresonator having an active gain medium and a passive Q-switch, a pump source for inducing resonation of the microresonator and the generation of laser signals, one or more electro-optic components, such as one or more non-linear crystals, amplifiers, oscillators or active gain mediums, for modifying the laser signals emitted by the microlaser and a beam steering element for aligning the laser signals emitted by the microresonator with the electro-optic components. The beam steering element is preferably controllably adjustable so as to precisely align the laser signals emitted by the microresonator with an electro-optic component. In order to provide more general alignment, the microlaser assembly can also include a mechanical alignment member.

Abstract: A solid-state laser device consists of a gain medium in the shape of a polyhedron. A beam enters the gain medium at one surface of the polyhedron and is reflected internally at one or more surfaces with each reflection occurring in approximate the same plane as the plane of incidence of the incident beam. The beam enters and exits the gain medium at different locations. Pump radiation enters the polyhedron through one or more faces. The laser device may be used as the gain medium for a laser oscillator or a laser amplifier. In one variation, the polyhedron contains an internal core section in which there is no gain material. In another variation, the gain medium further includes one or more surfaces oriented to achieve a 90 degree internal reflection of the beam.

Abstract: A solid state laser in which a slab of lasing material is held within an optical resonator is disclosed. The length of the slab in parallel to the optical axis of the resonator is between 5 and 1,000 mm, the width and thickness of the slab are 1-50 mm and 0.01-2 mm, respectively. The slab is designed in a way that causes the pump light to be confined when side- or end pumped by diode lasers. This is accomplished by either polishing the two largest area faces (referred to as upper and lower sides) of the slab and coating them with a material (dielectric or metallic) that is highly reflective at the emission wavelength, or by sandwiching the slab between dielectric materials that comprise a lower refractive index compared to the index of the slab. In alternative embodiments, the thin dimension of the slab may be selected so as to either guide the signal light or to allow free space propagation.

Abstract: A fiber-coupled laser based on a whispering-gallery-mode resonator formed of a laser gain medium and an angle-polished fiber coupler.

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

Abstract: A laser bar assembly module having a metal base plate (20) to support a diode or a laser diodes strip (22), this base plate being provided with a groove or area (21) holding the diode or diodes strip in position, a support (24) on which the metal base plate is installed, this support being provided with a flat laser bar bearing surface (26), this flat surface projecting along a direction perpendicular to it beyond the groove or area (21) holding the diode or diodes strip in position.

Abstract: A semiconductor laser basically includes a first cladding layer; an active layer; a second cladding layer; and a current constriction means for defining a current injection region in the active layer. The active layer has a gain region which acquires an optical gain by current injection thereto; a saturable absorption region in which current injection thereto little occurs and light effusion thereto occurs; and an outside region, being in contact with the saturable absorption region, in which current injection thereto little occurs and light effusion thereto little occurs. In this semiconductor laser, an effective band gap of the saturable absorption region is set to be larger than that of the outside region. With this configuration, carriers in the saturable absorption region are efficiently migrated to the outside region, so that the carrier lifetime in the saturable absorption region is actually shortened.

Abstract: The use of refractive optical elements to reduce or eliminate unwanted wavelength components from a laser emission. The method and apparatus described herein introduces modifications to the parallelism of one or more existing optical elements within the laser to dispersively separate wavelength components of the laser emission. According to embodiments of the invention, modifications in the parallelism can be made to the output coupler, intra-cavity polarizing optical components, and extra-cavity beamsplitter to accomplish separation of wavelength components without the introduction of additional optical components or reduction in the operating capacity of the laser. Additional optical components can be used to accomplish further separation of the wavelength components after the laser beam leaves the laser resonator.

Abstract: A stable multi-fold telescopic resonator is applied to a slab laser to provide a high power laser beam of a high optical quality. The current invention could be applied to both waveguide and free-space slab lasers with either gas or solid-state active media. A reduced sensitivity to misalignment is achieved through the use of two short-radii concave folding mirrors forming a nearly-confocal or confocal optical resonator. In order to obtain a nearly-symmetrical output beam profile from the large thickness slab lasing medium, the resonator includes a slit diaphragm(s), positioned between the slab and resonator mirrors and aimed to eliminate higher order laser modes in the direction transverse to the plane of the slab. Furthermore, a three mirror multi-fold telescopic resonator is provided by substituting one of the resonator mirrors with a surface of one of the folding mirrors.

Abstract: An optically-pumped laser having a gain medium configured to provide a low loss, three-dimensional integrated optical pump cavity that substantially confines optical pump radiation within the lasing volume, which is particularly useful for efficiently pumping solid state gain media that has low pump dopant concentration. The integrated pump cavity includes a plurality of boundaries contiguous with the gain medium. An optical pump source such as a laser diode array supplies optical pump radiation that is input into the gain medium through one or more pump cavity windows with a propagation direction transverse to a laser axis defined through the gain medium. In some embodiments, an optical surface is situated opposite the window to approximately recollimate the input pump radiation. The optical pump cavity may be designed to concentrate the optical pump radiation and approximately uniformly pump the entire volume of the lasing medium.

Abstract: A stripe portion extending in an <011> crystal axis direction of a compound semiconductor substrate (1) in which a {100} crystalline surface is made a major surface is formed between stepped portions (41), a laser resonator is formed in the stripe portion, the width of the stripe portion at one end surface of the laser resonator is made broader in width compared with the central portion and another end surface of the laser resonator. Then, in accordance with the shape of the stripe portion, the stripe shape of an active layer of the laser resonator is made broader in width than the center portion and the other end surface, whereby a semiconductor laser of a narrow field pattern with a low threshold value is obtained.

Abstract: A slab laser includes a laser-resonator and a plurality of generally-triangular prismatic slabs of a solid-state gain-medium located in the resonator. The prismatic slabs are cooperatively arranged such that laser-light circulating in the laser-resonator follows a convoluted path through the prismatic slabs. Each of the prismatic slabs changes the direction of the convoluted path at least once by about one-hundred-eighty degrees.

Abstract: A passively mode-locked short pulse laser arrangement (1) comprising a laser resonator to which a pump beam (3) is supplied, a laser crystal (4), in particular a titanium-sapphire-(Ti:S-) laser crystal, and laser mirrors (M1 to M7), the laser crystal (4), which is subjected to a thermal load on account of the beam focussing, being mounted on a cooling body (10) provided for the removal of heat, which cooling body includes a bore (13) for the passage of the laser beam (3; 8), and on which a, particularly platelet-shaped, crystal mount (11) of a material with good heat conducting properties, preferably of copper, is provided for an improved removal of heat, the laser crystal (4) being held in an opening (14) of this crystal mount (11) by lateral abutment on oppositely arranged walls (15, 16) of the opening (14) of the crystal mount (11), the opening (14) in the crystal mount (11) being in alignment with the bore (13) in the cooling body (10).