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

Abstract: A long wavelength infrared laser system is disclosed where radiation from laser sources such as frequency-doubled Nd:YAG or a Cr:LiSAF is used to resonantly pump a gain medium consisting of a holmium-doped fluoride crystal having a high active ion concentration. The laser pump source has a pulse duration that may be short enough to gain switch a particular transition or long enough to allow end-pumping with high energy densities without damage. The gain material has an absorption approximately resonant with the pump source wavelength, and the dopant concentration is selected to maximize absorption strength for a given excitation. The output radiation from the laser system consists of one or more wavelengths including, in particular 3.9 nm but also other infrared wavelgths such as 1.4 &mgr;m, 2.9 &mgr;m and 3.4 &mgr;m., several of which may be produced simultaneousely from the same laser material through the mechanism of cascade transitions.

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

Abstract: In a master oscillator-power amplifier (MOPA) hybrid laser system, the master oscillator (MO) utilizes a Nd3+-doped gain medium and the power amplifier (PA) utilizes a diode-pumped Yb3+-doped material. The use of two different laser gain media in the hybrid MOPA system provides advantages that are otherwise not available. The Nd-doped gain medium preferably serves as the MO because such gain media offer the lowest threshold of operation and have already been engineered as practical systems. The Yb-doped gain medium preferably serves in the diode-pumped PA to store pump energy effectively and efficiently by virtue of the long emission lifetime, thereby reducing diode pump costs. One crucial constraint on the MO and PA gain media is that the Nd and Yb lasers must operate at nearly the same wavelength. The 1.047 &mgr;m Nd:YLF/Yb:S-FAP [Nd:LiYF4/Yb:Sr5(PO4)3F] hybrid MOPA system is a preferred embodiment of the hybrid Nd/Yb MOPA.

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

Abstract: An infrared laser structure is stacked on top of a red laser structure with both having an inverted or p-side down orientation. The red/infrared stack laser structure is inverted and wafer fused to a blue laser structure to form a red/infrared/blue monolithic laser structure. The top semiconductor layer of the inverted red/infrared stack laser structure is a GaInP fusion bonding layer which will be wafer fused to the top semiconductor layer of the blue laser structure which is a GaN cladding/contact layer.

Abstract: An an infrared laser structure has an inverted or p-side down orientation. The infrared laser structure is inverted and wafer fused to a blue laser structure to form an infrared/blue monolithic laser structure. The top semiconductor layer of the inverted infrared stack laser structure is a GaInP fusion bonding layer which will be wafer fused to the top semiconductor layer of the blue laser structure which is a GaN cladding/contact layer.

Abstract: A solid-state laser oscillating device which is inexpensive and capable of obtaining a high power. A plurality of laser crystals (YAG laser crystals, etc.) (1a, 1b, 1c) are arranged along the optical axis of an optical resonator so as to maintain optical contact with one another. Adjacent ones of the laser crystals have surfaces facing each other with an adhesive layer (10, 20) interposed therebetween, to form an array in a straight-line as a whole. An adhesive having a low light absorbance with respect to a laser beam of oscillation wavelength or an excitation light is used for forming the adhesive layers (10, 20). If the refractive index of the adhesive is substantially equal to that of the laser crystals, optical matching is achieved. The adhesive layers (10, 20) may be replaced by some other transparent material. The adjacent laser crystals may be arranged with a narrow gap therebetween or held in surface contact with each other.

Abstract: The invention comprises a RE-doped MA.sub.2 X.sub.4 crystalline gain medium, where M includes a divalent ion such as Mg, Ca, Sr, Ba, Pb, Eu, or Yb; A is selected from trivalent ions including Al, Ga, and In; X is one of the chalcogenide ions S, Se, and Te; and RE represents the trivalent rare earth ions. The MA.sub.2 X.sub.4 gain medium can be employed in a laser oscillator or a laser amplifier. Possible pump sources include diode lasers, as well as other laser pump sources. The laser wavelengths generated are greater than 3 microns, as becomes possible because of the low phonon frequency of this host medium. The invention may be used to seed optical devices such as optical parametric oscillators and other lasers.

Abstract: A fiber laser 10 with square inner cladding 12, 29 may have a single core 11 codoped either with Ytterbium or Erbium or with Thulium and Holmium at a ratio of at least 10:1 operating in a single mode to provide eye-safe radiation with wavelengths above 1.5 micron. The single core laser has a pump clad cross sectional area about 2(10).sup.3 greater than the cross sectional area of the core. A multi-core laser has a plurality of single mode cores 28 doped with any rare earth ions, the cores equally spaced by at least two core diameters in an isometric array, in a cavity having a finesse of greater than ten, to produce a single, very bright phase-locked beam in the fundamental supermode. A method starts with hexagonal cladded-core rods 35, 36 in an isometric array, which are then fused and drawn down.

Abstract: A compact, continuous-wave blue laser is developed from a fiber made from heavy metal fluorides ("ZBLAN") doped with a rare-earth ion. The footprint required to create blue laser light is reduced because the fiber can be wound into spools of radius <25 mm and stacked one atop the other without cross talk. IR diodes (.lambda..about.790 nm and .lambda..about.1050 nm) are fiber-pigtailed to silica fiber in a conventional way. The light from the IR diodes is coupled to a single fiber through a 2.times.1 fiber coupler that has silica inputs and a ZBLAN output. The IR light optically excites the electrons of the rare-earth ions in the ZBLAN fiber host. This excitation causes the electrons to emit light at 480 nm (in the blue region of the visible spectrum) as they relax to the ground state. Dielectric mirrors feed back the emitted light. A high-reflector, high-transmitter ("HRHT") is the input coupler of the pumping light; a partial reflector, the output coupler.

Abstract: A laser source has two or more laser units and coupling means for coupling the laser beams from each unit so as to deliver a resulting beam for treating a surface. Concurrently with the laser surface treatment, the characteristics of the laser beam from each unit are adjusted to produce a resulting laser beam with a time profile of energy optimally adapted to said laser surface treatment. Homogenizing means homogenize the energy distribution of the resulting laser beam, so that the energy and spatial distribution of said resulting laser beam are concurrently adapted for the selected surface treatment.

Abstract: A Cr/Tm/Er-doped, yttrium- or lutetium-garnet host material crystal for a solid-state laser, wherein about 3 to about 8 atomic percent of the yttrium or lutetium, respectively, crystallographic sites are occupied by Tm.sup.3+ ions, about 7 to about 22 atomic percent of the yttrium or lutetium, respectively, crystallographic sites are occupied by Er.sup.3+ ions, and about 0.6 to about 1.6 atomic percent of the octahedral sites of the garnet structure are occupied by Cr.sup.3+ ions, which crystal lases under the influence of a pumping means at a wavelength of no more than about 2.7.mu..

Abstract: In a two laser media, Nd:phosphate glass and Nd:YLF are combined into a single laser. Generally, one broad band inhomogeneously broadened material and one narrow band homogeneously broadened material, with the two materials having overlapping center wavelengths are suitable.) The phase coherence property of Nd:YLF facilitates the initial formation of a coherent pulse. The broadband property of Nd:phosphate glass supports the generation of ultrashort laser pulse. Thus, this mode-locked hybrid Nd laser generates ultrashort coherent pulses more easily and reliably.

Abstract: The invention in one aspect is an optical fiber laser which includes a core having two different dopants. Pump signals having different wavelengths are introduced into the core through the cladding so that each dopant absorbs a different wavelength. In another aspect, the invention is an optical fiber amplifier which is pumped by at least one fiber laser having the two dopants.

Abstract: In a resonating-type solid-state laser oscillator including birefringent a solid-state element containing a laser active medium and providing a plurality of thermal lenses during excitation and reflecting mirrors arranged oppositely to each other on both sides of the solid-state element so that their optical axes are coincident to each other, a prescribed relationship is given among the refractive index and length of the solid-state element, the radii of curvature of the reflection mirrors, the distances between the reflecting mirrors and the solid-state element and the difference between 1/f of the plurality of thermal lenses by owing to birefringence of the solid-state element, so that oscillation areas due to the plurality of thermal lenses are separated from each other.

Abstract: A solid-state laser apparatus comprises a plurality of solid-state materials each having an active solid-state medium and arranged in a row with a predetermined space on an optical axis of light incident thereon. An optical rotation material and an angle adjusting instrument for adjusting an angle between the optical rotation material and the optical axis of incident light are disposed in at least a space selected from among the plural spaces. The laser apparatus further comprises a laser optical system for extracting a laser beam emitted by the plural solid-state materials.

Abstract: A multi-element, folded beam laser includes a plurality of laser medium elements, pumping means, a highly reflective reflector, an output coupler and one or more beam directors for redirecting the beam through the elements and between the reflector and the output coupler. An alternate folded beam ring laser and an alternate folded beam laser amplifier are also disclosed.

Abstract: An ultraviolet laser source which can stably emits ultraviolet light having a sufficient output and low coherence, as a light source for an exposure unit, for a long period of time, is compact, and allows easy maintenance. The laser source is constituted by 10.times.10 laser elements, i.e., a total of 100 laser elements. Each laser element includes a laser beam emitting section for emitting light having a long wavelength, i.e., visible or infrared light, and a wavelength converting section for converting the emitted laser beam into ultraviolet light. The laser beam emitting section includes a semiconductor laser, and a solid-state laser. The wavelength converting section contains a nonlinear crystal for converting the wavelength of incident light and outputting the resultant light.

Abstract: A laser for outputting visible light at the wavelengths of blue, green, orange and red light. This is accomplished through the doping of a substrate, such as an optical fiber or waveguide, with Pr.sup.3+ ions and Yb.sup.3+ ions. A light pump such as a diode laser is used to excite these ions into energy states which will produce lasing at the desired wavelengths. Tuning elements such as prisms and gratings can be employed to select desired wavelengths for output.

Abstract: The present invention is an integrated, diode laser-pumped, solid state lr which can be fabricated entirely with semiconductor fabrication techniques. The laser includes a substrate, a semiconductor light source grown over the substrate to provide pump light and a solid state laser grown over the substrate. The semiconductor light source produces pump light at a wavelength useful for pumping the solid state laser. The solid state laser includes a pump mirror transparent to the pump light, an output mirror, and a doped semiconductor layer deposited between the pump and output mirrors, the semiconductor, dielectric or polymer layer being doped with active metal ions. The pump light from the semiconductor light source is closely coupled to the solid state laser and passes through the pump mirror to pump the active metal ions.

Abstract: A surface emitting laser device with at least two active regions in one and the same optical, vertical cavity wherein the active regions are electrically connected in series.

Abstract: A solid-state laser in which a rod (10) of lasing material is held within an optical cavity formed within a cooling block (40) having a highly surface facing the rod. A longitudinal slit (44) formed in the block from the optical cavity to the outside allows the pumping light from an emission line (36) of semiconductor stripe lasers (30) fabricated on a laser bar (28) to irradiate the laser rod and multiply reflect within the optical cavity. Thereby, pump light is efficiently absorbed by the laser rod, and the laser rod is thermally controlled. Alternatively, cooling liquid (124) can flow axially along the laser rod and within an axially extending optical cavity formed by a reflective coating (125) deposited on a tube (122) enclosing the cooling liquid and having a slit (126) through which pump light is irradiated.

Abstract: An optical material comprises a host matrix (e.g. fluorozirconate glass such as ZBLANP) doped with an optical atom pair or ion pair, each pair comprising a sensitizer (e.g. Nd.sup.3+) and an activator (e.g. Pr.sup.3+). The sensitizer is capable of absorbing optical excitation energy of a single wavelength (e.g. in the 800 nm region of GaAlAs diode laser) and transferring this optical excitation energy to the activator. This causes emission of visible and/or infrared light when the activator relaxes back into any of its lower energy states. Optical devices containing the optical material, and methods for generating visible and/or infrared light involving the optical material are also disclosed.

Abstract: A laser host material LuLF (LuLiF.sub.4) is doped with holmium (Ho) and thulium (Tm) to produce a new laser material that is capable of laser light production in the vicinity of 2 .mu.m. The material provides an advantage in efficiency over conventional Ho lasers because the LuLF host material allows for decreased threshold and upconversion over such hosts as YAG and YLF. The addition of Tm allows for pumping by commonly available GaAlAs laser diodes. For use with flashlamp pumping, erbium (Er) may be added as an additional dopant. For further upconversion reduction, the Tm can be eliminated and the Ho can be directly pumped.

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

Abstract: A laser system includes a laser resonator cavity having a resonant path and an Er,Yb:glass lasing element with an output of from about 1.5 to about 1.6 micrometers within the laser resonator cavity. A diode array optically pumps the lasing element to emit light. A Q-switch lies along the resonant path within the laser resonator cavity. The Q-switch is formed of a host material having a concentration of uranium ions therein, so as to be a saturable absorber of the light emitted by the lasing element. The Q-switch is preferably a uranium-doped fluoride such as U:CaF.sub.2, U:SrF.sub.2, or U:BaF.sub.2.

Abstract: A cladding pumped optical fiber laser comprises a length of optical fiber having a rare earth-doped region of diameter d.sub.RE >d.sub.01 where d.sub.01 is the mode diameter of the LP.sub.01 mode of the fiber at the laser radiation at wavelength .lambda.. In one embodiment the fiber has a core diameter d.sub.c selected such that the LP.sub.01 mode is the only guided spatial mode of the fiber, and d.sub.RE is greater than d.sub.c. In another embodiment the fiber supports at least one higher order guided spatial mode, typically LP.sub.11 or LP.sub.02, and d.sub.RE is approximately equal to or larger than d.sub.c. Currently preferred embodiments comprise a grating-defined laser cavity that comprises a mode-coupling refractive index grating. Cladding pumped lasers according to the invention will typically have efficient conversion of pump radiation to laser radiation, and consequently can typically be shorter than analogous prior art cladding pumped lasers.

Abstract: A laser system is described in which two laser elements are configured as an oscillator and an amplifier in a common optical pumping section. Oscillator element is in a resonator and a divergent oscillator output beam is steered by a steering arrangement back to the amplifier element. The divergence of the beam from the resonator is adjusted, by moving output coupler element or selecting particular curvatures of resonator mirrors for example, to match the thermal lensing power of the amplifier element so that a substantially collimated output beam is produced.

Abstract: The present invention provides a laser diode-pumped solid-state laser resonator which can be scaled and pumped longitudinally including in a folded or zig-zag resonator cavity. The resonator employs opposed laser rod crystals paired with pump light diodes in a configuration which ensures good spatial overlap and can permit the simultaneous generation of one or more laser wavelengths. The resonator also has at one end thereof a total reflector, eg. a laser rod crystal or a mirror and at the other end thereof, a partial reflector i.e. a mirror, to resonate and amplify the laser beam in the system and outcouple a portion thereof as desired.

Abstract: A pulsed solid state laser system is disclosed which utilizes a plurality of individual laser rods which are sequentially pumped and whose beans are combined into a single interleaved output bean. The individual laser rods are pumped at an average power level which is below that for maximum output power from each rod, thereby obviating the need for refrigeration cooling. A compact optical system is disclosed which permits a constant beam size even at different pump levels and other advantages. A compact cooling system is also disclosed.

Abstract: A blue laser source outputting a beam having a wavelength of approximately 460 nm. A first laser cavity is formed around a Nd:YAG gain medium generating a first light beam having a wavelength of approximately 1064 nm. A second laser cavity, at least partially coextensive with the first laser cavity is formed around a Tm:ZBLAN gain medium generating a second light beam having a wavelength of approximately 810 nm. A non-linear KTP crystal is provided intracavity to both the first and second laser cavities to mix the first light beam and the second light beam and output a third light beam having a wavelength of approximately 460 nm. One of the mirrors forming the first or second laser cavity is coated to output a laser beam having a wavelength of approximately 460 nm.

Abstract: A blue and green laser generation method and device adopting the same wherein the method includes the steps of pumping an electron of a first element to a first energy level by employing a first pumping energy to thereby obtain an optoacoustic energy according to a first energy absorption; and pumping an electron of a second element to a second energy level being higher than the first energy level, by employing the optoacoustic energy as a pumping source, to thereby obtain blue and green lasers having a desired wavelength according to a second energy absorption. The device has a core having a predetermined refractive index and which is doped by an element for generating light in a band of a predetermined wavelength by means of energy absorption; and a cladding layer provided around the core and which has a refractive index different from that of the core.

Abstract: A dual wavelength pumped low noise fiber laser includes a fiber laser 10 comprising a pair of Bragg gratings 14,16 at opposite ends of a fiber laser cavity 18 which is co-doped with two rare-earth dopants, Er.sup.+3 Yb.sup.+3, so as to allow lasing to occur at a lasing wavelength .lambda..sub.L. A first pump signal 20 efficiently pumps the Yb to the excited state and the Yb energy is transitioned to the Er atoms which ultimately lase at the desire lasing frequency. Because Yb is pumped so efficiently, high pump absorption is achieved, thereby providing high laser output power and, consequently, reduced RIN. Simultaneously, a second pump signal 52 directly pumps the Er at a different wavelength .lambda..sub.P2 which populates the lasing transition more quickly, thereby allowing sufficient bandwidth of a closed loop control on the second pump signal 52 to control low frequency RIN spiking due to relaxation oscillations in the laser.

Abstract: An edge emitting laser device with at least two laser structures arranged in one and the same optical cavity. The laser structures are substantially arranged in the optical direction of propagation and each laser structure comprises an active region, said active regions being electrically connected in series.

Abstract: A fiber laser or amplifier in which the optical fiber gain medium has two or more nonconcentric core regions, each of which is capable of gain or lasing when optically pumped. The fiber may be single clad or double clad, with multiple core regions embedded within a common cladding region or within separate cladding regions. The core regions may be arranged in a linear, closely spaced hexagonal, rectangular matrix or some other configuration and positioned symmetrically or noncentrosymmetrically, centered or off-center within the core region or regions. The spacing between neighboring core regions may be far enough apart to minimize optical interaction between cores for independent light amplifying or laser action or be close enough for phase-locked operation of the multiple cores to occur. The cores may be doped with the same or different active ionic species, of which one or more could be upconverting ions.

Abstract: A planar waveguide and a process for making a planar waveguide is disclosed. The waveguide has a layer of doped host material formed on a substrate. The host material is a trivalent material such as a metal fluoride, wherein the metal is selected from the Group III B metals and the lanthanide series rare earth metals of the Mendeleevian Periodic Table. The dopant is a rare earth metal such as erbium. The waveguide has an emission spectrum with a bandwidth of about 60 nm for amplification of an optical signal at a wavelength of about 1.51 .mu.m to about 1.57 .mu.m. The waveguide is made by forming the layer of doped host material on a substrate. The film is formed by evaporating materials from two separate sources, one source for the dopant material and a separate source for the host material and forming a film of the evaporated materials on a substrate.

Abstract: A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr.sup.2+ -doped ZnS and ZnSe generate laser action near 2.3 .mu.m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d.sup.4 and d.sup.6 electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers.

Abstract: The present invention is a fluorozirconate laser host doped with a suffict amount of Tm.sup.3+ ions to permit significant emission at a wavelength between about 790 nm and about 830 nm when pumped at a wavelength or wavelengths to excite Tm.sup.3+ ions from the .sup.3 H.sub.6 ground state to the .sup.3 F.sub.4 excited state, and then from the .sup.3 F.sub.4 excited state to the .sup.3 H.sub.4 excited state.

Abstract: The present invention is a solid state laser, including: (1) a laser cavity defined by a first mirror and an opposing second mirror, where these mirrors are reflective at the output wavelength of the laser; (2) a laser medium disposed in the laser cavity, including a low phonon energy host material, doped with an amount of praseodymium ions sufficient to produce a longitudinal mode laser emission from the transition of the praseodymium ions from the .sup.3 F.sub.3 excited state to a lower energy state when the laser medium is pumped by an appropriate pump, where the energy gap between the .sup.3 F.sub.3 excited state and the lower energy state corresponds to the output wavelength of the laser; and (3) a pump for the laser medium.

Abstract: Plural planar optical devices are simultaneously pumped by a single pumping source. Various arrangements for accomplishing such pumping are disclosed. By utilizing these arrangements, the topology and routing of integrated arrays including optical devices are simplified.

Abstract: A method for preparing a material so as to exhibit second harmonic generation for optical radiation that passes through the material. The method includes a first step of providing a bulk glass comprised of substitutionally doped silica and a charge transfer dopant. The bulk glass is prepared for frequency doubling in accordance with a method that includes a step of irradiating the bulk glass with optical radiation having a first wavelength and a second wavelength, the bulk glass being irradiated for a period of time sufficient to obtain a desired amount of conversion efficiency of the first wavelength into the second wavelength. The silica is substitutionally doped with an element selected from the group consisting of Ge and Al, and the charge transfer dopant is selected from the group consisting of Ce.sup.3+, Nd.sup.3+, and Eu.sup.2+. In another embodiment of the invention the silica is substitutionally doped with Ge and the charge transfer dopant is comprised of naturally existing Ge defects.

Abstract: A tunable laser system having a wide tunable range, and narrow line widths, achieves relatively high output powers. The tunable laser system includes a master optical parametric oscillator which generates a seed beam, and a power optical parametric oscillator which is responsive to the seed beam to generate a narrow line width, high power output beam. The master OPO and power OPO comprise gain media consisting of BBO, tunable over a range from about 400 nanometers to more than 2000 nanometers. The master OPO includes line narrowing elements, such as a tunable grating, which limits the line width of the output beam to less than one wave number (centimeter.sup.-1). Pump energy is supplied to the master OPO and power OPO using a Nd:YAG laser with a harmonic generator, so that the second, third, or fourth harmonics of the primary 1064 nanometer line of YAG can be used to pump the BBO crystals. The power OPO may be an unstable resonator.

Abstract: A multiwavelength upconversion waveguide laser producing visible or ultraviolet wavelength radiation comprising a semiconductor laser diode producing relatively long wavelength radiation, a channel waveguide having a thin film material which converts the relatively long wavelength radiation into visible or ultraviolet wavelength radiation, and a optical resonator which recirculates the visible or ultraviolet wavelength radiation. The optical resonator may use an output optical coating or one or more Bragg grating reflectors as an output coupler. One or more optical resonators may be used to produce one or more visible or ultraviolet radiation wavelengths. One or more independently controllable lightwave modulators are used to modulate the visible or ultraviolet wavelength radiation.

Abstract: A laser capable of generating polychromatic or white light radiation is realized by employing dispersive and reflecting elements as the ends of a simple laser resonator cavity. The dispersive element either solely or in combination with an intracavity lens is arranged such that each wavelength component of the white light radiation is amplified by a different portion of the active medium. More specifically, forced oscillation or positive feedback for each wavelength component is achieved by operating a diffraction grating in an auto-collimation configuration or through the use of a distributed bragg reflector having a spatially varying index of refraction.

Abstract: The optical fiber is doped at the core thereof with Tm ions and Nd ions. When light at a wavelength in a 800-nm band for exciting the Nd ions, is incident upon the optical fiber through an incident portion thereof, the Nd ions emit light at a wavelength in the vicinity of 1,012 .mu.m. Through three excitations by absorption of light emitted from the Nd ions and/or energy transfer from the Nd ions, the Tm ions experience three excitation transitions and reach a third high energy level through first and second high energy levels. Thereafter, the Tm ions experience a radiative transition from the third high energy level, thereby to emit blue light at a wavelength of 480 nm.

Abstract: An optically-pumped or electron-beam-pumped solid-state laser employing as the phosphor material doped nanocrystal particles which as a result of quantum confinement can be caused to exhibit discrete levels in its conduction band that can overlap with the corresponding levels in the doping activator such that resonant energy transfer of excited carriers from the conduction band of the phosphor host to that of the activator will occur. The energy levels in the activator are such as to allow very fast carrier transitions to an intermediate level and a slower radiative transition to a ground state. The result is an energy level structure similar to that of a four-level laser but capable of more efficient conversion of the pumping energy to photon generation.

Abstract: A monolithic self-Q-switched laser generates laser pulses with short duration, high peak power, a single longitudinal mode, and extremely small pulse-to-pulse intensity fluctuations. The laser comprises of a length of solid-state laser material with a plurality of dopants, so that the material can generate coherent radiation for laser action and, in the same material, provide saturable absorption at the wavelength of the laser emission necessary for Q-switching. The distributed saturable absorber in the material provides a spectral stabilization mechanism that ensures single longitudinal-mode operation. The laser cavity is formed by the two end surfaces of the solid-state laser material with appropriate reflectivity coatings. When the laser material is pumped above the threshold condition, the laser device produces short pulses having high peak power in a single longitudinal mode and single transverse mode.

Abstract: Optical guiding of intense laser pulses over a distance of more than one Rayleigh length in a plasma is discussed herein using a multi-pulse technique. The first pulse or pulse sequence prepares a shock-driven, axially-extended radial electron density profile which guides a second pulse or sequence of pulses. The profile is also capable of guiding x-rays. The channel will support mode structure exactly analogous to that of an optical fiber waveguide. The method provides a means for guiding of a high intensity optical laser pulse or x-rays over distances well in excess of a Rayleigh length. The distances over which guiding occurs is limited only by the length of the preformed plasma and absorption and possible backscattering of the guided EM radiation. Applications of the method allow for compact x-ray laser devices and electron particle accelerators.

Abstract: A light source for an interferometric fiber optic gyroscope ("IFOG") includes a thulium (Tm.sup.+++) doped optical fiber which exhibits superluminescence in a wavelength region substantially centered at about 1.8 microns.