Abstract: An upconversion laser material includes a micro-sphere which is doped with an ion of a rare earth element and made of one selected from the group consisting of crystals and glasses. Thus, the micro-sphere achieves the light confinement therein and serves as a resonator. Therefore, the Q-value of the resonator becomes large. With this, it is possible to obtain the upconversion laser oscillation at room temperature.

Abstract: An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P.sub.2 O.sub.5, Al.sub.2 O.sub.3 and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules.

Abstract: An optical element comprising (i) a matrix having an Si--O covalent bond unit, wherein at least part of the silicon atoms of said Si--O covalent bond unit is covalently bonded to an aliphatic hydrocarbon group containing not more than 4 carbon atoms, and (ii) at least one functional material selected from the group consisting of an organic material showing a nonlinear optical effect, a material showing a refractive index-regulating action, and an organic dye for laser oscillation, said functional material being present within said matrix. A functional group is stably held in the matrix and fully manifests its function in the matrix.

Abstract: A glass fiber laser system includes a laser resonator cavity having a resonant path and an erbium-doped glass fiber lasing element with an output of from about 1.5 to about 1.6 micrometers within the laser resonator cavity. A light source directed into an input end of the glass fiber lasing element optically pumps the lasing element to emit light. A passive 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 crystal such as U:CaF.sub.2, U:SrF.sub.2, or U:BaF.sub.2.

Abstract: The present invention concerns an optical pumping system making use of a broad continuous absorption band in rare earth doped chalcogenide glasses. The absorption band is approximately 400 nm in width and extends from approximately 600 nm to 1000 nm. Through subjecting the glass to pumping light from an excitation source within the broad absorption band, photoluminescence emissions are produced. Size and strength of the pumping absorption band are such that great flexibility is provided in implementation of the excitation source. Specific embodiments of4 the present invention may utilize Er or Pr doped Ge.sub.33 As.sub.12 S.sub.55 or As.sub.2 S. Selection of the chalcogenide host may adjust the broad absorption band. As an example, a narrower gap chalcogenide glass, such as Ge.sub.28 Sb.sub.12 Se.sub.60, should extend the broad absorption band into the 1064 nm wavelength.

Abstract: An optical device includes a body of a semiconductor material having a waveguide therein along which light flows and means for providing gain to the light. A layer of an amorphous or polycrystalline metallic-ferromagnetic material extends along the waveguide and means, such as a permanent magnet, provides a magnetic field to the metallic-ferromagnetic material layer. This provides an optical isolator of the Faraday rotation type which can be integrated with a variety of material systems including those commonly used to fabricate semiconductor lasers, arrays and amplifiers.

Abstract: The present invention concerns an optical pumping system using a broad continuous chalcogenide emission band of approximately 190 nm in width. The broad emission band is induced by the rare earth doping of a chalcogenide glass. Co-doping using Pr and Er produces a photoluminescence band extending from approximately 1510 nm to 1700 nm. Alternatively, separately Pr and Er doped samples exhibit emission bands considerably wider then the characteristic Pr(1620 nm) and Er (1550 nm) emission bands typically realized in doped oxide glasses. According to the present invention these broad bands are used to produce optical gain over the continuous broad 190 nm band. An excitation source subjects the glass to pumping light to stimulate the broad band emissions. Applied to an optical amplifier, optical signals entering the chalcogenide glass anywhere within the broad range will be amplified.

Abstract: The present invention is directed to the preparation of two groups of transparent glass-ceramics exhibiting high optical clarity and containing essentially only one crystal phase. The first group consists essentially, in cation percent, of______________________________________ SiO.sub.2 20-35 PbF.sub.2 19-23 AlO.sub.1.5 10-20 YF.sub.3 3-7, CdF.sub.2 19-34 ______________________________________and the second group consists essentially, in cation percent, of ______________________________________ SiO.sub.2 20-35 PbF.sub.2 15-25 AlO.sub.1.5 10-20 YF.sub.3 3-7 CdF.sub.2 21-31 ZnF.sub.2 3-7. ______________________________________These glass-ceramics may be used to fabricate optical waveguide fibers. Also when doped with certain rare earth elements, notably Pr, Er, and Dy, the glass-ceramic materials may be used to fabricate optical amplifiers and lasers.

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: In a high energy laser system utilizing phosphate laser glass components to mplify the laser beam, the laser system requires a generated laser beam having an emission bandwidth of less than 26 nm and the laser glass components consist essentially of (on an oxide composition basis):______________________________________ Mole % ______________________________________ P.sub.2 O.sub.5 50-75 Al.sub.2 O.sub.3 >0-10 K.sub.2 O >0-30 MgO 0-30 CaO 0-30 Li.sub.2 O 0-20 Na.sub.2 O 0-20 Rb.sub.2 O 0-20 Cs.sub.2 O 0-20 BeO 0-20 SrO 0-20 BaO 0-20 ZnO 0-20 PbO 0-20 B.sub.2 O.sub.3 0-10 Y.sub.2 O.sub.3 0-10 La.sub.2 O.sub.3 0-8 Ln.sub.2 O.sub.3 0.01-8 ______________________________________whereinthe sum of MgO and CaO is >0-30;the sum of Li.sub.2 O, Na.sub.2 O, Rb.sub.2 O, and Cs.sub.2 O is 0-20;the sum of BeO, SrO, BaO, ZnO, and PbO is 0-20;the sum of B.sub.2 O.sub.3 and Y.sub.2 O.sub.3 is 0-10; andLn.sub.2 O.sub.3 represents the sum of the oxides of active lasing lanthanides of atomic number 58-71.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: A host acting as an optical emitter and a process of making the same for the .sup..about. 1.3 .mu.m to .sup..about. 1.55 .mu.m spectral region utilized in optical communications is disclosed. The host is Cr-activated willemite (Zn.sub.2 SiO.sub.4). Efficient band-emission at room temperature, with peak at 1.42 .mu.m, is observed on exiting the material in the near infrared, typically at 730 nm and 829 nm.

Abstract: An optical fibre amplifier (50) comprises a SiO.sub.2 --Al.sub.2 O.sub.3 --GeO.sub.2 single-mode optical fibre (52) doped with E.sub.r.sup.3+. It is pumped by 1.55 .mu.m and 1.47 .mu.m optical sources (54 and 56) whose optical outputs are combined by an optical coupler (58) and are then coupled to the fibre (52) by a further optical coupler (50). A source of optical signals to be amplified (62) is also coupled to the fibre (52) by the further coupler (60). The E.sub.r.sup.3+ ions provide a three-level lasing scheme with a fluorescence peak at about 1.53 .mu.m. Low noise amplification of optical signals in the long-wavelength tail of the fluorescence spectrum with suppressed ASE at the fluorescence spectrums peak wavelength is obtained as follows. The 1.47 .mu.m pump provides some low noise amplification of the optical signal but preferentially amplifies the 1.55 .mu.m pump source. The resultant 1.55 .mu.

Abstract: The present invention encompasses an apparatus for pumping a vibronic laser, which comprises: a transition-metal ion-containing solid state vibronic laser gain medium; a means for exciting said laser medium to emit coherent radiation said exciting means being a pumping source comprising at least one laser diode operating at a wavelength shorter than 750 nm; and an optical resonator means for generating and controlling said coherent radiation. The present invention also encompasses a method of pumping a vibronic laser comprising the steps of: generating a laser diode pumping beam at a wavelength shorter than 750 nm; exciting a transition-metal ion-containing solid state vibronic laser gain medium by impinging said laser diode pumping beam on said transition-metal ion-containing solid state laser gain medium, so as to excite the laser medium; and an optical resonator to emit coherent radiation.

Abstract: A fiber optical source of stimulated optical radiation comprises an optical fiber which includes a core doped with laser material having optical gain in two wavelength regions, the fiber additionally including a material in optical communication with said laser material in such a manner as to absorb radiation emitted from said laser material within one of said wavelength regions.

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: An optical signal amplifier comprising an optical waveguide fiber integrated by thallium ion exchange in a boron-free silicate glass doped with up to 5 weight % erbium oxide, the glass having a base composition, as calculated in weight percent on an oxide basis, consisting essentially of______________________________________ SiO.sub.2 38-67 Al.sub.2 O.sub.3 1.5-4.5 Na.sub.2 O 0-20 ZnO 1.5-8 K.sub.2 O 0-25 Li.sub.2 O 0-1 Na.sub.2 O + K.sub.2 O 15-30 PbO 0-37 BaO 0-7 P.sub.2 O.sub.5 0-10 P.sub.2 O.sub.

Abstract: A monolithically integrated photonic circuit combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material.

Abstract: A laser has a resonant cavity defined by a pair of mirrors (6, 10) butted to respective ends of a 3 m fluorozirconate optical fibre (14). The fibre (14) has a .DELTA.n of 0.014 and a cut-off wavelength of around 790 nm and is doped to about 500 ppm (weight) with erbium ions. An optical pump source (12) provides a pump signal at 971 nm which excites the erbium ions into the .sup.4 S.sub.3/2 energy level to provide lasing at about 546 nm. The laser may alternatively be pumped by a pump signal in the band 791 nm to 812 nm, preferably 801 nm. The pump source is preferably a high power semiconductor laser (16).

Abstract: A laser material for a solid-state laser that, when pumped by light having a wavelength in a suitable pump band, emits electromagnetic radiation having a wavelength lying in the range 2.0.ltoreq..lambda..ltoreq.2.1 .mu.m. The laser host material includes thulium-doped lutetium yttrium aluminum garnet (Tm:LuYAG) of approximate chemical composition (Tm.sub.x (Y.sub.w Lu.sub.1-w).sub.1-x).sub.3 Al.sub.5 O.sub.12, with x lying approximately in the range 0.01.ltoreq.x.ltoreq.0.5 and w lying in the range between 0.01 and 0.99. In particular, the Tm:LuYAG material produces light with wavelengths in the range .lambda.=2.020-2.024 .mu.m, where the normally-absorbing atmosphere has a transmission window with markedly reduced (or, alternatively, markedly enhanced) absorption. Another suitable group of laser materials has the chemical composition (Tm.sub.x (Y.sub.w Lu.sub.1-w-z Sen.sub.z).sub.1-x).sub.3 Al.sub.5 O.sub.12, with x lying approximately in the range 0.01.ltoreq.x.ltoreq.0.5, w lying in the range 0.01.ltoreq.

Abstract: An optical fibre amplifier comprises a thulium-doped optical fibre pumped at 790 nm by a semi-conductor diode laser coupled to the fibre via optical fibre coupler. The amplifier is optically coupled in series to a pair of systems fibres to provide amplification to optical signals.

Abstract: Power laser includes a non-linear medium (NL1) within which a first beam of fixed direction (I1) and a second beam of orientable direction interfere with each other, an amplifying medium (2) placed along the direction of the first beam for amplifying the received light for transmitting an amplified beam towards the non-linear medium (NL1), which retransmits this bean in the direction of the second beam, and therefore in an orientable direction.

Abstract: A diode-pumped monolithic laser is fabricated from a self-doubling host material co-doped with two ionic species, where one ionic dopant converts pump radiation to continuous radiation at a fundamental frequency and the other dopant acts as a saturable absorber to Q-switch the fundamental radiation which is then frequency doubled to produce pulsed high-intensity green light, the green light being either outputted or further frequency-doubled, into pulsed coherent UV radiation, by means of a non-linear crystal.

Abstract: Embodiments of the present invention are sulfur rich glass compositions comprising germanium, gallium and sulfur, which glass compositions have a low energy phonon spectrum and which glass compositions serve as a host for active materials in fabricating light sources such as fiber laser oscillators, light amplifiers, and superluminescent sources. In particular, such a laser oscillator, light amplifier or superluminescent source is comprised of an inventive glass composition which is doped with rare earth ions such as Pr.sup.3+ or Dy.sup.3+ for producing light output at wavelengths, among others, substantially at 1.3 um. Further embodiments of the present invention are light sources such as laser oscillators, light amplifiers and superluminescent sources which have emissions substantially at 1.3 um and which are comprised of an inventive glass composition which is doped with Dy.sup.3+ and Yb3+ ions, wherein Dy.sup.3+ ions are pumped by energy transfer from Yb3+ ions.

Abstract: A laser has a resonant cavity defined by a pair of mirrors (6, 10) butted to respective ends of a 3 m fluorozirconate optical fibre (14). The fibre (14) has a .DELTA.n of 0.014 and a cut-off wavelength of around 790 nm and is doped to about 500 ppm (weight) with erbium ions. An optical pump source (12 ) provides a pump signal at 971 nm which excites the erbium ions into the .sup.4 S.sub.3/2 energy level to provide lasing at about 546 nm. The laser may alternatively be pumped by a pump signal in the band 791 nm to 812 nm, preferably 801 nm. The pump source is preferably a high power semiconductor laser (16).

Abstract: A solid state laser apparatus is provided to generate a high quality and high power laser beam, and a laser machining apparatus is provided to perform laser machining by a laser beam generated from the solid state laser apparatus. In the solid state laser apparatus, a laser resonator includes a solid state component cooled in a cylindrical pipe by contacting liquid which is introduced through an inflow opening and discharged through an outflow opening, the solid state component having larger refractive index than that of the liquid, a light source turned ON by a power source to excite the solid state component, and an optical system transmitting light from the light source to the solid state component. Further, a surface roughness of the solid state component is adjusted so as to adjust an excitation distribution in a section of the solid state component.

Abstract: A solid state waveguide laser system is comprised of a cavity resonator formed of a solid state gain medium extending between input and output surfaces and having a reflectivity medium laterally bounding the gain medium and wherein the index of refraction of the reflectivity medium is greater than that of the gain medium.

Abstract: A tellurite glass particularly usable for an amplifier or oscillator utilizing an optical fiber or other guided wave structure. In approximate terms, the glass contain between 58 and 84 molar % of TeO.sub.2, up to 24 molar % Na.sub.2 O, and between 10 and 30 molar % of ZnO. Other alkali and divalent metals may be substituted for the Na and Zn respectively. Combinations of these tellurite glasses can be formed as an optical fiber (10) having a core (12) with a higher refractive index than that of the cladding (14). The tellurite glass of the core, when composed of at least 0.05 molar % Na.sub.2 O, can be doped with large amounts of Er, Pr, or Nd to act as a fiber amplifier at 1.5 or 1.3 .mu.m when pumped with light of a specified shorter wavelength. The core can be doped with other rare-earth metals which would provide optical amplifiers or oscillators at wavelengths appropriate to their lasing characteristics.

Abstract: Power output and power conversion efficiency of an intracavity non-linear optical laser is substantially increased by reducing the effect of thermal focussing per unit of pump energy enabling a stable resonator cavity at high input powers by utilizing a closely coupled reflector, multi-gain media configuration, and various pump source filters and/or semiconductor laser diode pumping.

Abstract: According to the present invention there are provided a solid-state laser device using a laser rod not smaller than 180 mm in length as a laser medium, thereby capable of providing a high output power, facilitating maintenance and inspection, and permitting the reduction of size and simplification in comparison with a conventional laser device using plural laser rods, as well as a machining apparatus using the said laser device as a machining energy source, and a solid-state laser device wherein a laser medium is held in a free state within a resonator so that a longitudinal direction of the laser medium is coincident with an optical axis direction of laser beam and so that the laser medium is capable of expansion or contraction in the said optical axis direction, thereby preventing the breakage of the laser medium and the deviation of the optical axis of laser beam.

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: Methods and appartus for upconverting laser sources and amplifiers that use solid state components throughout and achieve such operation with a continuous or quasi-continuous single band infrared pumping source using successive energy transfers between the pumping radiation and activator in the host of the lasant upconversion material under ordinary operating conditions.

Abstract: Scanning laser crystallization of p- and n- type hydrogenated amorphous silicon alloy cladding layers enhances the doping efficiency of such layers without changing the luminescence or other important properties of the middle i-layer in a p-i-n device. The dc dark conductivity of the doped layers increases by a factor of about 100 to about 10,000 above a sharp laser energy density threshold whose magnitude increases with decreasing impurity concentration. In one method, a doped amorphous silicon alloy layer is deposited on an amorphous glass substrate, scanned with laser irradiation, and then an intermediate i-layer is formed over this layer. Another doped amorphous silicon alloy layer is deposited on this layer, doped oppositely from the first doped layer. The second doped layer is then crystallized by scanning laser irradiation, leaving the underlying i-layer virtually unchanged in optical and electronic properties.

Abstract: An optical amplifier in the 1.26 .mu.m to 1.34 .mu.m spectrum range, comprising a solid substrate of fluoride glass doped with praseodymium in which a three-dimensional monomode waveguide is formed having an index difference .DELTA.n relative to the index of the fluoride glass lying in the range 4.times.10.sup.-3 and 8.times.10.sup.-2, said waveguide being associated by coupling means to an optical pump having a wavelength equal to 1.02 .mu.m .+-.0.1 .mu.m.

Abstract: A method for preparing a material so as to exhibit second harmonic generan 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: Optical amplifiers that are useful, for example, in optical communications are formed using a single crystal host waveguide and a dopant such as a transition metal. Through this combination, the amplified wavelength is adjustable and amplification at 1.3 .mu.m is possible.

Abstract: An optical signal amplifier with a waveguide path integrated into a glass body that is doped with optically active material. The signal to be amplified is transmitted through the waveguide and the pump power is coupled into the waveguide at one end. The waveguide comprises closely spaced adjacent guide lengths in the form of a spiral, zigzag paths between mirrors, or parallel paths with connecting semicircles at alternating ends of succeeding pairs of paths.

Abstract: In a thin film micro-optic gyroscope (MOG) (10) a waveguide resonator structure (14) has an optical transmission path formed within a surface of a substrate (12). In one embodiment the path includes a predetermined amount of dopant (12a) for providing regenerative gain to radiation of a predetermined wavelength propagating through the path. The dopant is provided at a predetermined concentration and is substantially uniformly distributed throughout the path. By example, the substrate is comprised of neodymium-doped glass. A pump source is optically coupled to the path for exciting the dopant to emit radiation, the pump source providing radiation at a wavelength of approximately one-half of the predetermined wavelength. For the example of neodymium-doped glass the predetermined wavelength is 1.06 microns.

Abstract: A laser is characterized by a glass gain medium which contains trivalent samarium Sm.sup.3+ ions and which, when optically pumped on one or a number of absorption bands to achieve excitation at or above the metastable .sup.4 G.sub.5/2 level, radiates light at a wavelength substantially corresponding to transitions from the .sup.4 G.sub.5/2 level of samarium.

Abstract: A 2.7Sg(m)m laser comprises a single mode fluoro-zirconate optical fibre doped with 0.086 mole % Er.sup.3+. C-W operation of the usually self-terminating lasing transition .sup.4 I.sub.11/2 to .sup.4 I.sub.13/2 is achieved by applying excitation energy to a suitable wavelength and intensity to elevate ions from the lower lasing level to maintain a population inversion between the upper and lower lasing levels during lasing. The laser may be pumped at a single wavelength of about 785 nm by a semiconductor laser.

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

Abstract: Disclosed is halide laser glass which comprises cationic components and anionic components. The cationic components are constituted by: Al ions; Zr ions and/or Hf ions; at least one kind of ions selected from the first group consisting of Ca ions, Sr ions and Ba ions; at least one kind of ions selected from the second group consisting of Mg ions, Y ions and alkali metal ions; and Er ions, the cationic components being present within the ranges: Al ions in a range of from 20 to 45 mol %, Zr ions and/or Hf ions in a range of from 0.

Abstract: A device and a method of generating blue laser light having a wavelength of approximately 450 nm by means of an upconversion process, said device comprising a single semiconductor laser which emits light having a wavelength of 640 to 700 nm, and a resonator cavity which comprises a glass composition of heavy metal fluorides, which glass composition contains trivalent thulium ions. The resonator cavity preferably consists of a glass fibre having a core of a glass composition which consists of heavy-metal fluorides containing 0.01 to 1 mol% of thulium fluoride and a cladding with a lower refractive index than the core. The device suitable for generating continuous blue laser light.

Abstract: A device for the correlation between optical beams having spatially modulated intensities has an active glass window, which on one side is illuminated at the same time by a reading and a pumping beam through one or a plurality of semitransparent mirrors. The reading beam has radiations with a wavelength equal to that of a transition between an intermediate and fundamental energy level. The pump beam has radiations with a wavelength corresponding to the energy of the highest power level of the material forming the active glass, obtaining on the other side of the window a light beam representing the correlation betwen the pumping and reading beams.

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

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

Abstract: A room temperature, 1.5 .mu.m band laser is described. The lasant material in the preferred embodiment is Er:YAG with a 1% Er.sup.3+ doping. The pumping radiation is an intense 1.53 .mu.m beam produced by a laser diode. The solid-state lasant material produced 1.5 .mu.m band radiation with high efficiency.

Abstract: A waveguide laser medium having an optical waveguide, which is used for effecting light amplification or laser oscillation and is formed by performing the ion exchange of alkaline ions contained in a predetermined portion of a laser glass substrate, which includes the alkaline ions and laser active ions, for another kind of ions, which operate to increase the refractive index of the laser glass, thereby making the refractive index of the predetermined portion become higher than that of the other portions of the laser glass substrate. Further, the laser glass substrate is made of, for example, phosphate glass containing neodymium ions as the laser active ions and further containing 0.01.about.8.0 mol % of Na.sub.2 O, from which Na.sup.+ ions are obtained as the alkaline ions, and the ion operating to increase the refractive index of the predetermined portion is Ag.sup.+ ions. Such a waveguide laser medium is employed in a waveguide laser.

Abstract: Glass compositions for high efficiency erbium.sup.3+ -doped optical fiber lasers, amplifiers and superluminescent sources are optimized for pumping by high power solid state lasers in the vicinity of 800 nm to provide amplified signals in wavelengths between 1.5 and 1.7 microns, a principal telecommunications window. A number of suitable host glasses for doping with erbium 3+ are identified wherein the excited state absorption/ground state absorption intensity ratio calculated at 800 nm is 1.00 or less.

Abstract: In a laser apparatus which includes a laser medium exhibiting thermally induced optical distortions, and flash lamp mounted near the laser medium to provide laser pumping radiation, an absorbing filter is mounted between the flash lamp and the laser medium for absorbing radiation in the output spectrum of the lamp which exhibits a low fluorescence efficiency in the laser medium. By absorbing radiation with the low fluorescence efficiency in the laser medium, heat which develops in the laser medium can be limited to control the thermally induced optical distortions.