Abstract: A semiconductor surface-emitting element having a light-emitting portion and formed of a plurality of semiconductor layers including a plurality of light-generating layers of a quantum well structure for generating lights having respective different emission spectra whose peak wavelengths are different from one another, and a light resonator consisting of a pair of reflecting layers between which the light-generating layers are interposed for reflecting the lights generated by the light-generating layers, so that a light resonated by the light resonator is emitted from the light-emitting portion.

Abstract: The present invention provides an apparatus for passively stabilizing the optical pathlength in tunable lasers. Lasers stabilized using the passive stabilization apparatus exhibit reduced mode hop and increased wavelength stability during temperature variations of the laser or surrounding environment. The stabilization makes the laser suitable for a broad range of applications including: optical signal generators and optical multimeters.

Abstract: Disclosed are a silicon thin film structure for optoelectronic devices and a method for manufacturing the same. The silicon thin film structure for optoelectronic devices, comprises a multi-layered structure consisting of a plurality of structural units, each comprising: a silicon base layer; and a luminescent, rare earth element-doped silica layer on said silicon base layer, or a multi-layered structure consisting of a plurality of structural units, each comprising: a silicon base layer; a lower undoped silica buffer layer for restraining the silicon layer from absorbing emitted light on said silicon base layer; a luminescent, rare earth element-doped silica layer for emitting light on said lower undoped silica buffer layer; and an upper, undoped silica buffer layer for restraining the silicon from absorbing emitted light on said luminescent, doped silica layer.

Abstract: A chiral laser apparatus comprises a layered structure configured to produce a photonic stop band, the layered structure including a upper chiral material layer, a middle excitable light-emitting layer, and a lower chiral material layer and an excitation source that, when applied to the layered structure, causes the middle light-emitting layer to emit electromagnetic radiation, such that polarized lasing at a lasing wavelength occurs in a direction perpendicular to the layered structure. The middle light-emitting layer may be configured to produce a defect such that lasing advantageously occurs at a wavelength corresponding to a localized photonic state within the photonic stop band. The excitation source may be an electrical power source connected to the layered structure via two or more electrodes. In another embodiment of the invention, the layered structure is replaced with a homogeneous chiral material doped with a light-emitting material.

Abstract: A defect causing a localized state is induced in a chiral structure composed of multiple chiral elements by twisting one element of the chiral structure with respect to the other elements along a common longitudinal axis such that directors of the element molecular layers that are in contact with one another are disposed at a particular “twist” angle therebetween, the twist angle being greater than a shift angle between directors of consecutive layers. The chiral twist structure may be utilized in a variety of applications such as filters, lasers and detectors. The defect caused by the twist may be made tunable by providing a tuning device for ly rotating one or more of the chiral elements with respect to one another to vary the twist angle and thus vary the position of the induced defect within a photonic stop band. Tunable defects may be advantageously utilized to construct wavelength tunable chiral filters, detectors and lasers.

Abstract: In a dye laser system, a porous bed filter is loaded with dye prior to operation of the system. With repeated firings, the dye solution is filtered by the porous bed filter to remove by-products of the laser process. Solute concentration is monitored and dye and additives removed by the filter are replenished by a metering pump. Precise temperature control assures consistent filtering of dye by the filter for more consistent color and energy output. To control the metering pump, the differential output of a two- channel absorption detector is digitized. The digitized signal is loaded into a counter which drives the metering pump. The useful lifetime of the dye solution is enhanced by incorporating pH buffers in the solution.

Abstract: Optical detection apparatus comprises a solid state laser having an intracavity optical waveguide that supports a lasing filament and operates in one of two states: (1) in a first state, the filament is fixed in one of two orientations, and (2) in a second state, the filament may be induced to switch or oscillate between the two orientations, or it may be suppressed altogether. At least one feature is located on the output facet off-center with respect to the waveguide cross-section in order to provide a preferred orientation for the filament. In one embodiment, a single feature is located off-center and optical radiation of one intensity is injected through the facet feature, thereby causing the laser to operate in one of its states, whereas injected radiation of another intensity causes the laser to operate in the other of its states. The injected radiation may be radiation emitted by the laser that is reflected by an object (e.g.

Abstract: A method for fabricating a Fabry-Perot laser having a cavity length and facet reflectivity product tuned to cause the laser to exhibit a relaxation oscillation frequency of at least 10 GHz, wherein the laser is capable of being modulated at 10 Gb/sec at drive currents between about 20 and 40 mA.

Abstract: In a dye laser system, a porous bed filter is loaded with dye prior to operation of the system. With repeated firings, the dye solution is filtered by the porous bed filter to remove by-products of the laser process. Solute concentration is monitored and dye and additives removed by the filter are replenished by a metering pump. Precise temperature control assures consistent filtering of dye by the filter for more consistent color and energy output. To control the metering pump, the differential output of a two-channel absorption detector is digitized. The digitized signal is loaded into a counter which drives the metering pump. The useful lifetime of the dye solution is enhanced by incorporating pH buffers in the solution.

Abstract: In a single-frequency laser and amplifier system, the radiation of a single-frequency, diode-pumped solid-state laser, preferably of a low power microcrystal laser or a monolithic ring-laser consisting of rare-earth-doped or transition-metal-doped crystal or glass materials, is coupled into a semiconductor amplifier chip (preferably GaAlAs, InGaAs or InGaAsP). The material system and the epitaxial structuring of the amplifier chip are selected to adapt it to the emission wavelength of the solid-state laser, so that it amplifies the single-frequency radiation of the solid-state laser and therefore generates an output beam which is intensified with respect to the coupled-in laser radiation.

Abstract: A high-capacity cryosorption vacuum pump system for a light-weight and compact chemical oxygen-iodine laser. The cryosorption vacuum pump system included a gas chiller and a bed of zeolite or other suitable sorption material. Gas exhausted from the chemical oxygeniodine laser is first chilled to about 100 degrees Kelvin and the condensable gases are removed. Cold and dry gas is then adsorbed onto a bed zeolite cooled to a temperature of approximately 80 degrees Kelvin. The zeolite bed uses a suitable zeolite material preferably in a granulated form and configured in layers several millimeters to several centimeters thick to provide an exposed surface of suitable size. The zeolite is enclosed in a suitable vacuum vessel and thermally insulated. Chilling of the zeolite is accomplished by a contact with suitable cryocooled surfaces or by exposing the zeolite to a cold light noble gas.

Abstract: A method for exposing light sensitive material to provide exposure patches representing the material sensitivity and which minimizes the effects of intermittency of the light sensitive material, including providing a source of laser light by producing a laser light beam by a continuous wave pump laser which produces a first beam of light and a continuous wave dye laser responsive to the beam of light to produce a second beam of light having gaussian intensity distributions in two orthogonal directions; shaping the second light beam so as to produce a substantially square wave intensity distribution in one direction, while the other direction has a gaussian distribution; and scanning the shaped second light beam through a target of different uniform densities and onto light sensitive material so as to produce a series of exposure patches in one scan of different densities but with the density in each exposure patch being uniform, whereby the effect of intermittency in the light sensitive material is minimized.

Abstract: A dye laser assembly for attaching to an optical microscope.

Abstract: A register using a single pin to provide two or more control signals (e.g., clock and data signals). The present invention decodes a three state input waveform to generate a clock/write signal and uses a three state clock waveform to generate a clock/read data signal. The present invention generally comprises a three-level receiver, a latch and an output driver to form a one-pin bidirectional interface used with a shift register. To write, the interface converts a three-level input signal into separate clock and data signals which drive the shift register. To read, the interface converts a bi-level input signal into a three-level output signal representing the output of the shift register. As a result, the present invention allows the programming of a device such as an erasable programmable read only memory (EPROM) in a clock chip while utilizing the fewest number of pins.

Abstract: Solid state lasers based upon conjugated polymers are disclosed. A conjugated polymer useful in the practice of this invention is a conjugated polymer which has a ground state and an excited state and which, in the form of a nondiluted thin film, meets the criteria of;i. having a strong absorption in the ground state with an absorption coefficient of at least about 10.sup.4 cm.sup.-1 and an absorption depth not greater than about 1 .mu.m,ii. having an efficient luminescence emission from the excited state; this emission being shifted to lower energy relative to the ground state absorption, andiii. providing stimulated emission which is not overwhelmed by photoinduced absorption, such that the thin film exhibits gain narrowing and amplified spontaneous emission. These conjugated polymers have gain lengths in the micron or even sub-micron regime and therefore exhibit laser action with low pumping threshold as thin solid films with thicknesses in the micron or even sub-micron regime.

Abstract: Dipyrrometheneboron difluoride dyes possessing a covalently attached basic amine moiety are described that have utility for staining acidic organelles. Samples comprising isolated acidic organelles, or a cell or cells containing acidic organelles, are stained by preparing an aqueous labeling solution of the dye and incubating the sample in the labeling solution for a time sufficient to produce fluorescent labeled acidic organelles.

Abstract: A solid-state dye laser and technique for achieving multiple output wavelength laser emission from a single solid-state dye laser media containing multiple dyes without tuning elements. When the multiple dyes within the single solid-state host are excited with a single wavelength pump source to lase, there results simultaneous multi-spectral output proportional to dye concentration ratios.

Abstract: A laser diode power combiner comprises a dye laser operably coupled to an array of laser diodes for combining optical power from the laser diodes into a single, coherent laser beam.

Abstract: Disclosed are solid state lasers and laser gain media which include lasing crystals having crystalline lattice incorporating lasable organic dye molecules in regular positions. The monolithic crystals are readily prepared and the organic dye can be varied across a broad range of available materials to vary the emission characteristics of the crystals.

Abstract: In a dye laser system, a porous bed filter is loaded with dye prior to operation of the system. With repeated firings, the dye solution is filtered by the porous bed filter to remove by-products of the laser process. Solute concentration is monitored and dye and additives removed by the filter are replenished by a metering pump. Precise temperature control assures consistent filtering of dye by the filter for more consistent color and energy output. To control the metering pump, the differential output of a two-channel absorption detector is digitized. The digitized signal is loaded into a counter which drives the metering pump. The useful lifetime of the dye solution is enhanced by incorporating pH buffers in the solution.

Abstract: A microfine light source is provided by a non-spherical particle containing a dye, which is irradiated with a laser beam under conditions that the particle emits light at a plurality of frequencies. A micromemory sensor which employs the light confinement properties of these non-spherical particles is also provided. The microfine light source is applicable to new physical and chemical processes, the processing and modification of particles, and to photon STM.

Abstract: A device permitting a single primary laser producing a collimated beam at a given wavelength, to be used for different purposes by converting the collimated beam to a beam of different wavelength. The device comprises a secondary laser disposed within a body removably attached to the distal end of an articulated arm delivery system attached to the primary laser. Preferably, the secondary laser is interchangeable with respect to the delivery system thus to extend the wavelength (color) coverage of the primary laser according to the required wavelength conversion. The secondary laser may include an optical crystal or a circulated organic dye solution within a removable cell or reservoir. Appropriate lenses are provided to focus the primary beam and to determine the spot diameter of the conversed beam.

Abstract: An apparatus and a method for precisely wavelength-tuning single longitudinal mode tunable laser beams by utilizing a wedge prism are disclosed in which, instead of a tuning mirror, a prism is rotated, so that a single longitudinal mode can be maintained without causing a mode hopping of the longitudinal mode, thereby precisely tuning the wavelength. That is, a wedge prism 4 is inserted into the single longitudinal mode tunable laser resonator, and the prism is rotated, thereby precisely tuning the wavelength of the laser beams.

Abstract: A method and apparatus for producing stimulated emission from a laser gain element containing an organic dye are described in which optical pumping is produced by visible laser diodes. Low threshold pump power and high optical conversion efficiency are achieved by producing a laser resonator mode waist at or near the laser gain element and spatially superimposing a pump mode waist at or near the laser resonator mode waist. Using low power visible AlGaInP laser diodes and the dyes rhodamine 700, oxazine 750, DOTCI or oxazine 1 in the laser gain element, incident pump threshold powers as low as 5.4 mW, optical conversion efficiencies of 49% and tunable emission between 700 nm and 800 nm were achieved. This laser was scaled to higher cw output power by using a DCM-based pump dye laser. In a preferred embodiment the laser resonator has two reflective elements in a nearly hemispherical configuration. Angular multiplexing of laser diodes to scale to higher laser diode pump power is described.

Abstract: This invention relates to derivatives of dipyrrometheneboron difluoride fluorescent dyes that have an absorption maximum at wavelengths longer than about 525 nm, and are chemically reactive with nucleic acids, proteins, carbohydrates, and other biologically derived or synthetic chemical materials to form dye-conjugates. The dye-conjugates generally have the structure: ##STR1## wherein at least one of the substituents R.sub.1 -R.sub.7, covalently bonds to a specific binding pair member, and further where at least one of the substituents R.sub.1 -R.sub.7 contains a bathochromic moiety that is heteroaryl or alkenyl. The remaining substituents, which may be the same or different, are hydrogen, halogen, alkyl (containing 1-5 carbon atoms), aryl, arylalkyl, or sulfo.

Abstract: A laser system comprises an optical head, a power supply and a computer for controlling the power supply. The optical head comprises a pair of mirrors and four pumping sections. Each pumping section comprises a pair of gas discharge lamps pumping an Nd:YAG laser element. The power supply provides the lamps with alternating current at 25 kHz so that the laser system produces a continuous, modulated or pulsed output light beam. The power supply comprises three boost converters connected in parallel for converting three phase mains supply to direct current and four DC-AC converters. Each DC-AC converter converts the DC output from the boost converters to an AC supply for the lamps of a respective one of the pumping sections.

Abstract: Apparatus for transversely irradiating a region equally from two directions using a single incident beam of substantially collimated radiation. The apparatus includes perpendicular reflective planes having a common edge and defining a corner region in which an irradiated region entirely within said corner region, said irradiated region being suitably positioned within said corner region such that said irradiated region does not intercept any ray of incident radiation from striking said common edge, said irradiated region receiving only radiation from two directions. Said irradiated region being directly irradiated from a first direction by incident radiation, and said irradiated region being also indirectly irradiated from a second direction opposite said first direction by incident radiation reflected from both of said planes.

Abstract: An interface module (10) for transverse energy input to dye laser modules is provided particularly for the purpose of delivering enhancing transverse energy beams (36) in the form of illumination bar (54) to the lasing zone (18) of a dye laser device, in particular to a dye laser amplifier (12). The preferred interface module (10) includes an optical fiber array (30) having a plurality of optical fibers (38) arrayed in a co-planar fashion with their distal ends (44) receiving coherent laser energy from an enhancing laser source (46), and their proximal ends (4) delivered into a relay structure (3). The proximal ends (42) of the optical fibers (38) are arrayed so as to be coplanar and to be aimed generally at a common point. The transverse energy beam array (36) delivered from the optical fiber array (30) is acted upon by an optical element array (34) to produce an illumination bar (54) which has a cross section in the form of a elongated rectangle at the position of the lasing window (18).

Abstract: This invention relates to derivatives of dipyrrometheneboron difluoride fluorescent dyes that have an absorption maximum at wavelengths longer than about 525 nm, and are chemically reactive with nucleic acids, proteins, carbohydrates, and other biologically derived or synthetic chemical materials. The dyes generally have the structure: ##STR1## wherein at least one of the substituents R.sub.1 -R.sub.7, is a reactive functional group, and at least one of the substituents R.sub.1 -R.sub.7 contains a bathochromic moiety. The bathochromic moiety is an unsaturated organic group, preferably heteroaryl or alkenyl. The remaining substituents, which may be the same or different, are hydrogen, halogen, alkyl (containing 1-5 carbon atoms), aryl, arylalkyl, or sulfo. The dyes are used to make novel conjugates with members of specific binding pairs that are ligands or receptors.

Abstract: This invention describes novel 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes containing heteroaryl substituents conjugated to the fluorophore and methods for their synthesis. The heteroaryl substituted compounds (heteroaryl dyes) generally have the structure: ##STR1## wherein any or all of the substituents R.sub.1 -R.sub.7, but at least one of such substituents, is a heteroaryl group, including 5- or 6-member rings, singly or fused, containing one or more heteroatoms. The new dyes that have spectral properties that are significantly shifted from those of the parent alkyl-substituted dyes, usually accompanied by an increase in photostability and in some cases by an increase in the extinction coefficient relative to the alkyl-substituted dyes. The general method of synthesis includes formation of pyrromethene salt intermediates followed by cyclization with boron trifluoride in the presence of a base to give heteroaryl-substituted dipyrrometheneboron difluoride dyes.

Abstract: A novel dye laser comprises a laser dye solution comprising a conductive polymer having the chemical formula ##STR1## wherein R comprises (C.sub.1 -C.sub.10)alkyl, R' is the same or different from R and comprises alkyl, substituted alkyl, benzyl, or substituted benzyl, such as --(CH.sub.2).sub.n CH.sub.3 or CH.sub.2 C.sub.6 H.sub.4 (CH.sub.2).sub.n Y, wherein Y is O-alkyl, alkyl, alkenyl or alkynyl and n is greater than 1 and up to 200, and for structure IV R" is the same or different from R and comprises (C.sub.1 -C.sub.10)alkyl, and x is greater than about 20, and a non-aqueous solvent; the solvent being substantially unable to chemically react with the polymer and to absorb and emit light at a wavelength similar to the conductive polymer, and a pumping energy source operably coupled therewith and capable of producing stimulated emmission of the dye solution.

Abstract: A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Abstract: In an external lasing dye sensor system, a stream of lasing dye free-flows cross an open area inside a chamber. An air sample comprising chemical vapor contaminants is pumped or drawn into the chamber. A laser beam is introduced into the chamber intersecting the lasing dye. A chemical reaction between the contaminants and the lasing dye result in a change in the emission spectra of the lasing dye. The change in emission spectra is detected and thus provides an improved apparatus for detecting low concentrations of chemical vapors in an air sample.

Abstract: A large (high flow rate) dye laser amplifier in which a continuous replened supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a relatively high flow rate and a specifically designed diffuser assembly for slowing down the flow of dye while, at the same time, assuring that as the dye stream flows through the diffuser assembly it does so in a stable manner.

Abstract: An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

Abstract: A large (high flow rate) dye laser amplifier in which a continous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell.

Abstract: A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner.

Abstract: A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability.

Abstract: A dye laser oscillator for producing a tuned dye beam is disclosed herein and includes, among other components, a beam output coupling assembly, a dye cell assembly, a beam expander assembly, an etalon assembly, and a grating assembly. Each of three assemblies is vertically supported from a horizontal base so as to be readily removable from the base without interference from or interfering with the other assemblies. The particular grating assembly disclosed is specifically designed for proper optical alignment with the intended path of the dye beam to be produced and for accurate pivotal movement relative to the beam path in order to function as a coarse tuning mechanism in the production of the ultimately tuned beam.

Abstract: A quantum well structure is disclosed, which is comprised of a quantum well layer of a thickness substantially equal to the de Broglie wavelength of electrons and carrier confinement layers of an energy gap greater than that of the quantum well layer. A second material of a lattice constant different from that of a first material primarily for the quantum well layer is disposed in the quantum well layer to provide a phase shift in the period of the crystal lattice of the first material, thereby forming energy levels in the forbidden band of the quantum well layer. A semiconductor device which employs such a quantum well structure and is so constructed as to utilize its physical phenomenon which is caused by the energy levels in the forbidden band. In concrete terms, the present invention has its feature in allowing ease in the fabrication of an intermediate infrared or blue light emitting device, for instance.

Abstract: In a lasing dye sensor system, a stream of lasing dye freeflows across an ea open to the atmosphere. A chemical reaction between contaminants in the atmosphere and the lasing dye result in the change of emission spectra of the lasing dye. The change in emission spectra is detected and provides an improved apparatus and method for detecting low concentrations of chemical vapors in the atmosphere.

Abstract: A dye laser system and method for operation thereof. The dye laser includes a laser cavity capable of lasing in response to an energy source, a circulation path for pumping a dye solution to the laser cavity, and a regeneration medium containing saturated dye solution at equilibrium with the concentration of the dye solution in the circulation path located in the circulation path so that the dye solution is regenerated by circulation through the regeneration medium. According to another aspect, there is provided a system and method for restoring dye solution degraded by use in dye laser. The system and method include a circulation path for conveying degraded dye solution to a regeneration medium containing a saturated dye solution at equilibrium with the concentration of the dye solution in the circulation path connected to the circulation path so that the dye solution in the circulation path may be regenerated by circulation through the regeneration medium.

Abstract: A method for releasing trialkylamines into the dye circulation stream of a dye laser and a filter cartridge containing a resin bound anion stabilizing agent for insertion into the dye circulation stream of a dye laser improves the performance thereof, especially with respect to excimer and flashlamp pumped coumarin and carbostyryl dye lasers. The resin bears quaternary ammonium groups, and borohydride, bromide, hudroxide or chloride may be used as the counter ion. A resin bound borohydride stabilizing agent is capable of releasing trialkylamine into the dye circulation stream and reducing the carbonyl functional groups of polyarbonyl material in the stream to less light absorbing alcohol functional groups. A resin bound chloride stabilizing agent is capable of releasing trialkylamine into the dye circulation stream as a quencher and radical scavenger.

Abstract: A monochromatic dye laser is constructed from a short cavity laser 61 with an external narrow bandwidth amplifier 62 designed to pass only a single mode. The frequency of the SCL is controlled by a servo fed from an interferometer which monitors the spacing of the laser mirrors, while the pass frequency of the NBA is controlled by a servo 68 fed by photodetectors 65,66 which monitor the amplitude of peripheral bands.

Abstract: A laser pulse generator utilizes intracavity doubling in an ultrathin beta barium metaborate crystal to produce femtosecond pulses in the ultrashort ultraviolet wavelength range. The generator includes a colliding-pulse passively mode-locked ring dye laser which propagates a pulsed beam of primary laser light in a cavity. The primary light beam has a repetition rate of 10.sup.8 Hz and a pulse width in the femtosecond range. The crystal is located in the cavity so that the primary beam strikes one crystal surface at Brewsters angle and propagates through the crystal at its phase-matching angle. The primary beam and its second harmonic are emitted from the opposite surface, the harmonic wave having the same repetition rate and substantially the same width as the primary beam, but one-half its wavelength.

Abstract: A length stabilized, dispersion compensated synchronously pumped mode locked dye laser is disclosed. The output of the dye laser is actively stabilized by monitoring the output power thereof and generating an error signal for actively adjusting the cavity length. The operation is enhanced by actively controlling the power of the pump pulses exciting the dye laser so that the power fluctuations in the dye laser are due primarily to fluctuations in cavity length. Stability is also enhanced by operating the cavity with a negative group velocity dispersion. The resultant lengthening of the output pulses is compensated by a pulse compressor, located outside of the cavity, which adds a positive group velocity dispersion to upchirp and shorten the pulses.

Abstract: A dye laser fluid dye solution replenishment system in which the portion of the lasing fluid passing through the laser head which has been activated to a lasing condition is separated from the remainder of the unactivated dye solution and is separately restored before being recombined into the fluid flow path. The thus separated and degraded dye solution, representing only the degraded component of the flowing dye solution, is filtered to remove the degradation products and restored to the desired dye solution component concentrations. The thus restored solution is reinserted into the fluid flow path through the laser head.

Abstract: There is disclosed an apparatus for translating the focal points of curved mirrors in a dye laser along a straight line comprising an experimentally selected pivot point for each mirror and a means for causing each mirror to pivot about its pivot point. Rotation of the mirror about the pivot point causes the incoming beam to strike the mirror in a different place on the curved surface such that the angle of reflection changes in such a manner as to compensate for the arcuate movement of the mirror around the pivot point. Also disclosed are hinge designs to allow a mirror to pivot about an apparent pivot point which is much farther away from the mirror than the hinge. Also disclosed are a method for attaching the mirror supports to the laser frame in dye laser construction and a method for tuning the dye laser so constructed for optimum lasing efficiency.

Abstract: There is disclosed an apparatus for translating the focal points of curved mirrors in a dye laser along a straight line comprising an experimentally selected pivot point for each mirror and a means for causing each mirror to pivot about its pivot point. Rotation of the mirror about the pivot point causes the incoming beam to strike the mirror in a different place on the curved surface such that the angle of reflection changes in such a manner as to compensate for the arcuate movement of the mirror around the pivot point. Also disclosed are hinge designs to allow a mirror to pivot about an apparent pivot point which is much farther away from the mirror than the hinge. Also disclosed are methods for attaching the mirror supports to the laser frame in dye laser construction and for tuning the dye laser so constructed for optimum lasing efficiency.

Abstract: Laser apparatus is disclosed which comprises a compact pulsed dye laser for high pulse repetition frequency operation. The pulsed dye laser includes a resonator cell having a passageway through which dye solution is circulated and a pump laser for optically pumping the resonator. In order to provide laser apparatus which is capable of very high performance, the dye solution is circulated through a narrow passageway at high flow rate and the pump laser is operated at a high pulse repetition frequency.