Abstract: A laser with distributed feedback utilizes an active laser medium, especiy a dye solution contained in a cell, excited by a pump radiation beam that passes through an optical grating or like device, and an optical imaging system arranged between the optical device and the laser medium; the imaging system, in combination with the optical device, forms a striped pump radiation pattern in the laser medium. The optical imaging system contains a microscope lens in retro position, or another scale reducing or demagnifying lens system, and may optionally, include a variable-focus lens for altering the imaging scale and, therefore, the wavelength of the laser emission.

Abstract: The solid metal current return in a typical commercial co-axial flashlamp replaced with a light transmissive current return which permits light from either or both surfaces of the flashlamp to be used to pump dye volumes. This enables one flashlamp to pump two dye volumes simultaneously, resulting in a significant increase in the overall efficiency of the co-axial flashlamp-pumped dye laser.

Abstract: A scanning beam laser pumped laser is disclosed which is capable of producing pulses of 50 or more microsecond duration with a repetition rate of 100 Hz or more and an energy content per pulse of 3 joules or more. Optics focus the output beam of the pumping laser onto the front surface of the pumped laser which may comprise a flowing dye cell. A rotating mirror synchronized with the pulse repetition rate of the pumping laser moves the spot across the dye in the pumped laser in a direction preferably orthogonal to the flow of dye therein. A spherical mirror behind the rear surface of the dye cell reflects radiant energy back toward the rotating mirror. Reflective radiance is turned therefrom to, in part, pass through the aperture of a beam-combining mirror. The small fraction of radiant energy passing through either a partially reflecting surface or a small aperature on the beam combining mirror enters a resonant cavity whose dimensions define the wavelength of the pumped laser.

Abstract: A new class of laser dyes has a lasing compound syn (R.sub.1, R.sub.2) bismanes that shows efficient laser action under flashlamp excitation. In the laser action spectral region there is little or no triplet-triplet absorption so that laser efficiencies in the range of 1 to 3 percent can be provided. Good solubility in many solvents (especially water) good photochemical stability and simplicity of preparation are inherent in this new lasing media.

Abstract: A dye laser is of compact, rigid and simple construction, with a folded resonator cavity contained on a single rigid block of material, such as aluminum. The block has two or three mirror mount locations, at least one of which is a machined surface which receives a mirror directly and rigidly, without provision for adjustment. The other mirror mount location(s) has an adjustable mirror mount, and this may be the mirror mount for the output mirror. A dye jet mounting block has a flat surface which engages against a flat surface on the exterior of the laser block, with fasteners allowing for rotation and translation of the dye jet block on the laser resonator block to provide for both rotational and translational tuning adjustment of the dye jet with respect to the resonator cavity and a pumping beam. The pumping beam preferably is folded by an adjustable pump mirror on its approach to the dye jet.

Abstract: A dye laser master oscillator is disclosed herein. This oscillator is intended to provide a single mode output, that is, a primary beam of light of a specific wavelength, but also has the tendency to provide secondary modes, that is, secondary beams of light at different wavelengths and slightly off-axis with respect to the primary beam as a result of grazing incident reflections within the dye cell forming part of the master oscillator. Also disclosed herein are a number of different techniques for reducing or eliminating these secondary modes.

Abstract: A dye laser capable of lasing at a plurality of wavelengths simultaneously, e.g. three, comprises a corresponding plurality of transparent containers 4, 5, 6 located between a partially-reflecting mirror 1 and a tiltably adjustable retroreflecting diffraction grating 2 with the containers transversely staggered. The staggered ends of the containers are irradiated by a shallow beam 9 from a pumping laser 7 and contain separate dye solutions whereof the emission spectra increase in wavelength from container to container starting from that container nearest the pumping laser. There are thus formed three parallel cavities which can lase simultaneously, tuned by the grating 2 operating in three different diffraction orders.

Abstract: A dye laser system especially useful for generating short pulses in response to excitation laser pulses directed to an appropriate dye contained between opposing mirrors that form a short cavity within a small, easily replaceable cell. The spacing of the mirrors is adjustable by application of a force from outside of the cell, thereby allowing control of the frequency of the laser output. The cell is self-contained, including a dye reservoir maintained in continuous liquid communication with the cavity for providing fresh dye to it.

Abstract: A semi-passive Q-switch can be used at 1.00 to 1.80 micrometers laser radiation, in combination with a laser to give an effective high peak power output.

Abstract: Apparatus for preventing deposition of dye on laser apparatus elements comprises a device for vacuum removal of dye vapor from a dye jet in the dye circuit of the laser.

Abstract: A control system for a dye laser is described, in which a pump pumps the dye from a supply vessel into a pressure vessel, in which there is an air pocket for damping vibrations, fluctuations in the pump delivery, etc. The dye passes out of the supply vessel as a jet via a nozzle. At least one sensor measures the dye filling level in the supply vessel and a control switches off the dye laser when the level in the supply vessel does not drop to the correct value after switching on the laser. The control system of the invention prevents the switching on of the laser if the level is too high or low before putting the laser into operation.

Abstract: An optical laser pumping system comprises means for providing a highly collimated pump radiation beam propagating along an axis, and an optical element which forms a concave, frustro-conical reflecting surface which is coaxial to said axis and tapers in the direction of beam propagation from an entrance end of large cross section, into which said beam enters, to a distal end of small cross section which surrounds said axis in spaced relationship. The laser medium is positioned between said ends along said axis.

Abstract: A distributed-feedback dye laser having a tuning mirror for reflecting a pumping beam onto an impinging region of a dye cell. A four-link equilateral-parallelogram structure pivotally attached to the mirror is adjustable to translate the tuning mirror along the path of the pumping beam incident on the mirror while simultaneously changing the angular orientation of the mirror. The pumping beam reflected from the tuning mirror is directed toward a predetermined point for all positions of adjustment whereby the beam impinges generally the same region of the dye cell for a wide range of incident angles. The dye cell impinged by the pumping beam may also have a surface, through which the generated laser beam is transmitted, oblique to the laser beam and perpendicular to the dye cell region impinged by the pumping beam.

Abstract: A multiple wavelength operating laser (10) having a pump cavity or enclosure (14) surrounded by an optical pumping arrangement (17) comprises a plurality of substantially concentric tubes (21A, 21B) each having windows for emission of radiation and enclosing respective bodies of liquid lasing media. The lasing media may be flowed through the respective tubes and are preferentially arranged so that the fluorescence spectra of the lasing medium in one tube overlaps the absorption spectra of the lasing medium in the adjoining tube so that the one lasing medium optically pumps the other lasing medium in addition to optical pumping from the optical pumping arrangement (17).

Abstract: Laser dyes of the class of 2-substituted oxazolo [4,5-b] pyridines which lase when flashlamp or nitrogen laser pumped.

Abstract: A method of producing individual short laser pulses in which a stimulatable laser medium is excited by a pump pulse in order to produce a population inversion above a laser threshold value, the population inversion being kept below the threshold value after emission of the short radiation pulse. The laser medium is common to two resonators and from it energy in the form of the desired individual short laser radiation pulse is first taken from the first resonator by means of a first relaxation process of given threshold value, relatively short time constant and relatively low quality factor, after which the inversion in the laser medium is kept below the preset threshold value of the first resonance process by a second relaxation process of relatively long time constant and relatively high quality factor in the second resonator coupled to the first.

Abstract: A dye laser oscillator in which one light beam is used to pump a continuous tream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

Abstract: A dye laser system wherein the dye medium is pumped by frequency doubled mode locked laser pulses from a Nd:YAG laser and also mode locked by colliding pulses in an anti-resonant ring having a saturable absorber.

Abstract: A plasma is induced in a transmissive medium, and causes a chirp to be impressed on an optical pulse. The chirped pulse when passed through a dispersing means is then compressed. Applications of this pulse compression technique include the generation of short pulses of infrared at high power levels. Picosecond pulses of 10 micron energy are generated by switching a 2 picosecond portion from the output of a multi-atmosphere laser oscillator, and amplifying the portion in a CO.sub.2 gain module operated at gain saturation to cause a plasma front to propagate with the portion being amplified. A blue chirp of the pulse results. The pulse is passed through a dispersive medium, and a substantial decrease in pulse width and increase in energy density occurs during successive passes of the pulse through the gain module. Pulses as short as 500 femtoseconds have been produced at power densities of the order of 10.sup.12 watts/cm.sup.2. A TE/CO.sub.

Abstract: A device is provided for fast frequency modulating the output spectrum of multimode lasers and single frequency lasers that are not actively stabilized. A piezoelectric transducer attached to a laser cavity mirror is driven in an unconventional manner to excite resonance vibration of the transducer to rapidly, cyclicly change the laser cavity length. The result is a cyclic sweeping of the output wavelength sufficient to fill the gaps in the laser output frequency spectrum. When such a laser is used to excite atoms or molecules, complete absorption line coverage is made possible.

Abstract: A method of obtaining a long-lived flashpumped laser dye with an output equivalent to commercial dyes and a low threshold of lasing using the N-methyl tosylate salt of 2-(4-pyridyl)-5-(4-methoxyphenyl) oxazole.

Abstract: A passive thermal control system for a flashlamp-pumped dye laser utilizes heated deionized water in a heat exchanger located in the reservoir of the dye lasing solution to minimize the temperature gradients in the dye lasing solution by decreasing the difference in temperature between the dye lasing solution and the deionized water flashlamp coolant.

Abstract: The effective lasing lifetime of coumarin 102 in 50:50 ethylene glycol is gnificantly extended by increasing the rate of pumping and photolysis, with a flashlamp in a laser system having a pyrex ultraviolet filter and an inert cover gas.

Abstract: A picosecond short cavity dye laser utilizes a piezoelectric translator to vary the length of the optical cavity in the laser to allow continuous tuning of the output wavelength. The laser includes a pair of closely spaced generally flat mirrors forming an optical cavity. A laser dye solution is inserted into the cavity. The short cavity laser is pumped by pulses from another laser to produce picosecond output pulses. The piezoelectric translator, which is attached to one of the mirrors, moves the mirror to tune the laser as an applied DC voltage is varied. The piezoelectric tuning of the dye laser allows the laser to operate in a tunable single axial mode.

Abstract: A laser tape system for use in the resonant cavity of laser consisting of a flexible tape carrying at least one lasing dye and adapted for insertion into the resonant cavity, and a drive mechanism for moving the tape such that different portions of the tape may be focused within the cavity.

Abstract: A laser-pumped laser system is disclosed, such as a dye laser which is optically pumped by an argon ion laser. An improved servo system is provided for maintaining relative alignment of the pump laser beam with respect to the dye laser cavity. This is accomplished by rotating the pump beam such that the beam defines a conical surface, by means such as an optically-transmissive rotating wedge. Such rotation provides dithering along two orthogonal axes, which provides the necessary control information to maintain pump beam alignment.

Abstract: The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

Abstract: A dye laser comprising a container retaining a dye solution for laser and an energy source for pumping connected to the container, the dye solution containing a pyrazoloazaxanthenoisoquinolinone dye.

Abstract: A dye laser (FIG. 1, 5 or 6) includes a pumping laser source (e.g. 11), an optical resonator (e.g. 13-15), and a dye solution or dye cell (e.g. 12) disposed in the path of the pumping laser light in the resonator. The dye cell disclosed herein comprises a pair of closely spaced transparent discs (21). A motor (26) serves to spin the discs at a high rate of speed. The pumping laser light in the resonator is focused on the discs at a predetermined angle (i.e. the Brewster angle). New, unbleached dye is injected axially with respect to the discs so that the spin force causes a radial flow of the dye solution between the spinning discs and, of course, past the pumping laser light spot.

Abstract: A dye cell holder adapted for removable engagement with a support in a dye laser arrangement is disclosed. The holder is particularly adapted to hold thin fragile dye cells. The holder comprises means for supporting such fragile cell which contains a dye solution and is to be pumped by a laser beam. The dye cell is retained against the support by a retaining means which is movable relative to the support in a manner to provide access to permit insertion of the dye cell into the holder and to permit removal of the cell from the support means.

Abstract: A dye laser having an improved dye jet nozzle and its method of manufacture is described. The exit aperture of the nozzle is provided by a nozzle end assembly made up of a plurality of blocks of material which are in optical contact with one another. The liquid channel defined by the blocks is provided with optically flat surfaces which minimize interference with uniform liquid flow therethrough. Moreover, edges are provided for the exit aperture defined by the blocks by polishing the same while they are supported, so that the resulting edges have a minimum of imperfections.

Abstract: A laser dye, 2-keto-4,6,8,8-tetramethyl-8,9-dihydro-2H-pyrano(3,2-g) quinoline, is prepared by mixing m-aminophenol and ethyl acetoacetate and heating the mixture.

Abstract: A right angle corner reflector is used to reflect different parts of a single incident collimated radiation beam such that a cylindrical region is equally irradiated transversely from four directions. The cylindrical region is positioned such that rays which strike the intersection of the corner reflector surfaces are tangent to the side of the cylindrical region. The cylindrical region is spaced from the corner reflector such that one quarter of the radiation incident upon the cylindrical region strikes the region directly, one quarter is first reflected from one of the corner reflector surfaces, one quarter is first reflected from the other corner reflector surface, and one quarter is reflected from first one and then the other corner reflector surface before striking the cylindrical region.