Abstract: An optical assembly is disclosed herein along with a method of operation for use in a dye lasing arrangement, for example a dye laser oscillator or a dye amplifier, in which a continuous stream of dye is caused to flow through a given zone in a cooperating dye chamber while the zone is being illuminated by light from a pumping beam which is directed into the given zone. This in turn causes the dye therein to lase and thereby produce a new dye beam in the case of a dye laser oscillator or amplify a dye beam in the case of a dye amplifier. The optical assembly so disclosed is designed to alter the pump beam such that the beam enters the dye chamber with a different cross-sectional configuration, preferably one having a more uniform intensity profile, than its initially produced cross-sectional configuration.

Abstract: Dye for a dye laser according to the general formula: ##STR1## wherein: X.sup.- is an acid anion andHet is the non-metal atoms necessary to complete a heterocyclic ring,n=1 - 3.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

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: 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 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 single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Abstract: Disclosed are organic laser dyes and more particularly o,o'-bridged oligophenylene laser dyes which when excited to lase emit radiation in various ranges and especially in the ultraviolet and violet ranges, that is, from about 300 nm to about 420 nm, of the light spectrum. An organic laser dye of this invention comprises an oligophenylene having at least one biphenyl moiety bridged between adjacent ortho positions via a single atom or a plural of atom substituents of various sizes. In one most preferred embodiment, the substituent bonded to the phenyl moieties forming the bridge is a carbon atom free of benzylic hydrogens. The bridging substituent can also be other atoms or groups free of reactive substituents. In another most preferred embodiment, the o,o'-bridged oligophenylene laser dyes are free of vinylene groups bonded directly to the phenyl moieties forming the oligophenylene chains.

Abstract: Disclosed are organic laser dyes and more particularly o,o'-bridged oligophenylene laser dyes which when excited to lase emit radiation in various ranges and especially in the ultraviolet and violet ranges, that is, from about 300 nm to about 420 nm, of the light spectrum. An organic laser dye of this invention comprises an oligophenylene having at least one biphenyl moiety bridged between adjacent ortho positions via a single atom or a plural of atom substituents of various sizes. In one most preferred embodiment, the substituent bonded to the phenyl moieties forming the bridge is a carbon atom free of benzylic hydrogens. The bridging substituent can also be other atoms or groups free of reactive substituents. In another most preferred embodiment, the o,o'-bridged oligophenylene laser dyes are free of vinylene groups bonded directly to the phenyl moieties forming the oligophenylene chains.

Abstract: A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

Abstract: A low-power, continuous wave laser beam is injected into the optical cavity of a high gain, high power, short pulsed laser. The output beam features excellent power and wavelength stability.

Abstract: An arrangement especially suitable for use in a laser apparatus for converting a plurality of different input light beams, for example copper vapor laser beams, into a plurality of substantially identical light beams is disclosed herein. This arrangement utilizes an optical mixing bar which is preferably integrally formed as a single unit and which includes a main body for mixing light therein, a flat input surface on one end of the main body, and a multi-faceted output face on the opposite end of the main body. This arrangement also includes means for directing the plurality of different input light beams onto the input face of the mixing base, whereby to cause the different beams to mix within the main body of the mixing bar and exit the latter from its multi-faceted output face as the desired plurality of substantially identical output beams.

Abstract: Aqueous solutions useful in dye lasers contain a substituted cyclodextrin-fluorescent dye inclusion compound, and an excess of the cyclodextrin. Such solutions give greater fluorescent yields than similar inclusion compounds made from non-substituted cyclodextrins.

Abstract: A new group of fluorescent organic materials having a variety of uses are described. They are especially useful as dye compounds in dye laser systems, and as photochemical agents in the treatment of diseased tissues using photodynamic therapy techniques. The materials involve a tri-cyclic compound having the following structure: ##STR1## In this structure, R.sub.1 -R.sub.21 represent a variety of organic and inorganic groups.

Abstract: An improved dye laser having a birefringent tuning filter comprised of one or more birefringent plates wherein each plate is oriented at Brewster's angle to the resonant light beam and is an integer multiple of the thickness of the thickness of the first plate characterized by the fact that the thickness of the first plate is chosen using a new tuning relationship so that a single order tuning curve covers a tuning range of interest. This single tuning curve is almost linear throughout the tuning range and has a tuning angle at the center of the range of approximately five degrees. Also, the tuning curve has a slope throughout the tuning range which provides sensitivity of selected wavelength to tuning angle which is neither too great nor too small. A further refinement in the structure is a non birefringent polarizing plate at Brewster's angle which increases the losses imposed upon light passing therethrough which is polarized at other than Brewster's angle.

Abstract: Disclosed are laser dye liquids, lasers utilized therewith and methods of formulating the laser dye liquids. A laser dye liquid of the present invention comprises a laser dye dissolved in a glycol ether solvent which is substantially free of solubilizing and viscosity altering additives, and which does not substantially interfere with the emission of coherent laser radiation when the laser dye liquid is excited by a pump source. Preferred glycol ether solvents of the instant invention are ethylene glycol phenyl ether (EPH) and propylene glycol phenyl ether (PPH). The laser dye liquids of the present invention are especially suited for use with jet stream dye lasers.

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.

Abstract: In one embodiment this invention provides a tunable laser device which is characterized by a dye laser medium which consists of a porous glass matrix containing an incorporated solution of a lasing dye, and which is adapted to operate continuously in combination with an optical pumping means.

Abstract: The present invention relates to laser dyes having improved characteristics comprising substituted and unsubstituted ring-bridged p-oligophenylenes having at least four and no more than 8 phenyl groups. These improved laser dyes can be excited by pump lasers and are capable of producing stimulated coherent emission in the near ultraviolet range, particularly in the range below 400 nm, and have improved photostability. The p-oligophenylenes used according to the invention have the following characteristics:(a) the number of bridges is a number from 1 to 7 but only one bridge exists between two adjacent phenylene groups;(b) each bridge in the O,O'-cis position engages two adjacent phenylene groups;(c) the bridges represent the same and/or different species from a defined group; and(d) the phenylene rings may either be unsubstituted, except for the bridges, or one or several phenylene rings in the molecule, independent of whether they are bridged or not, may have one or two radicals R.sub.

Abstract: A laser therapy system having improved effectiveness in surgical use, particularly in laser angioplasty, can be formed by employing a pulsed source of radiation. The pulsed energy source is preferably an excimer laser having a coherent beam of ultraviolet radiation and preferably is employed in conjunction with a dye laser to produce an output beam which is tunable over a wide portion of the ultraviolet and visible spectrum. The output beam is coupled via a novel coupling device to an optical fiber disposed within a surgical instrument, for example, a percutaneous catheter. The operative components are sealed in a gas-tight, liquid-tight housing. An electronic controller monitors and adjusts the output energy density, duration, and pulse repetition rate. In operation, a pulsed, high energy beam of extremely short duration is available to remove atherosclerotic plague with less damage to the underlying tissue and less chance of perforating the blood vessel wall.

Abstract: Normal stimulated Raman scattering (SRS) is done in a gas cell with pump and Stokes seed input beams. The pump photons excite gas molecules in the gas cell from their ground state and the Stokes seed photons stimulate the de-excitation of the molecules back to a lower state (emitting more Stokes photons in the process). The SRS enhancer entails inputting another beam at a frequency, different from the pump and seed, tuned between a third molecular state and the Raman virtual state created by the pump/seed off-resonant two-photon transition. The third laser enhances the Raman virtual state, thereby also enhancing the two-photon transition rate. Since the two-photon transition is the SRS process, the Stokes amplification is enhanced.

Abstract: A laser-active aqueous dispersion of a laser dye comprising microparticles containing a laser dye, with the microparticles being suspended in an aqueous liquid. The aqueous liquid has an index of refraction which is substantially equal to that of the microparticles.

Abstract: In a laser oscillator or laser amplifier, a so-called switching dye is used which strongly reduces the degree of amplification for the laser radiation after a short time interval, by means of transient absorption. Molecules or molecule systems in which a proton transfer takes place in the excited state can serve as switching dyes. The radiation pulse exciting the switching dye must have a sufficiently steep leading flank to assure that the excited state of the tautomeric form is rapidly occupied. The immediately following occupation of the ground state of the tautomeric form by emission of radiation and radiationless transitions, and/or of triplet states of the tautomeric and normal form by radiationless transitions, builds up a transient absorption and inhibits the rise of an inversion sufficient for renewed radiation emission.

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 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 CPM pulse laser device is provided which has a means for emitting pulses in two separate directions. A return system is provided for returning one of the pulses to the laser resonator in such a manner that the returned pulse is superposed on the other pulse which was propagated in the other direction. The return system preferably includes a total reflecting mirror or a nonlinear crystal. The position of the total reflecting mirror or nonlinear crystal is precisely adjusted to create the superposition.

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: 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 dye laser is described, comprising a cell containing a laser dye solution and a pumping energy source connected to the cell, wherein the laser dye solution contains a compound represented by formula (I): ##STR1## wherein n represents 0 or 1; m represents 0, 1, 2 or 3; L.sup.1 and L.sup.2 which may be the same or different each represents a methine or substituted methine group; R.sup.1 is a substituted or unsubstituted alkyl group, an alkenyl group or an aralkyl group; R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 which may be the same or different each represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an acyl group, a hydroxy group, a cyano group, or a substituted or unsubstituted amino group; Z represents atoms necessary to form a 5- or 6-membered ring which may have a substituent or may be condensed to another ring, X.crclbar.

Abstract: A dye laser system for emitting laser beams of various wavelengths, which includes a plurality of dye vessels apart from each other and a mirror for oscillating the laser beams and for reflecting the beams to a beam splitter. Two wavelength selectors are provided for directing a specific wavelength portion of the beams to the beam splitter and for directing a specific wavelength portion of the beams to the mirror.

Abstract: Dyestuff laser consisting of a reservoir, with a laser dyestuff solution contained therein, and a pumped light source associated therewith, which is capable of exciting the dyestuff solution to produce an emission, characterized in that the dyestuff solution contains, in a solvent which does not interfere with the emission, a dyestuff which, in the form of the free acid, corresponds to the general formula ##STR1## wherein R.sub.1 to R.sub.4 independently of one another represent hydrogen, alkyl, trifluormethyl, alkoxy, aralkoxy, alkenyloxy, halogen or the carboxyl, cyano, alkylsulphone, aryl-sulphone, carboxamide, sulphonamide or carboxylic acid ester group,R.sub.1 and R.sub.4 can additionally denote a fused-on benzene ring,n represents a number 2 to 6 ando, p, q and r independently of one another represent 0, 1 or 2,in a concentration, preferably of 10.sup.-2 to 10.sup.-5 mol/1, which emits laser radiation.

Abstract: Novel organic compound of the basic formula ##STR1## which have substantial luminescent emission characteristics and advantages.

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

Abstract: The output of a continuous wave modelocked Nd:YAG laser is first pulse compressed and then frequency doubled from infrared to green, to provide a new pumping source for a synchronously pumped dye laser. The disclosed apparatus and methods can achieve tunable subpicosecond pulses at relatively high average power, over 300 milliwatts. The 1064 nanometer output of the pulse compressor is frequency doubled to 532 nanometers so as to provide 3.5 picosecond pump pulses at 82 MHz and average power exceeding one watt. When this is used to pump a Rhodamine 6G dye laser, tunable pulses as short as 190 femtoseconds output can be obtained from the dye laser, with average power over 300 milliwatts. With the addition of a cavity dumper, tunable subpicosecond pulses of 80 kilowatt peak power have been generated.

Abstract: There is herein, disclosed a dye laser including a container for a dye solution and a pumping energy source coupled thereto, said dye solution containing a perimidone dye formula (I): ##STR1## wherein R.sup.1 is a hydrogen atom, an alkyl group, a trifluoromethyl group, an alkoxycarbonyl group, an alkoxycarbonylalkyl group, an aralkyl group or a phenyl group; R.sup.2 is an optionally substituted alkoxycarbonyl group, a cyclohexyloxycarbonyl group, tetrahydrofurfuryloxycarbonyl group, an aryloxycarbonyl group, a benzyloxycarbonyl group, an acyl group, a cyano group or an optionally substituted carbamoyl group; R.sup.3 and R.sup.4 which may be the same or different are each a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aralkyl group or an aryl group.

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: 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: Fluorescent dyestuffs of the general formula ##STR1## wherein R and R.sup.1 independently of one another represent hydrogen, a salt-forming cation, an alkyl radical with 1 to 16 C atoms or an aryl or aralkyl radical which is optionally substituted by non-chromophoric groups,R.sup.2 to R.sup.5 independently of one another represent hydrogen, alkyl, trifluoromethyl, alkoxy, aralkoxy, alkenoxy, aryloxy, halogen or a carboxyl, cyano, alkyl sulphone, aryl sulphone, aralkyl sulphone, carboxamide, sulphonamide or carboxylic acid ester group,o, p, q and s independently of one another represent 1 or 2 andm and n independently of one another denote 0, 1 or 2, it being possible for the sum of m and n to be 2 to 4,processes for their preparation and their use as laser dyestuffs.

Abstract: A source of linearly polarized light having a wavelength range of about 550 to 1100 nanometers provides light into one end of an optical fiber. A nonlinear crystal of the type that mixes the frequency of light passing therethrough is positioned adjacent the other end of the fiber. The fiber transmits light from the source to the crystal which increases its frequency up to 100%, dependent upon crystal selection providing light in the 250-550 nanometer wavelength range. Adjusting the radial orientation of the crystal with respect to the fiber optimizes conversion of light to the 250-550 nanometer range. Such light is shined into organic dye which emits fluorescent light in the range of about 400 to 1000 nanometers dependent upon the type of dye selected.

Abstract: Subpicosecond pulses less than 70 femtoseconds in duration are obtained with a synchronously pumped dye laser using a mixture of laser dye and a fast recovery saturable absorber which passes in a jet between folding mirrors in a laser cavity. The ratio of absorber to dye in the mixture is selected to compensate for dispersion effects in the laser medium which tend to limit the spectrum of the laser pulses and increase their duration.

Abstract: 2-(4-pyridyl)-5-aryloxazoles and certain quaternary salts of these compounds are useful as visible-wavelength lasing dyes. These dyes are used in solution with non-interferring polar solvents, such as low molecular weight alcohols, H.sub.2 O, and D.sub.2 O, to form lasing media useful in dye lasers. Such lasers generally include a reservoir for containing the laser dye solution and a pumping energy source operably coupled therewith for producing stimulated emission of the dye solution.

Abstract: Ultra-short individual laser pulses, having a half-amplitude duration of 100 picoseconds or less and a recurrence frequency of one Hz to one mHz are generated in a self Q-switching distributed feedback dye laser that employs a high density diffraction grating as a beam divider, dividing a primary beam from a pulsed pump laser into two excitation beams of +1 and -1 order; the excitation beams are directed, by two reversing mirrors, to impinge upon a focal line in a dye solution serving as an active laser medium. The pulses of the primary beam have a half-amplitude duration many times greater than 100 psec but no greater than 20 nsec, and the beam intensity is such that the stimulation of the dye does not exceed its laser threshold by more than 20%.

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 laser construction is described having a single resonator structure for both a dye laser optical cavity and one or more pump laser optical cavities. In the described embodiments, such resonator structure is formed principally from a plurality of parallel rods.

Abstract: A longitudinally pumped dye laser arrangement is disclosed. The arrangement comprises a unitary optical means, means for containing a lasing medium dye solution and means for reflecting lasing radiation towards the unitary optical means. The dye solution is located between the unitary optical means and the reflecting means. The reflecting means is proximate the dye solution. The unitary optical means is positioned relative to the containing means to focus a pumping beam into the dye solution and to collimate lasing radiation emerging from the containing means into an essentially parallel beam. This arrangement provides an economical and easily aligned longitudinally pumped dye laser.

Abstract: A dye laser is described that has an optical resonator structure which is modular in construction. The resonator includes a first base plate that has all of the optical elements typically found in a basic linear dye laser. A second base plate is rigidly securable to the first base plate to extend the resonator structure for either ring operation or for more differing linear dye laser configurations. The second base plate can include those optical elements required to cooperate with the optical elements on the first base plate to provide ring operation. Additional and differing modular units can be provided and secured to the two base plates making up the optical resonator structure to satisfy many different criteria. Moreover, a third base plate is rigidly securable between the first two base plates to further extend the resonator structure as desired.

Abstract: Oxazole dyes and certain quaternary salts of these compounds having a formula as follows: ##STR1## are useful as visible-wavelength lasing dyes. These dyes are useful in solution with non-interferring polar solvents, such as low molecular weight alcohols, H.sub.2 O and mixtures thereof, to form lasing media useful in dye lasers.

Abstract: A polydisperse aggregate of very small solid particles that form voids therebetween with a lasing dye solution in said voids to form a laser host medium is disclosed.

Abstract: A binary solvent for liquid dye laser systems comprising a surfactant having a hydrophobic end and a hydrophilic end in a viscous polar solvent provides a method of improving the output, efficiency and lifetime of laser dyes, particularly in non-flowing liquid dye laser systems.