Abstract: A long pulse alexandrite laser hair removal system is disclosed using light pulses of greater than 1 msec and fluences between 10 and 50 J/cm.sup.2. The use of an alexandrite laser allows good penetration while still achieving an acceptable combination of hemoglobin and melanin absorption. The use an index-matching application on the skin sections to be treated is also described. This substance will be absorbed into the epidermal layer to provide better coupling of the laser light into the skin. Also, and most advantageously, it will reduce reflections at the epidermal-dermal junction, which can lead to the damage of the skin. Also a topical thermal or photochromic indicator is suggested since skin irradiation in the near-infrared generally does not produce any characteristic skin color change as is found when using pulsed dye lasers, for example.

Abstract: A long pulse alexandrite laser hair removal system is disclosed using light pulses of greater than 1 msec and fluences between 10 and 50 J/cm.sup.2. The use of an alexandrite laser allows good penetration while still achieving an acceptable combination of hemoglobin and melanin absorption. The use an index-matching application on the skin sections to be treated is also described. This substance will be absorbed into the epidermal layer to provide better coupling of the laser light into the skin. Also, and most advantageously, it will reduce reflections at the epidermal-dermal junction, which can lead to the damage of the skin. Also a topical thermal or photochromic indicator is suggested since skin irradiation in the near-infrared generally does not produce any characteristic skin color change as is found when using pulsed dye lasers, for example.

Abstract: A combined sclerotherapy and light treatment method is described for the treatment of unwanted veins such as varicose and telangiectatic leg veins. Substantially increased success, in the range of 90-100%, has been achieved by implementing a dwell time of between 12 hours and 6 months between the light-based therapy and the sclerotherapy. Near infra-red wavelength light is preferably used in the light therapy due to its better depths of penetration through the skin to deeper lying, larger vessels such as varicose veins.

Abstract: Near-infrared selective photothermolysis for the treatment of ectatic blood vessels, for example, blood vessels of a portwine stain birthmark. This technique is especially applicable to deeper lying blood vessels in view of the better penetration of the near infrared light. Consequently, vessels are below a dermal/epidermal boundary can be reached. Near-infrared is defined as a range of approximately 700 to 1,200 nm. The optimal colors are near 760 or between 980 to 990 nm for most populations.

Abstract: A long pulsed dye laser device for selective photothermolysis comprises at least two pulsed dye lasers, such as flash lamp excited dye lasers, each generating corresponding pulsed laser beams successively in time. These lasers can be coordinated by a synchronizer that sequentially triggers the lasers. A combining network merges the pulse laser beams into a combined beam and a delivery system conveys the combined pulse laser beam to a patient. An example of a delivery device is a single optical fiber. This invention enables production of the necessary pulse widths, on the order of 2 msec, which can not be achieved by individual dye lasers, generally lower than 0.8 msec. Also disclosed is a selective photothermolysis method. This method comprises irradiating a tissue section of a patient with a pulsed laser beam having a changing color across a time period of the pulse.

Abstract: The present invention involves a system for transmyocardial revascularization of a beating heart, including a laser device for ablating wall tissue of the heart being treated, with a pacemaker connected to the heart being treated, to provide electrical signals to control the cardiac cycle of that heart, and a conditioning circuit connected to both the pacemaker and to the laser, to permit the controlled "safe period" firing of the laser. The laser includes an optic waveguide articulably arranged to irradiate the wall of the heart. The conditioning circuit is programmed to permit the firing of the laser upon the time of the cardiac cycle of the heart during a non-ventricular repolarization time period.

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 flashlamp-excited dye laser generating light pulses for therapy has a circulator which circulates a gain media through a dye cell. A controller coordinates operation by triggering flashlamps to excite the laser gain media while the circulator is circulating the gain media. This operation enables the generation of laser light pulses with a duration of at least one millisecond. If the flow velocity of dye solution is great enough such that the new solution enters the resonant cavity before the solutions in the cavity are substantially spent, ultra-long pulses with high fluences are possible. Specifically, longer pulses of up to 50 msec can be achieved with energies of up to 50 Joules. These energies enable reasonable spot sizes, which makes the invention relevant to dermal therapy, for example.

Abstract: An endoscopic light delivery system for delivering light to tissue includes a laser source for generating light. Fiber optics are optically coupled to the laser source for conveying the light generated by the laser source. A focusing surface is formed at an end of the fiber optics. The focusing surface of the fiber optics is shaped for redirecting light conveyed by the fiber optics in a direction lateral to the fiber optics for cutting tissue. A single optical fiber or a bundle of optical fiber can be used to transmit plural wavelengths of light for aiming cutting and coagulating.

Abstract: The individual outputs of a large laser diode array are combined using an optical transformer of diffractive optics. To allow for the tolerances in the laser array and combining optics required for mass production, the system further includes corrector optics. The corrector optics includes individual lens elements which are fabricated to provide specific correction of faults in the individual lasers and associated combining optics resulting from manufacturing tolerances. The preferred corrector lenses include diffractive lenses fabricated by laser milling.

Abstract: Calculi, stones, or calcified tissue are broken down for removal from within a body using laser pulses that are delivered via an optical fiber and have a wavelength and pulse duration selected to break down the object into smaller particles without delivering energy sufficient to cause damage to other tissue.

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: Method and apparatus for exciting particles in an environment in which a selected isotope, of broadened spectral absorption bandwidth, is exposed to laser radiation having a frequency bandwidth substantially narrower than the spectral width. The laser radiation is frequency swept entirely across the broadened spectral width of the absorption band of the selected isotope type particles to provide spectral matching with substantially all of these particles. A laser system is provided having the capability of sweeping a narrow spectral emission entirely across a broadened spectral absorption band.

Abstract: A dye solution reservoir system for a dye laser comprises a dye solution reservoir, main fluid circuit means for circulating dye solution between the reservoir and a dye laser, and a by-pass dye replenishment loop between the reservoir and the laser for (1) diverting a portion of the solution from the main circuit, (2) filtering substantially all solute, including the dye and other particles from that portion of the solution, (3) replenishing the solution by adding fresh dye solute, and (4) returning the replenished solution to the main circuit. In a preferred embodiment, the solution is filtered by a first filter for removing the dye solute and a second filter for removing degradation by-products and particulate matter. Reverse osmosis may be advantageously used as a part of this filtrate system. The advantage of such systems is a substantial reduction in the required reservoir capacity and enhanced dye recoverability.

Abstract: Method and apparatus for achieving isotopically selective adiabatic inversion, particularly for improved isotope separation efficiency. In a preferred embodiment for practicing the invention, chirped laser radiation induces photoionization of a vapor state material in isotopically selective excitation and ionization energy steps. A frequency sweep or "chirp" is provided in the excitation laser radiation at a controlled rate and over a range of frequencies which is limited to prevent loss of selectivity in the excitation. The frequency swept radiation has a theoretical capability of producing 100% inversion of ground state particles in the vapor. The features of the invention additionally permit excitation of a material to very high energy states useful in producing high frequency, ultraviolet lasing.

Abstract: Method and apparatus for achieving isotopically selective adiabatic inversion, particularly for improved isotope separation efficiency. In a preferred embodiment for practicing the invention, chirped laser radiation induces photoionization of a vapor state material in isotopically selective excitation and ionization energy steps. A frequency sweep or "chirp" is provided in the excitation laser radiation at a controlled rate and over a range of frequencies which is limited to prevent loss of selectivity in the excitation. The frequency swept radiation has a theoretical capability of producing 100% inversion of ground state particles in the vapor. The features of the invention additionally permit excitation of a material to very high energy states useful in producing high frequency, ultraviolet lasing.