Abstract: A compact high resolution grating spectrometer. A beam of expanding light from a light source is collimated and the collimated beam is expanded with a beam expander before illuminating a reflecting grating. The expansion of the beam permits high resolution in a small package. In preferred embodiments mirror arrangements are provided to produce double reflections off the reflecting grating to further improve the resolution of the spectrometer.

Abstract: A laser treatment device and process with controlled cooling. The device contains a rod with high heat conduction properties, which is transparent to the laser beam. A surface of the rod is held in contact with the tissue being treated and other surfaces of the rod are cooled by the evaporation of a cryogenic fluid. The cooling is coordinated with the application of the laser beam so as to control the temperatures of all affected layers of tissues. In a preferred embodiment useful for removal of wrinkles and spider veins, the rod is a sapphire rod. A cryogenic spray cools the walls. A first surface is in contact with the skin surface being treated and an opposite surface is contained in an anticondensation oil chamber that is optically connected to a laser beam delivering fiber optic cable.

Abstract: The present invention provides a process for substantially extending the useful life of fused silica elements used in high energy ultraviolet optical systems. The fused silica bulk material is pre-compacted by illuminating it with radiation prior to final mechanical fabrication and polishing to the required final surface figure. When the optical element is subsequently used in a high energy ultraviolet environment, it will continue to be compacted but at a lower effective rate. As a result, the useful life of fused silica optical elements can be increased substantially.In preferred embodiments the fused silica material is precompacted with multiple passes of short-pulse ultraviolet radiation. Multiple passes can reduce precompaction time. In one example useful life of the fused silica is increased from about 150 days to 3.8 years by about 5 days of precompaction.

Abstract: A stovepipe thermoelectric generator. The unit fits in a stovepipe of a coal or wood stove. At least one thermoelectric module is sandwiched between a hot side fin unit with fins extending into the flow of exhaust gases and a cold side fin unit with fins cooled by forced room air. A damper controls exhaust gas flow through a heat chamber, directing the exhaust gas through a generating side and a bypass side depending on a temperature indication. This prevents heat damage to the thermoelectric module. At least one fan is provided to force room air through cooling fins of the cold side fin unit An electric circuit is described for providing power for the fan and providing additional electric power for purposes such as charging a battery.

Abstract: A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. A working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at voltages high enough to create electrical discharge between the electrodes to produce very high temperature, high density plasma pinch in the working gas providing radiation at the spectral line of the active gas. An external reflection radiation collector-director collects radiation produced in the plasma pinches and directs the radiation in a desired direction. In a preferred embodiment the active gas is lithium and the buffer gas is helium and the radiation-collector is coated with the material used for the electrodes. A good choice for the material is tungsten.

Abstract: A piezoelectric positioner. First and second piezoelectric stacks are mounted on a rigid frame. A T-lever defining a yoke and a lever arm is disposed so that the yoke overlies the piezoelectric stacks. A compression element is position so as to hold in compression both stacks in-between the frame and the yoke. A programmable voltage source is programmed to provide elongating voltages alternatingly to the first and the second stacks to cause the stacks to alternatingly expand against compressive forces produced by the compression element so as to cause the yoke to rock back and forth and to cause the T-lever arm to swing back and forth. A tool beam is flexibly connected to the T-lever arm. A tool beam restraint restrains movement of the tool beam to back and forth motion in a single direction. In a preferred embodiment a tool is mounted on the tool beam.

Abstract: A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.

Abstract: A tangential fan and cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential position of blade members can shift monotonically or reversibly between ends. Blade members are stiffened by optimally selecting the number and placement of hub members to control the natural vibration frequency of the fan. Methods of forming tangential fans include casting, and machining from a solid block. Monolithic structures can be joined, typically by electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Tangential fans produced have mechanical rigidity, accurate tolerances, and low contaminant concentrations. Blade members can be formed into air foil shapes.

Abstract: An excimer laser system with a fluorine control having a fixed volume inject bottle in which fluorine is injected prior to it being injected into the laser chamber. A manifold and feedback control system is provided to permit precise injection at rates approaching continuous fluorine injection. The system permits the laser to be operated in a small sweet spot as measured by a narrow range of charging voltage.

Abstract: A line narrowed laser having a grating based line narrowing module, etalon-based line narrowing output coupler and a technique for tuning the laser. The etalon based output coupler is adjusted to preferentially reflect light at or near the spectral maximum produced by the grating. Substantial improvement in line narrowing results from the amplification in the laser resonance chamber of light at or near the grating spectral maximum which is preferentially reflected by the etalon based output coupler. Several preferred methods are disclosed for tuning the etalon based output coupler to match the wavelength selected by the grating based line narrowing module.

Abstract: A high pulse rate pulse power source for supplying controlled high energy electrical pulses at rates of 2000 Hz or greater. The source includes a pulse generating circuit including a charging capacitor, a solid state switch and a current limiting inductor. Pulses generated in the pulse generating circuit are compressed in at least two pulse compression circuits and a step-up pulse transformer increases peak voltage to at least 12,000 volts. A very fast regulated resonant power supply is provided for charging the charging capacitor in less than 400 microseconds and a pulse control system including a programmed processor controls the charging of the charging capacitor to an accuracy of less than about one percent at a rate of at least 2000 charges per second.

Abstract: An electric discharge gas laser having a laser cavity in which is contained a laser gas and a fan for circulating the laser gas. The fan is supported in position radially by a roller bearing system and axially at least in part by magnetic forces. In a preferred embodiment the magnetic forces are supplied by a brushless DC motor in which the rotor of the motor is sealed within the gas environment of the laser cavity and the motor stator is located outside the gas environment. The magnetic center of the rotor is offset from the center of the stator to produce a magnetic reluctance generated force on the shaft that acts axially on the shaft toward the non-drive end and is reacted by a ball and plate bearing assembly mounted along the axis of rotation at the opposite end of the shaft.

Abstract: An improvement to a sliding door system for a shower-bathtub installed adjacent to three walls of a bathroom. The sliding door system includes an upper track that has the following elements: (1) at least two wheel supports, (2) at least two wheel stays positioned above the two wheel supports, and (3) at least two lower bearing supports positioned at least five inches below the two wheel supports. The upper track is rigidly attached to the two short walls of the shower-bathtub and provides enough support so that the presence of a lower track is unnecessary. In a preferred embodiment, the outside wall of the bathtub and the two short shower walls comprise molded dams.

Abstract: A self-powered combustion furnace unit. A combustion furnace providing circulating hot fluid heating is equipped with a thermoelectric generator comprised of a plurality of thermoelectric modules mounted on the furnace. The heat from the combustion provides a high temperature hot side heat source for the thermoelectric modules and the fluid of the circulating hot fuid system provides the cold side heat sink for the thermoelectric modules. Electric power produced by the thermoelectric modules powers a motor driving a pump which circulates the circulating hot fluid. In a preferred embodiment low cost, high temperature thermoelectric modules are provided which comprise thermoelectric elements installed in injection molded eggcrates. The thermoelectric modules are held in close contact with the hot side heat exchanger and the cold side heat sink with a spring force such as that provided by Belville springs.

Abstract: The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod.

Abstract: The present invention provides a very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. Very small quantities of a stablizing additive consisting of oxygen or a heavy noble gas (xenon or radon for KrF lasers, or krypton, xenon or radon for ArF lasers), are added to the gas mixture. Tests performed show substantial improvements in energy stability with the addition of about 30 ppm of xenon to a KrF laser. Tests show improved performance for the ArF lasers with the addition of about 6-10 ppm of Xe or 40 ppm of Kr. In a preferred embodiment very narrow bandwidth is achieved on a KrF laser by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line-narrowing module were replaced with calcium fluoride prisms.

Abstract: A process for controlling pulse energy and integrated energy dose in bursts of pulses produced by an excimer laser. The energy of each pulse in each burst is measured. The rate of change of pulse energy with charging voltage is determined. A pulse energy error is determined for a previous pulse of the present burst. An integrated dose error is also determined for all previous pulses in the current burst. A charging voltage for the next pulse is determined using the pulse energy error, the integrated dose error, the rate of change of energy with charging voltage and a reference voltage. In a preferred embodiment, the rate of change of energy with voltage is determined by dithering the voltage during two pulses of each burst, once lower and once higher. The reference voltage is a voltage calculated using prior energy and voltage data. In this embodiment, the method of determining the reference voltage during a first portion of the pulse is different from the method used during a latter portion of the burst.

Abstract: An overhead support system. An array of spoked rimless wheels are located over a space and supports at least one overhead cart from which a load is supported with a tension element. The load can be moved horizontally in the space by applying a horizontal force to the load causing the cart to move over the array of spoked rimless wheels carrying the load in the horizontal direction. The spoked rimless wheels rotate permitting the tension element to pass horizontally through the array of spoked rimless wheels. In preferred embodiments the spoked rimless wheel has the general shape of a star or a daisy and is referred to as a star wheel or a daisy wheel and the cart has a circular bottom surface. In preferred embodiments casters are mounted on top of the star wheels or daisy wheels to permit easy horizontal movement of the cart over the wheels. In other preferred embodiments the daisy wheels are flat on top and casters are mounted on the circular bottom of the cart.

Abstract: A reliable, modular, production quality narrow-band KrF excimer laser capable of producing 10 mJ laser pulses at 1000 Hz with a bandwidth of about 0.6 pm or less. The present invention is especially suited to long-term round-the-clock operation in the lithographic production of integrated circuits. Improvements over prior art lasers include a single upstream preionizer tube and acoustic baffles. A preferred embodiment includes reduced fluorine concentration, an anode support bar shaped to reduce aerodynamic reaction forces on blower bearings, a modified pulse power system providing faster pulse rise time, an output coupler with substantially increased reflectivity, a line narrowing module with CaF prism beam expanders, a more accurate wavemeter, a laser computer controller programmed with new and improved pulse energy control algorithm.

Abstract: A testing device to test and troubleshoot APUs that is designed to be small, rugged, light weight, and easily adaptable to many different APU applications. Using a special multi-wire cable system, test and monitor circuits are imposed between the APU control panel and the ECU and also between the ECU and the LRUs. LRU electrical circuits are subjected to short electrical pulses and the resulting current flow is monitored. Defective LRUs are detected by a very low or zero current measurement indicating an open circuit or by an excess current flow indicating a short circuit. The testing device does not include standard monitoring equipment such as voltmeters and oscilloscopes which would require calibration. Instead, the APU Tester's signal selector equipment routes a selected APU signal to the APU Tester's front panel test jacks for easy monitoring of circuit resistance and signal characteristics using standard external monitoring equipment which can be separately calibrated.