Abstract: There is disclosed herein several gas resupply valves for replenishment of lost gas in gas lasers in general and argon ion lasers in particular. The first embodiment uses a valve which controls flow of gas into a metering volume. The metering volume has an aperture therein which is microscopically small and which has a diffusion constant for gas moving through the aperture which is less than the time the valve is held open. The second embodiment uses the same general structure, but separates the soft sealing member of the valve from the solenoid core which moves to open and close the valve. The soft sealing member is attached to the valve body and supported above a valve seat surrounding the opening of the metering volume. The third embodiment uses a thin diaphragm which overlies a flat surface of the valve body in which are formed an input port and an output port. A solenoid applies pressure against the diaphragm to cause it to flatten against the flat surface thereby sealing the valve.

Abstract: An optical bar code reader using a light source which can be switched on quickly and includes provision for activating the light source and related devices only when data is actually being gathered, rather than wasting a large amount of beam on time and energy as in prior software based scanners.

Abstract: An apparatus and method project light in two orthogonal planes to provide reference planes of light for use in laying out a construction site or the like. The apparatus comprises a laser light source for providing a source beam of light, and a light diverting arrangement. The light diverting arrangement diverts a first portion of the source beam of light to project a first thin reference fan beam of light substantially in a first reference plane, and diverts a second portion of the source beam of light to project a second thin reference fan beam of light substantially in a second reference plane. The second reference plane is substantially perpendicular to the first reference plane. The apparatus may advantageously be used in laying out a grid.

Abstract: A high efficiency pumping scheme mode matches the TEMOO laser mode volume with a plurality of linearly spaced laser diode pumping sources positioned along a lateral side of a block of laser material. The cavity resonator within the block is configured in a tightly folded zig-zag configuration. Pump radiation from the diode pumping sources is collimated by an optical fiber and the fold angle is selected to mode match the pump radiation to the mode volume.A laser oscillator is followed by one or more cascaded amplifier stages including a block of laser material arranged in a tightly folded zig-zag configuration. Pump radiation from the diode pumping sources is collimated by an optical fiber and the fold angle is selected to mode match the pump radiation to the mode volume.

Abstract: A method and apparatus are disclosed for controlling an off-line dc power supply circuit including a printed circuit board. The power supply circuit comprises a source of unregulated dc input power and a power transformer which separates the circuit into a primary side and a secondary side. An error amplifier compares an output dc voltage generated at a secondary winding of the power transformer to a reference voltage to generate an error signal representative of the difference error therebetween. The error signal is coupled from the secondary side of the power supply circuit to the primary side of the power supply circuit by means of a capacitor formed from traces on opposite sides of the printed circuit board. A solid state switch selectively connects the unregulated dc input power to a primary winding of the power transformer to regulate the power supply circuit in the primary side of the circuit in response to the error signal which is generated in the secondary side of the circuit.

Abstract: A fiber laser for producing subpicosecond pulses is formed by placing a laser fiber in a resonant cavity, in either a linear or closed loop configuration. The laser fiber is formed of two different types of fibers joined in series, a gain fiber which contains the laser gain medium followed by a pulse shaping fiber which uses the phenomenon of solution pulse shaping to shorten the pulses. An initially formed pulse recirculates many times in the resonator; on each pass the pulse is both amplified and shortened until steady state is reached. The zero dispersion wavelength of the pulse shaping fiber is chosen to be slightly less than the laser wavelength. The fiber is pumped by a continuous source, particularly CW laser diodes. The initial pulse can be formed by a self starting technique produced by selecting the proper length of the laser fiber, or else a mode locker/acousto-optic shutter can be placed in the cavity.

Abstract: A method and apparatus for comparing substances against other substances or against themselves over time. The method involves taking a chromatogram from each substance and converting each chromatogram to a histogram. The histograms have one bar for each peak on the chromatogram. These histograms are then cross-correlated and the 0th, 1st, 2nd and 3rd moments of the cross-correlation function are calculated. A similarity number in terms of the number of peaks of difference between the two samples compared is then generated by dividing the 3rd moment by the 2nd moment, and the results are displayed. The apparatus of the invention provides the means to gather the data needed for the chromatograms, calculate the histograms, cross-correlation functions and moments and the similarity number and display the result.

Abstract: An optical assembly isolator and laser system incorporating the same. The isolator attaches to an end of the laser system along the optical axis of the laser system. The isolator includes a flow loop wall, an optical assembly wall, an outer wall connecting the foregoing two walls, and at least one baffle wall included in the volume defined by the outer wall. The flow loop wall and the baffle wall include open first and second apertures, and the optical assembly wall supports an optical assembly. When the isolator is in place on the laser system, the first and second apertures and the optical assembly all align with the optical axis of the laser system. The edges of the first aperture and the flow loop wall can be slanted and oriented with respect to the primary flow through the laser system to induce a small circulation and redirect any entering shock waves and entrained contaminated gas toward the outer wall.

Abstract: There is disclosed herein a pump check valve test system embodied in a pump control system which control pump speed based upon actual pressure and upon actual pump speed and desired flow rate. The check valve test system disables the portion of the control system which controls pump speed based upon desired flow rate during the test. The test is comprised of timing the time it takes the pump to rotate through the portion of each cycle wherein the check valve is supposed to close and comparing this time to a known value.

Abstract: A laser beam alignment system includes a transmitter which establishes a laser reference plane by continuously rotating a horizontal laser beam about the transmitter. A remotely located receiver senses the elevation of the laser reference plane and reflects a portion of the laser energy back to the transmitter where the reflected energy is employed to produce a signal indicative of the range of the receiver and its location with respect to a reference axis. The position of the receiver is thus established in three dimensions.

Abstract: A fiber laser having a single mode fiber core of laser material is pumped by a high power coherent laser diode source by providing a multi-mode fiber around the single mode core to define a pump cavity which propagates pump radiation while allowing the pump radiation to couple to the single mode core. Laser diode arrays and extended emitter laser diodes can be used to pump a single mode fiber by inputting the pump radiation into the multi-mode fiber surrounding the single mode fiber core. The milti-mode fiber has a much greater diameter than the single mode core.

Abstract: A nonstandard spherical resonator which produces laser radiation having spherical modes of oscillation is formed entirely within a sphere of laser gain material. The resonator is pumped to produce the spherical modes. By pumping an isotropically coated sphere at normal incidence the entire sphere forms the resonator, and the laser radiates uniformly in all directions as from a point source. By pumping obliquely to totally internally reflect the laser radiation at the surface of the sphere, or by applying an equatorial coating on the sphere to internally reflect the laser radiation, toroidal region within the sphere forms the resonator. The pumping volume can be controlled so that the laser radiation is single longitudinal mode and single frequency by limiting the active mode volume. Prisms can be used for input and output coupling to the toroidal resonator; and optical fiber can also be used for output coupling. A compact laser design uses a Nd:YAG sphere pumped by a laser diode.

Abstract: A sample metering valve for both liquid samples and slurry samples with entrained gas bubbles. The sample metering valve for liquids is comprised of a piston with sample chambers formed in the side thereof said piston moving freely into and out of a cylinder having an aperture matching the size of the piston. Sealing is provided by a seal which has no dead volume which cold flows under a spring bias to maintain the seal under various operating conditions. The sample metering valve for slurry samples includes a syringe embodiment having separately moving piston and valve in a cylinder. The syringe valve sucks up sample with a piston, isolates the sample with the valve and compresses the entrained gas bubbles with the piston. Another embodiment uses three, three way valves which are coupled to a pump and a means to compress the sample.

Abstract: A bore tube free end support structure is positioned between an outer cylindrical envelope and an inner capillary bore tube of a laser. The support structure has outer and inner pluralities of circumferentially-spaced spring fingers integrally connected to and extending from respective outer and inner peripheries of a solid annular disc-like middle portion thereof. The outer spring fingers are alternately bent in opposite directions. The outer end of each outer spring finger defines a pair of pointed corners adapted to dig into the inside surface of the glass outer envelope of the laser, so as to anchor the support structure firmly in position with respect thereto. The inner spring fingers all extend in the same direction and each is arcuate-shaped in a longitudinal section therethrough.

Abstract: There is disclosed a diode snubber for the voltage transients generated in the parasitic inductance of a switched resistor when current therethrough is interrupted. Also disclosed is the use of such a diode snubber in: a series switched resistor regulator; a shunt switched resistor regulator; a hybrid switched resistor regulator and a passbank switched resistor regulator. Also disclosed is the use of a linear dissipative regulator in all these forms of switched resistor regulators to maximize the effiency of power delivery to the load.

Abstract: There is disclosed herein several gas resupply valves for replenishment of lost gas in gas lasers in general and argon ion lasers in particular. The first embodiment uses a valve which controls flow of gas into a metering volume. The metering volume has an aperture therein which is microscopically small and which has a diffusion constant for gas moving through the aperture which is less than the time the valve is held open. The second embodiment uses the same general structure, but separates the soft sealing member of the valve from the solenoid core which moves to open and close the valve. The soft sealing member is attached to the valve body and supported above a valve seat surrounding the opening of the metering volume. The third embodiment uses a thin diaphragm which overlies a flat surface of the valve body in which are formed an input port and an output port. A solenoid applies pressure against the diaphragm to cause it to flatten against the flat surface thereby sealing the valve.

Abstract: There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the input and output capacitors. The flyback voltage transients may be used to step up or step down the input voltage by varying the pulse width of the pulses in the swicthing pulse trains. In embodiments where the switching transistors are placed in the middle of the primary windings, better suppression of radio frequency emissions and current in safety ground wires is achieved.

Abstract: There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the input and output capacitors. The flyback voltage transients may be used to step up or step down the input voltage by varying the pulse width of the pulse in the switching pulse trains. In embodiments where the switching transistors are placed in the middle of the primary windings, better suppression of radio frequency emissions and current in safety ground wires is achieved.

Abstract: There is disclosed a diode snubber for the voltage transients generated in the parasitic inductance of a switched resistor when current therethrough is interrupted. Also disclosed is the use of such a diode snubber in: a series switched resistor regulator; a shunt switched resistor regulator; a hybrid switched resistor regulator and a passbank switched resistor regulator. Also disclosed is the use of a linear dissipative regulator in all these forms of switched resistor regulators to maximize the efficiency of power delivery to the load.

Abstract: A method and an apparatus for preionizing a lasing gas mixture in a gas discharge laser. A short pulse of ionizing particles, such as electrons produced by an electron beam are beamed from the electron source, through a window and into the laser container to preionize a gas mixture containing CO.sub.2, N.sub.2, and He. Immediately after the gas mixture has been preionized, the discharge voltage is raised from a sustaining level to a discharge-maintaining level. The gas mixture can be maintained in its excited state for an extended time, and a longer pulse of laser light results. The electron beam and the discharge voltage can be coordinated by a control system connected to the high voltage sources used to produce the electron beam and the gas discharge.