Abstract: A fast axial flow laser includes a vessel which houses heat exchangers and a pump which imparts the pumping action throughout the laser. Only one housing is necessary and this housing can also be used as an optical bench for the resonator. In one embodiment a positive displacement rotary pump is utilized and a retoreflector included to mount three fold mirrors. In the folded configuration the retroreflector provides angular stability in any two orthogonal planes parallel to the laser beam.

Abstract: An ion laser includes a plurality of thin refractory metal disk members with the perimeter of the disks embedded directly into a ceramic plasma tube. A central aperture is formed in the middle of each disk, and a plurality of apertures are formed around the periphery of the disk. In the fabrication process, ceramic powder is compacted to form an outer plasma tube. Two separate tubes, each with electrodes and embedded washer ends, can be formed and fused to form a single tube. The disks (with the surrounding compacted ceramic disposed around the periphery of the disk) are stacked within the plasma tube and the green ensemble of ceramic and metal is fired in only one furnace step with controlled atmospheres. Hermetic cathode and anode electrodes are also formed in the same firing through the plasma tube. Ends are sealed with a mirror-mount of the Brewster window structure, in one embodiment either laser welded or soldered to a refractory metal end disk embedded in the green ceramic at the ends of the tube.

Abstract: A control system particularly for a modulated laser diode such as for use in laser printers, laser communication systems, optical data storage and other uses employs bipolar integrated circuitry on a single chip with very few external components. The circuit is simple and of low cost and dependable construction and compensates for relatively slow changes in the output characteristics of the laser diode as caused by aging, temperature changes or other varying conditions. The drift compensation is accomplished through current differencing and combining a current difference signal with a modulation input signal to drive the laser diode.

Abstract: A tool for use in establishing a precise level line or plumb line or line for alignment uses a visible laser diode for projecting the line. The tool is relatively small and compact, drives the laser diode using batteries contained in the tool, and includes tilt compensation for use on surfaces which are not level, up to about 5.degree. off level, for still delivering a truly plumb or truly horizontal beam. A manual selector device is provided for shifting the beam from a vertical orientation to a horizontal orientation when desired. Specific forms of tilt compensation apparatus are disclosed.

Abstract: A miniaturized Q-switch is added to the resonant cavity of a compact laser diode pumped solid state laser to produce short high peak power pulses which are input into a single mode optical fiber to form a compact continuum generator. Q-switching the compact laser diode pumped solid state lasers takes advantage of the relatively high gain and short cavity length to provide a desirable combination of pulsewidth and pulse energy. Nd:YAG or Nd:YLF are useful solid state laser materials for Q-switching, or other longer lifetime rare earth ions such as erbium or holmium for greater energy storage. The Q-switch is formed of a material such as TeO.sub.2, SF.sub.10, or LiNbO.sub.3 with an acoustooptic figure of merit substantially greater tha fused silica. The high peak powers of the lasers are sufficient to exceed the threshold for Raman conversion in the fiber which produces a series of red shifted bands ending in a continuum by stimulated Raman scattering.

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: A honeycomb structure is coated with a catalyst to promote reassociation of CO and O.sub.2 gases to form CO.sub.2. The structure is positioned near the outlet of an optical resonator of a flowing gas CO.sub.2 laser. It is preferably positioned within a gas feedback flow system. Utilization of a honeycomb structure minimizes interference of the gas flow within the laser assembly and reduces the introduction of contaminants.

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 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 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 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: An optical component of a laser, of the type including a hot gas plasma region, a cold gas region, and producing large photon fluxes, includes an optical element and a coating means on a surface of the optical element exposed to the photon fluxes. The coating means is comprised of a material adapted to minimize photoreduction of the optical element induced by exposure to the photon fluxes. Optical elements of the present invention include windows, birefringent plates, intracavity lenses, polarizers and mirrors. The coating means includes a material selected from the group comprising Al.sub.2 O.sub.3, BeO, Y.sub.2 O.sub.3, MgO, B.sub.2 O.sub.3, Sc.sub.2 O.sub.3, LiF, NdF.sub.3, ThF.sub.4, Na.sub.3 AlF.sub.6, and mixtures thereof.

Abstract: A compact counter-type bar code scanner produces a "five-apparent-source" scan geometry within an optimum scan volume above the deck of the bar code reader, with a total scanner housing height of less than 13 centimeters, and preferably about 11.5 centimeters. The optics are maximized to achieve approximately the same bar code reading efficiency and reliability as in previous much deeper bar code scanners producing similar scan geometry by reflecting the scanned beam off three surfaces, the last of which is horizontal.

Abstract: A system for control of a bar code scanner threshold with deliberate decay includes monitoring a selected scan signal characteristic of characteristics and electronically determining whether sets of signal characteristics represent a bar code or extraneous noise, and, if noise is indicated, raising the black/white threshold until noise is no longer detected. The monitored characteristics can include frequency of perceived black/white transition. In a preferred embodiment, the raw scan signal is processed through two circuits, a first circuit wherein a threshold is generated based on the signal and a selected threshold criterion, and a second circuit wherein the threshold generated in the first circuit is applied to the signal to produce a bar signal output, which output is then monitored by a noise recognition device. If noise is perceived by the noise recognition device, a threshold offset signal is generated. The threshold generated in the first circuit is raised by adding to it the threshold offset signal.

Abstract: An ion laser includes a plurality of thin refractory metal disk members with the perimeter of the disks embedded directly into a ceramic plasma tube. A central aperture is formed in the middle of each disk, and a plurality of apertures are formed around the periphery of the disk. In the fabrication process, ceramic powder is compacted to form an outer plasma tube. Two separate tubes, each with electrodes and embedded washer ends, can be formed and fused to form a single tube. The disks (with the surrounding compacted ceramic disposed around the periphery of the disk) are stacked within the plasma tube and the green ensemble of ceramic and metal is fired in only one furnace step with controlled atmosphere. Hermetic cathode and anode electrodes are also formed in the same firing through the plasma tube. Ends are sealed with a mirror-mount of the Brewster window structure, in one embodiment either laser welded or soldered to a refractory metal end disk embedded in the green ceramic at the ends of the tube.

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 housing construction for a POS type bar code scanner with multiple apparent source scan geometry includes only two main housing components. Each a casting to which one or a number of routing mirrors are bonded so as to precisely locate the plane of each mirror. The routing mirrors are bonded to the castings preferably on spherical ball type locaters integral with the castings, and their positions are non-adjustable. Other mirrors and collection optics are also retained on the lower and the upper casting. For precisely locating the two castings with respect to each other upon assembly, the castings have three-point contact, coupled with casting bores and removable fasteners with shoulders of precise diameter, so that the relative casting positions are accurately located as to both tilt and lateral shifting. The spherical ball locating devices for the mirrors are positioned, on each of the two castings, with reference to the precision-located connection bores and contact points on that housing.

Abstract: A method and apparatus for obtaining a more uniform output signal strength among various scan lines of a multiple scan line laser bar code reader involves switching of the gain level in the return signal amplifier of the bar code reader apparatus, in accordance with the position of the laser beam in the scanning sequence and in accordance with known information relating to the relative response that can be expected from each different scan line. This enables a better uniformity in signals from the reading of bar codes, regardless of which scan line was used to read the code, by compensating for inevitable variations in return signal strength on different scan lines, particularly in a shallow-profile slot scanner.

Abstract: A gas laser such as an argon or krypton laser has an annular gas reservoir surrounding a laser bore. A series of heat-dissipating fins are connected to the laser bore and extend between the exterior of the laser bore and the interior of the coaxial gas reservoir, arranged so as to allow air to pass over the fins as it travels lengthwise in the annular space between the bore and the gas reservoir. The gas reservoir, which communicates directly with the interior of the bore via one or more tubes, can be supported in position by the fins. The gas reservoir supplies additional makeup gas for the laser bore, as the gas in the bore is slowly consumed over the life of the laser, thereby prolonging the life of the laser without gas recharge. In addition to its storage function, the coaxial annular reservoir also serves to duct cooling air, drawn by a blower, directly over the exterior of the bore and over the cooling fins, greatly improving the cooling efficiency of the laser.

Abstract: A hand worn laser bar code reader scanner device is of compact design and adapted to be worn comfortably on the back of the hand of the user. A switch associated with the laser is attached to a hand strap such that the bar code reader is switched on and off by deliberate flexure of muscles in the user's hand. This enables the user to point his hand in a natural manner toward the bar code subject matter to be read, and, through the automatic switch, frees the fingers of his hand for use on other operations without removal of the laser device from the hand.