Abstract: A method and system for stabilizing the phase relationship of two RF-controlled mode locked lasers involves monitoring the output of both lasers and, with a phase detector/comparator, generating a voltage proportional to the phase difference between the two lasers. The voltage is amplified and filtered and fed into a voltage controlled phase delay connected to the mode locker of one of the lasers. The phase delay operates to delay the RF signal to the one laser according to the desired phase relationship. By disclosed methods and apparatus a single laser can also be stabilized to its own RF drive source to reduce noise effects, two lasers can be individually stabilized to a single RF source, or two lasers can each be stabilized to their own separate RF sources.

Abstract: An optical component of a laser of the type including a hot gas plasma region, a cold gas region and producing large photon fluxed 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, intra-cavity lenses, polarizers and mirrors.

Abstract: A plasma tube for a gas laser includes a series of heat webs and insulative spacers between the heat webs, with tungsten bore insert members supported by the heat webs and having aligned apertures defining a laser discharge path. To produce the plasma tube, the heat webs, spacers and other connected components are assembled in a vertical stack outside the ceramic tube of the laser, with a stacking gauge which helps assure that the heat webs are correctly spaced apart within close tolerances. The heat webs lie adjacent to annular metallized areas on the inside surface of the ceramic tube when the assembly is inserted into the tube, which is precision-formed ceramic tubing. The tube assembly is heated in vertical orientation to expand the heat webs diametrically so that they engage outwardly against and are brazed to the metallized areas of the ceramic tube.

Abstract: A transmitter for an alignment system in which a field of electromagnetic radiation is propagated in a non-planar reference cone is disclosed. The transmitter includes a source for providing a collimated beam of electromagnetic radiation directed parallel to a beam axis. A cantilever strand supports a bob within the beam. The bob has a conical reflecting surface to reflect the collimated beam conically. Optimally, the cantilever strand and bob are chosen to provide a deflection between the bob and plumb which is substantially one-half of any angular error between the beam axis and plumb. In an especially preferred form, a housing surrounds the bob and has inner and outer surfaces which minimize temperature effects on the orientation of the reference plane. Also, detectors are provided to sense when the angular error between the beam axis and plumb is outside of an acceptable range.

Abstract: A laser instrument of the kind used to read or to detect light reflected from a target which is spaced from the laser instrument comprises a laser for generating a laser beam for transmission to the target, and a detector for detecting light reflected from the target and a trifocal, composite, single piece lens system. The trifocal lens system receives the laser beam from the laser at an angle which is off the optical axis of the lens system, routes the received laser beam onto the optical axis for transmission through the lens system and toward the target, collects light reflected from the target and images and transmits the collected light along the optical axis to the detector means. In a specific embodiment of the invention the trifocal, composite, single piece lens system is a plastic molded structure.

Abstract: A detector device for a rotating light beam, which beam defines a reference plane, includes a pair of adjacent detector elements which provide detection signals when illuminated by the beam. If the beam is above or below a first reference band, the detection signals differ sufficiently in amplitude to actuate a comparator. An averaging circuit determines if the beam is above or below the first reference band during a certain number of a set of immediately preceding rotations of the beam, and appropriate visual and audible indication are produced. The device may also provide an indication that the beam is above or below a second reference band which is aligned with, but wider than, the first reference band. The widths of the reference bands may be adjusted.

Abstract: Apparatus for projecting a laser beam to provide simultaneously a stationary reference beam and a moving reference beam, which rotates in a plane normal to the stationary reference beam, includes a beam diverting arrangement for intercepting a primary beam and for splitting the beam into the two reference beams. The beam diverting arrangement includes first and second deflecting elements which deflect the beam by 90.degree. with respect to the primary beam. A portion of the primary beam, striking the first deflecting element, passes through the element and is shifted slightly by refraction. This shift is compensated by a third beam deflecting element which is fully transmissive, and which refracts the stationary reference beam into alignment with the primary beam. By cutting the first and third deflection elements from the same sheet of material and reorienting the elements appropriately, slight deviation from parallelism in the opposing surfaces of the sheet of material are compensated.

Abstract: A window assembly for a laser uses a uniaxial crystalline material such as quartz for the window, secured directly in a hard seal to a metal tubular end component. In order to avoid significant differential thermal expansion between the quartz window and the end component, the quartz crystal is cut in a Z-normal configuration, whereby the thermal expansion and other physical properties of the window are isotropic in the plane of the window. The ability to make a reliable direct seal to a metal component offsets any disadvantages of the Z-normal configuration thought to be controlling in the prior art. Through the disclosed method for assembling and mounting the window, reflection loses are reduced to a practical minimum comparable to that of any preferred conventional window orientation.

Abstract: A laser alignment system includes a transmitter and one or more receivers. The transmitter produces an alignment field by projecting laser energy in a non-planar reference cone, and the receivers locate this reference cone with photodetectors. The laser energy in the alignment field is modulated at 8 kHz and the signals produced by the photodetectors are filtered and amplified to increase the range of the system. Each receiver operates a display which indicates when it is aligned in the reference cone, and it produces an out-of-level indication when the transmitter is not properly aligned.

Abstract: A sealed rotary compressor is provided which includes separate pump and gear chambers. Disposed within the pump chamber is a set of rotors operatively associated with a set of gears rotatably mounted within the gear chamber. A substantially pressure differential exists between the two chambers. Rotational power is applied directly to the rotors through a static seal rather than through the gears which are utilized primarily to transmit the dynamic load. The pump chamber is defined by two end plates with a surrounding thin-walled housing. Within the pump chamber are interior thin wall members with the rotary members disposed therebetween and defining inlet and outlet pockets operatively associated with a pump housing inlet and outlet means.

Abstract: The power output of a gas laser is maximized by (1) suppressing high order transverse modes, (2) broadening the gain curve to increase the number of axial modes that can lase in a given length of cavity and to thereby reduce power variation due to longitudinal mode sweeping resulting from thermal effects on cavity length, (3) suppressing unwanted infrared lasing activity, and (4) reducing beating noise resulting from frequency offset due to dispersion.

Abstract: A hand held laser bar code reader includes a motion sensor and associated circuitry to disable energization of the laser unless the bar code reader has just undergone some degree of motion. This safety feature avoids the possibility of the bar code reader's being held motionless for a long enough time to cause retinal damage to a human eye.

Abstract: A fast axial flow carbon dioxide laser has a laser head arranged to provide multiple folding of the laser beam into two, four or more linear passes. The construction of the head is such as to provide for generating either one laser beam or a pair of beams, by adjustment of optics. Located centrally in the laser head is a single exhaust manifold for exhausting all of the axially flowing gas from a series of colinear and spaced parallel discharge tubes on opposite sides of the exhaust manifold. Gas flow is from two outer inlet manifolds toward the central exhaust manifold, so that optics of the system are isolated from contamination and from the hot exhaust. Adequate distribution of gas within each discharge tube is assured by the manner in which the flowing gas is directed into the discharge tubes.

Abstract: An articulated joint of changing the direction of a light beam passing through the joint has an inlet for the incoming light beam, an outlet for the outgoing light beam, two turning mirrors and three precision bearing units associated with the turning mirrors for permitting rotation of the mirrors with a minimum amount of error of angular displacement of the redirected beam. An apparatus providing movement of at least a portion of a beam delivery system and directing an outlet beam to a desired location includes the articulated joint, a motion delivery device operatively associated with the joint and connecting means disposed between the joint and the motion delivery device. The connecting means are adapted to provide relative motion between an attachment of the connecting means to the joint and an attachment of the connecting means to the motion delivery device.

Abstract: A compact laser head for a solid state laser has a miniaturized laser rod and output coupling mirror which form a miniaturized laser cavity. A miniaturized frequency doubler crystal placed in the cavity provides frequency doubled output. The laser head is connected by an optical fiber to a separate power suply which contains a laser diode pumping source. A quick disconnect connector enables the fiber optic to be easily connected to the laser head. Pumping radiation is transmitted through the optical fiber to longitudinally end pump the laser rod using fiber coupling imagery. The fiber is aligned with the rod by the connector and the pumping radiation is imaged into the rod by a focussing sphere. The pumping volume is matched to the lasing volume which is determined by the cavity geometry. The quick disconnect laser head allows interchange of different heads with different output characteristics while using a single power supply.

Abstract: An apparatus for projecting a laser beam in a reference plane includes several imrovements. A generally cylindrical, one-piece molded transparent lighthouse structure overlies the rotatable pentaprism beam diverting assembly of the apparatus. The lighthouse structure is mounted on the housing so as to allow transmission therethrough of the rotating laser beam projected by the beam diverting assembly. The lighthouse structure has a tapered or conical configuration facilitating molding thereof, but which produces a divergence of the laser beam as it passes through the structure. A continuous resilient flexible ring is adapted to releasably attach to the apparatus housing and tightly fit about the lighthouse structure for removably anchoring the structure to the housing in a sealed relationship, providing a water-tight enclosure for the pentaprism beam diverting assembly and imposing a generally uniform attaching pressure about the lighthouse structure.

Abstract: A method and apparatus for monitoring and verifying laser processes detects infrared radiation along a laser process path at a point apart from and behind the point where the laser processing is actually occuring at a particular time. A window value of temperatures (proportional to detected infrared radiation) is determined and utilized to monitor the process. If the temperature profile corresponding to the detected infrared radiation is not within the window value a signal is generated which can trigger a different number of events.

Abstract: A neodymium or other rare earth doped solid state laser is pumped by a matched high efficiency laser diode, resulting in a compact, high efficiency and long lifetime laser assembly. Output is in the near infrared range, but can be converted to the visible spectrum by an intra-cavity frequency doubler. A doubling crystal, which may be a KTP crystal, is placed at an optimum location in the laser cavity. Polarization of the beam may be achieved simply by stressing a non-birefringent rod, prior to frequency doubling, or by using a birefringent material such as Nd:YLF for the rod. An amplitude noise suppression etalon may also be placed at an optimum position in the laser cavity; alternatively a ring cavity or pair of quarter wave plates can be used. A folded cavity configuration produces a pair of beam waists in the cavity. Pulsed operation can be produced by means of a Q-switch.

Abstract: A laser beam projection device includes a laser plasma tube assembly having a laser plasma tube and a generally cylindrical casing surrounding the tube. The plasma tube is positioned within the casing such that the beam produced by the tube is aligned with the casing and emerges from the casing through a circular opening at one end thereof. A support frame is provided for mounting the laser plasma tube assembly and also for mounting one or more optical elements in precise alignment with respect to the beam produced by the tube assembly. The frame includes an annular member for engaging the circular opening in the casing in order to align the casing with respect to the frame. The frame further defines a pair of non-parallel alignment surfaces, spaced from the annular member, to contact the outer surface of the casing near the end thereof opposite the circular opening. The casing defines an inner beveled surface surrounding the opening through which the beam emerges.

Abstract: A laser alignment system includes a remote indicator to display the alignment data when the main receiver is out of sight. The remote indicator receives both operating power and alignment data through a connecting cable to the main receiver. A Liquid Crystal Display (LCD) is used in the remote indicator because of its inherently low power consumption. To make the LCD visible under conditions of reduced ambient lighting, a light source illuminates the LCD from behind. A lighting control circuit turns the light source on only when alignment data is present in order to limit battery drain on the main receiver.