Spectra-physics Gmbh

Spectra Physics Lasers, Inc.

Other

Photon, Inc.

Spectra Physics, Lpd

David L Wright

Lee R Carlson

Denes A Hegedus

Alan B Petersen

Steven M Jarrett

Michael F Miller

Marc K Von Gunten

Martin E Riley

John P Goldsborough

Gary W DeBell

Kenneth A Ruddock

Alfred O Feitisch

John P Ekstrand

Kevin K Holsinger

John L Cole

Shinan-Chur S Sheng

John M Fleischer

Jeffrey L Kaiser

Dennis Reeder

Shinan S Sheng

Alan B Peterson

Rexford J Abbott

Kurt G Klavuhn

Troy M Artusy

A device for covering food () during microwave heating includes a microwavable flexible sheet () having a substantially smooth, food-facing surface () that is free of openings. The sheet () has a configuration including size, shape, and weight distribution for flexibly draping the sheet () over the food () on a rigid structure () such that the flexibly draped sheet () overhangs and folds loosely over an outer perimeter of the rigid structure thereby forming at least a partial enclosure around the food () when the sheet contacts at least a portion of an outer perimeter of the food-containing rigid structure (). During microwave heating, the at least a partial enclosure around the food () substantially contains food-splattering () inside while allowing steam () to escape through an opening () formed between the flexibly draped sheet () and the outer perimeter of the rigid structure ().

Microwavable flexible sheets for draping over food during microwave heating

Disclosed is a laser system including a high reflector and an output coupler defining a resonator; a gain medium positioned in the resonator that produces optical gain at more than two desired wavelengths; a coarse selection system, positioned in the resonator and coupled to the gain medium, that produces single transverse modes at the desired wavelengths, with transmission values at the desired wavelengths selected such that power output at the desired wavelengths is maximized, and with transmission values at undesired wavelengths selected to retard lasing at the undesired wavelengths; and a fine selector positioned in the resonator and coupled to the gain medium, having a optical length such that all of the desired wavelengths are substantially simultaneously resonant within the optical length; whereby an output beam is generated. Also disclosed are full-color holography systems and three-dimension laser Doppler velocimetry systems incorporating the inventive laser system.

Single resonator for simultaneous multiple single-frequency wavelengths

The crystal isolation system of the present invention protects a laser crystal from environmental factors such as humidity and dust. A crystal is placed in a housing which has two ports in it, and flexible tubes are placed in each port. Cap pieces cover the ends of the tubes and prevent deleterious environmental factors such as dust and moisture from entering the isolation system while allowing laser light to enter the system. A desiccator attached to the system removes moisture from the air inside the system, and an led and detector apparatus are is used to help indicate the remaining useful life of the desiccant in the desiccator.

Crystal isolation housing

Phase-locking means are provided for synchronizing the pulse timing of two (or more) passively mode-locked pulsed lasers. The phase-locking is carried out at a frequency much higher than that of the fundamental repetition rate of the lasers because it results in much higher sensitivity. The signal from the two bandpass filters is applied to a phase detector. A phase-locked loop circuit ('PLL') is employed to generate an error signal which is applied to a piezoelectric transducer ('PZT') attached to a mirror in one of the laser cavities. Corrections in the position of the mirror driven by the error signal help reduce the effects of phase noise in the relative fundamental repetition frequencies of the two lasers so that they are effectively synchronized with one another with a 'jitter' of less than 1 ps.

Apparatus and method for improved time synchronization of pulsed laser

An optical system for the attenuation of laser light for measurement purposes which includes four logical subassemblies including a first attenuator subassembly for the attenuation of high power laser light, a second attenuator subassembly for lower power attenuation of the laser light, a third lens subassembly for collecting beam size data simultaneously at multiple locations in space, and a fourth logical subassembly including a beam measuring assembly for recording the beam size data received from the lens subassembly for analysis of the beam characteristics. The first attenuator subassembly is provided with a pair of reflecting, opposed facing, fixed wedges. The reflecting wedges are selectively tilted to eliminate interference effects between their inward facing reflecting surfaces. The second attenuator subassembly further includes a pair of opposed facing and movable wedges arranged in series with a fixed filter. The lens subassembly includes a positive optical lens for focusing the beam into a series of beam splitters which redirect the beam data for simultaneous collection on a beam measuring assembly. The beam measuring assembly preferably also includes a fixed filter disposed in front of the light collection surface.

Measuring laser beam parameters using non-distorting attenuation and

An actuator for controlling alignment of an object that is characterized by an alignment plane, such as mirrors used in optical cavities, comprises a mounting frame, and a one piece alignment member formed of piezoelectric material having a first end and a second end that is secured to the mounting frame at the second end. On the first end, a first object contact, a second object contact, and a third object contact are secured defining an object plane. A means is provided for holding the object in contact with the first, second and third object contacts so that the alignment plane of the object has a predetermined relationship with the object plane defined by the object contacts on the tubular member. Electrodes are formed on the tubular member for establishing an electrical field between the surfaces of the alignment member so that the positions of the first object contact, second object contact and third object contact are controlled. By controlling the positions of the object contacts on the first end of the tubular member, precise tilting and translation of the alignment plane of the object is accomplished.

Piezoelectric actuator for planar alignment

A disk, or heat web, is generally circularly shaped, and has a circumferential lip normal to the plane of the disk. A split ring, fabricated from a material having a low co-efficient of thermal expansion fits within the circumferential lip. A generally circularly shaped expansion member, made from a material having a relatively high coefficient of thermal expansion, fits within the split ring. A suitable brazing material is placed between the split ring and the circumferential lip of the disk. The heat produced by the brazing process expands the split ring and allows it to be brazed into place when the assembly is placed on the inside of the cylindrical member.

Interference fit laser disk

An apparatus for applying a load to an etalon so as to enable the accurate tuning of desired frequencies or ranges of frequencies. The invention includes first and second optical surfaces separated and disposed highly parallel with respect to each other by an electric longitudinal spacer member. A biasing means applies a longitudinal load to the elastic longitudinal spacer member. The applied load is uniformly distributed throughout the spacer member by a longitudinal load distribution means, which is disposed between said biasing means and at least one of said optical surfaces. The distance, d, between the first and second optical surface is directly proportional to the load applied by the biasing means. The load may be varied, in one embodiment of the invention, using a bias adjustment means acting in mechanical cooperation with the biasing means.

Etalon apparatus

A laser structure utilizes air cooling and RF induction excitation of a gaseous active medium. A means for exciting the active medium is provided including a switching power supply utilizing pulse width modulated switching to provide an RF energy output. The RF output is coupled to a tank circuit which comprises a capacitor, an inductor, and at least one coupling structure. A means for generating a magnetic field-along the axial length of the laser bore is provided and can comprise either permanent magnets or a DC source coupled to the coupling structure. The laser further includes means for dissipating heat from the laser bore by utilizing the coupling structures as convective cooling fins with forced air circulated thereabout.

Air cooled RF induction excited ion laser

A low coupling beam splitter with no cross-polarization error or critical alignment tolerances is formed of a quartz piece having a first planar face in the optical path in the plane of the cross-polarization and at or near Brewster's angle to the beam. A second planar face is in the interior optical path in the plane of the cross-polarization and off of Brewster's angle to the beam, so that a majority of the component having the dominant polarization is transmitted along the optical path, while a small fraction of the component having the dominant polarization and a portion of the cross-polarized component are reflected along a first interior sample path. A third planar face is in the first interior sample path in the plane of the dominant polarization and at or near Brewster's angle to the reflected beam. Thus, a portion of the component having the dominant polarization is reflected as a sample beam, and the majority of the component having the cross-polarization is transmitted away from the sample beam. A standard photodetector can be placed in the sample path for monitoring the power or position of the beam, with no error due to the cross-polarized component.

Low coupling beam splitter and laser power or position monitor using same

A laser comprising a first mirror having a shape. The shape is generally spherical for typical lasers with the shape of the mirror being defined by the radius of curvature of a reflective surface on the mirror. A second mirror is provided mounted with the first to define a laser cavity. The cross-sectional sizes of the modes of oscillation within the laser cavity are defined by the shape of the first mirror. An aperture at a given location having a fixed cross-sectional size is mounted with the laser cavity. Alternatively, a laser bore which forms an effective aperture at a given location is used. A means is mounted with the first mirror for adjusting the shape of the first mirror so that the cross-sectional size of a selected mode at the given location matches the cross-sectional size of the aperture.

Laser with adjustable mirror for mode control

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.

Optical component of a laser

A temperature responsive, gas entrapping material contained in a chamber connected to a gas laser tube selectively entraps gas to regulate the pressure in the laser tube. A temperature regulator adjusts the temperature of the gas entrapping material and thereby controls the pressure of the gas in the laser tube. The temperature of the gas entrapping material can be adjusted by cooling or by heating. The pressure in the laser tube is monitored. The tube voltage can be used to monitor the pressure. Temperature adjustment of the gas entrapping material permits development of optimum gas pressure in the laser tube for different wave lengths. In one embodiment the laser is a krypton gas laser and the gas entrapping material is activated charcoal or alumino-silicate. The gas entrapping material may be heated, during assembly of the gas laser, to a temperature high enough to remove foreign material which might otherwise interfere with the operation of the laser tube.

Method and apparatus for regulating pressure in laser tubes

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. The heat webs are of a special configuration that substantially eliminates hoop stress in the ceramic tube under conditions of rising and falling temperature in the discharge tube. For adding gas to the discharge tube, a special fill system is connected to the discharge tube for metering small and precise volumes of gas into the discharge tube when needed. The construction of the fill system also aids in heat-cleaning steps in the assembly of the laser, and in the initial gas fill. A cooling system for the discharge tube, surrounding the ceramic tube, includes a variable pitch helical flow diverter for effecting more efficient and uniform cooling of the discharge tube.

Gas laser construction

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.

Growing community of inventors

Redwood City, CA, United States of America

David L Wright