Active Media With Particular Shape Patents (Class 372/66)
  • Patent number: 5436920
    Abstract: A laser device including a wavelength converter of internal resonator type comprises a laser diode 20 for excitation, a light emission section 22 as a solid laser medium excited by the laser 20 and a wavelength converter 23 for converting the wavelength of the laser light from the excited solid laser. The solid laser medium of the light emission section 22 comprises a semiconductor crystal of GaAs, AlGaAs or GaAs-AlGaAs. A second harmonic wave light of a fundamental wave of 0.8 .mu.m band can be easily generated by using a solid laser medium such as a GaAs crystal, an AlGaAs crystal or a superlattice crystal thereof.
    Type: Grant
    Filed: May 18, 1994
    Date of Patent: July 25, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hisashi Minemoto, Yusuke Ozaki, Nobuo Sonoda
  • Patent number: 5432811
    Abstract: A laser has been developed with an active laser element which, in certain aspects, employs no mirrors but instead has a lasant rod with ends formed to produce total or nearly total internal reflection and an output window surface at one end from which a laser beam exits the device. In one aspect a rod end or ends are formed in the shape of polyhedrons whose surfaces reflect oscillating radiation. Also disclosed is a laser with an active laser emitter with a lasant rod with a first end formed in the shape of a polyhedron and a second flat end adjacent to or in contact with a plate or plates of solid reflective, coated or uncoated material, which are next to each other or spaced apart by spacer apparatus, e.g. rings. Such a laser emitter may be used in a laser device without other mirrors or reflectors.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: July 11, 1995
    Assignee: Tecnal Products, Inc.
    Inventors: Valeri G. Polushkin, Sergey A. Kokhanovsky, Evgeny A. Federov, deceased
  • Patent number: 5418804
    Abstract: A controlled spectrum generation laser arrangement achieving greater uniformity in the optical power spectral distribution is realized by employing a matching plate that conforms the boundary interface of the active medium with the shape of the focal surface of the pump radiation. The matching plate ensures that for any portion of the active medium the pump radiation is focused at its boundary interface so as to achieve a uniform pump beam intensity.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 23, 1995
    Assignee: American Biogenetic Sciences, Inc.
    Inventors: Andrei G. Zhiglinsky, Alexander M. Izmailov
  • Patent number: 5418803
    Abstract: A laser capable of generating polychromatic or whim light radiation is realized by employing a diffraction grating and reflecting element as the ends of a simple laser resonator cavity. The dispersive element either solely or in combination with an intracavity lens is arranged such that each wavelength component of the white light radiation is amplified by a different portion of the active medium. Forced oscillation or positive feedback for each wavelength component is achieved by operating the diffraction grating in an auto-collimation configuration.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 23, 1995
    Assignee: American Biogenetic Sciences, Inc.
    Inventors: Andrei G. Zhiglinsky, Alexander M. Izmailov
  • Patent number: 5410559
    Abstract: A high power, highly efficient laser that produces a polarized, round diffraction limited gaussian beam is disclosed. A strong thermal lens laser crystal with controlled ellipticity, is mounted in a laserhead and pumped by a fiber-bundle-coupled diode source. The pump beam diameter in the crystal is greater than the crystal's TEMOO mode diameter. The laser operates well over a large range of pump powers. Its slope efficiency in the TEMOO mode is greater than 40%, with an overall efficiency greater than 25%. One of the lasing crystals used is Nd:YVO4. This material exhibits high gain and a short upper state lifetime. These properties make it attractive in designing a Q-switched laser, or one that is insensitive to optical feedback.
    Type: Grant
    Filed: February 4, 1994
    Date of Patent: April 25, 1995
    Assignee: Spectra-Physics Lasers, Inc.
    Inventors: William L. Nighan, Jr., Mark S. Keirstead
  • Patent number: 5394420
    Abstract: A multiform crystal 10 suitable for laser applications is described. The multiform crystal 10 comprises at least two single crystal segments 12 fused together with a joint 14 therebetween, the joint being substantially optically transparent to light propagating through the crystal 10. The multiform crystal 10 is formed by polishing two single crystal segments 12 to form at least one optically flat face on each segment. The polished faces are cleaned and contacted against one another to form a joint 14 between the crystal segments 12. Substantially all the oxygen in the joint 14 is removed. The joint 14 is maintained at a sufficiently high temperature and pressure to join the segments 12 together at the joint forming the substantially optically transparent joint 14. Mounting fixtures suitable for holding the crystal segments 12 firmly against one another in a furnace, without causing undesirable thermal expansive forces to be exerted on the segments 12, are also described.
    Type: Grant
    Filed: January 27, 1994
    Date of Patent: February 28, 1995
    Assignee: TRW Inc.
    Inventors: Robert H. Senn, Loren E. Record
  • Patent number: 5371758
    Abstract: Apparatus for transversely irradiating a region equally from two directions using a single incident beam of substantially collimated radiation. The apparatus includes perpendicular reflective planes having a common edge and defining a corner region in which an irradiated region entirely within said corner region, said irradiated region being suitably positioned within said corner region such that said irradiated region does not intercept any ray of incident radiation from striking said common edge, said irradiated region receiving only radiation from two directions. Said irradiated region being directly irradiated from a first direction by incident radiation, and said irradiated region being also indirectly irradiated from a second direction opposite said first direction by incident radiation reflected from both of said planes.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: December 6, 1994
    Assignee: Exxon Research and Engineering Company
    Inventor: Shawn M. Dougal
  • Patent number: 5365538
    Abstract: A slab waveguide pumped channel waveguide laser includes a slab waveguide having a primary pump guiding layer with a first index of refraction and having first and second opposing faces and a peripheral edge including a mirrored surface, and cladding means having a second index of refraction lower than the first index of refraction, proximate the first and second opposing faces; at least one rare earth doped channel waveguide laser having a third index of refraction higher than the first index of refraction disposed in the primary guiding layer; and means for introducing pumping energy into the guiding layer to reflect between the mirror surfaces and energize the laser.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: November 15, 1994
    Assignee: The Charles Stark Draper Laboratory Inc.
    Inventors: Richard Tumminelli, Farhad Hakimi, John R. Haavisto
  • Patent number: 5363391
    Abstract: A technique for passively removing heat from an optical element in a laser system through its optically transmissive faces. Heat is removed by way of optically transmissive heat sinks or other heat conducting media disposed adjacent the optically transmissive surfaces of the optical element. Heat is transferred out of the optical element in a direction parallel to the direction of propagation of energy, thus minimizing problems associated with thermal gradients. Devices employing optical elements such as nonlinear frequency conversion crystals and laser crystals may utilize the heat management approach of the present invention to achieve better performance. Heat is transferred to the heat conducting media by direct contact, or through narrow gas-filled gaps disposed between the optical element and the heat conducting media.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: November 8, 1994
    Assignee: Hughes Aircraft Company
    Inventors: Steven C. Matthews, James S. Sorce, Mario P. Palombo
  • Patent number: 5349600
    Abstract: A high-output, single fundamental transverse mode solid state laser is disclosed which uses a semiconductor laser array as an excitation light source. The solid state laser comprises: a laser element which includes a core containing an element added as a laser medium, a cladding containing no such laser medium element, and reflecting mirrors coated over the cladding surface for repeatedly reflecting incident excitation light so that it may repeatedly pass through the core; an excitation light source formed by semi-conductor laser or light emitting diode array; means for guiding the excitation light from the excitation light source to one side of the laser element for incidence thereto; and a resonator for the oscillation of the solid state laser.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: September 20, 1994
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Osamu Shinbori, Yoshinori Mimura, Yukio Noda, Tetsuya Nakai
  • Patent number: 5319653
    Abstract: An integrated optical component structure designed to operate at a rare earth ion fluorescence wavelength .lambda..sub.1 comprises at least a thin layer of a mixed rare earth fluoride solid solution having the formula (1-x)(M.sub.1-y M'.sub.y F.sub.2)-x TRF.sub.z deposited on a substrate of a monocrystalline semiconductor material where M and M' denote an alkaline earth ion, TRF.sub.z denotes a rare earth fluoride, x is in the range ]0,1[ and y is in the range [0,1]. The component structure finds applications in telecommunications using optical waveguides.
    Type: Grant
    Filed: November 19, 1992
    Date of Patent: June 7, 1994
    Assignee: France Telecom
    Inventors: Pierre-Noel Favennec, Helene L'Haridon, Danielle Moutonnet, Albert Barriere, Sebastien Raoux, Bruno Nombelli
  • Patent number: 5309471
    Abstract: Optically pumped laser minicavity, its production process and laser using said cavity, wherein the minicavity comprises an electrically insulating, parallelepipedic, solid emitter (1b), having two polished parallel lateral faces (6, 8), a monocrystalline substrate (2) and several monocrystalline layers epitaxied on the substrate and having in directions parallel to said faces a hardness equal to that of the substrate, one of the layers constituting a guide layer (4) able to guide the light emitted by the emitter and the pumping light and another layer (12) constituting a non-guiding protective layer, the protective layer and the substrate constituting two opposite faces of the emitter perpendicular to the lateral faces, laser activating ions being contained within the substrate and/or in one of the layers. In the case of an internal cavity, semi-reflecting mirrors (9, 10) are placed on the lateral faces of the emitter.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: May 3, 1994
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Bernard Chambaz, Isabelle Chartier, Bernard Ferrand, Denis Pelenc
  • Patent number: 5289490
    Abstract: The present invention relates to a solid state laser generation apparatus which is composed of modularized solid state lasing units which enable construction of a compact cascading laser apparatus having a low lasing threshold value and a high laser generation efficiency. A lasing rod and the electrodes for the excitation of the rod are housed in a common module casing which has depressed sections on its external surface. When assembling two modular units, one of the module units is rotated axially with respect to the other in such a way to insert the electrodes into the depressed section on the external surface of the neighboring module so as to minimize the mechanical interference caused by the neighboring components. By utilizing such a modular arrangement, the lasing rod spacing between the neighboring module units can be shortened, thus resulting in lower coupling losses between the adjacent rods even during the initial phase of the operation.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: February 22, 1994
    Assignee: Ishikawajima-Harima Heavy Industries Co., Ltd.
    Inventors: Yoshito Taniu, Mikinori Shono, Koichiro Wazumi, Akihiro Nishimi
  • Patent number: 5287373
    Abstract: Solid state laser gain media of the composition Cr.sup.+3 :XYZF.sub.6 wherein X is an alkali metal ion; Y is an alkaline earth metal ion, Cd.sup.+2 or Mg.sup.+2 ; and Z is Al.sup.+3, Ga.sup.+3 or Sc.sup.+3 are provided with gradient Cr doping levels for reducing thermally generated stress/strain in the lasing operation.
    Type: Grant
    Filed: August 17, 1992
    Date of Patent: February 15, 1994
    Assignee: AlliedSignal Inc.
    Inventors: William R. Rapoport, Michael L. Shand, Dave Narasimhan
  • Patent number: 5280534
    Abstract: A crystalline material for use in a solid state tunable laser is YAG:Mn wherein the Mn is predominantly trivalent. The laser is tunable in the yellow-orange range (0.59-0.63 .mu.m) and the near infrared range (1.04-1.2 .mu.m).
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: January 18, 1994
    Assignee: Polaroid Corporation
    Inventors: Pavle Gavrilovic, Shobha Singh
  • Patent number: 5278860
    Abstract: This invention relates to face-pumped slab lasers of the type that have laser head assemblies constructed of individual components, which are rigidly attached together, in order to form an integral structure. Such structures of this type, generally, allow a face-pumped slab laser component to be assembled and disassembled easily and quickly.
    Type: Grant
    Filed: September 28, 1992
    Date of Patent: January 11, 1994
    Assignee: General Electric Company
    Inventors: John L. August, Jr., Mark J. Kukla, Todd J. Rockstroh, Nobuaki Iehisa
  • Patent number: 5249196
    Abstract: An internally folded scalable laser has a gain medium with an internal face nd an external face and at least one internal-fold face subtending an angle which may be about 90.degree.. An output coupler that is partially reflective of the resonator mode is oriented to receive and reflect resonator mode in a direction normal to the internal face to avoid resonator mode astigmatism and to define a folded hemispherically-shaped resonator cavity extending from the output coupler and through an active volume in the gain medium to the external face. A pumping mode source disposed adjacent to the external face is oriented to focus a first pumping mode in a direction normal to the external face in a boom waist at or inside the external face in the folded resonator cavity to define an active volume in the gain medium and to avoid pumping mode astigmatism.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: September 28, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Richard Scheps
  • Patent number: 5239549
    Abstract: A composite slab laser medium provided with a non-doped layer containing substantially no laser active materials and a first and second doped layers provided at both sides of the non-doped layer, respectively, in such a manner to hold the non-doped layer, each of which contains a laser active material. In this composite slab laser, a first surface of the first doped layer and a second surface of the second doped layer are in contact with the outside of the composite slab laser medium and are parallel with each other. Further, a laser oscillation or an optical amplification is performed by extracting a laser beam which travels in a zig-zag path undergoing total internal reflection at the first and second surfaces employed as alternate reflecting surfaces within the composite slab laser medium. Moreover, layers made of laser glass containing Nd.sub.2 O.sub.3 of from 3 to 9% by weight is employed as the doped layers. Furthermore, a total of the thicknesses of the first and second doped layers is of from 0.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: August 24, 1993
    Assignee: Hoya Corporation
    Inventors: Hidemi Tajima, Mitsuhisa Moriyama
  • Patent number: 5237576
    Abstract: An article, such as an optical communication system, which includes a laser formed in an optical waveguide or optical fiber having a rare-earth-doped core or core portion. In one embodiment, the optical resonant cavity of the laser is at least partially defined by a distributed Bragg reflector formed in a portion of the core. In contrast to the prior art, the length of the optical resonant cavity is about 5 cm or less.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: August 17, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: David J. DiGiovanni, Victor Mizrahi, John L. Zyskind
  • Patent number: 5237580
    Abstract: A CO.sub.2 slab waveguide laser (10) is disclosed including a pair of spaced apart electrodes (36,38) having opposed light reflecting surfaces. The electrodes are dimensioned in a manner to guide light in a plane perpendicular to the reflecting surfaces. Light parallel to the reflecting surfaces is not constrained other than by the resonator mirrors (30,32). The resonator structure includes a negative branch unstable resonator in the nonwaveguide dimension. A stable resonator is used in the waveguide dimension but the mirror spacing from the end of the guide is based in part on the configuration of the unstable resonator. A unique support structure is disclosed for maintaining the electrodes in a spaced apart orientation without confining the discharge. Further refinements are disclosed for cooling the laser and for accommodating thermal expansion of the parts.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: August 17, 1993
    Assignee: Coherent, Inc.
    Inventor: Wayne S. Mefferd
  • Patent number: 5235605
    Abstract: A wavelength-tunable, injection-seeded, dispersion-compensated, dispersively-pumped solid state laser includes a lasing medium; a highly reflective mirror; an output coupler; at least one isosceles Brewster prism oriented to the minimum deviation angle between the medium and the mirror for directing light of different wavelengths along different paths; means for varying the angle of the highly reflective mirror relative to the light from at least one Brewster angle for selecting a predetermined laser operating wavelength; a dispersion compensation apparatus associated with the lasing medium; a laser injection seeding port disposed between the dispersion compensation apparatus and one of the mirror and coupler and including a reflective surface at an acute non-Brewster angle to the laser beam for introducing a seed input; a dispersion compensation apparatus associated with the laser medium including opposite chirality optical elements; the lasing medium including a pump surface disposed at an acute angle to th
    Type: Grant
    Filed: November 18, 1992
    Date of Patent: August 10, 1993
    Assignee: Schwartz Electro-Optics, Inc.
    Inventors: Glen A. Rines, Peter F. Moulton, James Harrison
  • Patent number: 5224117
    Abstract: A gas laser is designed with the following features: The laser is a slab laser, in which a plasma space (5) of a limited height is formed for the laser-active plasma between mutually opposing surfaces (11, 21) of two wall parts (10, 20); the wall parts (10, 20) are components of a coupling chamber with at least one coupling wall (30), which is connected to at least one distribution chamber (40,), whereby by injecting the high-frequency energy through the coupling wall (30), the gas plasma is activated in the desired manner over its entire length. The high-frequency energy for exciting the plasma lies in the gigahertz range, for which a magnetron is used, for example.
    Type: Grant
    Filed: October 17, 1991
    Date of Patent: June 29, 1993
    Assignee: Siemens Aktiengesellschaft
    Inventors: Wolfgang Kruger, Hubert Grosse-Wilde
  • Patent number: 5222094
    Abstract: A ring laser (10) incorporates a laser rod (R) with end faces (R.sub.1, R.sub.2). The first face (R.sub.1) is coated for high reflectivity at the laser wavelength and the second (R.sub.2) for high transmission at this wavelength. The first face (R.sub.1) provides one cavity end mirror, and a concave mirror (M.sub.1) spaced apart from the rod (R) provides the other. A rhombic prism (P) between the rod (R) and mirror (M.sub.1) defines differing (figure of eight) forward and return paths (14 to 17, 18 to 21) for cavity radiation passing from one end mirror (R.sub.1 or M.sub.1) to the other and returning. The prism (P) presents Brewster's angle refracting surfaces. The second rod face (R.sub.2) is tilted to produce an optical path in two planes. A magnetic field (B) along the rod axis (R.sub.a) produces Faraday rotation of polarization. This counteracts rotation arising from non-coplanar optics for one direction of propagation around the laser cavity (10) but not the other.
    Type: Grant
    Filed: November 13, 1991
    Date of Patent: June 22, 1993
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: David C. Hanna, William A. Clarkson
  • Patent number: 5210768
    Abstract: The laser system features a plurality of thin solid-state gain channels mounted radially about a common axis. These gain channels may be excited by multiple flashlamps or by extended arrays of light-emitting-diodes. The gain channels are also mounted in a parallel configuration within a single optical resonator and thereby share a common cavity mode. The resonator may be a stable resonator, a conventional unstable resonator, or a toric resonator. Each resonator configuration may be externally phase-locked via external reference oscillator injection or by self-injection via an internally generated master oscillator. When incorporating a very large number of gain channels, the concept provides an efficient and inexpensive means for constructing extremely high powered, optically-pumped, lasers in very small physical packages.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: May 11, 1993
    Inventor: Herb J. J. Seguin
  • Patent number: 5177764
    Abstract: The present invention provides a means of inducing unidirectional oscillation in monolithic and composite ring lasers in which the light path is planar. The intracavity optical diode that enforces unidirectional oscillation in the planar ring oscillator is achieved by a combination of the nonreciprocal Faraday effect, a linear birefringence effect in which the principal axes of the birefringence are not parallel and perpendicular to the plane of propagation of the ring light path, and one or more partial polarizer effects. The present invention enables experimental optimization of polarization transformations within a planar ring oscillator, even if the oscillator is monolithic, and also provides a means of tuning the frequency of the planar ring oscillator.
    Type: Grant
    Filed: January 9, 1990
    Date of Patent: January 5, 1993
    Assignee: Harmonic Lightwaves, Inc.
    Inventor: Alan C. Nilsson
  • Patent number: 5177762
    Abstract: A saturable reactor comprising a magnetic core (1) having an annular or an elongated race-track configuration, an electrical insulator (6) disposed around the magnetic core and a conductor winding (3) wound around the insulator (6). A coolant duct (7) is provided in the insulator to extend radially transversely across the magnetic core and having a radially separated inlet and outlet (8,9). A saturable reactor may comprises an annular magnetic core (51), a conductor winding including a first conductor (55) surrounded by the magnetic core (51) and a second conductor (56) disposed around the magnetic core and connected to the first conductor (55) through a load. A control winding (54) extends through the first and second conductors (55,56), and at least one of the first and second conductors (55,56) has a notch or a through hole (57,59) for insulatingly receiving the control winding (54) therein.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: January 5, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yukio Sato, Mitsuo Inoue, Kenyu Haruta, Akihiro Suzuki, Hitoshi Wakata
  • Patent number: 5159605
    Abstract: A semiconductor-laser-pumped, solid-state laser includes a semiconductor pumping laser emitting pumping light, a solid-state laser medium arranged to be excited by the pumping light, and a laser resonator structure for emitting laser light from the solid-state laser medium. The solid-state laser medium is plate shaped having a thickness less than the broadening width of the pumping light in the solid-state laser medium. The semiconductor laser is arranged close to the face of the solid-state laser medium, and the laser resonator structure has optical axis coinciding with that of the pumping light.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: October 27, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigenori Yagi, Takashi Yamamoto, Mayumi Fujimura
  • Patent number: 5151916
    Abstract: An electric discharge tube for a gas laser in which a laser gas flow axis and a laser oscillation optical axis are coaxial and a discharge direction of discharge pumping is perpendicular to those axes. The internal sectional form of a discharge tube (1) perpendicular to the laser oscillation optical axis is made rectangular and the internal diameter of nondischarge sections (10a, 10b) is made larger than the diagonal line of the discharge tube (1). The section of laser beams generated in a rectangular discharge region (11) becomes substantially rectangular in shape and the laser beams are externally output intact, whereby a substantially rectangular beam mode is obtained.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: September 29, 1992
    Assignee: Fanuc Ltd.
    Inventors: Nobuaki Iehisa, Etsuo Yamazaki
  • Patent number: 5148444
    Abstract: A tunable, single-frequency, solid-state ring laser includes a solid-state laser material pumped by laser-diode light and at least one additional external piece which reflects the intra-cavity lasing light in a closed loop such that the plane of polarization is changed in an appropriate amount to compensate for magneto-optic change (Faraday rotation) of the plane of polarization, which occurs either inside the solid-state material or in one of the external pieces which traversed by the intra-cavity lasing beam. At least one of the external elements has the ability to change the optical path length of the intra-cavity lasing beam in order to tune the laser frequency by means of mechanical movement, electro-optic properties, magneto-optic properties, or some combination of the above properties.
    Type: Grant
    Filed: August 18, 1988
    Date of Patent: September 15, 1992
    Assignee: Harmonic Lightwaves, Inc.
    Inventor: Josef Berger
  • Patent number: 5131002
    Abstract: An external cavity semiconductor laser system is disclosed wherein multiple segments of semiconductor material are excited with an array of pump sources. In one embodiment, a laser beam is reflected in a pattern to pass through multiple excited segments on a wafer of semiconductor material. In another embodiment, a series of wafers disposed in a laser cavity are excited. This pumping system spreads out the thermal load while providing a high power, high quality, laser beam.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: July 14, 1992
    Assignee: Massachusetts Institute of Technology
    Inventor: Aram Mooradian
  • Patent number: 5125001
    Abstract: This invention relates to a solid laser device with a slab-shaped laser medium. One example of a solid laser device according to the invention, comprises: a slab-shaped laser medium having one pair of optically smooth surfaces confronting each other through the optical path; first and second mirrors arranged on the optical path in such a manner that the first and second mirrors are confronted with each other through the laser medium; a resonator which forms an unstable resonator in the direction of width of the laser medium, and a low order stable resonator in the direction of thickness of the laser medium; and laser beam emergence medium for taking a laser beam out of the a resonator and outputting the laser beam from the device.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: June 23, 1992
    Assignee: Mitsubishi Denki K.K.
    Inventors: Shigenori Yagi, Kazuki Kuba, Junichi Nishimae, Takashi Yamamoto
  • Patent number: 5119389
    Abstract: In a solid-state laser device comprising a laser medium which is located within a plurality of resonance optical paths and which has a plurality of medium lengths forming parts of the resonance optical paths, at least one of the medium lengths within the resonance optical paths is selected such that a third level laser beam can be oscillated while at least one of the remaining medium lengths is different from the first of the medium lengths and is selected such that a fourth level laser beam is oscillated.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: June 2, 1992
    Assignee: Hoya Corporation
    Inventor: Sho Amano
  • Patent number: 5117437
    Abstract: Continuous laser action is sustained by a new pumping mechanism which relies exclusively on cooperative electronic transitions of coupled atoms or ions in solids. The present invention is the first of a new class of laser device which depends on energy-sharing interactions between colliding atoms in gases or active dopants in solid laser media to create the population inversion needed for amplification of light. In one specific embodiment, a laser crystal which is formed of calcium fluoride is doped heavily with trivalent erbium, and is provided with reflective coatings on respective first and second surfaces. A pumping energy is supplied whereby a pair of atoms are elevated to an initial excited state. Subsequently, one of the atoms loses energy so as to assume a ground state, the energy released thereby being made available to excite the second atom to a still higher quantum energy state.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: May 26, 1992
    Assignee: The University of Michigan
    Inventor: Stephen C. Rand
  • Patent number: 5117433
    Abstract: A second harmonic generator of the present invention utilizes Cerenkov radiation as a useful coherent short-wavelength light source. The second harmonic generator includes an aberration correction means to collimate the second harmonic to form a parallel plane wave having a high flatness. The aberration correction means is provided on an exit end face of a nonlinear waveguide which generates the second harmonic, and a glued cone prism, a cone prism having a conic exit end face changed in accordance with birefringence of the nonlinear waveguide, or a diffraction grating is used as the aberration correction means.
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: May 26, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Kimio Tatsuno, Hironori Yanagisawa
  • Patent number: 5103452
    Abstract: Disclosed is an x-ray laser system comprising a laser containing generating means for emitting short wave length radiation, and means external to said laser for energizing said generating means, wherein when the laser is in an operative mode emitting radiation, the radiation has a transverse coherence length to width ratio of from about 0.05 to 1. Also disclosed is a method of adjusting the parameters of the laser to achieve the desired coherence length to laser width ratio.
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: April 7, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Richard A. London, Mordecai D. Rosen, Moshe Strauss
  • Patent number: 5099492
    Abstract: A compact RF excited annular laser system has a stable resonator with a high quality output beam. The stable resonator has internal axiconical and annular mirrors to conform with the annular lasing medium, and to convert the annular beam into a compact cylindrical beam. Mode control is achieved by a combination of diffractive effects in both the annular beam and the compact beam.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: March 24, 1992
    Assignee: Optomic Technologies Corporation, Ltd.
    Inventors: Avigdor Zajdman, Oded Amichai
  • Patent number: 5086433
    Abstract: The field of the invention is that of power lasers pumped by coherent optical sources, such as laser diodes. The aim of the invention is to provide a structure of illumination of a laser rod enabling both efficient removal of the calories released by the coherent optical pumping sources and high homogeneity of the rod pumping operations. The structure is characterized in that the optical sources of at least one set of optical sources are arranged on one and the same delocalized support and in that said structure comprises reflecting means for the transmission, towards the rod, of the illumination beam from said set of delocalized optical sources.
    Type: Grant
    Filed: June 12, 1990
    Date of Patent: February 4, 1992
    Assignee: Thomson-CSF
    Inventors: Jean-Paul Pocholle, Michel Papuchon, Claude Puech
  • Patent number: 5084888
    Abstract: A laser medium for use in a composite slab type laser, wherein laser active layers are divided in the longitudinal direction of the laser medium by removing at least a part of a region, which is deviated from a zigzag path and a laser beam to be extracted therefrom does not pass through. Thereby amplified spontaneous emission can be weaken and parasitic oscillation can be effectively suppressed, and further laser oscillation and light amplification can be performed for a long period of time.
    Type: Grant
    Filed: December 26, 1990
    Date of Patent: January 28, 1992
    Assignee: Hoya Corporation
    Inventors: Hidemi Tajima, Takayasu Mochizuki
  • Patent number: 5084889
    Abstract: A laser medium for use in a slab laser having a light absorbing member provided in a region, wich is deviated from a zigzag path to be followed by a laser beam to be extracted therefrom and thus the laser beam does not pass through. Thereby, parasitic oscillation can be effectively suppressed, and laser oscillation and light amplification can be performed for a long period of time.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: January 28, 1992
    Assignee: Hoya Corporation
    Inventor: Hidemi Tajima
  • Patent number: 5084882
    Abstract: This invention relates to a phased-array laser oscillator/amplifier system consisting of looped fibre lasers whose two optically polished end faces are stacked together to form a single output aperture near to which is positioned a single laser mirror in the case of the laser oscillator configuration of the invention or an optical window in the case of the laser amplifier configuration, which is index-matched to said output aperture, the said fibre bundle laser medium being optically excited via the said single aperture composed of the fibre ends. In the case of the laser oscillator configurations of the invention, the single laser mirror is partially transmitting and allows the output laser beam to emerge as a phase-locked beam formed by adding together all the outputs from the individual fibre laser ends.
    Type: Grant
    Filed: March 9, 1990
    Date of Patent: January 28, 1992
    Assignee: Phased Array Lasers Pty. Ltd.
    Inventor: John L. Hughes
  • Patent number: 5084896
    Abstract: A laser apparatus comprises a hollow waveguide containing a lasing gas composition; structure for directing radiation into the waveguide and for directing radiation out of the waveguide; and electrical exciting structure operatively associated with at least part of the waveguide. The waveguide defines a convoluted, continuously curved path having a helicoidal shape. The waveguide has a concave, non-closed transverse section with an open inner portion and is disposed within a gas-tight container containing the lasing gas composition. The waveguide is a laterally open groove formed internally in a cylindrical block disposed within the container.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: January 28, 1992
    Assignee: L'Air Liquide, Societe Anonyme pour l'etude ei l'Exploitation des Procedes Georges Claude
    Inventors: Jacques Landry, Philippe Van Der Have, Vincent Pon on
  • Patent number: 5052815
    Abstract: A ring laser is provided with only two reflecting surfaces to define the cavity. A gain medium is located between the reflecting surfaces. At least one optical interface is located within the cavity and is oriented such that the beam will be deflected by refraction to create a ring path. The angle of incidence of the beam with the interface should be less than Brewster's angle and the surface should have an antireflective coating. The interface can be located on the lasant material, on a non-linear optical material or on a passive optical element. Preferably, the device is arranged to achieve unidirectional and single frequency operation. When the ring is used for intracavity second harmonic generation, the resultant output is amplitude stable because of the avoidance of mode beating. The second harmonic radiation is generated unidirectionally increasing useable output.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: October 1, 1991
    Assignee: Coherent, Inc.
    Inventors: John L. Nightingale, John K. Johnson
  • Patent number: 5050173
    Abstract: A phase-locked fibre bundle laser oscillator made up of one or more active fibre loops as illustrated. The single mode fibre has a doped core surrounded by cladding and has its ends positioned in a common plane forming a two core aperture which is optically polished to a twentieth wavelength. Fibre end faces are coupled by index matching material to a single, partially transmitting, dielectric mirror and the oscillator is side pumped via the output of an array of laser diodes.
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: September 17, 1991
    Assignee: Phased Array Lasers Pty Ltd.
    Inventor: John L. Hughes
  • Patent number: 5048027
    Abstract: A scalable laser system system providing a single, phase-locked output which comprises a flexible bundle of single mode optical fibers with the optically polished end faces at one end being index matched via matching material to a single, partially transmitting, output mirror. The opposite end of the bundle is divided into a series of smaller bundles whose end faces are index matched to the ends of a series of solid state laser media. These are optically pumped by remotely sited laser diode arrays via additional bundles and mirrors, which are 100% reflective at the laser wave-length.
    Type: Grant
    Filed: March 9, 1990
    Date of Patent: September 10, 1991
    Assignee: Austral Asian Lasers Pty. Ltd.
    Inventors: John L. Hughes, Barry L. Hudson
  • Patent number: 5048044
    Abstract: Various examples of an optically pumped laser are described. In each example, a laser member formed from active laser material is located in an optical cavity and a source of pumping light is arranged so that pumping light passes into the laser member through a side surface. A deflecting means is provided which ensures that the pumping light makes an initial pass followed by at least one, and preferably at least two, further passes across the laser member. In the further passes, the pumping light has a substantial component long the optical axis. Consequently, a relatively long absorption path for the pumping light is achieved. In one example, the laser member is an Nd:YAG bar (20), the pumping light source is an array (23) of laser diodes, and the deflecting means takes the form of a series of facets (27) formed along a side of the bar (20). In another example, the deflecting means is a diffraction grating.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: September 10, 1991
    Assignee: Lumonics, Ltd.
    Inventor: Clive L. M. Ireland
  • Patent number: 5048026
    Abstract: A side pumped, fiber optic amplifier comprises an optical fiber, having a first refractive index, formed of a laser material, such as Nd:YAG. A jacket, which surrounds the optical fiber, has a second refractive index, lower than the first refractive index. This jacket is cone shaped and tapers from a large end to a small end. High power laser diodes are mounted on the large end to introduce pump light to pump the optical fiber material. The cone-shaped jacket focuses this pump light to an interaction region at the small end, where the jacket material is quite thin, e.g. on the same order of magnitude as the diameter of the optical fiber. The focused light is absorbed by the optical fiber in this interaction region, and causes an electronic population inversion in the laser fiber material. A signal propagating through the optical fiber stimulates spontaneous emission from the optically excited laser material, thereby resulting in amplification of the signal.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: September 10, 1991
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Herbert J. Shaw, Michel J. F. Digonnet
  • Patent number: 5034953
    Abstract: In a laser device for producing a laser beam along a first predetermined direction by exciting a slab-shaped laser medium by an excitation member, a reciprocating motion is carried out along a second predetermined direction transverse to the first predetermined direction and is divided into a plurality of cycles which have different amplitudes. Both edge zones of the slab-shaped laser medium are excited and heated by the excitation member during a selected one of the cycles while they are not excited during the remaining cycles. Thus, heat accumulated in the edge zones is diffused and dissipated by intermittently heating the edge zones. The slab-shaped laser medium may be reciprocated relative to the excitation member. Alternatively, the excitation member may be reciprocated relative to the slab-shaped laser medium.
    Type: Grant
    Filed: June 29, 1989
    Date of Patent: July 23, 1991
    Assignee: Hoya Corporation
    Inventor: Hiroshi Sekiguchi
  • Patent number: 5021742
    Abstract: This invention relates to a laser amplifier which achieves substantially enhanced gains by diverging the laser beam in a gain medium having a substantially rectangular shape. In particular, at least one laser beam is passed through a lens or other suitable means to cause it to diverge at a predetermined angle and the diverging beam or beams are caused to pass through the gain medium in a manner such that a beam makes only a single pass through any section of the medium, with the total number of passes through the medium by the beam(s) applied to the medium being an even number. The angle at which the beam diverges should be such as to maintain a near optimum laser power extraction efficiency for the beam. If a single beam is supplied to the medium, it makes an even number of passes through the medium with mirrors, prisms, or other suitable means being provided as the beam exits the medium after each pass except the last pass to fold the beam back into the medium for a subsequent pass.
    Type: Grant
    Filed: September 19, 1988
    Date of Patent: June 4, 1991
    Assignee: Science Research Laboratory, Inc.
    Inventor: Jonah H. Jacob
  • Patent number: 5018164
    Abstract: A pulsed beam from an excimer laser is used for precision ablation of cadmium telluride (CdTe) and other materials to fabricate and delineate devices in electronic microcircuit structures. The fluence of the beam may be adjusted to selectively remove one constituent of the material, such as cadmium vs. tellurium, at a higher rate than the other constituent, while maintaining the integrity of the material surface. The beam may selectively remove an epitaxial layer of CdTe, CdZnTe, or HgCdTe from a GaAs substrate. The beam may be directed through a projection mask and optical system onto a material to form an image for patterned ablation. The optical system may focus an image of the mask on the material to form vertical sidewall patterns, or slightly defocus the image to form curved sidewall patterns and/or concave and convex lens structures for optical arrays.
    Type: Grant
    Filed: September 12, 1989
    Date of Patent: May 21, 1991
    Assignee: Hughes Aircraft Company
    Inventors: Peter D. Brewer, Jennifer J. Zinck
  • Patent number: 5012481
    Abstract: An improved pumping arrangement for use in a face pumped or edge pumped slab laser, this arrangement comprising upper and lower housing members able to be removably secured together in an operational relationship. The lower housing member has in a central portion thereof, a body of solid state laser host material, with the laser host material typically having a rectangular cross-section with top and bottom surfaces, opposing side surfaces, and opposing end faces. The lower housing member also is configured to have a pair of spaces running the length of the laser host material. The upper housing member has on its underside, a pair of parallel flashlamps set a distance apart. The lower housing member is able to receive the upper housing member in an interfitted, operative relationship, in which the flashlamps are received in the respective spaces alongside the body of solid state laser host material.
    Type: Grant
    Filed: March 9, 1990
    Date of Patent: April 30, 1991
    Assignee: Martin Marietta Corporation
    Inventor: Carlos A. Casteleiro