Plural Cavities Patents (Class 372/97)
-
Patent number: 4918701Abstract: A semiconductor laser arrangement is composed of two quasi-index guided laser diodes each with a light intensifying layer arranged in a plane shared by both diodes. The characteristics of the laser diodes are such that one polarization state predominates in one diode, while the other polarization state predominates in the other diode. Any desired degree of polarization dependency of the gain is set by the ratio of the operating currents of the two diodes, so that isotropic amplification can be achieved.Type: GrantFiled: August 7, 1989Date of Patent: April 17, 1990Assignee: Siemens AktiengesellschaftInventors: Markus-Christian Amann, Bernhard Stegmueller
-
Patent number: 4916710Abstract: A multi-point light emission type semiconductor laser device including a plurality of light emission points which are produced on a p type or n type semiconductor layer monolithically and are capable of being driven independently includes electrically insulating or semi-insulating semiconductor regions provided at intermediate portions of light emission points in the p type or n type semiconductor layer. A separation groove is further produced up to reaching the insulating or semi-insulating regions from the side opposite to the semiconductor layer. Thus, respective light emission points are perfectly electrically separated each other by this separation groove and the region.Type: GrantFiled: May 4, 1989Date of Patent: April 10, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Ryo Hattori
-
Patent number: 4912718Abstract: The invention is based on the knowledge that a laser can be used as a basic component and that the energy can be doubled by coupling together two basic components according to the invention and that the energy can be tripled by using three basic units, and so on. The power laser constitutes one module with corners, at least two modules that are at least substantially the same are connected to each other, and the modules are connected at corners of the modules by means of a connecting flange having an interior that is impermeable to laser beams, the connecting flange establishing a rectilinear joint between two gas pipelines of different modules.Type: GrantFiled: August 4, 1988Date of Patent: March 27, 1990Inventor: Hans Klingel
-
Patent number: 4910746Abstract: A multiple crystal, single pumping cavity laser system comprises an optical pumping cavity, several laser crystal rods disposed in the cavity and having differently sized diameters and with their axes parallel, an optical coupling device for coupling the rods in a chain of increasing diametrical size, an optical pumping source for providing an optimum pumping level for the largest rod, and attenuators for all but the largest sized rod for attenuating the energy absorbed by the smaller rods. Since all of the laser rods are disposed and pumped in a single pumping capacity, only a single pumping source is required. The housing containing the pumping cavity is thermally and mechanically isolated from the rail holding the other system components to prevent shock from being transmitted to the other components.Type: GrantFiled: November 9, 1988Date of Patent: March 20, 1990Inventor: Peter Nicholson
-
Patent number: 4910738Abstract: By using a polarization controller, a semiconductor laser apparatus oscillating in the transverse magnetic mode in mode-locked state is realized, and a short optical pulse is generated. By coupling this mode-locked semiconductor laser to a wavelength conversion element, a second harmonic wave is generated, and an even shorter optical pulse is obtained at a higher power.Type: GrantFiled: November 28, 1988Date of Patent: March 20, 1990Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshihiro Fujita, Jun Ohya
-
Patent number: 4894833Abstract: Surface emitting lasers are laterally aligned and coupled together and also have their light output signals combined. This results in greater phase and frequency coherency and narrower and reduced amplitude sidelobes. Preferably, not more than two lasers are longitudinally aligned along the same axis for still greater coherency compared with adding the light output signals of more than two longitudinally aligned lasers. The lasers can be of the DH-LOC type or of the QW type.Type: GrantFiled: August 9, 1988Date of Patent: January 16, 1990Assignee: General Electric CompanyInventor: Donald B. Carlin
-
Patent number: 4891817Abstract: Laser apparatus is disclosed which comprises a compact pulsed dye laser for high pulse repetition frequency operation. The pulsed dye laser includes a resonator cell having a passageway through which dye solution is circulated and a pump laser for optically pumping the resonator. In order to provide laser apparatus which is capable of very high performance, the dye solution is circulated through a narrow passageway at high flow rate and the pump laser is operated at a high pulse repetition frequency.Type: GrantFiled: June 13, 1988Date of Patent: January 2, 1990Assignee: Eastman Kodak CompanyInventor: Francisco J. Duarte
-
Patent number: 4890295Abstract: Laser apparatus includes an outer envelope which contains a plurality of laser discharge tubes. Each of the laser discharge tubes includes copper pieces which, when vaporised, acts as a laser amplifying medium. Each of the laser discharge tubes is of the maximum volume compatible with good efficiency which, when combined with the output power of the other tubes, enables a very high power output to be achieved compared with previously known tubes.Type: GrantFiled: May 11, 1988Date of Patent: December 26, 1989Assignee: English Electric Valve Company LimitedInventors: Graeme L. Clark, Arthur Maitland
-
Patent number: 4884282Abstract: An improved coupled waveguide laser array which provides a set of in-phase, phase locked optical beams is disclosed herein. The improved laser array of the present invention includes first and second coupled cavities for providing first and second beams in a first direction, respectively. The first and second cavities have substantially parallel longitudinal axes and apertures at first ends thereof for emitting the first and second beams. A mirror is mounted in a plane transverse to the longitudinal cavity axes and includes a first partially transmissive section mounted in optical alignment with the first cavity. The mirror further includes a first substantially reflective section mounted in optical alignment with the second cavity.Type: GrantFiled: June 27, 1988Date of Patent: November 28, 1989Assignee: California Institute of TechnologyInventor: William B. Bridges
-
Patent number: 4881237Abstract: Two-dimensional surface-emitting diode laser arrays are described that take advantage of both the advanced state of development of linear laser arrays with conventional cleaved end faces and the rapid development of Si heat sink technology. A hybrid array consists of linear arrays of edge-emitting lasers that are mounted in grooves with flat bottoms and 45.degree. sidewalls etched in the top of a Si substrate containing microchannels for fluid flow on the backside. The 45.degree. sidewalls of the top Si grooves are coated with a highly reflecting metallic layer. These 45.degree. mirrors deflect the laser emission from the cleaved end faces of the linear laser arrays by 90.degree. so the emission is normal to the array surface. Use of the integral microchannel heat sink in the bottom of the Si substrate provides excellent heat removal capabilities for high power density operation.Type: GrantFiled: August 26, 1988Date of Patent: November 14, 1989Assignee: Massachusetts Institute of TechnologyInventor: Joseph P. Donnelly
-
Patent number: 4878223Abstract: A semiconductor laser array device comprising a substrate with a plurality of grooves and an active layer disposed over the substrate, resulting in optical waveguides within the active layer corresponding to the grooves, wherein the grooves are disposed over the entire area of the substrate and a means for preventing the injection of current into some of the grooves that are positioned outside of the central area of the substrate is disposed whereby the other grooves positioned in the central area of the substrate constitute a laser array portion of the semiconductor laser array device.Type: GrantFiled: July 26, 1988Date of Patent: October 31, 1989Assignee: Sharp Kabushiki KaishaInventors: Taiji Morimoto, Hiroyuki Hosoba, Mitsuhiro Matsumoto, Mototaka Taneya, Sadayoshi Matsui
-
Patent number: 4868833Abstract: A lasing medium (3) and a Raman medium (20) share a common optical cavity. The lasing medium (3) projects laser light into the Raman medium (20) and, when a threshold intensity within the Raman medium is reached, the Raman medium absorbs the laser light and re-radiates coherent light at a shifted frequency. Optical elements within the system provide an optical cavity for the lasing medium and a second cavity for the Raman medium.Type: GrantFiled: August 10, 1987Date of Patent: September 19, 1989Assignee: Hughes Aircraft CompanyInventors: Robert D. Stultz, Donald E. Narhi
-
Patent number: 4864587Abstract: A pulsed gas laser having two spaced optical resonators each associated with a pair of high voltage electrodes. The first and second pairs of electrodes are positioned within a common plasma chamber including means for circulating a laser gas successively between the two pairs of electrodes. A common heat exchanger removes the heat energy from the two regions of plasma excitation. A high voltage pulse generator connected to the electrodes includes timing means for delaying the application of high voltage pulses to the second pair of electrodes, the delay being either (a) less than the time required for an acoustic shock wave to travel through the lasing gas from the first to the second pair of electrodes or (b) longer than the time required for the shock wave created by the discharge of the first pair of electrodes to die out. Each optical resonator is provided with an adjustable mirror arranged to reflect laser pulses to and from a mirror grating.Type: GrantFiled: September 2, 1986Date of Patent: September 5, 1989Assignee: Laser Science, Inc.Inventor: Ali Javan
-
Patent number: 4860303Abstract: The solid metal current return in a typical commercial co-axial flashlamp replaced with a light transmissive current return which permits light from either or both surfaces of the flashlamp to be used to pump dye volumes. This enables one flashlamp to pump two dye volumes simultaneously, resulting in a significant increase in the overall efficiency of the co-axial flashlamp-pumped dye laser.Type: GrantFiled: January 17, 1989Date of Patent: August 22, 1989Assignee: The United States of America as represented by the Secretary of the ArmyInventor: Stephen D. Russell
-
Patent number: 4856015Abstract: A semiconductor laser array device has a relatively wide light-emitting area with many semiconductor lasers and a shielding layer selectively disposed with respect to peripheral regions of the light-emitting area such that the rate of heat emission from the center part can be increased relative to that from the peripheral regions. Temperature distribution on the light-emitting area can thus be made uniform and laser light can be emitted from the entire laser emitting area under a phase-synchronized condition.Type: GrantFiled: June 7, 1988Date of Patent: August 8, 1989Assignee: Sharp Kabushiki KaishaInventors: Sadayoshi Matsui, Mototaka Taneya, Mitsuhiro Matsumoto, Hiroyuki Hosoba
-
Patent number: 4853933Abstract: A radiation generator in which substantially all the radiation modes are locked with respect to one another comprises a radiation generating cavity defined by mirrors and a crystal for generating a continuous train of non-transform limited pulses of coherent radiation. An external cavity is positioned in association with the radiation generating cavity whereby radiation may pass in use in both directions between the two cavities. The external cavity is defined by a medium having a non-linear transmission characteristic which may be substantially non-dispersive for radiation from the generating cavity, and/or which has a negative group delay dispersion. The radiation path length is such that pulses fed into the external cavity are fed back to the radiation generating cavity in synchronism with a later pulse from the generating cavity.Type: GrantFiled: September 30, 1987Date of Patent: August 1, 1989Assignee: British TelecommunicationsInventors: Keith J. Blow, David C. Wood
-
Patent number: 4852117Abstract: A resonant waveguide cavity, preferably a loop, is fabricated from an active material doped host glass and includes a wavelength dispersive lateral coupling designed to preferentially support wavelengths in a selected bandwidth. Pumping light is provided to excite the active material so that the supported wavelengths stimulate in phase emission to increase their amplitude with the amplified signal presented to an output fiber. Where a signal generator is desired, the pumping light can be used to drive the resonant cavity into oscillation to provide a CW output at one of the cavity supported wavelengths.Type: GrantFiled: April 16, 1987Date of Patent: July 25, 1989Assignee: Polaroid CorporationInventor: Hong Po
-
Patent number: 4852107Abstract: A laser resonator has a semitransparent outlet mirror and a first mirror, with an active element between the mirrors, all the elements arranged perpendicular to the optical axis of the resonator. A shutter is provided behind the first mirror and a second mirror is arranged behind the shutter, perpendicular to the optical axis of the resonator. The second mirror is fully reflective for radiation with stronger laser transition and the first mirror is fully reflective for radiation with weaker laser transition and fully penetrable for radiation with stronger transition. The resonator can change frequency simply by opening or closing the shutter. It can be advantageously used, for example, in the design and construction of laser scalpels.Type: GrantFiled: April 28, 1987Date of Patent: July 25, 1989Assignee: Ceske vysoke uceni technicke v PrazeInventors: Karel Hamal, Jan Marek
-
Patent number: 4849986Abstract: An arrangement of optical resonators which are composed of elongated optical waveguides comprising reflectors arranged at their end faces, one group of the waveguides being coupling resonators and a second group of the waveguides being useful resonators which are arranged in a substrate with the useful resonators being adjacent one surface thereof. A laser active material is provided adjacent the one surface of the substrate and can be either a semiconductor laser material or can be a light pump laser material. At least one of the waveguides of the useful resonators being composed of optically passive material, which has good wave-conducting properties, and being positioned adjacent to the laser active material so that a wave field excited in the waveguide can be intensified by the laser active material.Type: GrantFiled: August 11, 1987Date of Patent: July 18, 1989Assignee: Siemens AktiengesellschaftInventors: Manfred Boerner, Reinhard Mueller, Gert Trommer
-
Patent number: 4847848Abstract: A semiconductor laser device comprises: a semiconductor laser including laser resonators for emitting laser beams forward and backward oppositely along a plurality of parallel axes; a photodetector including a plurality of photodetector elements for detecting intensities of the laser beams emitted backward; and a waveguide located between the semiconductor laser and the photodetector for guiding the backward emitted laser beams to the corresponding ones of the photodetector elements, the waveguide including a plurality of guide grooves for guiding the backward emitted laser beams.Type: GrantFiled: February 16, 1988Date of Patent: July 11, 1989Assignee: Sanyo Electric Co., Ltd.Inventors: Yasuaki Inoue, Kimihide Minakuchi, Norio Tabuchi
-
Patent number: 4841541Abstract: An improved ring laser system having mutual coupling between two or more ring laser resonators employs a two-step coupling process, in which coupling power is coupled into the adjoint forward mode of an adjacent resonator, from which it diffractively couples to the forward mode. A portion of forward-mode power is coupled into the adjoint reverse mode from which it diffractively couples to the reverse mode within each resonator. A portion of this reverse mode power is used to coupled into other resonators. A complementary configuration employs forward-mode radiation as the coupling radiation.Type: GrantFiled: July 20, 1988Date of Patent: June 20, 1989Assignee: United Technologies CorporationInventors: Edward A. Sziklas, John A. Benda
-
Patent number: 4840456Abstract: Electrical signals with frequencies ranging from several tens of megahertz to hundreds of gigahertz are generated by detecting the optical output from a novel double-external-cavity diode laser system. The system provides a convenient means of measuring the frequency response of high speed photodetectors, and it can also be used for the optical generation and transmission of microwave or millimeter wave carriers in applications such as phased array radars.Type: GrantFiled: December 28, 1987Date of Patent: June 20, 1989Assignee: GTE Laboratories IncorporatedInventor: Donald M. Fye
-
Patent number: 4841528Abstract: Higher efficiency in cavity dumping and frequency doubling in a laser used to produce modulated output beam pulses is achieved by deflecting light out of the resonant cavity to a third mirror through a frequency doubler using an electro-optic modulator and a polarizing beamsplitter in the resonant cavity, or using just an acousto-optic modulator to deflect light out of the laser cavity in response to a control signal (electric or acoustic). The frequency doubler in front of the third mirror rotates the frequency doubled light so that it will pass out of the laser cavity through the polarizing beamsplitter, while undoubled frequency light is reflected by the polarizing beamsplitter back into the gain medium of the laser. In the case of using a type-II frequency doubler, a dichroic beamsplitter deflects out the frequency doubled light and passes the undoubled frequency light to the polarizing beamsplitter for return to the laser gain medium.Type: GrantFiled: September 6, 1988Date of Patent: June 20, 1989Assignee: California Institute of TechnologyInventors: Donald L. Sipes, Jr., Deborah L. Robinson
-
Patent number: 4831628Abstract: A method of selective area epitaxial growth using a scanning ion beam is described.Type: GrantFiled: November 10, 1986Date of Patent: May 16, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Won-Tien Tsang
-
Patent number: 4831629Abstract: An optically uncoupled laser array is modified at its current confinement geometry to introduce nonuniformity in effective optical cavity width and/or length among the different lasers comprising the laser array. An array laser comprising a plurality of spaced lasing elements with an optical cavity for generating and propagating radiation under lasing conditions with each of the laser elements being optically uncoupled from one another is enhanced by an extended spectral emission linewidth and reduction in temporal coherence. This extended spectral emission linewidth and reduction in temporal coherence is accomplished by changing the gravity gain or loss for at least a majority of the laser elements relative to each other whereby a different longitudinal mode(s) of operation and frequency of operation exist for each such laser element.Type: GrantFiled: September 1, 1987Date of Patent: May 16, 1989Assignee: Xerox CorporationInventors: Thomas L. Paoli, Robert D. Burnham, Robert L. Thornton
-
Patent number: 4823353Abstract: A semiconductor laser array apparatus comprising a semiconductor laser array device having a plurality of active waveguides in a parallel manner with an optical phase-coupling between the adjacent waveguides and an optical phase-shifting means attaining a 180.degree. phase-shift between the adjacent laser beams emitted from the adjacent waveguides of the laser array device, the phase-shifting means being disposed in the vicinity of one of the facets of the laser array device.Type: GrantFiled: October 8, 1987Date of Patent: April 18, 1989Assignee: 501 Sharp Kabushiki KaishaInventors: Mototaka Taneya, Mitsuhiro Matsumoto, Sadayoshi Matsui
-
Patent number: 4823357Abstract: A laser transmitter is disclosed in which the laser combines the outputs of numerous laser diodes using dichroic combination to produce a high power, diffraction limited beam which may be transmitted at minimum beam divergence using the full aperture of the transmitter telescope. The individual diode beams are combined and superimposed in the laser, and are transmitted superimposed in the near and far field of the transmitter telescope. The dichroic combining process is as follows. A collimate beam of a first wavelength is directed at a narrowband or long wave pass filter which is tilted slightly (about 10 degrees). This beam passes through the filter. A beam of a second wavelength is directed toward the exit side of the filter (which acts as a mirror) at such an angle that the second beam is reflected colinear with the first beam and superimposed on it. This process of superimposing the laser beams continues as each laser beam from the laser diodes is added to form a combined laser beam.Type: GrantFiled: November 10, 1986Date of Patent: April 18, 1989Assignee: The United States of America as represented by the Secretary of the Air ForceInventor: William L. Casey
-
Patent number: 4823349Abstract: A flowing gas laser, of the kind in which gas flows continuously through the lasing region and is circulated through the heat exchanger for cooling before being returned to the lasing region, comprises a resonator module and a blower module. The optical components of the laser are mounted on an outer surface of the resonator module, and the resonator module has an interior structure for conducting the circulating gas to the lasing region. The blower module has heat exchange structure for cooling the circulating gas and has a blower for pumping the circulating gas. The blower module is physically separated from the resonator module to prevent the heat and vibration of the blower module from distorting or otherwise affecting the structure or the performance of the optical components. Ducting the interconnects the resonator module and the blower module for circulating the gas between these modules.Type: GrantFiled: March 31, 1987Date of Patent: April 18, 1989Assignee: Rofin-Sinar, Inc.Inventors: Dale E. Koop, Joseph F. Rando
-
Patent number: 4809285Abstract: Method and device for correlating the spontaneous emission of photons into laser fields. Atoms of a common lasing medium of multiple laser fields are excited into a coherent superposition of upper levels. When photons are emitted into the laser fields, these emissions are coherent or correlated. The method and correlated emission laser of the invention utilize this correlation to quench the spontaneous emission noise inherent in active laser systems.Type: GrantFiled: December 15, 1986Date of Patent: February 28, 1989Assignee: University of New MexicoInventor: Marlan O. Scully
-
Patent number: 4809290Abstract: An opto-electronic switch which shows a good signal rejection ratio between modes is also of particularly small dimensions. The switch comprises a semiconductor laser 1 having four contacts 12, 12', 13, 13' which provide gain guiding under two stripe windows 18, 19. By varying the bias currents supplied to the individual contacts 12, 12', 13, 13', or inputting optical control signals to the waveguiding channels under the stripe windows 18, 19, different configurations of optical output from the laser 1 can be achieved. The two contacts, 12, 12' and 13, 13', associated with each stripe window 18, 19 are effectively a signal stripe contact with a discontinuity. It is thought that diffractive transverse coupling at the discontinuity allows the use of a shorter device than in known directional switches. With feedback, the switch operates as a memory device. The switch finds particular application in optical communications, for instance in signal routing.Type: GrantFiled: March 10, 1987Date of Patent: February 28, 1989Assignee: British Telecommunications public limited companyInventors: Ian H. White, Richard S. Linton, John E. Carroll
-
Patent number: 4805185Abstract: The invention comprises a semiconductor laser 10 having an attached etalon 18 which imposes two additional reflective cavity resonance conditions on a laser diode 12. The etalon has partially reflective front surface 26 and an inner surface 24 which act in conjunction with the internal cavity of the laser diode 12 to reduce side mode emission from the laser. This results in laser emission of a single dominant mode, i.e., a single discrete wavelength of coherent light, from surface 22.Type: GrantFiled: March 4, 1986Date of Patent: February 14, 1989Assignee: The United States of America as represented by the Secretary of the Air ForceInventor: Robert J. Smith
-
Patent number: 4805179Abstract: A GaAs/AlGaAs-transverse junction stripe (TJS) laser with p-n junction formation by crystal plane dependent doping is described. The laser structure includes a molecular beam epitaxy (MBE)-deposited hetero-structure comprising AlGaAs layers with an active GaAs layer sandwiched therebetween. These layers are grown on the patterned surface of a GaAs substrate which provides (100)-plane oriented planar ridges and grooves, the edges being (111A)-plane oriented. p-n homojunctions are formed in the GaAs layer at the intersections of the (111A) and (100) crystal planes. Ohmic contacts are provided for applying currents of at least the threshold level of the junctions. These TJS lasers can be used to form 1- or 2-dimensional arrays of phase-coupled lasers for providing high optical power output.Type: GrantFiled: September 23, 1987Date of Patent: February 14, 1989Assignee: International Business Machines CorporationInventors: Christoph S. Harder, Heinz Jaeckel, Heinz P. Meier
-
Patent number: 4799234Abstract: A narrow-band laser transmitter including a semiconductor laser and an external optical resonator in the form of a wavelength-selective fiber directional coupler. A partially reflecting feedback device is provided so that output power of the transmitter can be taken from the resonator. The frequency selective fiber directional coupler is formed by a dispersive double core fiber and the feedback device is supplied with radiant laser energy that is coupled over from one core into the other core and that portion of the radiant energy which has been coupled over is allowed to pass as output power of the transmitter by the feedback device.Type: GrantFiled: September 14, 1987Date of Patent: January 17, 1989Assignee: Siemens AktiengesellschaftInventors: Klaus M. Haeussler, Julius Wittmann, Gisela Gaukel, Franz Auracher
-
Patent number: 4797892Abstract: A longitudinally coupled, coherent, surface emitting semiconductor laser array in a monolithic wafer is disclosed. Active regions of diode laser-striped semiconductor material are focused ion beam (FIB) micromachined to form transversely disposed channels of symmetric, opposed, generally parabolic mirrored surfaces. Diode laser pairs, emitting laser energy in a generally horizontal plane, are longitudinally injection-coupled (phase-locked) by semi-transmissive, opposed regions that are micromachined into the otherwise reflective parabolic surfaces of the channel. Coherent, laser energy is reflected thereby generally normally away from the surface of the monolithic structure.Type: GrantFiled: May 11, 1987Date of Patent: January 10, 1989Assignee: Oregon Graduate CenterInventors: Richard K. DeFreez, Richard A. Elliott, Joseph Puretz
-
Patent number: 4797891Abstract: The present invention relates to phased-array semiconductor lasers having a radiation angle turnable by oscillating independently and stably between the fundamental supermode and the higher order supermode and switching the radiation angles by utilizing the property that their radiation angles are different.Optical switching and optical scanning, that have been difficult in the prior art, can be made more easily by use of a semiconductor laser having a turnable radiation angle.The objection of the present invention can be accomplished by disposing separate electrodes at the emission stripes and at the gap between the stripes in the phased-array semiconductor laser.Further, the present invention may be accomplished by dividing at least one stripe electrode in order to form electrode regions. When the current is applied to all the electrodes, oscillation occurs in the highest order mode and the beam is emitted in another direction.Type: GrantFiled: December 15, 1986Date of Patent: January 10, 1989Assignee: Hitachi, Ltd,Inventors: Kazuhisa Uomi, Misuzu Yoshizawa, Yuichi Ono, Naoki Chinone, Takashi Kajimura
-
Patent number: 4796263Abstract: The invention relates to an optical manifold permitting a single pumping source to be utilized to selectively pump a plurality of laser sources. Switching of the emission from the pumping source to the laser source is accomplished by a plurality of FTIR switches. A second group of FTIR switches is utilized to switch the output beams of the laser sources to a common output path.Type: GrantFiled: December 21, 1979Date of Patent: January 3, 1989Assignee: Westinghouse Electric Corp.Inventor: Robert W. Rampolla
-
Patent number: 4794605Abstract: A technique in which one or more phase conjugation cells, such as stimulated Brillouin scattering cells, are controlled by use of a seed beam injected into the cells. When a laser beam is focused into a phase conjugation cell, a reflected phase conjugated beam is produced. The seed beam is injected at the same frequency and in the same direction as the expected phase conjugated beam, and is adjusted to control the phase and other characteristics of the phase conjugated beam. In multiple cell arrays, seed beams are employed to ensure phase coherency of multiple beams. For lower energy applications, use of the seed beam allows a phase conjugation cell to be operated with incident beams of lower energy than would be needed without the seed beam.Type: GrantFiled: March 13, 1986Date of Patent: December 27, 1988Assignee: TRW Inc.Inventors: Robert Aprahamian, Theodore C. Salvi
-
Patent number: 4791644Abstract: A laser system utilizing a Stimulated Brillouin Scattering SBS cell to produce optical phase conjugate retroreflection for nonmonochromatic light from a laser system.Type: GrantFiled: December 31, 1985Date of Patent: December 13, 1988Assignee: General Electric CompanyInventor: George Dube'
-
Patent number: 4783789Abstract: Annular lasing apparatus. A plurality of combinations of substantially cylindrical optical components with appropriate laser gain materials are disclosed for generating approximately cylindrical substantially uniform regions of laser radiation suitable for the uniform irradiation of bulk materials for purposes of photochemical processing thereof. Superposition of contributions from the output of two or more laser oscillators having cylindrical optics were also found to provide adequate uniformity in a radiation volume of significant proportions thereby permitting the efficient utilization of laser radiation in a well-characterized irradiation region. Moreover, the use of cylindrical optics permits the radiation volume to be tailored to the particular requirements of the photochemical or photophysical material processing technology.Type: GrantFiled: July 2, 1985Date of Patent: November 8, 1988Inventor: Warren W. Higgins
-
Patent number: 4778238Abstract: Communications Systems particularly suited for manipulating stimulated Brillouin scattering (SBS), or similar tunable laser amplification effects, to acheive improved means for selecting an optical signal from many such signals carried on a single fiber. This disclosure also describes means for producing a tunable, spectrally-narrow line to power this laser amplification. The disclosure also describes an improved polarization-sweeping device which allows the system to handle variable polarization of signals, when necessary. It also discloses other subsystems and apparatus facilitating the optimum signal-tapping process, including heterodyning procedures, a low-band-width channel-indentification means, and a new laser, all particularly useful in the system described. The laser is also useful in other systems where a tunable, spectrally narrow, stable source is required.Type: GrantFiled: August 1, 1985Date of Patent: October 18, 1988Inventor: John W. Hicks
-
Patent number: 4779286Abstract: A laser optical cavity extends between two end reflectors (11, 12) and is defined by at least three sections. A number of folding reflectors (14) are provided for directing radiation emerging from one section into the next. An active medium is contained in the sections and excitation means are provided to produce laser action. A rigid support member (10) supports the end reflectors (11, 12) and the folding reflectors (14) around a generally cylindrical surface such that a continuous optical path extends between the end reflectors (11, 12) by way of each folding reflector (14) in turn. At least three of the laser sections extend across a substantial part of the area with the cylinder (10) and each section crosses at least one other section at or near to the axis of said cylinder as viewed along that axis.Type: GrantFiled: June 25, 1987Date of Patent: October 18, 1988Assignee: Ferranti plcInventor: David I. Wheatley
-
Patent number: 4768201Abstract: A semiconductor laser array which includes a plurality of active wave guide in a substantially parallel manner disposed on first and second laser opposing laser facets so as to be optically coupled and so that adjacent wave guides converse into one or more active wave guides on an opposing laser facet. The laser array exhibits stable operations and a high output power in a single narrow beam. The active wave guides have identical vertical modes and a phase difference of zero degrees.Type: GrantFiled: July 30, 1985Date of Patent: August 30, 1988Assignee: Sharp Kabushiki KaishaInventors: Mototaka Taneya, Sadayoshi Matsui, Seiki Yano, Saburo Yamamoto
-
Patent number: 4764936Abstract: A semiconductor laser array device comprising an oscillation operating area provided with a plurality of first index-waveguides in a parallel manner and a non-oscillation operating area provided with a plurality of second index-waveguides in a parallel manner through which laser light produced in said oscillation operating area are guided through the waveguide from said oscillation operating area to the end facets of the second index-waveguides of said non-oscillation operating area, wherein the second index-waveguides are different in length between the adjacent waveguides and the end facet of each of the second index-waveguides does not function as a cavity facet of the laser but it functions as the light-emitting facet of the device.Type: GrantFiled: August 28, 1986Date of Patent: August 16, 1988Assignee: Sharp Kabushiki KaishaInventors: Mototaka Taneya, Mitsuhiro Matsumoto, Hidenori Kawanishi, Sadayoshi Matsui
-
Patent number: 4760580Abstract: An injection laser array has 2.sup.n output elements (1) coupled by Y couplers (2, 4, 6) and (n-1) in sets of intermediate elements to a single element (7) in a tree configuration. The face end of the single element is provided with a high reflectivity coating (8) while those of the 2.sup.n output elements are provided with low a reflectivity coating (9).Type: GrantFiled: March 31, 1987Date of Patent: July 26, 1988Assignee: STC PLCInventors: George H. B. Thompson, James E. A. Whiteaway
-
Patent number: 4751715Abstract: A multiple cavity waveguide laser is formed of a pair of face to face contiguous dielectric blocks 70, 72in the facing surfaces of which are formed pairs of mating waveguide grooves 78, 80, 82, 84having an electrode partition 92 sealed to and between the adjacent mating blocks to separate one pair of waveguide cavities from another, thereby forming four closely spaced waveguide cavities. In another embodiment, the partition 26 between the two dielectric blocks 10, 12 is thin conductive material, and dielectric partitions 36, 38 are provided between cavities of each pair in a single dielectric block. The internal surfaces 40, 42, 44, 47 of each cavity opposite the common electrode 26 are plated with an electrically conductive material, and suitable electrical connections 56, 58, 18 are made from the internal electrodes to the exterior of the blocks.Type: GrantFiled: September 30, 1986Date of Patent: June 14, 1988Assignee: Hughes Aircraft CompanyInventor: Alan R. Henderson
-
Patent number: 4748632Abstract: A method and apparatus for controlling an external cavity of a semiconductor laser to maintain its emission in a single longitudinal mode. The length of the external cavity is varied by an electromagnet acting on ferromagnetic material attached to a copper foil reflector. Total optical power output of the laser is monitored and single longitudinal mode operation is achieved by maximizing the power output. An active technique employs modulation of the reflector position about a mean value. The magnetic manipulation of the reflector may find application in other laser systems, e.g. gas lasers.Type: GrantFiled: November 3, 1983Date of Patent: May 31, 1988Assignee: British Telecommunications plcInventor: Keith R. Preston
-
Patent number: 4745607Abstract: A grating in the upper reflecting layer (103 or 203) of an antiresonant reflecting optical waveguide is used to extract energy of a selected wavelength from the waveguiding layer (102 or 202) into the reflecting layer. In one embodiment the reflecting layer (103) is designed as a gain medium which is pumped in the region of a grating (120) and optically terminated at each end of the device such that the embodiment serves as a laser having a long cavity provided by the waveguiding layer (102) with the gain provided in the short grating region. In a second embodiment the reflecting layer (203) in the region of a grating (211) has an opposite conductivity dopant from that of the waveguiding layer (202) such that the device in this region may be backbiased to serve as a wavelength selective photodetector. By placing two wavelength photodetectors in tandem with gratings (211 and 212)of different pitches a wavelength demultiplexing photodetector is provided.Type: GrantFiled: October 8, 1986Date of Patent: May 17, 1988Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Thomas L. Koch
-
Patent number: 4742526Abstract: A semiconductor laser array device comprising an optical waveguide which is in a single mode or a multiple mode in the center portion thereof and is in a branching mode at each of both end portions thereof to form a plurality of branching waveguides which are positioned symmetrically with respect to the waveguiding direction of the laser beams and which are parallel to each other near the facets, thereby oscillating laser beams with a 0.degree.-phase shift therebetween.Type: GrantFiled: January 6, 1986Date of Patent: May 3, 1988Assignee: Sharp Kabushiki KaishaInventors: Sadayoshi Matsui, Mototaka Taneya, Mitsuhiro Matsumoto
-
Patent number: 4737962Abstract: A compound resonator type semiconductor laser device comprising a multiple-layered crystal structure having a first laser operation area which contains a resonator for laser oscillation and a second laser operation area which contains a resonator a facet of which is shared with that of the resonator in the first laser operation area; and an electric current feeder for injecting a current into said multiple-layered crystal structure, and wherein said facet of the resonator in the first laser operation area, which is shared with the facet of the resonator in the second laser operation area, is covered with a protective film to attain a high reflectivity therein, the other facet of the resonator in the first laser operation area is covered with a protective film to attain a low reflectivity therein, and the other facet of the resonator in the second laser operation area is covered with a protective film to attain a high reflectivity therein.Type: GrantFiled: May 15, 1985Date of Patent: April 12, 1988Assignee: Sharp Kabushiki KaishaInventors: Saburo Yamamoto, Hiroshi Hayashi, Nobuyuki Miyauchi, Shigeki Maei, Taiji Morimoto
-
Patent number: 4730327Abstract: A semiconductor laser diode comprising first and second parallel optically coupled waveguides is disclosed. The waveguides extend between first and second partially reflecting end facets. The first waveguide terminates at the first facet with a high reflection coating and at the second facet with an anti-reflection coating. The second waveguide terminates at the first facet with an anti-reflection coating and at the second facet with a high reflection coating. Thus, the feedback path for the laser involves portions of both waveguides and the coupling region therebetween. As a result, no standing waves are set up in either waveguide near the portions of the end facets which are anti-reflection coated and from which radiation is emitted so that processes which cause emitting facets to fail at high powers are mitigated.Type: GrantFiled: December 16, 1985Date of Patent: March 8, 1988Assignee: Lytel IncorporatedInventor: Eugene I. Gordon