Patents Examined by Rodney B. Bovernick
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Patent number: 5811839Abstract: The present invention provides a semiconductor light-emitting device including a first clad layer comprising a first conductive type of AlGaAsP compound, a second clad layer that is located next to the first clad layer, comprises a first conductive type of AlGaInP compound and has a thickness of up to 0.5 .mu.m, an active layer that is located next to the second clad layer and comprises a first or second conductive type AlGaInP or GaInP, a third clad layer that is located next to the active layer, comprises a second conductive type of AlGaInP compound and has a thickness of up to 0.5 .mu.m, and a fourth clad layer that is located next to the third clad layer and comprises a second conductive type of AlGaAsP compound, and/or a light-extracting layer that comprises a second conductive type AlGaP or GaP and has a thickness of 1 .mu.m to 100 .mu.m.Type: GrantFiled: August 31, 1995Date of Patent: September 22, 1998Assignee: Mitsubishi Chemical CorporationInventors: Kenji Shimoyama, Nobuyuki Hosoi, Katsushi Fujii, Atsunori Yamauchi, Hideki Gotoh, Yoshihito Sato
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Patent number: 5812571Abstract: A laser cluster for high-power applications includes an array of VCSELs. The array of VCSELs includes a center VCSEL and one or more peripheral VCSELs displaced from the center VCSEL in a hexagonal closest-packing arrangement sharing a pair of common electrical contacts. Each VCSEL in the array is flip-chip mounted on a heat sink to present the backside of the VCSEL. A multimode optical fiber is coupled to receive laser light from the array of VCSELs. The array of VCSELs is operable to generate a laser burst at a wavelength in a range from 950 nm to 1050 nm. In a process for fabricating a VCSEL that can be clustered for high-power applications, a bottom n-doped mirror stack is deposited above an n-doped gallium arsenide substrate. An active region including indium gallium arsenide is deposited above the bottom mirror stack. A top p-doped mirror stack is deposited above the active region. Electrical contacts are applied to the top mirror stack and to the substrate. The laser cluster is packaged and sealed.Type: GrantFiled: October 25, 1996Date of Patent: September 22, 1998Assignee: W. L. Gore & Associates, Inc.Inventor: Frank H. Peters
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Patent number: 5812580Abstract: A multi-layer high reflective dielectric optical coating deposited on a laser diode facet that shifts the high amplitude peak of the electric field associated with the reflection of light away from the interface between the semiconductor material and the reflective coating, and into the reflective coating itself. By shifting the electric field peak in this manner, the laser diode can operate at much higher optical output powers without inducing catastrophic optical damage at the non-output facet.Type: GrantFiled: November 5, 1996Date of Patent: September 22, 1998Assignee: Coherent, Inc.Inventors: Rashit F. Nabiev, Ian Edmond, Michael Jansen, Fang Fang
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Patent number: 5809194Abstract: A process for marking an outer jacket of an oscillating lay cable to indicate the locations of switchbacks thereunder. The process includes the step of providing detectable markings on an unjacketed cable core in predetermined position relative to the switchback. The process further includes the steps of sensing the detectable markings with a sensor prior to extruding an outer jacket over the cable core, predicting the location of the sensed markings on the cable core after a cable jacket has been extruded, and providing a marking on the cable jacket at a predetermined position relative to the predicted location of the sensed marking.Type: GrantFiled: June 7, 1995Date of Patent: September 15, 1998Assignee: Alcatel NA Cable Systems, Inc.Inventor: Raymond Gordon Lovie
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Patent number: 5809049Abstract: The present invention monitors the RF drive circuitry of a linear laser transmitter. In one preferred embodiment of the present invention, a filtered RF signal from the monitor diode is amplified and then input to a peak detector. The output of the peak detector is then fed to the input of a threshold detector, wherein the threshold detector determines whether the output of the peak detector is above a predetermined threshold. If the output of the peak detector falls below the predetermined threshold an alarm is generated at the status monitoring ports of the laser transmitter.Type: GrantFiled: December 19, 1996Date of Patent: September 15, 1998Assignee: Lucent Technologies Inc.Inventors: Mark Steven Schaefer, David B. Winick
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Patent number: 5809051Abstract: A vertical cavity laser emission component emitting via the surface at a wavelength lying in the range 1.3 .mu.m to 1.55 .mu.m, the component comprising a stack having two mirrors which reflect at the emission wavelength, plus one or more layers which are interposed between the two mirrors and which constitute an amplifying medium for the emitted radiation, wherein, in the vicinity of the amplifying medium, at least one of the mirrors presents a layer of Al.sub.x Ga.sub.1-x As where x lies in the range 0.8 to 1, which layer is selectively oxidized around an active central zone of the amplifying medium. In the method, two samples are grown epitaxially, one on an InP substrate and the other on a GaAs substrate, the two samples obtained in this way are assembled together by epitaxial adhesion of a GaAs layer of the second sample on an InP layer of the first sample, and the resulting sample is subsequently etched and then oxidized by hydrolysis.Type: GrantFiled: September 20, 1996Date of Patent: September 15, 1998Assignee: France TelecomInventor: Jean-Louis Oudar
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Patent number: 5809052Abstract: A semiconductor laser array driving method for driving a semiconductor laser array having a plurality of light-emitting points arranged on a base member. The semiconductor laser array driving method has a step of driving the plurality of light-emitting points by a driving pulse current of a pulse width and a duty factor meeting an inequality: .DELTA.T.sub.1 /.DELTA.T.sub.0 <1/2, where .DELTA.T.sub.0 is a temperature rise in active layers of the light-emitting points when the semiconductor laser array is driven in a continuous drive mode using a continuous current, and .DELTA.T.sub.1 is a temperature rise in the active layers of the light-emitting points when the semiconductor laser array is driven in a pulse drive mode using a pulse current. In the semiconductor laser array driving method, the plurality of light-emitting points are driven by a driving pulse current having a duty factor of 0.4 or below meeting an inequality: y<3.1 exp(-8.9x), where x is a duty factor and y is a pulse width (.mu.s).Type: GrantFiled: October 18, 1996Date of Patent: September 15, 1998Assignee: Fuji Xerox Co., Ltd.Inventors: Yasuji Seko, Akemi Murakami, Hiromi Otoma, Nobuaki Ueki, Hideki Fukunaga, Hideo Nakayama, Mario Fuse
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Patent number: 5809195Abstract: A modular optical fiber ribbon has a repetitive color identifier arrangement for the individual coated fibers defining one or more adjacent modules. Each module is identified by a digital code imprinted or otherwise marked on the top surface of the ribbon so that each individual fiber in the entire ribbon structure is uniquely identified. Each module or portion thereof can be broken out from the ribbon by means of a break-out tool which is sufficiently hard to cut the matrix bonding material which holds the fibers in the ribbon configuration, but which is not hard enough to cut the fiber coating.Type: GrantFiled: January 24, 1997Date of Patent: September 15, 1998Assignee: Lucent Technologies Inc.Inventors: Robert J. Brown, Kenneth Wade Jackson, Kenneth Martin Kroupa, Clyde Jefferson Lever, Stephanie Holland Webb
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Patent number: 5809050Abstract: An integrated laser-based light source that generates an output light beam having a controlled intensity. The light source comprises a package, a laser, a light sensor, and a beam splitter. The beam splitter is mounted in the package, together with the laser and the light sensor. The laser has one and only one light-emitting face from which it radiates a light beam as a radiated light beam. The light sensor generates an electrical signal representing the intensity of light energy falling on it. The beam splitter divides the radiated light beam into a fraction and a remainder, the remainder being the output light beam. The beam splitter operates by diffraction, scattering, or transmission to direct the fraction of the radiated light beam towards the light sensor.Type: GrantFiled: January 25, 1996Date of Patent: September 15, 1998Assignee: Hewlett-Packard CompanyInventors: Richard R. Baldwin, Scott W. Corzine, William D. Holland, Leif Eric Larson, David M. Sears, Michael R.T. Tan, Shih-Yuan Wang, Albert T. Yuen, Tao Zhang
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Patent number: 5805628Abstract: A semiconductor laser device includes a semiconductor substrate of a first conductivity type; opposed light emitting facets; a double heterojunction structure disposed on the semiconductor substrate and including an optical waveguide that extends between the facets and comprises a light emitting region and a lens region, the lens region being between the light emitting region and one of the facets, the double heterojunction structure including a plurality of AlGaAs series compound semiconductor layers which are thicker in the light emitting region than in the lens region; and a current blocking structure disposed on both sides of the double heterojunction structure and including a lower AlGaAs series compound semiconductor layer of the first conductivity type, an intermediate AlGaAs series compound semiconductor layer of a second conductivity type, opposite the first conductivity type, and an upper AlGaAs series compound semiconductor layer of the first conductivity type.Type: GrantFiled: October 23, 1996Date of Patent: September 8, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Shoichi Karakida, Norio Hayafuji, Tatsuya Kimura, Motoharu Miyashita, Hirotaka Kizuki, Takashi Nishimura
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Patent number: 5805624Abstract: A vertical cavity surface emitting laser (VCSEL) that generates light having a desired wavelength, greater than one micron. The laser comprises a substrate, a lower mirror region, an active region and an upper mirror region. The substrate consists essentially of GaAs. The lower mirror region is adjacent the substrate and is lattice matched to the substrate. The active region is sandwiched between the upper and lower mirror regions, and includes a central quantum well region and a gallium arsenide layer sandwiched between the quantum well region and each of the lower mirror region and the upper mirror region. The central quantum well region includes a quantum well layer consisting essentially of GaN.sub.x As.sub.(1-x). The GaN.sub.x As.sub.(1-x) of the quantum well layer has a lattice constant and a band gap dependent on x. The value of x sets the bandgap of the GaN.sub.x As.sub.(1-x) of the quantum well layer to a value corresponding to light generation at the desired wavelength, greater than one micron.Type: GrantFiled: July 30, 1996Date of Patent: September 8, 1998Assignee: Hewlett-Packard CompanyInventors: Long Yang, Danny E. Mars
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Patent number: 5805631Abstract: A laser for outputting visible light at the wavelengths of blue, green, orange and red light. This is accomplished through the doping of a substrate, such as an optical fiber or waveguide, with Pr.sup.3+ ions and Yb.sup.3+ ions. A light pump such as a diode laser is used to excite these ions into energy states which will produce lasing at the desired wavelengths. Tuning elements such as prisms and gratings can be employed to select desired wavelengths for output.Type: GrantFiled: July 26, 1996Date of Patent: September 8, 1998Assignee: The Regents of the University of CaliforniaInventors: Ping Xie, Timothy R. Gosnell
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Patent number: 5805630Abstract: An array of semiconductor diode lasers (11, 12) is a very suitable radiation source for various applications such as optical read and write systems and laser printers. Such an array includes a semiconductor body (10) with a substrate (1) and a layer structure provided thereon in which at least two lasers (11, 12) are formed which are mutually separated by a groove (20). In the known array, the groove (20) reaches down into the substrate (1), so that the lasers (11, 12) are electrically separated from one another. According to the invention, the array of lasers (11, 12) is provided with a groove (20) with a major portion (d) of its depth (D) which is situated within the substrate (1). As a result of this, the lasers (11, 12) of the array show a surprisingly low crosstalk. Preferably, the portion (d) of the groove (20) situated in the substrate (1) is at least 3 .mu.m deep. The best results are obtained with depths (d) of approximately 10 up to at most 40 .mu.m.Type: GrantFiled: July 11, 1994Date of Patent: September 8, 1998Assignee: U.S. Philips CorporationInventors: Adriaan Valster, Carolus J. Van Der Poel, Jeroen J. L. Horikx
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Patent number: 5805627Abstract: Embedded layers having a high resistance or an inverse conductivity with respect to a ridge structure are formed on either side of a ridge structure which is formed to correspond to an light emission region of a laser diode. The embedded layers confines a current in the ridge structure and moderates light-confinement performance in the ridge structure at an emitting end of the laser diode.Type: GrantFiled: October 23, 1995Date of Patent: September 8, 1998Assignee: Fujitsu LimitedInventors: Shinichi Kubota, Haruhisa Soda
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Patent number: 5802087Abstract: To prevent a power supply from being covered with dew for circuit protection and to downsize or simplify a laser apparatus: An excitation lamp 10 and a YAG rod (laser medium) 12 of a laser oscillator are disposed within a chamber 14. Heat-generating electrical components or elements of the power supply, such as diodes D1-D6 of a three-phase full-wave rectifier circuit 24, IGBT 26, GTR 30 and output transistors of driver circuits 34 and 36 are mounted on a heat sink 46. A water-cooled cooling apparatus 50 supplies deionized water (cooling water) DW whose temperature is controlled at a predetermined temperature, for instance, 25-35 degrees centigrade to the heat sink 46 of the power supply via pipes 72 and 76 as well as the chamber 14 of the laser oscillator via pipes 70 and 74.Type: GrantFiled: January 11, 1996Date of Patent: September 1, 1998Assignee: Miyachi Technos CorporationInventor: Kohji Takaichi
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Patent number: 5802090Abstract: A semiconductor laser diode which emits radiation in the 2-5 micrometer wavelength range and operates at room temperature. The laser diode includes an active layer of an In.sub.x Ga.sub.1-x As.sub.y Sb.sub.1-y alloy and a separate cladding layer on each side of the active layer. One of the cladding layers is of n-type conductivity and the other cladding layer is of p-type conductivity. At least the n-type cladding layer, and preferably both cladding layers, are of either an InAlPSb or an InGaPSb alloy.Type: GrantFiled: May 13, 1997Date of Patent: September 1, 1998Assignee: David Sarnoff Research Center, Inc.Inventors: Pamela Kay York, Ramon Ubaldo Martinelli
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Patent number: 5802093Abstract: A continuous wave photolytic iodine laser has a gain cell for receiving a continuous supply of gaseous fuel. The gain cell is connected to laser beam transfer optics, a laser resonator for shaping a laser beam, and a lamp. The lamp is driven by a microwave subsystem such that a laser gain medium is pumped through the gain cell. The continuous wave photolytic iodine laser of the present invention incorporates a closed loop fuel system for presenting gaseous fuel to the gain cell at a rate sufficient to sweep any lasing by-products out of the gain cell, thereby preventing quenching of the lasing process. The fuel system also includes a condenser for converting the gaseous fuel to a liquid after it has passed through the gain cell, a scrubber for removing the by-products of the lasing process from the fuel, and an evaporator for converting the recycled liquefied fuel back to a gas. The closed loop fuel system also includes a pump for pressurizing and transporting the liquefied fuel.Type: GrantFiled: May 22, 1996Date of Patent: September 1, 1998Inventors: Sallie S. Townsend, Philip R. Cunningham
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Patent number: 5802088Abstract: A stack type semiconductor laser device, which has a large overlapped area of beam patterns made by laser beams irradiated from a plurality of semiconductor laser elements, is disclosed. A first semiconductor laser element is formed on an N-type semiconductor substrate and is bonded to a surface of a pedestal at the side of an N-type electrode thereof through a solder layer. On the other hand, a second semiconductor laser element is differently formed on a P-type semiconductor substrate, and an N-type electrode thereof is bonded to a P-type electrode of the first semiconductor laser element through a solder layer in such a way that the laser beam irradiation planes of both semiconductor laser elements face in the same direction.Type: GrantFiled: September 25, 1996Date of Patent: September 1, 1998Assignee: Nippondenso Co., Ltd.Inventors: Yoshinori Otsuka, Kinya Atsumi, Yuji Kimura
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Patent number: 5802092Abstract: A diode laser source including a laser diode whose emitting element array or elements or subarray is divided into a plurality of concurrently driven laser segments. Beam filling and focusing optics are disposed in front of the segments so that light from the segments in each element or subarray converges to a single overlapping spot. The optics include a beam filling lens array collimating the light from the segments and either a single focusing lens or a second lens array focusing the collimated light to corresponding spots. In the case of a element laser diode array, each multi-segment element or subarray of the array is individually addressable so as to be driven independently from the other multi-elements array elements. The segmentation of laser elements improves laser life by reducing thermal gradients and isolating any local failures to a single segment, while separately focusing of the segments of each subarray to overlapping light spots increases the tolerance of the source to local failures.Type: GrantFiled: October 25, 1996Date of Patent: September 1, 1998Assignee: SDL, Inc.Inventor: John Endriz
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Patent number: 5802084Abstract: The mode-locked laser with improved pulse power output can be realized by combining an optical oscillator with a flared CW or modulated gain amplifier. An optical filter or isolator may be disposed between the oscillator and amplifier to avoid feedback of spontaneous noise. A two-segment laser is devised by providing a flared gain section between a modulated gain section and an absorber section within the integrated semiconductor laser. The flared section may taper from a larger modulated gain section to a smaller cross section absorber section or vice versa. Various combinations of absorber sections coupled to modulated gain sections by CW gain or passive flared gain sections may be combined with various arrangements of reflectors and tapered CW gain amplifiers are cascades of such amplifiers and modulated gain pairs.Type: GrantFiled: November 14, 1994Date of Patent: September 1, 1998Assignee: The Regents of the University of CaliforniaInventors: John E. Bowers, Alan Mar, Roger J. Helkey, Judy Karin