Abstract: The invention relates to the field of optical parametric oscillators (OPO), especially to an essentially vertical monolithic system (S) for parametric conversion from a pump wave with a pump wavelength, said system comprising at least two resonant cavities (6, 7). Said cavities are coupled by at least one coupling mirror (3), at least one of the cavities comprising an active non-linear medium, and the at least one coupling mirror being arranged in such a way that the parametric frequencies associated with the pump wavelength are located in the stop line of the at least one mirror for an injection direction of the pump wave essentially according to the axis of the system.

Abstract: A robust scalable laser. The laser includes plural fiber laser resonators. A cavity that is external to the fiber laser resonators combines plural laser beams output from the plural fiber laser resonators into a single output laser beam. In a specific embodiment, the plural fiber laser resonators are eye-safe double-clad Er:YAG laser resonators that are pumped via laser diode arrays.

Abstract: Fundamental-wavelength pulses from a fiber a laser are divided into two portions and the two portions are separately amplified. One of the amplified fundamental-wavelength pulse-portions is frequency-doubled. The frequency doubled portion is sum-frequency mixed with the other amplified fundamental wavelength pulse-portions to provide third-harmonic radiation pulses.

Abstract: Included are: a gain chip having a gain unit and a phase control region; a current supply for causing a positive current to flow to the phase control region; a voltage supply for applying a bias voltage to the phase control region; and a control unit for selectively driving the current supply or the voltage supply depending on a direction of the wavelength shift. The control unit drives the current supply when a laser wavelength is to be shifted to a shorter wavelength side from a wavelength with the current supply and the voltage supply being turned off, and drives the voltage supply when the laser wavelength is to be shifted to a longer wavelength side from a wavelength with the current supply and the voltage supply being turned off.

Abstract: A normally opaque waveguide interacting with a drop-filter cavity can be switched to a transparent state when the drop filter is also coupled to a dipole. This dipole induced transparency may be obtained even when the vacuum Rabi frequency of the dipole is much less than the cavity decay rate. The condition for transparency is a large Purcell factor. Dipole induced transparency can be used in quantum repeaters for long distance quantum communication.

Abstract: An improved resonator and optical cavity is adapted for use with a chemical laser that has a nozzle upstream of the resonator that emits a gain medium in a flow direction, and a pressure-recovery system downstream of the resonator. The optical resonator comprises first and second optical elements that are spaced apart from one another along an optical axis. Each of the optical elements has a selected geometry and a selected optical transmissivity to permit transmissive outcoupling of a beam of laser radiation from the resonator, the outcoupled beam being transmitted about the optical axis. The transmissivity and geometry of each optical element is selected to define an unstable region between the optical elements and around the optical axis, and a stable region in a region surrounding the unstable region and spaced apart from the optical axis.

Abstract: A laser amplification system is disclosed that enables reliable operation over large ambient temperature operating window, as well as a significant reduction of laser temperature sensitivity typically associated with diode pumped lasers. The techniques employed by the system effectively eliminate damaging gain hot spots and lower ASE and ESA thresholds, thereby increasing laser peak and average power levels. Additionally, the techniques allow for thermal programming of active gain medium material to minimize thermally induced aberrations. In one particular example embodiment, a variable dopant concentration multi-pass laser amplifier is provided having a customized active ion concentration profile, tailoring the combination of laser absorption and gain distribution using a ceramic YAG host.

Abstract: A semiconductor device includes a substrate, a semiconductor layer formed on the substrate, and an optically functional portion formed by using at least a portion of the semiconductor layer. The optically functional portion performs light emission or light reception. The semiconductor device further includes a first driving electrode that is electrically connected to a semiconductor layer on a surface of the optically functional portion, and the first driving electrode drives the optically functional portion. The semiconductor device further includes an encapsulating electrode that is formed on the semiconductor layer to surround periphery of the optically functional portion, and electrically connected to the first driving electrode.

Abstract: Edge-emitting light source and method for fabricating an edge-emitting light source. The edge-emitting light source includes a photonic crystal having at least one waveguide region. An edge-emitting semiconductor structure having a light emitting active layer is incorporated within the at least one waveguide region. Light emitted by the edge-emitting semiconductor structure and within the bandgap of the photonic crystal is confined within the waveguide region and guided out of the photonic crystal through the waveguide region.

Abstract: An optical coupling device for coupling light with an optical waveguide comprises a mirror formed within an optical waveguide. The mirror comprises a first material, a first reflective end, and a second reflective end. The first material is light conducting and has a first refractive index. The first and second reflective ends reflect and transmit light. The mirror has an axis line. The optical coupling device is useful for extracting light from a waveguide and providing a backlight for a liquid crystal display.

Abstract: Provided is a pump laser integrated vertical external cavity surface emitting laser (VECSEL). The VECSEL may include a surface emitting laser unit including a first active layer having a multiple quantum well structure emitting light having a first wavelength, a reflective layer may be formed on the first active layer, and an external mirror may be disposed opposite to a lower surface of the first active layer and defining a cavity resonator together with the reflective layer. A pump laser unit may be formed on a part of the surface emitting laser unit and may have a perpendicular light emissive surface emitting a pump beam having a second wavelength for exciting the first active layer. A beam reflector may be formed on the light emissive surface of the pump laser unit and reflecta pump beam that is incident from the pump laser unit to the first active layer.

Abstract: A first light feedback element is arranged at an optical distance L1 from a front facet of a semiconductor laser from which an output light is emitted on an optical path of the output light. An i-th light feedback element is arranged at an optical distance Li from the front facet on the optical path of the output light, where i=2 to n, n is a positive integer not less than 2, and Li>L1. L1 and Li satisfies ((M?1)+0.01)<(Li/L1)<(M?0.01), where M is a positive integer not less than 2, satisfying (M?1)<(Li/L1)?M.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium but not the optical switch. When the primary resonator is closed by the optical switch, and pulses are not being amplified, CW radiation is generated in the secondary resonator and prevents the gain-medium from being saturated. When the optical switch is operated to cause the primary resonator to amplify pulses, generation of CW radiation in the secondary resonator ceases.

Abstract: A stabilised gain semiconductor optical amplifier (CG-SOA) includes and active waveguide (1) comprising an amplification medium (2), extending in longitudinal (Z), lateral (X) and vertical (Y) directions, and coupled to a laser oscillation structure comprising at least two resonant cavities (13, 14) extending in first (D1) and second (D2) directions which are different from the longitudinal direction (Z) of the active waveguide (1) and arranged in such a way as to permit the establishment of laser oscillations having at least two different relaxation oscillation frequencies.

Abstract: Objects are achieved by an optical semiconductor device comprising: a structure 61 including a substrate 50, a diffraction grating 52a, an active layer 54 and a refractive index control layer 60; and an laser element 100 including an electrode 92a for the active layer, an electrode 92b for the refractive index control layer and an electrode 92c for switching, wherein a pre-bias current is previously supplied from the electrode 92a for the active layer to the active layer 54 in a state where a switching current is not supplied from the electrode 92c for switching to the active layer 54, and then while a current Idrive for activation is supplied from the electrode 92a for the active layer to the active layer 54, the laser element 100 is turned on by supplying the switching current Isw from the electrode 92c for switching to a part of the active layer 54, as well as turning off the laser element 100 by halting the supply of the switching current Isw.

Abstract: An ultra-low heat laser that does not rely on florescence cooling. Generally, the inventive laser includes a pump source operable at a pump frequency and a gain medium disposed to receive energy from the source and lase at a frequency close to the pump frequency. In the illustrative embodiment, the laser is a solid state laser having a gain medium which is resonantly pumped to lase at a frequency within 5% of the pump frequency. However, in the best mode and in accordance with the present teachings, the gain medium lases at a frequency within 1% of the pump frequency. In the illustrative embodiment, the laser gain medium ion has a rich Stark energy level structure and the laser active gain medium has oscillator strengths at transitions wavelengths that allow an ultra-low quantum defect operation. The pump source has a wavelength output centered to correspond to a predetermined pump band and an emission band subtended by an absorption bandwidth thereof.

Abstract: A normally opaque waveguide interacting with a drop-filter cavity can be switched to a transparent state when the drop filter is also coupled to a dipole. This dipole induced transparency may be obtained even when the vacuum Rabi frequency of the dipole is much less than the cavity decay rate. The condition for transparency is a large Purcell factor. Dipole induced transparency can be used in quantum repeaters for long distance quantum communication.

Abstract: A system and method for generating ultraviolet laser radiation by pumping a ruby based active laser medium in a second complex laser cavity with an output from a first complex laser cavity. The laser system includes a first complex optical cavity a second complex optical cavity, an output from the first complex optical cavity at a second harmonic of the first fundamental frequency pumps a ruby based active medium of the second complex optical cavity. In some embodiments, the ruby based active medium can be Cr:Al2O3 type ruby.

Abstract: A laser amplification system is disclosed that enables reliable operation over large ambient temperature operating window, as well as a significant reduction of laser temperature sensitivity typically associated with diode pumped lasers. The techniques employed by the system effectively eliminate damaging gain hot spots and lower ASE and ESA thresholds, thereby increasing laser peak and average power levels. Additionally, the techniques allow for thermal programming of active gain medium material to minimize thermally induced aberrations. In one particular example embodiment, a variable dopant concentration multi-pass laser amplifier is provided having a customized active ion concentration profile, tailoring the combination of laser absorption and gain distribution using a ceramic YAG host.

Abstract: A fiber ring laser is provided, which includes an optic amplifier, a first optical coupler (OCP), a second OCP, a first fiber ring, a second fiber ring, a first polarization controller (PC), and a second PC. The first fiber ring is coupled to the optic amplifier, the first and the second OCPs. The second fiber ring is coupled to the first and the second OCPs. The optic amplifier amplifies a first laser beam with a specified wavelength range. The first fiber ring receives the first laser beam. The first and the second fiber rings respectively provide a first and a second resonant cavities. The first and the second PCs respectively control polarization states of the first and second resonant cavities. The first laser beam resonates in the first and the second resonant cavities to generate a second laser beam with a first and a second wavelengths.

Abstract: A laser system comprises first and second laser sub-cavities each including a gain medium arranged to produce volume gain gratings. The laser system further includes a beam combiner arranged to combine emission from each cavity and direct emission from one cavity to the other. As a result a stale, phase-locked coherently combined emission system is provided.

Abstract: The invention relates to an unipolar quantum cascade laser comprising a plurality of adjacent semiconductor multilayer structures arranged in a periodic sequence through which an electron flow can be generated by providing at least two contact points, each of the multilayer structures having an optically active area comprising at least one quantum film structure in which there is at least one upper energy level and one lower energy level for the electrons, between which said levels light emitting electron transitions occur, as well as having a transition area comprising a plurality of semiconductor layers through which electrons from the lower energy level of said optically active area pass into the upper energy level of an optically active area of an adjacent semiconductor multilayer structure, which is directly adjacent to the transition area in the direction of electron transport, wherein the electron transitions and the electron transport occur solely in the conduction band of the semiconductor multilayer

Abstract: To provide surface-emitting type semiconductor lasers and methods of manufacturing the same in which the polarization direction of laser light can be readily controlled, a surface-emitting type semiconductor laser includes a vertical resonator above a substrate. The vertical resonator includes a first mirror, an active layer and a second mirror disposed in this order from the substrate. The vertical resonator has a plurality of unit resonators. An emission region of each of the unit resonators has a diameter that oscillates in a single-mode.

Abstract: A laser chamber is provided that increases power, initiation, and discharge efficiency over single chamber lasers by providing a multi-fold laser chamber, protrusions, discharge segmentation and inversion techniques.

Abstract: Techniques, apparatus and systems for providing compensation mechanisms for mode-locked lasers and optical amplifiers and a dispersion compensation mechanism to allow a mode-locked laser and an optical amplifier to be optically coupled to each other and to share a common diffraction grating for a dispersion compensation element for the laser and a separate dispersion compensation element for the amplifier.

Abstract: A laser device includes an outcoupling mirror, a laser medium, a phase-conjugate mirror based on stimulated Brillouin scattering, and an end mirror all arranged along an optical axis of the laser device. A controllable modulator is positioned between the phase-conjugate mirror and the end mirror. The outcoupling mirror and the end mirror form a start cavity. The outcoupling mirror and the phase-conjugate mirror form a main cavity.

Abstract: A laser equipment for outputting output lights having different wavelengths includes: a substrate; an excitation light generation element for emitting excitation lights including surface emitting laser elements and disposed on the substrate; and a light converter having a pair of second reflection layers and a solid laser medium layer, both of which provide a resonator. The solid laser medium layer is capable of generating lights having different peak wavelengths by receiving the excitation lights. The light converter is disposed on an output surface of the excitation light generation element.

Abstract: A laser arrangement comprising a first and a second resonant cavity for generating a first and a second fundamental wavelength. A first and a second non-linear region are provided in the second cavity for sum-frequency mixing of the radiation generated in the first cavity and in the second cavity, and for frequency-doubling of the radiation generated in the second cavity, respectively.

Abstract: A fiber ring laser is provided, which includes an optic amplifier, a first optical coupler (OCP), a second OCP, a first fiber ring, a second fiber ring, a first polarization controller (PC), and a second PC. The first fiber ring is coupled to the optic amplifier, the first and the second OCPs. The second fiber ring is coupled to the first and the second OCPs. The optic amplifier amplifies a first laser beam with a specified wavelength range. The first fiber ring receives the first laser beam. The first and the second fiber rings respectively provide a first and a second resonant cavities. The first and the second PCs respectively control polarization states of the first and second resonant cavities. The first laser beam resonates in the first and the second resonant cavities to generate a second laser beam with a first and a second wavelengths.

Abstract: A frequency-tripled laser-resonator has three resonator-branches. The branches are optically connected with each other by one or more polarization-selective devices. Unpolarized fundamental radiation is generated by optically pumping a gain-element in one branch of the resonator. The polarization-selective device provides that radiation in the other branches is plane-polarized, with the polarization planes of radiation entering the branches perpendicular to each other. Two optically nonlinear crystals are located in one of the branches of the resonator in which the fundamental radiation is plane-polarized and arranged to generate third-harmonic radiation. Three-branch resonators including two gain-elements having a optical relay therebetween, and a three-branch ring-laser-resonator are also disclosed.

Abstract: A structure includes a photonic crystal layer which has a first member having a first refractive index and having a surface with a plurality of holes periodically arranged therein, and includes a low-refractive-index layer adjacent to the photonic crystal layer and having a second refractive index that is lower than the first refractive index. The relative refractive index difference between the first refractive index and the second refractive index is 0.10 or lower. Third members having a third refractive index that is higher than 1.0 are disposed in the holes.

Abstract: An optical switch includes an optical source; a plurality of tunable optical resonators or tunable waveguides in optical communication with the optical source; and a tuning device configured to selectively route an optical beam from the optical source to at least one optical destination by tuning at least one of the optical resonators or tunable waveguides, in optical communication with at least one optical destination, to a wavelength characteristic of the optical beam.

Abstract: In one embodiment, a gain medium for an external cavity diode laser (ECDL) includes a gain section to provide a gain operation on optical energy in the ECDL that is controlled by a first electrical signal, a semiconductor optical amplifier (SOA) section disposed adjacent to the gain section to amplify the gained optical energy responsive to a second electrical signal, and a trench disposed between the gain section and the SOA section to act as an integrated mirror. Other embodiments are described and claimed.

Abstract: Provided is a light emitting structure which can emit light having a plurality of wavelength distributions from a single light emitting structure, can be integrated at high density, and can control a radiation mode pattern of radiation light and polarization thereof. A stacked three-dimensional photonic crystal is composed of a plurality of three-dimensional photonic crystals having photonic band gaps different from one another, which are stacked. Each of the plurality of three-dimensional photonic crystals includes a resonator in which a point defect is formed.

Abstract: Optical switches and logic devices comprising microstructure-doped nanocavity lasers are described. These switches and logic devices have gain and thus can be cascaded and integrated in a network or system such as for example on a chip. Exemplary switching elements switch the intensity, wavelength, or direction of the output. Exemplary logic devices include AND, OR, NAND, NOR, NOT, and XOR gates as well as flip-flops. Microfluidic sorting and delivery as well as optical tweezing and trapping may be employed to select and position a light emitter in a nanooptical cavity to form the nanolaser.

Abstract: Laser apparatus and methods involving multiple amplified outputs are disclosed. A laser apparatus may include a master oscillator, a beam splitter coupled to the master oscillator, and two or more output heads optically coupled to the beam splitter. The beam splitter divides a signal from the master oscillator into two or more sub-signals. Each output head receives one of the two or more sub-signals. Each output head includes coupling optics optically coupled to the beam splitter. An optical power amplifier is optically coupled between the beam splitter and the coupling optics. Optical outputs from the two or more output heads do not spatially overlap at a target. The master oscillator signal may be pulsed so that optical outputs of the output heads are pulsed and substantially synchronous with each other.

Abstract: A variable light controlling device comprising a substrate, an optical waveguide disposed on the substrate, a first heater and a second heater to change the optical waveguide's temperature is fabricated. And a total amount of the power supplied to the first and the second heater, or a total amount of heat emitted from both of the first and second heater, is maintained substantially constant. Then, the substrate is protected from temperature changes, thereby, stable and quick wavelength tuning operations are realized.

Abstract: A switching mechanism (6) and a diode pumped laser system (1) incorporating the switching mechanism (6) that allows a single diode laser pump source (2) to be selectively directed to one of two or more resonant laser cavities (11a,11n). The switching mechanism (6) comprises an optical element that is movable between a first position that directs the output of the diode laser (2) along a Diode first path (8a) and a second position that directs the output of the lase diode along a second path (8n).

Abstract: Sensors are provided which enable detection with a high sensitivity in microchemistry and biochemical analysis by using devices integrated into a compact configuration and can be freely disposed on desired positions of a channel to perform detection. A measuring apparatus for detecting information and outputting light according to the information, the apparatus comprising: an active layer for emitting light and a micro-optical cavity, wherein light emission is limited in the active layer due to the influence of the selection of a photoelectromagnetic field mode, the selection is made by the micro-optical cavity, the light emission and a degree of selection of a photoelectromagnetic field mode is changed according to an environmental condition of the micro-optical cavity, so that the light emission is changed and the environmental condition is measured according to a change in the light emission.

Abstract: An ultra-low heat laser that does not rely on florescence cooling. Generally, the inventive laser includes a pump source operable at a pump frequency and a gain medium disposed to receive energy from the source and lase at a frequency close to the pump frequency. In the illustrative embodiment, the laser is a solid state laser having a gain medium which is resonantly pumped to lase at a frequency within 5% of the pump frequency. However, in the best mode and in accordance with the present teachings, the gain medium lases at a frequency within 1% of the pump frequency. In the illustrative embodiment, the laser gain medium ion has a rich Stark energy level structure and the laser active gain medium has oscillator strengths at transitions wavelengths that allow an ultra-low quantum defect operation. The pump source has a wavelength output centered to correspond to a predetermined pump band and an emission band subtended by an absorption bandwidth thereof.

Abstract: An optical structure comprising an optical resonator is provided. The optical resonator comprises a first set of nested closed optical regions, forming a distributed feedback resonator structure with a direction of radially alternating optical refractive index, and a second set of nested optical regions, forming a distributed feedback resonator structure with a direction of radially alternating optical refractive index. Each optical region of the second set is interrupted by a first gap region with a lower refractive index, wherein the first gap regions substantially overlap in the direction of radially alternating optical refractive index. The first set is arranged nested within the second set and the optical structure further comprises a first optical waveguide optically coupled to the optical resonator via a first waveguide portion reaching into the first gap regions and being arranged coplanar to the optical resonator.

Abstract: An improved resonator and optical cavity is adapted for use with a chemical laser that has a nozzle upstream of the resonator that emits a gain medium in a flow direction, and a pressure-recovery system downstream of the resonator. The optical resonator comprises first and second optical elements that are spaced apart from one another along an optical axis. Each of the optical elements has a selected geometry and a selected optical transmissivity to permit transmissive outcoupling of a beam of laser radiation from the resonator, the outcoupled beam being transmitted about the optical axis. The transmissivity and geometry of each optical element is selected to define an unstable region between the optical elements and around the optical axis, and a stable region in a region surrounding the unstable region and spaced apart from the optical axis.

Abstract: An intracavity frequency-doubled includes a laser resonator including at least one gain element and two optically nonlinear crystals. The two optically nonlinear crystals independently double the frequency of fundamental radiation in the resonator. In one example the crystals are arranged to generate two frequency-doubled beams that are orthogonally plane-polarized with respect to each other. The beams can be combined by a polarization-selective combiner to form a common output.

Abstract: A unipolar semiconductor laser is provided in which an active region is sandwiched in a guiding structure between an upper and lower cladding layer, the lower cladding layer being situated on a semiconducting substrate. The unipolar semiconductor laser comprises a raised ridge section running from end to end between end mirrors defining the laser cavity. The ridge section aids in optical and electrical confinement. The ridge waveguide is divided in a plurality of cavity segments (at least two). Lattice structures can be arranged on and/or adjacent to these cavity segments. Each cavity segment is in contact with upper metallic electrodes. A metallic electrode coupled to the bottom surface of the semiconducting substrate facilitates current injection through the device.

Abstract: A plurality of subresonators (12, 14), having different design configurations, share a common resonator section (18) such that the lasing action can be substantially synchronized to provide coherent laser pulses that merge the different respective pulse energy profile and/or pulse width characteristics imparted by the configurations of the subresonators (12, 14). The subresonators (12, 14) may share a laser medium (42) in the common section, or each distinct subresonator section (28, 36) may have its own laser medium (42). Exemplary long and short subresonators (12, 14) generate specially tailored laser pulses having a short rise time and a long pulse width at one wavelength or two different wavelengths that may be beneficial for a variety of laser and micromachining applications including memory link processing.

Abstract: A plurality of subresonators (12, 14), having different design configurations, share a common resonator section (18) such that the lasing action can be substantially synchronized to provide coherent laser pulses that merge the different respective pulse energy profile and/or pulse width characteristics imparted by the configurations of the subresonators (12, 14). The subresonators (12, 14) may share a laser medium (42) in the common section, or each distinct subresonator section (28, 36) may have its own laser medium (42). Exemplary long and short subresonators (12, 14) generate specially tailored laser pulses having a short rise time and a long pulse width at one wavelength or two different wavelengths that may be beneficial for a variety of laser and micromachining applications including memory link processing.

Abstract: An optical resonant modulator includes an optical ring resonator and an optical loop that is coupled to the optical ring resonator by two couplers. The optical ring resonator can have a hybrid design in which the ring resonator is formed on an electro-optically passive material and the optical loop is formed on an electro-optically active material. An amplification section can be inserted between the electro-optically passive and the electro-optically active sections. In analog applications, an optical resonator includes a Mach Zehnder interferometer section having an input and an output, with a feedback path coupling the output to the input. Applications of the optical modulator of the invention, and a method for modulating an optical signal also are disclosed.

Abstract: Semi-integrated external cavity diode laser (ECDL) designs including integrated structures comprising a gain section, phase control section, and optional modulator section. Each integrated structure includes a waveguide that passes through each of the sections. A mirror is defined in the structure to define one end of a laser cavity. A reflective element is disposed generally opposite a rear facet of the gain section, forming an external cavity therebetween. A tunable filter is disposed in the external cavity to effectuate tuning of the laser. During operation, a modulated drive signal is provided to the phase control section. This modulates an optical path length of the laser cavity, which produces an intensity (amplitude) modulation in the laser output. A detector is employed to produce a feedback signal indicative of the intensity modulation that is used for tuning the laser in accordance with a wavelength locking servo loop.

Abstract: A single mode high power vertical cavity surface emitting laser (VCSEL) using photonic crystals. A photonic crystal is included in at least one mirror layer of a VCSEL. The reflectivity of the photonic crystal is dependent on the wavelength and incident angle of the photons. The photonic crystal can be formed such that the VCSEL lases at a single mode. Because a single mode is generated, the aperture of the VCSEL can be enlarged to increase the power that is generated by the VCSEL for that mode. The photonic crystal can be used with or without DBR layers. The photonic crystal, in one example, forms an external cavity.

Abstract: A microcavity structure includes a first waveguide that includes a first photonic crystal microcavity. A second waveguide includes a second photonic crystal microcavity. A microcavity active region is created by overlapping the first and second microcavities.