Abstract: The invention relates to an optical system in the ray path of a confocal fluorescence microscope, comprising at least one laser light source (1, 2), a device positioned in the illuminating/detecting beam (3, 4, 5) for separating the exciting light (8) from the fluorescent light (9), an objective (10) arranged between the device and the object (7), and a detector (11) positioned downstream of the device situated in the detecting beam (5). The aim of the invention is to increase the fluorescence yield of the system while retaining its compact structure.

Abstract: A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the uses of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: In a solid-state laser in which a gain crystal is polished to have the Brewster angle or a solid-state laser comprising a dichroic concave mirror to which light enters at an incidence angle which is not zero, astigmatism generally occurs in pumping light. By tilting a focusing lens for pumping light with respect to the optical axis of the pumping light, the astigmatism is compensated. The tilting angle is determined in such a manner that synthetic focusing points in the sagittal and tangential planes, of a series optical system of a focusing lens, a dichroic concave lens, and a gain crystal are calculated and the focusing points almost coincide with focusing points in a cavity mode.

Abstract: A multiple spectral line Raman laser having adjustable relative power output between different spectral lines is provided. The laser includes a lasing cavity, first and second reflectors optically coupled to a back end of the cavity that reflects substantially all light having wavelengths of &lgr;1 and &lgr;2, respectively, and a tunable reflector assembly optically coupled to a front end of the cavity that reflects a selected proportion of said light having wavelengths of &lgr;1 and &lgr;2 in response to a single source of strain to control relative power output of light at these wavelengths. The lasing cavity may be a linear length of gain fiber, and the tunable reflector may include a single fiber Bragg grating (FBG) having a trapezoidal reflection profile, or a pair of fiber Bragg gratings mounted on either side of a flexible substrate such that when the substrate is bent, one FBG stretches while the other is compressed.

Abstract: An apparatus for laser beam targeting and method of laser cutting or marking of an article is disclosed. In one aspect of the invention, the laser beam targeting apparatus comprises at least one laser scan head comprising at least one motor driven deflector for scanning a linearly polarized laser beam across a target, and a polarization control device comprising at least one Brewster plate wherein the polarization control device rotates the Brewster window around an axis parallel to the laser beam to thereby gradually transmit or deflect the laser beam in order to control the level of laser beam energy scanning across the target in accordance with the movement of the at least one deflector and a laser scanner.

Abstract: An apparatus for adjusting an orientation of an optical component mounted within a laser resonator with suppressed hysteresis includes an electromechanical device, a drive element, and a mechano-optical device coupled to the mounted optical component. The drive element is configured to contact and apply a force to the mechano-optical device in such a way as to adjust the orientation of the mechano-optical device, and thereby that of the optical component, to a known orientation within the laser resonator. The optical component is mounted such that stresses applied by the mount to the optical component are homogeneous and substantially thermally-independent.

Abstract: An electron beam pumped semiconductor laser screen and an associated fabrication method are described which provide a display screen that has a relatively long operating lifetime, is less expensive to produce, and operates at lower electron voltages and near room temperature conditions. The laser screen includes a multi quantum well active gain region having quantum wells of GaInP and barrier layers of (AlxGa1−x)InP, thereby permitting operation in the visible, red spectrum. Moreover, the first layer epitaxially grown on the sacrificial substrate is an etch stop layer of (GaxAl1−x)yIn1−yP that acts as an etch stop during the subsequent etching of the sacrificial substrate and may also be used to adjust the cavity length to the correct resonance condition. The laser screen also includes an output mirror having alternating layers of two different compositions of GaxAl1−xAs that are epitaxially grown on the multi quantum well active gain region.

Abstract: A solid-state laser having an excitation light source, a lens system for focusing an excitation light produced from the light source, and a laser resonator which is laser-oscillated in response to the focused excitation light. The resonator includes only a gain medium and a solid-state medium having dispersion of a wavelength dependence opposite to that of the gain medium, and surfaces of the gain medium and the solid-state medium, which are respectively at opposite sides of opposing surfaces of the gain medium and the solid-state medium, are reflectively coated and act as mirror surfaces. At least one of the other surfaces of the gain medium and the solid-state medium, which ate positioned inside the resonator and are opposite to each other, is polished to a curved surface. The gain medium is excited by the focused excitation light so that the laser oscillation is made in the resonator.

Abstract: A grating based line narrowing unit with bi-directional beam expansion for line narrowing lasers. In a preferred embodiment a beam from the chamber of the laser is expanded in the horizontal direction with a three-prism beam expander and is expanded in the vertical direction with a single prism. A narrow band of wavelengths in the expanded beam is reflected from a grating in a Littrow configuration back via the two beam expanders into the laser chamber for amplification.

Abstract: A method and apparatus for generating optical pulses using an active mode-locking laser that includes a first modulation device, an optical selection device, a second modulation device and an amplification device. The method includes the steps of using the first modulation device to modulate a lightwave, selecting a modulation lightwave signal having a high frequency component by passing a lightwave through the optical selection device in a first direction, using the second modulation device to modulate a lightwave, selecting a modulation lightwave signal having a high frequency component by passing a lightwave through the optical selection device in a second direction, amplifying the lightwave selected by the above step, and supplying the amplified lightwave to the first modulation device.

Abstract: A fiber-optic laser source capable of emitting multiple useful wavelengths at the same time, including multiple ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define a first set of possible lasing wavelengths corresponding to ITU grid lasing wavelengths, and a resonant filter for defining a subset of the first set of wavelengths. The arrangement is enclosed in a ring resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator may also comprise in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in a set of single cavity longitudinal modes.

Abstract: A wavelength monitor capable of obtaining an optical detection signal of high quality is proposed. In the wavelength monitor, a light incident surface of an optical filter is disposed with an inclination relative to the light incident direction. With this arrangement, it is possible to make the route of a reflection light that has been reflected from the light incident surface of the optical filter deviate large from the route of an incident light that has been incident to the optical filter. Consequently, the reflected light is prevented from being incident to a semiconductor laser device or optical detectors.

Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam is generated by a tunable laser source and portions thereof are filtered by an absolute reference filter and the periodic filter. First the frequency of the laser source is automatically locked on the absolute reference filter, and then the frequency response of the periodic filter is locked relative to the frequency of the laser source. The frequency response of the periodic filter is therefore continuously maintained at the proper calibration. User input and output are provided to pass the user light beam through the stabilized periodic filter independently of the filter stabilization process. A broadband absolutely calibrated optical source and a method for absolutely calibrating an optical spectrum analysis device are also provided.

Abstract: An apparatus for generating a coherent laser beam from an emission of a series of diode lasers, comprising at least one row of source diodes and a system for transforming the primary light emission emitted by the source diodes into secondary coherent light emission, wherein the system for transforming the primary emission into secondary coherent light emission includes a hologram, which comprises an image of an interference pattern of the primary light emission and the secondary coherent light emission, so that when illuminating the hologram with the primary light emission, the hologram reflects the secondary coherent light emission and in that a mirror is provided in the path of the secondary coherent light emission, which reflects at least some of the secondary coherent light emission via the hologram to the diode lasers.

Abstract: This disclosure discusses techniques for obtaining wavelength selected simultaneously super pulsed Q-switched and cavity dumped laser pulses utilizing high optical damage threshold electro-optic modulators, maintaining a zero DC voltage bias on the CdTe electro-optic modulator (EOM) so as to minimize polarization variations depending on the location of the laser beam propagating through the CdSe EOM crystal, as well as the addition of one or more laser amplifiers in a compact package and the use of simultaneous gain switched, Q-switched and cavity dumped operation of CO2 lasers for generating shorter pulses and higher peak power for the hole drilling, engraving and perforation applications.

Abstract: This invention provides a laser scanning microscope in which a harmonic generator for modulating a laser beam Q having passed through an optical fiber into a laser beam Qb having a wavelength different from that of the laser beam Q, and sending the laser beam Qb to a scanning type optical microscope main body is integrally attached to the scanning type optical microscope main body.

Abstract: A solid state laser, includes laser rod tubes (10, 117) crimped onto each end of a laser rod (15, 121) with PTFE seal rings (25, 118) compressed between the laser rod and the laser rod tube. The compressed seal rings provide an improved leak tight seal in a laser pumping chamber. Each laser rod tube (10) provides a mounting and holding area (20) for supporting the laser rod ends therein while protecting and sealing the end faces of the laser rod. A swaging tool (40) and method for swaging the laser rod tube (10) onto the laser rod (15) to provide a compression fit are provided. The compression seal and swaging method are usable in a variety of leak tight sealing applications.

Abstract: The method and system operate to calibrate a transmission laser of the dense wavelength division multiplexer (DWDM) and to lock the laser to a selected transmission wavelength. In one example, the transmission laser is a widely tunable laser (WTL) to be tuned to one of a set of International Telecommunications Union (ITU) transmission grid lines for transmission through an optic fiber. To lock the WTL to an ITU grid line, a portion of the output beam from the WTL is routed through the etalon to split the beam into a set of transmission lines for detection by an etalon fringe detector. Another portion of the beam is routed directly to a laser wavelength detector. A wavelength-locking controller compares signals from the two detectors and adjusts the temperature of the etalon to align the wavelength of one of the transmission lines of the etalon with the wavelength of the output beam, then controls the WTL in a feedback loop to lock the laser to the etalon line.

Abstract: An optical element includes a base member formed of a material transmitting a light of a predetermined wavelength therethrough and an optical acting surface provided on the base member. The optical acting surface has a plurality of micro structures smaller than the predetermined wavelength for creating potential confining one of an electron and a dipole moment therein, and desired optical action utilizing the light of the predetermined wavelength discharged by the vibration of the electron or the dipole moment confined in the potential formed by the micro structures.

Abstract: A wavelength tuning system adjusts an external cavity of a laser about two orthogonal axes for aligning features of a diffractive optic with a third orthogonal axis about which the diffractive optic is pivoted for providing selected wavelength feedback to the laser. A laser mount supports the laser, and a mounting arm supports both the diffractive optic and a reflective optic in a fixed orientation with respect to each other. A flexural member forms at least part of a connection between the mounting arm and the laser mount in a relative orientation for optically coupling the diffractive optic to the laser within the external cavity. The mounting arm is pivoted with respect to the laser mount about the pivot axis by an actuator for varying a wavelength of a diffracted portion of the output beam returned to the laser without significantly varying an angular orientation of the output beam with respect to the laser mount as reflected from the reflective optic.

Abstract: External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about one-hundred milliwatts (100 mW) or greater, even at wavelengths in the ultraviolet region of the electromagnetic spectrum. These high output powers can be provided even in single axial-mode operation.

Abstract: The present invention provides a semiconductor laser module. A semiconductor laser module (1A) comprising a semiconductor laser element (2a) and an optical fiber (3a) optically coupled by an optical coupling means (2b) is provided, wherein on the optical fiber (3a), a reflective portion (4) and a birefringence fiber (3a) are provided, the birefringence fiber (3a) is provided at least from the incident end on the side of the optical coupling means (2b) to immediately before the reflective portion (4), a connection portion (6) is provided at least at one point in the longitudinal direction of the birefringence fiber (3a), and in the connection portion (6), two eigen axes of X axes and Y axes are connected so that the eigen axes intersect each other at an established angle &thgr;.

Abstract: A cavity has a longitudinal hollow having opposite open ends. An excitation source, such as a YAG rod, is accommodated in the hollow of the cavity. A hollow, cylindrical rod holder is inserted into each of the opposite open ends of the hollow and is fitted over a corresponding end of the YAG rod. A seal is fitted into a hollow of the rod holder adjacent to a portion of the rod holder fitted over the end of the YAG rod. The seal includes an annular seal body with a U-shaped section, e.g. made from Teflon®, and fitted over an outer periphery of the YAG rod to grip the YAG rod, as well as a spring fitted in a groove of the seal body provided by the U-shaped section so as to circumferentially surround a gripped portion of the YAG rod.

Abstract: The laser resonator system includes a first reflector; a second reflector; at least a first gain medium; a second gain medium; and, an Offner relay system. The first gain medium and the second gain medium are operatively positioned relative to the first and the second reflectors. The first and second gain media generate a laser beam. The Offner relay system is operatively positioned between the first and the second gain media for relaying the laser beam between the first and the second gain media. The laser resonator system uses the Offner relay system for optimal transmission of the laser beam between the two gain media.

Abstract: The present invention provides a wavelength-tunable laser apparatus which is capable of obtaining a high output while suppressing the generation of spontaneous emission, as well as having a broad wavelength-tunable range.

Abstract: An efficient F2 laser is provided with improvements in line selection, monitoring capabilities, alignment stabilization, performance at high repetition rates and polarization characteristics. Line selection is preferably provided by a transmission grating or a grism. The grating or grism preferably outcouples the laser beam. The line selection may be fully provided at the front optics module. A monitor grating and an array detector monitor the intensity of the selected (and unselected) lines for line selection control. An energy detector is enclosed in an inert gas purged environment at slight overpressure. A blue or green reference beam is used for F2 laser beam alignment stabilization and/or spectral monitoring of the output laser beam. The blue or green reference beam advantageously is not reflected out with a atomic fluorine red emission of the laser and is easily resolved from the red emission.

Abstract: A semiconductor surface light-emitting device comprises, in a multi-layered structure formed on a substrate, a light-emitting part surrounded by a groove or grooves, provided with an active layer, a vertical cavity and a current aperture, a peripheral part external to the grooves, and a connecting portion connecting the light-emitting part with the peripheral part. There is provided an empty space or a high-resistance region on the upper part of this multi-layered connecting portion, which includes at least the current aperture formed layer or the active layer. This configuration effectively eliminates a path for a leakage current flowing into the peripheral part from the light-emitting part.

Abstract: The inventive chiral laser achieves lasing by placing an electro-luminescent emitting layer with quarter wave plate properties and a layer of cholesteric liquid crystal (CLC) between two electrodes. The electrode connected to the emitting layer is highly reflective and serves as a source of electrons, while the second electrode, connected to the hole-transporting CLC, serves as a source of holes. The recombination of electrons and holes in the emitting layer produces luminescence. If a right handed CLC structure is used, then right circularly polarized emission is reflected from the CLC as right circularly polarized light, and then converted to linear polarized light by passing through quarter wave plate emitting layer. It is then reflected by the electrode and converted again into the right circularly polarized light in a second pass through the quarter wave plate emitting layer.

Abstract: A distributed feedback laser device includes a semiconductor base having a ridge waveguide structure projecting from its principal plane. The ridge waveguide structure extends with a predetermined width from one edge of the semiconductor base to an opposite edge. A diffraction grating layer is confined within the ridge structure. The ridge waveguide structure is formed by etching using an SiO2 film and a resist film as masks so that the diffraction grating layer is produced with substantially the same width as, or a less width than, the width of the ridge waveguide structure. A &lgr;/4 shift diffraction grating or a chirped diffraction grating is preferably employed.

Abstract: A vertical-external-cavity surface-emitting laser (VECSEL) is formed by providing a monolithic portion having a first laser cavity mirror and an active region disposed on the first mirror. The cavity is completed with a second laser cavity mirror, such as a DBR, deposited onto the light-receiving end of an optical device, such as an optical fiber. The DBR-on-fiber-end is mounted with respect to the active region to complete the laser cavity and to provide automatic coupling of the output laser light into the fiber.

Abstract: The method and system operate to maintain a widely tunable laser (WTL) at a selected transmission wavelength. To lock the WTL to an ITU grid line, a portion of the output beam from the WTL is routed through the etalon to split the beam into a transmission line for detection by an etalon fringe detector. Another portion of the beam is routed directly to a laser wavelength detector to determine the power of the beam. A wavelength-locking controller compares signals from the two detectors and adjusts the temperature of the etalon to align the wavelength of one of the transmission lines of the etalon with the wavelength of the output beam, then controls the WTL in a feedback loop to lock the laser to the etalon line. The wavelength-locking controller thereafter monitors the temperature of the etalon and keeps the temperature constant to prevent any wavelength drift attributable to the etalon.

Abstract: A tunable laser system where incoming light is separated into wavelength separated light; the separated light is focused into a plurality of single wavelength focal spots. The laser system includes a locally controllable reflectivity array having a plurality of individually controllable localized reflective elements corresponding to and reflecting one of the plurality of focal spots. A wavelength filter substantially allows wavelengths of the incoming light separated by a specified frequency to emerge as filtered light, while substantially barring other wavelengths. The separated light includes this filtered light. An elongation element for elongates the wavelength separated light into a plurality of elongated single wavelength focal spots. The locally controllable reflectivity array includes a plurality of sets of a plurality of individually controllable localized reflective elements, each set corresponding to and reflecting one of the elongated single wavelength focal spots.

Abstract: A method for tuning a laser via a temperature control loop that linearizes a non-linear characteristic of a thermal electric cooler (TEC) element used to adjust the temperature of tuning components and corresponding laser apparatus. One or more TEC elements are thermally coupled to respective tuning components, such as etalon filters. The TEC elements provide a heat transfer function (cooling rate) in response to a received electrical input (drive signal), wherein the relationship between the cooling rate and the drive signal is non-linear. An un-compensated drive signal produced by the control loop is compensated such that the open loop gain of the control loop is linearized via a linearizer control block. In effect, the non-linear transfer function of the TEC element is cancelled out by the linearizer control block to produce a linear relationship between the cooling rate and the drive signal.

Abstract: A method for selecting free spectral ranges (FSR) of intra-cavity optics to optimize reliability of the channel switching mechanism and corresponding apparatus. In particular, the optimal relationship between the FSR of the internal etalon and the FSR of the laser cavity is derived. For the external cavity diode lasers (ECDL) the optimal relationship between the FSR of the internal etalon and the FSR of the gain chip is also derived. Equations are derived for selecting free spectral ranges of various optical cavities so as to create a locally commensurate condition under which the relative position of the lasing mode with respect to the transmission peak of the laser's tunable filter (e.g., etalon plus channel selector) does not change when the laser hops between adjacent channels.

Abstract: An optically pumped laser has a gain medium positioned inside of an optical resonator cavity and disposed about a resonator optical axis. An optical pumping source is positioned outside of the optical resonator cavity. A reflective coupler with a coupler body, and an interior volume passing therethrough is positioned proximal to the optical pumping source. Light from the pumping source passes into an entrance aperture of the reflective coupler to an exit aperture of the reflective coupler positioned distal to the optical pumping source. The interior volume of the reflective coupler is bounded by a reflective surface, an entrance aperture and the exit aperture, and is substantially transparent to radiation from the optical pumping source. The reflective surface has a high reflectivity matched to radiation from the optical pumping source.

Abstract: In a diode-pumped laser amplifier the inventive object is to increase the tolerance of the amplifier arrangement relative to variations of the input parameters significantly, so that fine-tuning is no longer necessary for guaranteeing the stability of the amplifier. Into a laser-active solid-state medium where a thermal lens of a strength which is different in orthogonal planes is generated in consequence of the irradiated pump radiation, a laser beam to be amplified is directed into the laser-active solid-state medium while being focused in the plane with a strong thermal lens, wherein a beam waist that is being generated lies in the area of the thermal lens. The laser amplifier can be used for amplifying the radiation of an oscillator.

Abstract: A method of wavelength locking and mode monitoring a tuneable laser that includes two or more tuneable sections in which injected current can be varied, including at least one reflector section and one phase section. Laser operation points are determined as different current combinations through the different laser sections, and the laser operates at a predetermined operation point. The wavelength of light emitted by the laser is detected by a wavelength selective filter. The laser is controlled in an iterative process in which alternated currents through the reflector section and, when applicable, its coupler section, and the current through the phase section are adjusted. The currents through the reflector section and the coupler section are adjusted to obtain a minimum ratio between power rearwards and power forwards. The current through the phase section is adjusted to hold the wavelength constant, the wavelength being measured against a wavelength reference.

Abstract: A deep-ultraviolet violet laser beam which is a harmonic and is generated inside a nonlinear optical element (101) is emitted outside the nonlinear optical element (101), being spaced from a green laser beam, which is a fundamental wave. The green laser beam emitted outside the nonlinear optical element (101) is reflected by an input-coupling mirror (102) and applied again into the nonlinear optical element (101) in order to form a closed optical path for the fundamental wave. Also, the deep-ultraviolet laser beam emitted outside the nonlinear optical element (101) is reflected by a reflecting mirror (28) other than the input-coupling mirror (102) in order to emit the deep-ultraviolet laser beam from a deep-ultraviolet laser beam-generating section (20).

Abstract: A method of filtering an input optical signal, the method including the step of: (a) utilising the phase response of a Gires-Tournois resonator to produce a corresponding spatial separation in a predetermined wavelength range of the input optical signal. The method further preferably can include the step of: (b) projecting substantially orthogonal beams onto the surface of a Gires-Tournois resonator at slightly different angles of incidence and utilising the phase difference in the phase response of the orthogonal beams to spatially separate the predetermined wavelength range. A birefringent wedge can be utilised to separate a polarised input beam into the substantially orthogonal beams for projection onto the surface of the Gires-Tournois resonator.

Abstract: An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately &rgr;Lcrystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

Abstract: A semiconductor pump laser comprises a ridge waveguide electro-optical structure, which converts a ridge injection current into light and an integrated wavelength selective facet reflector. This reflector controls the longitudinal modal operation of the pump laser. Specifically, the reflector comprises a first reflective structure for reflecting light to return through the ridge waveguide electro-optical structure. A second reflective structure provides wavelength-selective reflectivity when operating in combination with the first reflective structure. In other words, the phase of light reflected from the first and second reflective structures is such that the net reflectivity of the facet is wavelength selective, or favors certain wavelengths over other wavelengths.

Abstract: A compound intercavity interferometer for a free-electron laser (FEL) comprising at least two beam splitters positioned at a predetermined angles with respect to optical pathways. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope of meaning of the claims.

Abstract: An electrically variable optical filter includes a first optical element including a first angled face and a second optical element including a second angled face. The second angled face is substantially parallel to and spaced apart from the first angled face. At least one separation actuator is affixed between the first optical element and the second optical element and is operable to change a separation distance D between the first angled face and the second angled face. Light waves transmitted through the first optical element are selectively transmitted through to or reflected away from the second optical element as a function of wavelength and the separation distance D.

Abstract: The semiconductor laser has a resonance cavity composed of a gain chip, a Mach-Zehnder wide tuning port, and a wavelength-selective mirror component formed either as a ring resonator or a reflective Fabry-Perot etalon. Optical signals generated by the gain chip propagate through the wide tuning port and into the wavelength-selective mirror component and are then reflected back to the gain chip. The wavelength-selective mirror component is configured to reflect only those optical signals having wavelengths within a set of sharp peaks so that the laser cavity resonates only within the sharp peaks. The wavelength-selective mirror component is heated to adjust internal dimensions to maintain one of the sharp peaks at a selected emission wavelength. As optical signals pass through the wide tuning port, the signals are split between two channels of differing lengths resulting in optical interference.

Abstract: An arrangement for the resonant frequency doubling of multimode laser radiation with resonators is provided, including mirrors and an optically nonlinear material. The arrangement ensures a dispersion-free tuning of the length of a passive resonator, and enables the frequency doubling of a multimode laser, which is resonant simultaneously for all modes of the laser radiation, and which is achieved by pairs of mutually oppositely disposed movable elements of an optically transparent material, such as prisms (P1, P2). The prisms are brought into the beam path of the resonator (R), formed from mirrors (M1 to M4) and optically nonlinear material (BBO). The prisms are movable elements (P1, P2) which are connected to adjusting elements such as piezoactuators, so that the optical length of the resonator (R) can be tuned and compensation for dispersion attained.

Abstract: A laser-radiation source includes a laser delivering an output beam, a lens, and an optical arrangement for dividing the output beam into a main beam and an auxiliary beam. The main and auxiliary beams are coupled by the lens into entrance faces of respectively a main optical fiber and an auxiliary optical fiber. The entrance face of the main optical fiber is located on the optical axis of the lens. The entrance face of the auxiliary optical fiber is laterally displaced from the optical axis of the lens.

Abstract: A multi-channel light source for use with a wavelength division multiplexed optical communication system includes a modified vertical cavity surface emitting laser (VCSEL) including a gain region and a resonator reflector layer at a first end for coupling with an optical fiber. An optical or electrical pumping source excites a gain region of the laser. An external cavity couples at a second end of the modified VCSEL and has a mirrored end for forming a resonant cavity with the resonator reflector layer permitting the light source to produce a multi-channel optical signal. The modified VCSEL has a cavity length that is substantially extended compared with a conventional VCSEL.

Abstract: Vertical cavity surface emitting lasers (VCSELs) and methods of making the same are described. The VCSELs include reliability-enhancing layers that perform specific functions at one or more critical locations within a VCSEL structure to reduce or prevent defect formation and migration that otherwise might degrade VCSEL performance, for example, by increasing optical absorption in the mirror stacks or by degrading the electro-optic properties of the active region. In particular, the reliability-enhancing layers are configured to perform one or more of the following functions within the VCSEL structure: gettering (i.e., removing defects or impurities from critical regions), strain balancing (i.e., compensating the lattice mismatch in the structure to minimize strain), and defect suppression (i.e., creating alloys that reduce the formation of defects during growth or post-growth activities).

Abstract: Apparatus and methods that provide a tunable laser output wavelength which varies linearly or with high predictability over time, and which can provide tuning speeds of greater than 100 nanometers per second. The apparatus includes a laser resonator cavity having first and second reflective elements, at least one of which is movable to provide a constant change in output wavelength with respect to time. A tuning assembly associated with the movable reflective element is structured, configured, and positioned to adjust the movable reflective elements such that constant changes in output wavelength and high tuning speeds are provided.

Abstract: The invention relates to a microlaser cavity (10) having: a solid active medium (2) emitting at least in a wavelength range between 1.5 and 1.6 &mgr;m, and a saturable absorber (4) of formula CaF2:Co2+ or MgF2:Co2+ or SrF2:Co2+ or BaF2:Co2+ or La0.9Mg0.5-xCoxAl11.433O19 or YalO3:Co2+ (or YAl5-2xCoxSixO3 YAl(1-2x)CoxSixO3) or Y3Al5-x-yGaxScyO12:Co2+ (or -3Al5-x-y2zGaxScyCozSizO12 Y3Al5-x-y-2zGaxScyCozSizO12) or Y3-xLuxAl5O12:Co2+ (or Y3-xLuxAl5-2yCoySiyO3) or Sr1-xMgxLayAl12-yO12:Co2+ (or Sr1-xMgx-yCoyLazAl12-zO12, with 0<y<x) Sr1-xLaxMgxAl12-xO19:Co2+ (or Sr1-xLaxMgx-yCoyAl12-xO19 , with 0<y<x).