Abstract: In a method for producing a resonant cavity light emitting device, a seed gallium nitride crystal (14) and a source material (30) are arranged in a nitrogen-containing superheated fluid (44) disposed in a sealed container (10) disposed in a multiple-zone furnace (50). Gallium nitride material is grown on the seed gallium nitride crystal (14) to produce a single-crystal gallium nitride substrate (106, 106?). Said growing includes applying a temporally varying thermal gradient (100, 100?, 102, 102?) between the seed gallium nitride crystal (14) and the source material (30) to produce an increasing growth rate during at least a portion of the growing. A stack of group III-nitride layers (112) is deposited on the single-crystal gallium nitride substrate (106, 106?), including a first mirror sub-stack (116) and an active region (120) adapted for fabrication into one or more resonant cavity light emitting devices (108, 150, 160, 170, 180).

Abstract: The present invention is directed a method of fabricating a VCSEL. First, a substrate with a back surface and a front surface is provided. Then, a first reflector, an active region, and a second reflector are disposed on the front surface. The first reflector is disposed on the front surface. The active region is interposed between the first reflector and the second reflector. Then, anti-reflection features are formed into the back surface of the substrate to reduce specular reflection of light into the active region.

Abstract: A linear cavity design to produce a traveling wave operation as in a ring laser without the ring cavity design. All fiber configurations may be used to implement fiber lasers based on the linear cavity design.

Abstract: A laser source includes a laser medium having a back facet and a front surface, whereby the laser medium is adapted to emit a laser beam through the front surface into an external cavity defined in length by a cavity end mirror reflecting the laser beam back towards the laser medium. A wavelength tunable filter is arranged between the laser medium and the cavity end mirror adapted for tuning the wavelength of the laser beam. The laser medium, the wavelength tunable filter, and the cavity end mirror are arranged in a spatially linear cavity structure substantially in a line without angular redirection of the laser beam in the cavity between the laser medium and the cavity end mirror. At least one portion of the laser beam within the cavity after passing the wavelength tunable filter and before again passing the laser medium is coupled out as an output beam of the laser source, and the cavity end mirror is provided to be partly transparent for coupling out a first output beam.

Abstract: The present invention provides a vertical-cavity surface emitting laser (VCSEL) diode and a method for producing the same. In this method, an n-type and a p-type ohmic contact electrodes are previously disposed, and then two pairs of distributed Bragger reflectors (DBRs) are formed. At last, a permanent metal substrate is plated. According to the present invention, reflectivity of the DBRs can be preserved without damage during rapid thermal annealing, and thus brightness of the laser diode is improved.

Abstract: A method and apparatus for converting a Gaussian laser beam into a propagating far field diffraction pattern using an off-axis diffractive optic. This propagating far field pattern is focused by a lens to obtain a flattop intensity at the focal plane. The technique is based on the idea of Fourier transform pairs and produces a small spot diameter with a useable depth of field. A focused uniform intensity profile can be useful for many laser applications.

Abstract: The present invention provides systems and methods for filtering particles and assisting gas flow management within laser systems. In one embodiment, a laser apparatus (100) includes an elongate laser chamber defining a chamber cavity (130) and an electrode structure (140) disposed therein. The electrode structure includes an anode (148) spaced apart from a cathode (146). The laser includes an elongate baffle (174) disposed in the laser chamber. The baffle is adapted to arrest a plurality of particles generated within the chamber. In this manner, the baffle operates as a passive filtration system to help filter particles generated within the chamber during laser operation, and may further provide gas flow management capabilities.

Abstract: This invention relates to a laser cavity with passive triggering by saturable absorbent and with controlled polarization, and to a laser and in particular to a microlaser containing the said cavity and means of pumping this cavity. The invention also relates to a process for manufacturing the said microlaser. The laser cavity with controlled polarization comprises a substrate made of Y3Al5O12 (YAG) active laser material that may or may not be doped, on which a monocrystalline layer of saturable absorbent doped YAG material is deposited directly by liquid phase epitaxy or by a similar process, in which the said active laser material has a [100] orientation, and in which the said monocrystalline layer of saturable absorbent material is deposited with the same [100] orientation.

Abstract: A surface emission semiconductor laser device capable of substantially completely controlling the plane of polarization is obtained. This surface emission semiconductor laser device comprises a first multi-layer reflector, an emission layer formed on the first multi-layer reflector and a second multi-layer reflector formed on the emission layer, and at least either the first multi-layer reflector or the second multi-layer reflector includes a striped part worked in a striped manner in a prescribed period.

Abstract: A tunable laser and laser tuning method based on the use of a tunable etalon in reflection as a mirror within a laser cavity and forming an end reflective surface thereof. The laser emission wavelength is not necessarily at a wavelength of peak etalon reflectivity. A preferred embodiment makes use of a microelectromechanical etalon to tune an external cavity semiconductor.

Abstract: Fiber gratings (5), (6) having substantially the same reflection center wavelength are provided in an optical fiber (4). The fiber gratings (5), (6) reflects to the semiconductor laser element (1), only a component at the reflection center wavelength of laser light emitted from the semiconductor laser element (1).

Abstract: An object is to obtain an even energy distribution of a laser beam in one direction, thereby conducting a uniform laser annealing on a film. A laser irradiation apparatus comprising: a lens for dividing a laser beam in one direction; and an optical system for overlapping the divided laser beam, characterized in that the shape of the laser beam entering into the lens has edges vertical to the above-mentioned direction.

Abstract: A tunable laser and laser tuning method based on the use of a tunable etalon in reflection as a mirror within a laser cavity. The laser emission wavelength is not necessarily at a wavelength of peak etalon reflectivity. A preferred embodiment makes use of a microelectromechanical etalon to tune an external cavity semiconductor laser.

Abstract: An optical device including a laser with a laser cavity having a gain curve with a maximum at a wavelength ?max; and an optical carrier coupled to the cavity. The optical carrier includes a grating that defines a reflection peak coefficient at a wavelength ? that is less than the wavelength ?max by at least 10 nanometers at ambient temperature.

Abstract: A semiconductor laser device, module, and method for providing light suitable for providing an excitation light source for a Raman amplifier. The semiconductor laser device includes an active layer configured to radiate light, a spacer layer in contact with the active layer and a diffraction grating formed within the spacer layer, and configured to emit a light beam having a plurality of longitudinal modes within a predetermined spectral width of an oscillation wavelength spectrum of the semiconductor device. A plurality of longitudinal modes within a predetermined spectral width of an oscillation wavelength spectrum is provided by changing a wavelength interval between the longitudinal modes and/or widening the predetermined spectral width of the oscillation wavelength spectrum.

Abstract: A wavelength selecting optical element such as a narrow band-pass filter or the like is provided between a semiconductor laser and a light wavelength conversion element formed of a bulk-shaped wavelength conversion crystal. The wavelength selecting optical element selects a wavelength of a laser beam which is to be reflected by an end surface of the light wavelength conversion element to be fed back to the semiconductor laser.

Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.

Abstract: A semiconductor laser module has a Fabry-Perot type semiconductor laser device, an optical fiber, and first and second lenses. The tip of the optical fiber, on which the laser beam falls, is askew polished. The optical fiber is fixed in such a manner that the axis of the optical fiber makes an angle with respect to an optical axis of the laser beam. Coatings that avoid reflection are formed on the tip of the optical fiber, and on the first and second lenses.

Abstract: A circuit module including at least one Application Specific Integrated Circuit (ASIC) and a plurality of Vertical Cavity Surface-Emitting Laser (VCSEL) array modules is built using a standard ceramic or organic Multi-Chip Module (MCM) package substrate, resulting is a high density device with a small footprint. Interconnection between the electronic devices and the VCSEL array modules is accomplished using standard integrated circuit packaging technology and flexible connectors. Optical connections from the VCSEL arrays to fiber optic cables are made possible by integrating industry-standard optical connectors onto the package. Optical receiver and transceiver modules may also be incorporated into the circuit module.

Abstract: A method of fixing an optical component includes the steps of scoring a surface of a support, bringing an optical component into close contact with the scored surface of the support, and flowing a fluid adhesive along kerfs produced by the scoring. An optical component support has a surface provided with scoring kerts for fixing the optical component. The method and support enable fixing of an optical component by a thin, uniform adhesive layer, without fine polishing of the optical component and the surface of the support.

Abstract: A standing wave self-compensating laser resonator for preventing the utilization efficiency of a laser beam from being lowered, while at the same time, improving the quality of the laser beam wherein, a first reflecting apparatus 21 having first and second reflecting surfaces 21a, 21b disposed at a right angle to each other and a second reflecting apparatus 22 having third and fourth reflecting surfaces 22a, 22b disposed at a right angle to each other face each other such that ridges 21c, 22c are orthogonal, a third reflecting apparatus 123 having two reflecting surfaces which are approximately parallel to and face from each other is provided between the second reflecting surface 21b and fourth reflecting surface 22b, a laser medium 23 is provided between the first reflecting surface 21a and third reflecting surface 22a, and the laser beam is not incident on the ridges 21c, 22c.

Abstract: A cavity assembly includes a mounting member, an active gain medium, at least one electro-optic component and at least one alignment assembly. The mounting member defines an aperture within which the active gain medium is disposed, and is comprised of a thermally conductive material. The alignment assemblies are disposed relative to the active gain medium, and are configured to receive the electro-optic components such that electro-optic components at least partially align with the active gain medium. The alignment assemblies are rotatably disposed relative to the active gain medium such that relative rotation of the alignment assemblies and the active gain medium alters the alignment of the respective electro-optic components with respect to the active gain medium. The cavity assembly may be mounted within a thermally conductive housing to transfer heat away from the active gain medium.

Abstract: An optical monitor device and method are presented aimed at providing low-loss monitoring of an optical signal confined in an optical guiding structure. An optical resonator structure is placed spatially adjacent to the guiding structure and is optically coupled to the guiding structure, and an optical detector is optically coupled to the resonator structure. The coupling between these elements is such that the coupling of light from the guiding structure to the optical resonator is smaller then the coupling of light from the resonator to the optical detector.

Abstract: A method for compensating thermal optical effects in the beam path of an arrangement containing optical components uses, for the purpose of optical compensation in the beam path, optical elements which have different material properties in cooperation. For the purpose of compensation, heating by means of radiation absorption, radial thermal conduction for generating a power-dependent temperature distribution, and/or thermal dispersion for generating a thermal lens are distributed over the different elements.

Abstract: The invention pertains to wavelength-agile optical filters suitable for wavelength-division-multiplexed (WDM) optical communications networks. More particularly, the invention pertains to optical filters with a wavelength reference that can be remotely switched to arbitrarily selectable channels on a standard grid, and to re-configurable optical communications networks employing same. The present invention provides a communication apparatus with a tunable filter which may be used in a wide range of applications including tuning an external cavity laser (ECL), selecting a wavelength for an add/drop multiplexer and providing channel selection and feedback for a wavelength locker. The filter may be utilized as a discrete component or in combination with circulators, wavelength lockers and gain medium. The filter may be implemented in whole or in part as part of a gain medium.

Abstract: The present invention is a method and apparatus for using ring resonators to produce narrow linewidth hybrid semiconductor lasers. According to one embodiment of the present invention, the narrow linewidths are produced by combining the semiconductor gain chip with a narrow pass band external feedback element. The semi conductor laser is produced using a ring resonator which, combined with a Bragg grating, acts as the external feedback element. According to another embodiment of the present invention, the proposed integrated optics ring resonator is based on plasma enhanced chemical vapor deposition (PECVD) SiO2/SiON/SiO2 waveguide technology.

Abstract: A gas discharge tube such as a ring laser gyroscope includes a block. A cathode has an inwardly extending foot that engages the block. Additionally, or alternatively, an insulator is arranged to inhibit shorting between plasma in the block and a flange of the cathode.

Abstract: Heretofore, if the beam size of the resonance mode is made small in a long resonator length, there arises a problem that the operation of the laser resonator becomes easy to be unstable and hence the adjustment thereof becomes difficult. A laser resonance includes: a laser material; a telescope for magnifying a laser beam which has been made incident from the laser material and for reducing a laser beam which has been made incident from the side opposite thereto; a flat reflecting mirror for reflecting the laser beam which has been made incident from said telescope; a telescope for magnifying the laser beam which has been reflected by the flat reflecting mirror to be reduced by the telescope and to be amplified by the laser material to be made incident thereto; and a flat reflecting mirror for reflecting the laser beam which has been made incident from the telescope.

Abstract: A wavelength-selectable laser with a resonance region formed by two reflecting surfaces include a gain medium generating a laser beam, a first filter, and a second filter. The first filter has a first controllable transmission region and transmits a first predetermined wavelength region of the laser beam generated in the gain medium, the first predetermined wavelength region matching the first controllable transmission region. The second filter has a plurality of periodically arranged second transmission regions and transmits a second predetermined wavelength region of the laser beam transmitted by the first filter, the second predetermined wavelength region matching one of the second transmission regions.

Abstract: A laser light source is equipped with a semiconductor light-emitting device, a first wavelength selector, and a second wavelength selector. The first and second wavelength selectors are used to select the wavelength of the light emitted from the light-emitting device, and constitute an external resonator. The semiconductor light-emitting device is provided with a stripe, which is formed oblique to the cleaved end facets of the light-emitting device that do not constitute the external resonator. The end facets of the semiconductor light-emitting device are provided with coatings, which become antireflective coatings with respect to the selected wavelength.

Abstract: The present invention relates to a cascaded multi-wavelength Raman fiber laser adapted for emitting radiation of at least one wavelength &lgr;s1, with a length of optical fiber (13) having input (15) and output (16) sections, means (11) for introducing pump radiation of wavelength &lgr;p into said length of optical fiber (13), at least one pair of spaced-apart reflector means (151,161; . . .

Abstract: A process evaluates an aging property of a distributed Bragg reflector (DBR) laser. The process includes illuminating a Bragg grating of the distributed Bragg reflector (DBR) laser with light while the DBR laser is both supplied a tuning current and not lasing. The process also includes performing an action to the DBR laser responsive to a wavelength of a Bragg peak in a portion of the light reflected by the Bragg grating and a value of the tuning current supplied during the illuminating.

Abstract: A vertical resonator laser diode and a method for fabricating it are described. Electrical connecting contacts can be disposed on a common main surface of the laser diode, for example its light exit side. For this purpose, in the course of the fabrication method, a contact-making zone is produced by indiffusion of impurity atoms, by which zone that side of the pn junction which is remote from the main surface can be electrically conductively connected to the main surface and be provided with a corresponding connecting contact.

Abstract: An exposure apparatus to be used with an excimer laser as a light source includes an optical system disposed along a path of excimer laser light, a chamber for accommodating the optical system therein and having an inside space being able to be replaced by a predetermined gas, a gas circulation mechanism having a gas circulation path for connecting a gas discharging port for discharging a gas from the chamber and a gas supplying port for supplying a gas into the chamber, and a switching device for selectively using plural purifiers disposed in the gas circulation path.

Abstract: An ultra-broadband, variable and multiple wavelength, waveform shaping apparatus is disclosed that excels with the ability to yield light pulses shaped in waveform, variable and multiple in wavelength over an ultra-broad bandwidth, the pulses being as short as in the order of pico-seconds or less, or even in the order of femto-seconds.

Abstract: An optical module includes a light-emitting device that outputs laser light, a temperature detection unit that is arranged in proximity to the light-emitting device and detects the temperature of the light-emitting device, a wavelength monitor unit that receives laser light outputted from the light-emitting device and having passed through an optical filter and monitors the wavelength of the laser light, and a temperature adjustment unit that adjusts the wavelength of laser light outputted from the light-emitting device based on a signal outputted from the wavelength monitor unit. The temperature adjustment unit adjusts the wavelength of the laser light so as to fall within a wavelength range, in which the wavelength is adjustable by the wavelength monitor unit, based on a signal from the temperature detection unit, and then adjusts the wavelength of the laser light so as to be locked at a predetermined wavelength based on the signal from the wavelength monitor unit.

Abstract: An error signal generation system and method for continuous and accurate positioning of a tunable element used in association with a coherent light source. A tunable element is positioned in a coherent light beam with a fixed frequency or wavelength, and a detector is positioned in association with the light beam and tunable element that is capable of generating an error signal indicative of spatial losses associated with the positioning of the tunable element in the light beam. A tuning assembly is operatively coupled to the tunable element and detector and is configured to position the tunable element according to the error signal generated by the detector.

Abstract: The present invention relates to a wavelength-swept laser and a method for generating laser output. The wavelength-swept pulse laser according to one aspect of the present invention uses spontaneous mode-locking to produce a pulse output with the center wavelength continuously varying with time. On the contrary, the wavelength-swept laser according to another aspect of the present invention suppresses mode-locking to produce continuous output by tuning the filter frequency change speed to the frequency shift speed of the frequency shifter. The lasers of the present invention are applicable to optical sensing or WDM optical communication.

Abstract: A discontinuous phase element (86, 204) is disposed between the reflector (20, 23) elements of an optical resonator in order to suppress unwanted modes propagating within the cavity, and to preferentially allow the existence of preferred modes within the cavity. The discontinuous phase element (204) operates by producing sharp changes in the phase distribution of the undesirable modes, so that their propagation losses are sufficiently high prevent their build-up. This is achieved by introducing a discontinuous phase change to these modes at locations where they have high intensity. At the same time, the desired modes suffer 0 or 2&pgr; phase change, or have low intensity at the discontinuity, and so are unaffected by the discontinuous phase element. Such elements can be used in a single element or a double element configuration, and can be used in passive cavities or active cavities, such as lasers.

Abstract: A semiconductor optical amplification system that uses a single-mode fiber angle-coupled to a semiconductor wave-guide medium with optical gain. This design is particularly simple and relevant to optical fiber systems, but it may be generalized to include other implementations as well, in which other spatial mode filters are employed. A chip design is employed in which lowest order mode has a size greater than about 5 micrometers (&mgr;m). Thus, much smaller facet angles can be employed while still avoiding self-oscillation. More specifically, according to some aspects of the invention, facet angles of less than 4 to 5 degrees are utilized.

Abstract: A solid laser apparatus has either a combination of a lowpass filter and a highpass filter or a bandpass filter provided in its output control circuit for increasing the gain and adjusting the phase of a signal in the vicinity of the relaxation oscillating frequency. Also, a solid laser apparatus has the phase shift circuit provided in its output control circuit for advancing the phase of a signal in the vicinity of the relaxation oscillating frequency thereof. Moreover, a solid laser apparatus has a pseudo notch filter, which is arranged for the gain to have a local minimum at the relaxation oscillating frequency of the solid laser apparatus, provided in the output control circuit so that the peak of the gain transmission characteristic of the nonlinear optical device or of a combination of the nonlinear optical device and the microchip laser crystal is offset.

Abstract: A laser apparatus includes a semiconductor laser element, a surface-emitting semiconductor element including a first mirror, a second mirror, and a modulation unit. The semiconductor laser element emits first laser light having a first wavelength. The surface-emitting semiconductor element is excited with the first laser light, emits second laser light having a second wavelength which is longer than the first wavelength. The first mirror in the surface-emitting semiconductor element is arranged on one side of the first active layer. The second mirror is arranged outside the surface-emitting semiconductor element so that the first and second mirrors form a resonator in which the second laser light resonates. The modulation unit modulates the surface-emitting semiconductor element.

Abstract: A wavelength-locked, integrated optical signal source structure using a semiconductor laser device is disclosed. The optical source structure has a semiconductor laser formed on a semiconductor substrate, and an etched portion coupled with an output end of the semiconductor laser. The etched portion is configured to pass on a first amount of light beam radiated by the semiconductor laser, and to reflect a second amount of light beam by a given reflection angle. A multiple microcavity is formed in a position spaced apart from the etched portion, and the first amount of light beam is incident upon the multiple microcavity. The optical source structure has a first optical detector for detecting the first amount of light beam passing through the multiple microcavity, and a second optical detector for detecting the second amount of light beam reflected by a slanted, reflecting surface portion of the etched portion.

Abstract: Provided are a semiconductor laser device capable of increasing an emission angle of a laser beam, an astigmatic correction plate used therefor and a method of arranging the astigmatic correction plate. In order to correct the astigmatism of a laser beam emitted from a first laser light source or a second laser light source, the astigmatic correction plate is arranged so as to intersect diagonally an optical center line (an optical axis) of the laser beam, and the astigmatic correction plate, the first light source and the second light source are arranged so that an optical axis of the first laser light source coincides with a center line (CL) of an effective diameter of an aperture and a distance from the second laser light source to the astigmatic correction plate in a direction parallel to the optical axis is shorter than a distance from the first laser light source to the astigmatic correction plate.

Abstract: A light frequency locker (10) able to accept a light beam (14) generated by a controllable light source (12) into a light diverter (16) and impart to it a transverse displacement characteristic which can be detected in a light detection unit (20) connected to a processor (22). The processor (22) then controls the light source (12). Optionally, a light diverger (18) may be provided to enhance angular resolution. The light diverter (16) and the light diverger (18) may either transmit or reflect the light. The light diverter (16) may particularly include a diffraction grating (116, 156), Fabry-Perot interferometer (216), multiple slit plate (316), or an acousto-optical unit (416).

Abstract: A method for modulating the output of an optically pumped, tunable VCSEL. Two approaches are disclosed. In a first approach, the output of the VCSEL is modulated by modulating the pump laser. In a second approach, the output of the VCSEL is modulated by modulating a voltage applied across the active region.

Abstract: A unit cell is disclosed that facilitates the creation of a layout of at least a portion of a microelectromechanical system. The unit cell includes a plurality of electrical traces. Some of these electrical traces pass through the unit cell. Other electrical traces extend only part way through the unit cell. At least certain boundary conditions exist for the unit cell that allow the same to be tiled in a row and in a manner that results in adjacently disposed unit cells in the row being electrically interconnected in the desired manner.

Abstract: A laser beam pointing and positioning system includes first and second rotatable diffraction gratings. Each grating deviates a laser beam by a predetermined angle of deviation. The relative rotational position of the gratings is controlled to change the beam steering angle and direction of a laser beam. A maximum beam steering angle of twice the angle of deviation may be achieved in any direction. The diffraction gratings may be etched on transmissive substrates of optical glass, sapphire, silicon (Si), Zinc Selenide (ZnSe), Zinc Sulfide (ZnS), or Germanium (Ge). The substrates may be positioned within rotary elements coupled respectively to electromechanical positional control elements to rotate the gratings.

Abstract: A laser transmitter capable of transmitting large numbers of WDM channels but requiring locking of only a single channel. Each of the channels can be individually modulated using an external modulator.

Abstract: The invention relates to the stabilization of high power semiconductor laser diode sources as they are extensively used in the field of optical communication. Such lasers are mostly employed as so-called pump laser sources for fiber amplifiers, e.g. erbium-doped fiber amplifiers, and are designed to provide a narrow-bandwidth optical radiation with a stable power output in a given frequency band. To improve the wavelength locking range of such laser sources when operating without an active temperature stabilizing element, an external reflector providing very high relative feedback is used. The reflectivity bandwidth of the external reflector is broadened for improving the stability of the laser source. In commonly employed optical fibers for conducting the laser beam, the external reflector is formed by one or a plurality of appropriately designed fiber Bragg gratings.