Abstract: A method for calibrating a preferred disposition for a moveable first mirror of an optical switch core of a photonic crossconnect device relative to a second mirror thereof, the method comprising the steps of determining approximate geometric coordinates of the first mirror relative to the second mirror, effecting a laser light crossconnection between the first and second mirrors to produce data from which to provide first order corrections to refine the geometric coordinates, and effecting a further laser light crossconnection between the first mirror and a third mirror, to produce data from which to provide second order corrections to further refine the geometric coordinates, whereby to calibrate the first mirror such that upon initiation of a laser light crossconnection involving the first mirror, a switching element detects deviation of the first mirror from the preferred disposition thereof and effects corrective changes.

Abstract: A laser transmitter adapted for use in small spaces such as pipes and sewers includes a housing having two exit windows positioned in generally orthogonal planes. The laser transmitter includes a leveling mechanism that is capable of directing a collimated beam through a select one of the two exit windows, in a generally horizontal direction at a specified grade irrespective of whether the laser transmitter is oriented generally horizontally or generally vertically.

Abstract: A device and a process for integrating light energy transmit and/or receive functions with active devices such as GaAs or InP devices or light emitting devices, such as lasers. The device and process includes forming a passivation layer on top of the active device and forming a silicon photodetector on top of the passivation layer. The photodetector may be formed utilizing a standard solar cell growth process and may be formed as a mesa on top of the active or light-emitting device, thus forming a relatively less complicated semiconductor with an integrated monitoring device.

Abstract: The invention provides a surface emission laser which can be operated with low-current drive, and a manufacturing method therefor. The invention also provides a light reception element which provides high-speed modulation, and a manufacturing method therefor. The invention also provides an optical transceiver module which provides enhanced optical connection efficiency. An opening portion from the other surface side of the semiconductor substrate to the end portion on the semiconductor substrate side of the light emission portion is formed on the semiconductor substrate of the surface emission laser, and a lens made of a transparent resin is formed through the use of the side surface of the opening portion.

Abstract: A GaN series surface-emitting laser diode and a method for manufacturing the same are provided. The GaN series surface-emitting laser diode includes: an active layer; p-type and n-type material layers on the opposite sides of the active layer; a first-distributed Bragg reflector (DBR) layer formed on the n-type material layer; an n-type electrode connected to the active layer through the n-type material layer such that voltage is applied to the active layer for lasing; a spacer formed on the p-type material layer with a laser output window in a portion aligned with the first DBR layer, the spacer being thick enough to enable holes to effectively migrate to a center portion of the active layer; a second DBR layer formed on the laser output window; and a p-type electrode connected to the active layer through the p-type material layer such that voltage is applied to the active layer for lasing.

Abstract: The prior art distributed feedback laser having an InGaAlAs active layer involves a problem that its laser characteristics are deteriorated at high temperature due to the high device resistance. According to the present invention, a ridge type laser is fabricated by: forming an InGaAlAs-MQW layer 104 on a n-type InP substrate 101; growing a p-type InGaAlAs-GRIN-SCH layer 105, a p-type InAlAs electron stopping layer 106 and a p-type grating layer 107 in this order on the InGaAlAs-MQW layer 104; forming a grating; and regrowing a p-type InP cladding layer 108 and a p-type InGaAs contact layer in this order. The concave depth of the grating is smaller than the thickness of the p-type grating layer 107.

Abstract: There is provided a surface emitting semiconductor laser satisfying a requirement of making a transverse mode stable and having characteristics of high output power, low resistance, high efficiency, and high speed response and a method for manufacturing the surface emitting semiconductor laser. Five holes are formed on the top surface of an upper multilayer reflection film formed in the shape of a post by the use of a focused ion beam (FIB) processing unit. One hole is formed on the surface of an upper multilayer reflection film corresponding to the center position of a square current injection region which is about 8 ?m square and the remaining four holes are formed at the corners of the square current injection region, for example, at the positions about 2 ?m square away from the one hole to produce four light emitting spots.

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: A beam parameter monitoring unit for coupling with an excimer or molecular fluorine (F2) laser resonator that produces an output beam having a wavelength below 200 nm includes an on-line laser pulse energy detector. This, in turn, allows output pulse energy stabilization to the same degree of accuracy, which is crucial for stability of exposure dose and other process parameters in microlithography and industrial applications.

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: 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 wide-slit lateral growth projection mask, projection system, and corresponding crystallization process are provided. The mask includes an opaque region with at least one a transparent slit in the opaque region. The slit has a width in the range of 10X to 50X micrometers, with respect to a X:1 demagnification system, and a triangular-shaped slit end. The triangular-shaped slit end has a triangle height and an aspect ratio in the range of 0.5 to 5. The aspect ratio is defined as triangle height/slit width. In some aspects, the triangular-shaped slit end includes one or more opaque blocking features. In another aspect, the triangular-shaped slit end has stepped-shaped sides. The overall effect of the mask is to promote uniformly oriented grain boundaries, even in the film areas annealed under the slit ends.

Abstract: The invention concerns a composite diamond window (10) which includes a CVD diamond window pane (12) which is mounted to a CVD diamond window frame (14). The frame (14) is thicker than the pane (12) and has a radiation transmission aperature (16) therein across which the pane spans.

Abstract: Selectively oxidized vertical cavity lasers emitting near 1300 nm using InGaAsN quantum wells are reported for the first time which operate continuous wave below, at and above room temperature. The lasers employ two n-type Al0.94Ga0.06As/GaAs distributed Bragg reflectors each with a selectively oxidized current aperture adjacent to the active region, and the top output mirror contains a tunnel junction to inject holes into the active region. Continuous wave single mode lasing is observed up to 55° C.

Abstract: A method involves aligning each of two optical components to be joined relative to a common standard, removing the common standard, and joining each of two optical components to each other in alignment.

Abstract: A recess 14 is provided in a lens accommodating portion 13 of a laser holder 10 for holding a collimator lens C, whereby positional accuracy and adhesion strength of the lens and a light source are improved.

Abstract: A semiconductor laser device which has a diffraction grating partially provided in the vicinity of an active layer formed between a radiation-side reflection film provided on a radiation-side end surface of a laser beam and a reflection film provided on a reflection-side end surface of the laser beam, and which outputs a laser beam having a desired oscillation longitudinal mode based on a wavelength selection characteristic of at least the diffraction grating. The diffraction grating is formed in isolation with an isolation distance of Ls=15 ?m from the radiation-side reflection film.

Abstract: An optical device has a back facet (27) and a front facet (29; 29?) opposite to each other, and includes a laser (23) adapted to emit light essentially perpendicular to said back facet; a modulator (25; 51; 55) having an input end and an output end (35; 53; 57), respectively, and adapted to receive and modulate light emitted from said laser and to output modulated light at said modulator output end; and a window region (33) arranged between said modulator output end and said device front facet, said device being further arranged such that modulated light output from said modulator is transmitted through said window region and is output from said device through said device front facet. The modulator is bent such that the modulated light output from said modulator is propagating essentially in a direction (34), which is angled (?; ?) with respect to the normal (Z; 71) of said device front facet.

Abstract: Disclosed is an illuminating optical unit in an image display unit for displaying an image by irradiating a GLV (spatial modulation device) with a laser beam and modulating the laser beam based on an image signal inputted to the GLV, which includes a polarized light rotation means for equally dividing a polarized light component of the laser beam into a P polarized light component and an S polarized light component, a polarized light beam splitter for separating from each other the P polarized light component and the S polarized light component equally divided by the polarized light rotation means, and an optical path difference generation means for generating an optical path difference not less than the coherence length of the laser beam between the laser beam of the P polarized light component and the laser beam of the S polarized light component.

Abstract: A light source apparatus equipped with a GaN type semiconductor laser, wherein deformation of the shape of the light spot due to fluctuations in the drive current of the light emitting element is prevented, is provided. A light source apparatus equipped with a GaN type semiconductor laser is provided with a slit panel or other spatial filter for eliminating stray light, which amounts to 20% or less of the total output occurring when the GaN type semiconductor laser is driven at maximum output, from the light emitted from the GaN type semiconductor laser.

Abstract: An excimer or molecular fluorine laser system includes a discharge chamber filled with a laser gas mixture at least including a halogen-containing molecular species and a buffer gas, multiple electrodes within the discharge chamber connected to a discharge circuit for energizing the gas mixture, and a resonator for generating a laser beam including an optical component made of MgF2. The optical component made of MgF2 has been previously cleaved along a predetermined plane, such that the refractive indices of the birefringent MgF2 material for orthogonal polarization components of the beam are either at least approximately equal so that the polarization of the beam due to the influence of the birefringent nature of the MgF2 material is not substantially reduced, or are approximately maximum so that at least a portion of one of the components is rejected by the resonator so that the polarization of the beam is increased due to the birefringent nature of the MgF2.

Abstract: A multiple source array for illuminating an object including: a reflective mask having an array of spatially separated apertures; at least one optic positioned relative to the mask to form an optical cavity with the mask; and a source providing electromagnetic radiation to the optical cavity to resonantly excite a mode supported by the optical cavity, wherein during operation a portion of the electromagnetic radiation built-up in the cavity leaks through the mask apertures towards the object.

Abstract: A laser array and method of making same has precision fiducial marks that aid in the alignment of the laser array. The invention requires forming additional optical features adjacent to the laser array that is used to write fiducial marks on an opposite surface in the medium containing the laser array. Fiducial marks are formed when high intensity collimated beams of light are directed through the optical features onto a treated portion of the transparent medium. Fiducial accuracies of 1 micron are possible by using this approach.

Abstract: A semiconductor laser device includes an active layer configured to radiate light, a light reflecting facet positioned on a first side of the active layer, and a light emitting facet positioned on a second side of the active layer thereby forming a resonator between the light reflecting facet and the light emitting facet. A diffraction grating is positioned within the resonator along a portion of the length of the active layer and the laser device is configured to operate as a multiple mode oscillation device. A window structure is provided between an end of the active layer and one of the light reflecting and light emitting facets, and the window structure is configured to reduce a reflectivity of the one of the light reflecting and light emitting facets.

Abstract: Accordingly, a method of suppressing energy spikes is provided comprising projecting a laser beam through a mask having a slit pattern comprising a corner region with edges, and a blocking feature with the corner region to reduce energy spikes projected on a substrate. An alternative method is provided, wherein the corner region is modified such that it is replaced by a more tapered shaped region, preferably a triangle. Also provided, are a variety of mask designs incorporating both corner regions, with and without one or more blocking features, and triangular regions, with or without one or more blocking features. The mask designs provide examples of mask modifications that may be used to reduce energy spikes.

Abstract: The present invention is directed toward a window or foil that transmits incident radiation with high efficiency and that is coupled to a cooling means to dissipate heat from radiation losses occurring within the window. In one aspect the invention provides an energy-transmitting system that includes a nonmetallic window and means for cooling the window. In a second aspect the invention provides a laser assembly including a laser cavity enclosed by a wall that has one or more surfaces, wherein at least one surface includes an actively cooled window of the invention. In various embodiments of both the energy-transmitting system and the laser assembly the window includes a dielectric material, or a semiconducting material such as silicon. In addition a corrosion-resistant coating may be deposited on at least one surface of the window.

Abstract: The invention is directed to a coated metal fluoride crystals that are resistant to laser-induced damage by a below 250 nm UV laser beam; methods of making such coated crystals, and the use of such coated crystals. The method includes the steps of providing an uncoated metal fluoride crystal of general formula MF2, where M is beryllium, magnesium, calcium, strontium and barium, and mixtures thereof, and coating the uncoated metal fluoride crystal with a coating of a selected material to thereby form a coated metal material resistant to laser induced damage. Preferred coating materials include MgF2, MgF2 doped fused silica and fluorine doped fused silica.

Abstract: A distributed Bragg reflector (DBR) for a vertical cavity surface emitting laser (VCSEL) has a semiconductor material system including the elements aluminum, gallium, arsenic, and antimony. Use of antimony in the DBR structure allows current to be pumped through the DBRs into an active region to provide for long wavelength, continuous wave operation of the VCSEL.

Abstract: Accordingly, a method of suppressing energy spikes is provided comprising projecting a laser beam through a mask having a slit pattern comprising a corner region with edges, and a blocking feature with the corner region to reduce energy spikes projected on a substrate. An alternative method is provided, wherein the corner region is modified such that it is replaced by a more tapered shaped region, preferably a triangle. Also provided, are a variety of mask designs incorporating both corner regions, with and without one or more blocking features, and triangular regions, with or without one or more blocking features. The mask designs provide examples of mask modifications that may be used to reduce energy spikes.

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 narrow band ultraviolet laser device which can restrict a change in temperature gradient at light transmitting sections and maintain laser light at a high grade. To this end, the ultraviolet laser device includes light shielding elements (37A to 37C) having light transmitting sections (47A to 47C) each constituted by an opening for transmitting laser light (11), and light shielding sections (49A to 49C) that surround the light transmitting sections (47A to 47C), remove an undesired laser light (11A) from an optical path and shape the laser light (11) into a predetermined form, wherein heating means (45) for heating the light transmitting sections (47A to 47C) are provided in the vicinity of the light shielding elements (37A to 37C).

Abstract: A waveguide device in the form of either a solid-state laser or amplifier is divided into separate pumping and output mode control sections along at least one direction of the device by leaving a portion of a core of the device unclad or by depositing appropriate coatings on different sections of the core or by contacting/bonding materials with different refractive indices to different sections of the core or by a combination of these approaches. The core has a pump input surface for receiving pumping radiation at a pumping wavelength and one or more output surfaces for emitting a laser beam at an output wavelength. When used as an amplifier, the core also has a laser input surface which may be the same as one of the output surfaces.

Abstract: A system for the reforming of a laser beam having a circular sector shaped beam cross section into a laser beam with a rectangular beam cross section, incorporates a mirror whose surface is shaped as the circular sector of a reflective parabolic rotational body. With only one mirror, and with only minor image aberrations, the circular sector shaped laser beam can be reformed into a rectangular laser beam.

Abstract: The invention relates to an High Repetition Rate UV Excimer Laser which includes a source of a laser beam and one or more windows which include magnesium fluoride. Another aspect of the invention relates to an excimer laser which includes a source of a laser beam, one or more windows which include magnesium fluoride and a source for annealing the one or more windows. Another aspect of the invention relates to a method of producing a predetermined narrow width laser beam.

Abstract: A laser comprising: a front mirror and a rear mirror which are disposed so as to establish a reflective cavity therebetween; a gain region disposed between the front mirror and the rear mirror, the gain region being constructed so that when the gain region is appropriately stimulated by light from a pump laser, the gain region will emit light; and one of the front mirror and the rear mirror being positioned to admit pump light into the reflective cavity, the one of the front mirror and the rear mirror having a low and substantially constant reflectance over a pumping wavelength range and having a high and substantially constant reflectance over a lasing wavelength range.

Abstract: An excimer or molecular fluorine laser system includes a discharge tube filled with a gas mixture, multiple electrodes within the discharge tube and connected to a discharge circuit for energizing the gas mixture, a resonator for generating a laser beam, and at least one window structure including a first window and a second window. The first window initially seals the discharge tube and transmits the beam. The second window is initially unexposed to the gas mixture. The window structure is configured such that the second window is movable into position for sealing the discharge tube and transmitting the beam when the first window becomes contaminated.

Abstract: A laser system comprises a laser diode with an active region and reflectors at both ends. An outcoupling aperture is located between the reflectors to couple light out of the device through the surface. The gain region increases in width as it nears the outcoupling aperture.

Abstract: A GaN series surface-emitting laser diode and a method for manufacturing the same are provided. The GaN series surface-emitting laser diode includes: an active layer; p-type and n-type material layers on the opposite sides of the active layer; a first-distributed Bragg reflector (DBR) layer formed on the n-type material layer; an n-type electrode connected to the active layer through the n-type material layer such that voltage is applied to the active layer for lasing; a spacer formed on the p-type material layer with a laser output window in a portion aligned with the first DBR layer, the spacer being thick enough to enable holes to effectively migrate to a center portion of the active layer; a second DBR layer formed on the laser output window; and a p-type electrode connected to the active layer through the p-type material layer such that voltage is applied to the active layer for lasing.

Abstract: A laser device capable of efficiently oscillating laser light and always obtaining a stable beam form is provided. For this purpose, in the laser device including an amplifying section (18) in which a laser medium is amplified to oscillate laser light (11), and an optical element for separating part of the laser light (11) oscillated, and shaping a beam form of the laser light (11) into a desired form to output the same, wherein the optical element has at least either one of a partial reflecting portion (26) for partially reflecting the laser light (11) or a non-reflective portion (28) for transmitting the laser light (11) at high transmissivity, each of which is provided on approximately a center portion, and a total reflecting portion (27) which is provided outside a perimeter of the partial reflecting portion (26) or the non-reflective portion (28), and which reflects the laser light (11) at high reflectivity.

Abstract: A stray light cutting structure for an optical device provided with an optical component through which a predetermined light beam travels in parallel to the optical axis of the optical device is provided. The structure is for cutting stray light, which travels at an angle to the optical axis of the optical device to enter the optical component through one end face thereof, and includes at least one notch formed on one side face of the optical component.

Abstract: Disclosed is a semiconductor laser device capable of minimizing the spot diameter of a laser light and also capable of improving the transmittance of light passing through a fine aperture. The semiconductor laser device comprises a light absorption film provided with a fine aperture on the outside of the light-emitting surface of the semiconductor laser element. The aperture is formed such that the aperture width W1 in a direction parallel to the polarizing direction of the laser light is smaller than half the oscillation wavelength of the semiconductor laser element, and the aperture width W2 in a direction perpendicular to the polarizing direction is larger than the aperture width W1.

Abstract: A resonating cavity system of a tunable multi-wavelength semiconductor laser. The system has a laser, a collimating lens, a grating, a slit plate, and adjustable mirrors. The laser has two ends. The first end is coupled to the cavity, and the second end outputs the laser beam. The grating is located in the lasing path between the first end of the semiconductor laser and the plate, and the plate is located before the adjustable mirrors. Each adjustable mirror is aligned to the corresponding slit of the plate. Lasing paths extend from the first end of the laser, through the grating, the lens, a plurality of the slits of the plate, to the adjustable mirrors. Each mirror can be adjusted independently to ensure each beam is reflected accurately back to each resonating path. Thereby, a feature of equal lasing gains of all the resonating paths is guaranteed.

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: Disclosed is a surface-emitting laser device which eliminates an absorption loss of a p-type doped layer and reduces a scattering loss in a mirror layer and a carrier loss due to a current induction, comprising a first conductive type of semiconductor substrate; a bottom mirror layer formed on the semiconductor substrate and composed of a first conductive type of semiconductor layer; an active layer formed on the bottom mirror layer; an electron leakage barrier layer formed on the active layer and having an energy gap larger than the active layer; a current induction layer formed on the electron leakage barrier layer and a second conductive type of semiconductor layer; a current extension layer formed on the current induction layer and composed of the second conductive type of semiconductor layer; and a top mirror layer formed on the current extension layer, wherein the top mirror layer includes undoped center portion and its both end having the second conductive type of dopant diffusion region.

Abstract: An actuator for continuously aligning the primary mirror relative to the scraper the other resonator mirrors and the feedback mirror in a high power laser resonator, comprised of extended portions of the resonators primary mirror, feedback mirror and scraper mirror for a low power laser beam to travel parallel to but offset from the high power laser beam for aligning the mirrors. The low power laser beam is used to measure the position of the mirrors in the resonator. The low power beam is split into a beam which is incident on a quadrant cell for measuring the tip and tilt of the feedback mirror relative to the primary mirror and a beam which measures the translation of the feedback mirror relative to the primary mirror. A controller receives the data form the quadrant cells and sends signals to actuators on one mirror to move it relative to the other thus keeping the mirrors in constant alignment.

Abstract: The present invention provides a semiconductor laser, an optical head, an optical disk apparatus and the manufacturing method of the semiconductor laser wherein the recording density of a recording medium can be enhanced by increasing the intensity of a laser beam output from a small aperture and the miniaturization and the enhancement of a data transfer rate are enabled. For the semiconductor laser, a low-reflective multilayer film is buried in the small aperture and further, a TiO2 film having a high refractive index is arranged on the side of the surface of an opening. The wavelength of a laser beam is reduced in the TiO2 film and near-field light easily leaks out from the aperture provided to a metallic shade.

Abstract: Disclosed is a semiconductor laser device capable of minimizing the spot diameter of a laser light and also capable of improving the transmittance of light passing through a fine aperture. The semiconductor laser device comprises a light absorption film provided with a fine aperture on the outside of the light-emitting surface of the semiconductor laser element. The aperture is formed such that the aperture width W1 in a direction parallel to the polarizing direction of the laser light is smaller than half the oscillation wavelength of the semiconductor laser element, and the aperture width W2 in a direction perpendicular to the polarizing direction is larger than the aperture width W1.

Abstract: The present invention provides a method and apparatus for controlling laser power, using at least two Brewster windows which are aligned along an axis which is parallel to the direction of the laser beam and which are rotatable around said axis, wherein the first Brewster window is rotated in one direction and the second Brewster window is rotated in the opposite direction. Preferably, both Brewster windows only have to rotate each through +/−45° to control transmission of the laser beam from maximum to minimum.

Abstract: Fluorine laser device capable of obtaining laser light with strong monochromatic property and large power is provided. For this purpose, the fluorine laser device is in a fluorine laser device including a laser chamber (2) in which a laser medium including fluorine is contained and is excited to thereby oscillate laser light (11), a front slit (116) disposed in front of said laser chamber (2) and having a front opening (33) for transmitting the laser light (11), and a rear slit (117) disposed behind said laser chamber (2) and having a rear opening (34) for transmitting the laser light (11), at least one of the front slit (116) and the rear slit (117) is a slit (16; 17) in which a slit inclined plane (35) is formed on a surface at a laser chamber side to make one of the front opening (33) and the rear opening (34) convex.