Abstract: A light irradiation device includes: a light source configured to output light having coherence; a light focusing element having a focusing axis and a non-focusing axis intersecting with the focusing axis and configured to focus the light on a focusing line so as to generate planar light; and an aperture mask having an opening part that limits a part of luminous fluxes of the light transmitted from the light source to the light focusing element. The opening part of the aperture mask has opening edges disposed to extend in a direction along the focusing axis of the light focusing element, and, in a case in which the opening edges are projected onto the focusing line, corresponding projected portions have linear spreads.

Abstract: A laser device includes a laser oscillator configured to emit a laser beam, and an optical unit configured to receive the laser beam and emit the laser beam outside. The optical unit includes: a partially transmissive mirror configured to reflect a part of the laser beam toward the outside and transmit a remaining part of the laser beam; a diffusion plate configured to diffuse the laser beam which has passed through the partially transmissive mirror and deflect the laser beam in a predetermined direction, at a predetermined diffusion angle; and a photodiode configured to receive the laser beam deflected by the diffusion plate, and output an electric signal. The laser device is configured such that deviation of an optical axis of the laser beam is monitored based on the electric signal of the photodiode.

Abstract: A laser is disclosed having a housing formed of a block of glass-ceramic. The block is machined (or otherwise formed) to define one or more channels that act as a waveguide in two dimensions for light within the laser resonator. The channels extend between cavities also formed within the block which retain optical components of the laser, e.g. one or more of the gain medium, cavity mirrors, intermediate reflectors etc. The positioning, shape and size of each cavity is bespoke for the optical component it holds in order that each optical component is retained in optical alignment rigidly against the sides of the cavity.

Abstract: A laser device is a laser device that includes an output unit that outputs seed light to a light amplifying unit. The output unit has a light source unit that outputs, as the seed light, rays of light with a plurality of wavelengths lying within a gain range of the light amplifying unit, and a seed light control unit that controls an intensity-time waveform of the seed light output from the light source unit.

Abstract: The invention generally provides systems and methods for particle detection for minimizing microbial growth and cross-contamination in manufacturing environments requiring low levels of microbes, such as cleanroom environments for electronics manufacturing and aseptic environments for manufacturing pharmaceutical and biological products, such as sterile medicinal products. In some embodiments, systems of the invention incorporate a housing having an outer surface being a first antimicrobial surface and a touchscreen being a second antimicrobial surface. In some embodiments, substantially all of the outer surfaces of the system are antimicrobial surfaces. In some embodiments, the first antimicrobial surface may comprise an Active Screen Plasma alloyed layer. In some embodiments, the housing may comprise a molded polymer substrate and a metal coating layer bonded to the molded polymer substrate such that at least some exterior surfaces of the housing are metal coated surfaces.

Abstract: A CO2 laser that generates laser-radiation in just one emission band of a CO2 gas-mixture has resonator mirrors that form an unstable resonator and at least one spectrally-selective element located on the optical axis of the resonator. The spectrally-selective element may be in the form of one or more protruding or recessed surfaces. Spectral-selectivity is enhanced by forming a stable resonator along the optical axis that includes the spectrally-selective element. The CO2 laser is tunable between emission bands by translating the spectrally-selective element along the optical axis.

Abstract: Provided herein are systems and methods of manufacture and operation for a compact laser to achieve high-intensity output pulses. These compact laser resonators and methods rely upon separate and distinct functions of the laser resonator to be operated in balance such that the functions, while deleterious when separate are supportive of laser generation and growth when combined within a small volume laser resonator as described herein. The combined elements of the described laser resonator include a delicate balance that allows the laser to operate between plane-parallel operation and unstable operation. This operation mode further allows distinct methods of construction and operation that allow the compact laser to be reliably assembled and tested during assembly. Therefore, despite requiring a delicate balance of disparate elements, the described laser resonator results in a compact robust laser.

Abstract: A computer-implemented system and method of analyzing spatial, temporal and contextual elements of data for predictive decision-making. The computer-implemented method includes receiving a first set of rules and receiving first data and second data including spatial, temporal and contextual elements. The computer-implemented method also includes identifying each rule of the first set for which the received first data and the received second data is a respective candidate. For the identified rules for which the received first data is a candidate, and for the identified rules for which the received second data is a candidate, the respective received first data and received second data is indexed by its temporal, spatial or contextual elements as a function of the identified rules. The computer-implemented method also includes identifying an event as satisfying an identified rule in memory using the indexed first and second data.

Abstract: The system and method for enhancing and suppressing radio frequency (RF) emissions in a laser induced plasma system using a second laser. A first igniter laser is used at short pulse widths and a second heater laser is used at longer pulse widths. By varying the energy of the heater laser and/or the timing of the arrival of the heater laser with respect to the igniter laser suppression and/or enhancement of the radio frequency (RF) emission from the induced plasma system is possible.

Abstract: Light emission efficiency is increased in an eye-safe light source by regulating light distribution properties. An eye-safe light source includes a package, a semiconductor laser that emits laser light from a left light emission end surface and a right light emission end surface, and a wire that is joined to the semiconductor laser. The semiconductor laser is joined to the package such that the laser light is emitted parallel to an upper surface of a lead frame of the package. The package includes reflection surfaces that face the left light emission end surface and the right light emission end surface and reflect the laser light. In top view, a direction in which the wire extends is perpendicular to a direction of emission of the laser light.

Abstract: A sealed sensor apparatus for a light fixture includes a housing. The housing has a base portion configured to house circuitry of the sensor apparatus. The housing include an integral cylindrical extension projecting from the base portion. The cylindrical extension has an interior surface defining an interior cavity. The cylindrical extension has an exterior surface radially spaced from the interior surface. A gasket may be received about the exterior surface of the cylindrical extension. A lens may be sealingly mounted to the cylindrical extension.

Abstract: A laser device is provided for generating a helical-shaped optical wave and includes: (i) a gain region located between one first end defined by a first mirror and a second end defined by an exit region, (ii) a second mirror arranged so as to form with the first mirror an optical cavity including the gain region and a gap between the exit region and the second mirror, (iii) apparatus for pumping the gain region so as to generate the optical wave, wherein the laser device further includes at least one apparatus for shaping the light intensity and/or phase profiles of the optical wave and arranged for selecting at least one rotary-symmetrical transverse mode of the optical wave, the rotary-symmetrical transverse mode being chosen between those with a radial index equal to zero and with an azimuthal index being an integer with a module higher or equal to 1.

Abstract: Methods and apparatus for generation of radiation by high harmonic generation, HHG. The apparatus comprises: a chamber for holding a vacuum, the chamber comprising a radiation input, a radiation output and an interaction region at which, in use, a medium is present, the chamber being arranged such that, in use, when driving radiation propagates through the radiation input and is incident upon the medium, the medium emits radiation via HHG, the emitted radiation propagating through the radiation output; and at least one plasma generator at the radiation input and/or the radiation output for generating a plasma volume allowing the driving radiation and emitted radiation, respectively, to propagate through the plasma volume.

Abstract: An optical protractor that employs a spiral phase plate resonator (SPPR) device for measuring a roll angle between two points on a static surface or a rotating surface. The protractor includes a tunable laser source that generates a laser beam. The SPPR device is responsive to the laser beam, and includes opposing reflective surfaces that reflect the beam back and forth in the device, where one of the reflective surfaces includes a spiral step index that causes multiple reflected beams having different phases to be combined as an output beam from the device having an optical vortex intensity pattern defined by the phases of the multiple beams, and where the intensity pattern includes radial light intensity lines. The protractor includes a lens that projects the output beam onto the element and the intensity pattern is detected to measure the roll angle.

Abstract: An excimer laser generator and an excimer laser annealing equipment are disclosed to improve the convenience of window replacement, improve the replacement efficiency and reduce the gas waste. The excimer laser generator includes a reflector, an active medium cavity and an output mirror arranged in sequence. The active medium cavity has a first opening facing the reflector and a second opening facing the output mirror. The excimer laser generator further includes two replacement units respectively arranged between the first opening and the reflector, and between the second opening and the output mirror. Each of the replacement units includes a support plate and a driving component. The support plate is provided with a plurality of windows, and the driving component is adapted for driving the support plate so that one of the plurality of windows seals a corresponding opening.

Abstract: One example embodiment includes an optical subassembly (OSA). The OSA includes a leadframe circuit, an optical port, and an active optical component subassembly. The active optical component subassembly is mounted to the leadframe circuit. The optical port is mechanically coupled to the leadframe circuit.

Abstract: A light emitting device includes: a base; a laser element disposed on an upper face of the base and adapted to laterally emit a laser beam; a phosphor member disposed on the upper face of the base; a first optical member disposed on the upper face of the base, the first optical member comprising an entry-side lateral face through which the laser beam enters during use and an exit-side lateral face through which the laser beam exits during use, and the first optical member being configured to change a traveling direction of the laser beam such that the laser beam transmitted through the first optical member irradiates an upper face of the phosphor member; and a cap comprising: a light shielding member, and a light transmissive member located over the through hole, the laser element, the phosphor member, and the first optical member.

Abstract: A data-encoding system includes a source of unencoded data, and a first encoder interoperably coupled to the source, wherein the first encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a first data rate. The data encoding system further includes a second encoder interoperably coupled to the source, wherein the second encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a second data rate in which the second data rate exceeds the first data rate. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A housing for an optically pumped semiconductor (OPS) laser resonator is terminated at one end thereof by an OPS-chip. The laser resonator is assembled on a platform with the OPS-chip at one end of the platform. The platform is fixedly attached to a baseplate at the OPS-chip end of the platform. The remainder of the platform extends over the baseplate with a gap between the platform and the baseplate. A pump-laser is mounted directly on the baseplate and delivers pump radiation to the OPS-chip.

Abstract: An apparatus and a method for stabilizing output of a light source are disclosed. The stabilization device located outside of a light source comprises a stabilization element, and a stabilization controller configured to control a light output from the light source so that a part of the light output and other part of the light cross propagate in the stabilization element.

Abstract: Systems and methods to stabilize a laser frequency include a birefringent resonator that introduces an arbitrary phase difference between two polarization components of the laser beam, a polarizing beam splitter to separate the two polarization components after the birefringent resonator, and a differential detector to monitor the separated two polarizations, based on which an error signal can be produced to control a servo to adjust the laser frequency or resonator resonance frequency accordingly. The birefringent resonator can comprise a fiber ring, a whispering gallery mode (WGM) resonator, or any other birefringent ring resonator. A servo can be included in the systems and methods to lock the laser frequency to the resonant frequency of the birefringent resonator or to lock the resonator resonant frequency to the laser frequency. One or more polarization controllers can also be employed to adjust the polarization state of the laser beam.

Abstract: A laser and methods for providing a continuous wave output beam. The laser and method includes positioning a micro-plasma chip capable of creating micro-plasmas within a resonant cavity. A gas is input into the resonant cavity and flows around the micro-plasma chip. Micro-plasmas ignite and excite the gas to create metastables. The metastables are further excited by an optical pump having an energy sufficient to cause the metastables to lase.

Abstract: A self-seeding high power laser includes a spatial filter; an optical relay for circulating a low power un-distorted optical beam, an adaptive optic optically coupled to the output of the optical relay; a high power amplifier optically coupled to an output of the adaptive optic phase control element, wherein adaptively modified phasefront injected by the adaptive optic cancels distortions produced by the high power amplifier; a beamsplitter optically coupled to the high power amplifier for splitting the high power un-distorted optical beam into a high power output beam as the output of the self-seeding high power laser, and a low power beam; a focusing lens; a detector for detecting a metric of the low power beam; and a controller for adaptively controlling the adaptive optic to maximize the power of the high power amplifier, based on the detected metric.

Abstract: A plurality of gas jet nozzles having equal angular separation around a central axis eject gas flows towards the central axis. The gas flows collide and form a gas channel from the neutral gas, the gas channel having a gas density depression at the center of the intersecting gas flow, where the gas density depression is surrounded by a higher density gaseous wall along the central axis. Ionization of the gas in the center produces a plasma channel that can guide a laser pulse fired into the gas along the central axis. The geometric arrangement of the gas jets and/or the backing pressure of the gas flows are configured to produce a gas channel having a predetermined density profile such that the ionized gas forms a plasma channel laser guiding structure configured to guide a laser pulse having predetermined spatial parameters.

Abstract: A laser pulse amplifier device (100) includes an amplifying cavity (10) comprising an amplifying laser gain medium (11) and multiple cavity mirrors (12.1 to 12.7) spanning a cavity light path (13), wherein the amplifying cavity (10) is configured for an amplification of laser pulses (1) circulating along the cavity light path, and a multi-pass amplifier (20) being optically coupled with the amplifying cavity (10) and comprising multiple deflection mirrors (22) spanning a multipass light path (23), wherein the multi-pass amplifier (20) is configured for a post-amplification of laser pulses (2) coupled out of the amplifying cavity (10), wherein the amplifying cavity (10) and the multi-pass amplifier (20) are arranged such that the laser gain medium (11) of the amplifying cavity (10) is included as an active medium in the multi-pass light path (23) of the multi-pass amplifier (20). Furthermore, a method of amplifying laser pulses is described.

Abstract: A computer-implemented system and method of analyzing spatial, temporal and contextual elements of data for predictive decision-making. The computer-implemented method includes receiving a first set of rules and receiving first data and second data including spatial, temporal and contextual elements. The computer-implemented method also includes identifying each rule of the first set for which the received first data and the received second data is a respective candidate. For the identified rules for which the received first data is a candidate, and for the identified rules for which the received second data is a candidate, the respective received first data and received second data is indexed by its temporal, spatial or contextual elements as a function of the identified rules. The computer-implemented method also includes identifying an event as satisfying an identified rule in memory using the indexed first and second data.

Abstract: An optical amplifier includes a solid state gain-element. The gain-element is pumped by pump-radiation from a diode-laser bar. The diode-laser radiation is delivered from the diode-laser bar to the gain-element entirely via a tapered light-guide which guides the radiation only in a fast-axis direction of the diode laser bar. The tapering of the light-guide reduces fast-axis divergence of the pump-radiation by about a factor of ten. The pump-radiation is delivered to the gain-element as a line of radiation homogenized in the fast-axis direction.

Abstract: This invention provides new methods and apparatus for rapidly analyzing single bioparticles to assess their material condition and health status. The methods are enabled by a resonant cavity to measure optical properties related to the bioparticle size and refractive index. Refractive index measurements are useful for determining material properties and biomolecular composition of the bioparticle. These properties and composition are dependent on the health state of the bioparticle. Thus, measured optical properties can be used to differentiate normal (healthy) and abnormal (diseased) states of bioparticles derived from cells or tissues. The methods are illustrated with data obtained from a resonator with a gain medium.

Abstract: A light source for a photonic integrated circuit may comprise a reflection coupling layer formed on a substrate in which an optical waveguide is provided, at least one side of the reflection coupling layer being optically connected to the optical waveguide; an optical mode alignment layer provided on the reflection coupling layer; and/or an upper structure provided on the optical mode alignment layer and including an active layer for generating light and a reflection layer provided on the active layer. A light source for a photonic integrated circuit may comprise a lower reflection layer; an optical waveguide optically connected to the lower reflection layer; an optical mode alignment layer on the lower reflection layer; an active layer on the optical mode alignment layer; and/or an upper reflection layer on the active layer.

Abstract: Provided is a light-emitting element having high luminance and high directivity and emitting light in a controlled polarization state. The light-emitting element comprises substrate 3 and light emitting part 10 disposed on substrate 3 for emitting light in which light intensity of a polarization component in first direction x parallel to substrate 3 is higher than light intensities of polarization components in other directions. Light emitting part 10 includes active layer 12 for generating light and a plurality of structural bodies 14a disposed on a light-emitting side of light emitting part 10 with respect to active layer 12 and arrayed two-dimensionally along a surface substantially parallel to active layer 12. Each of structural bodies 14a has width w1 along first direction x and width w2 along second direction y perpendicular to first direction x, width w1 along first direction x and width w2 along second direction y being different from each other in a cross section parallel to active layer 12.

Abstract: A vertical cavity surface emitting laser (VCSEL) nanoscope is provided. The VCSEL nanoscope combines a VCSEL with a nano-scale aperture using a support member to separate the aperture from the VCSEL emission face. The resulting device is a useful near-field probe with a wide variety of applications.

Abstract: A laser adjustment system can include an adjustable seed-beam restrictor, configured to be attachable to a stretcher-compressor in a transverse-adjustable manner, and to restrict an incidence of a seed beam, generated by an oscillator, on the stretcher-compressor, wherein the stretcher-compressor is configured to be integrated into a chirped pulse amplification laser engine, and to stretch a duration of seed pulses of the seed beam.

Abstract: A laser diode device including a housing having a mounting area in a cavity of the housing, at least one laser diode chip that emits electromagnetic radiation through a radiation exit area during operation, at least one covering element which is transmissive, at least in places, to the electromagnetic radiation generated by the laser diode chip during operation, and a deflection element, that directs at least part of the electromagnetic radiation generated by the laser diode chip during operation in a direction of the covering element, wherein the radiation exit area of the laser diode chip runs substantially transversely or substantially perpendicularly with respect to the mounting area and/or with respect to the covering element, the covering element connects to the housing, and the covering element tightly closes the housing.

Abstract: A gas discharge chamber that uses a calcium fluoride crystal which reduces a breakage due to mechanical stress (window holder and laser gas pressure), thermal stress from light absorption, and the like, increases the degree of linear polarization of output laser, and suppresses degradation due to strong ultraviolet (ArF, in particular) laser light irradiation. A first window (2) and a second window (3) of the gas discharge chamber have an incident plane and an emitting plane in parallel with a (111) crystal plane of their calcium fluoride crystal. With respect to an arrangement where laser light entering the calcium fluoride crystal passes through a plane including a <111> axis and a <001> axis of each of the first window (2) and the second window (3) as seen from inside the chamber (1), the first window (2) and the second window (3) are arranged in positions rotated in the same direction by the same angle about their <111> axis.

Abstract: A system and method of operating a high repetition rate gas discharge laser system. The system includes a gas discharge chamber having a hot chamber output window heated by the operation of the gas discharge laser chamber, an output laser light pulse beam path enclosure downstream of the hot chamber window and comprising an ambient temperature window, a cooling mechanism cooling the beam path enclosure intermediate the output window and the ambient window. The gas discharge chamber can include a longitudinally and axially compliant ground rod, including a first end connected to a first chamber wall, a second end connected to a second chamber wall, the second chamber wall opposite the first chamber wall and a first portion formed into a helical spring, the ground rod providing mechanical support for a preionizer tube.

Abstract: A light radiating device capable of reducing production costs and preventing sealing defects for a display device, and a method of fabricating an organic light emitting diode (OLED) display device using the same are provided. The light radiating device includes a light source to generate light and a light modifier, including a transmissive region and a non-transmissive region, that define an exposure region on a substrate. The method includes applying a frit to at least one of a first substrate having a pixel region and a second substrate, plasticizing the frit, and aligning the first substrate, the second substrate, and a light radiating device to define an exposure region on the at least one of the first substrate and the second substrate, and radiating the light to the frit to couple the first substrate and the second substrate.

Abstract: In a GaN-based laser device having a GaN-based semiconductor stacked-layered structure including a light emitting layer, the semiconductor stacked-layered structure includes a ridge stripe structure causing a stripe-shaped waveguide, and has side surfaces opposite to each other to sandwich the stripe-shaped waveguide in its width direction therebetween. At least part of at least one of the side surfaces is processed to prevent the stripe-shaped waveguide from functioning as a Fabry-Perot resonator in the width direction.

Abstract: A vertical cavity surface emitting laser (VCSEL) nanoscope is provided. The VCSEL nanoscope combines a VCSEL with a nano-scale aperture using a support member to separate the aperture from the VCSEL emission face. The resulting device is a useful near-field probe with a wide variety of applications.

Abstract: A semiconductor laser element includes a laminate composed of a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer; and a second embedded layer that is in contact with the second conductivity type semiconductor layer, has a stripe-like groove parallel to the cavity direction, and is composed of an insulator, the groove is embedded with a first embedded layer composed of a dielectric on the cavity end face side, and with a conductive layer on the inside.

Abstract: An array of vertical-cavity surface emitting lasers (VCSELs) may be fabricated with very high fill-factors, thereby enabling very high output power densities during pulse, quasi-continuous wave (QCW), and continuous wave (CW) operation. This high fill-factor is achieved using asymmetrical pillars in a rectangular packing scheme as opposed prior art pillar shapes and packing schemes. The use of asymmetrical pillars maintains high efficiency operation of VCSELs by maintaining minimal current injection distance from the metal contacts to the laser active region and by maintaining efficient waste heat extraction from the VCSEL. This packing scheme for very high fill-factor VCSEL arrays is directly applicable for next generation high-power, substrate removed, VCSEL arrays.

Abstract: Multi-pass optical imaging apparatus includes a concave mirror in combination with two retro-reflecting mirror pairs and at least one reflective surface. The mirror, the retro-reflecting mirror pairs and the reflecting surface are arranged such that a light-ray input into the apparatus parallel to and spaced apart from the optical axis of the concave mirror and incident on the concave mirror is caused to be incident on the thin-disk gain-medium at least four times, with each of the four incidences on the gain-medium being from a different direction. If the input ray is plane-polarized, the arrangement provides that the polarization orientation of the ray on each incidence on the gain-medium is in the same orientation.

Abstract: A method of manufacturing a semiconductor laser having an end surface window structure includes the steps of forming a groove near at least the formation position of the end surface window structure of a substrate, and growing a nitride-based group III-V compound semiconductor layer including an active layer formed of a nitride-based group III-V compound semiconductor including at least In and Ga on the substrate.

Abstract: A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.

Abstract: Embodiments are directed to systems and methods for adjusting a wavelength, bandwidth or both. Such systems and methods may be applicable to laser beams within a laser cavity or amplifier. For some embodiments, such systems and methods may be used to allow a user to set a desired wavelength and bandwidth of a short pulse laser system for operation at those parameters without further adjustment by the user.

Abstract: In a GaN-based laser device having a GaN-based semiconductor stacked-layered structure including a light emitting layer, the semiconductor stacked-layered structure includes a ridge stripe structure causing a stripe-shaped waveguide, and has side surfaces opposite to each other to sandwich the stripe-shaped waveguide in its width direction therebetween. At least part of at least one of the side surfaces is processed to prevent the stripe-shaped waveguide from functioning as a Fabry-Perot resonator in the width direction.

Abstract: Provided are a laser induced thermal imaging (LITI) mask, a laser irradiation apparatus including the LITI mask, and a method of manufacturing an organic light emitting device by using the LITI mask. The LITI mask including an opening corresponding to a pixel region and an opening corresponding to an edge of a pixel is used to form an organic layer in an upper portion of a substrate of an organic light emitting device, thereby transferring the organic layer to an edge of the pixel region.

Abstract: A optical apparatus (201) for use in an laser imaging system (200) is provided. The optical apparatus (201) includes one or more optical elements (215) that are configured to create an intermediate image plane (217) in the laser imaging system (200). A diffractive optical element (216) is then disposed at the intermediate image plane (217) to reduce speckle. The diffractive optical element (216) includes a periodically repeating phase mask (218) that can be configured in accordance with steps, vortex functions, Hermite-Gaussian functions, and so forth. Smooth grey-level phase transitional surface (337) can be placed between elements (333,334) to improve brightness and image quality. The periodically repeating phase mask (218) makes manufacture simple by reducing alignment sensitivity, and can be used to make applicable safety standards easier to meet as well.

Abstract: The present disclosure relates to a laser crystal device (1) for short pulse lasers, comprising a container (4), the interior of which is sealed relative to the environment and which contains a technically pure atmosphere with windows (12, 13) in the side walls (12, 13) for the passage of laser radiation (16), which in operation passes through a laser crystal (6), wherein the window (12, 13) has an inclination of the Brewster angle to the beam path of the laser radiation (16) and a mounting (5) for the laser crystal (6) is provided within the container (4), the windows (12, 13) are inclined to each other by double the Brewster angle and are placed at an adequate distance from the laser crystal (6) position, with relation to the laser beam properties, wherein the beam cross section at the windows (12, 13) is sufficiently large in order to guarantee a peak intensity at the windows (12, 13) which is sufficiently reduced in relation to the peak intensity of the laser beam (16) at the laser crystal (6) for avoidin

Abstract: A mode selection technique in a laser is described wherein a recess is formed in a surface of a waveguide in the laser. The recess provides a region of free space propagation within the waveguide which preferentially selects the lowest order mode. A mode selective RF excited CO2 slab laser, having a stable resonator in the waveguide dimension and a negative branch unstable resonator in the non-waveguide dimension, is constructed and the position and size of the recess is considered to provide low order mode selection.

Abstract: Non-rigidly coupled, overlapping, non-feedback optical systems for spatial filtering of Fourier transform optical patterns and image shape characterization comprises a first optical subsystem that includes a lens for focusing a polarized, coherent beam to a focal point, an image input device that spatially modulates phase positioned between the lens and the focal point, and a spatial filter at the Fourier transform pattern, and a second optical subsystem overlapping the first optical subsystem includes a projection lens and a detector. The second optical subsystem is optically coupled to the first optical subsystem.