Abstract: An optically active linear single polarization device includes a linearly birefringent and linearly dichroic optical waveguide (30) for propagating light and having single polarization wavelength range (48). A plurality of active dopants are disposed in a portion (34) of the linearly birefringent and linearly dichroic optical waveguide (30) for providing operation of the waveguide in an operating wavelength range (650) for overlapping the single polarization wavelength range (48).

Abstract: A right angle light diverter includes a hexagonal tube that is bent at a right angle that is coated with a highly reflective coating on the inside surface. An incoming light beam may be homogenized upon entering an input port of the hexagonal tube and may be evenly diverted at a right angle at a reflection section while the homogenized profile may be maintained. A right angle optical splitter may include at least one additional output section. An incoming light beam may be homogenized and may be split into at least two outgoing beams that may be diverted at right angles at reflection sections. The right angle light diverter and the right angle optical splitter may be suitable for, but not limited to, applications in aircraft industry, both military and commercial. They may be used, for example, in connection with airborne laser programs, in commercial airplanes, and in military jets.

Abstract: An LED light source has a housing having a base. A hollow core projects from the base and is arrayed about a longitudinal axis. A printed circuit board is positioned in the base at one end of the hollow core and has a plurality of LEDs operatively fixed thereto about the center thereof. In a preferred embodiment of the invention the hollow core is tubular and the printed circuit board is circular. A light guide with a body that, in a preferred embodiment, is cup-shaped as shown in FIGS. 2 and 4a, has a given wall thickness “T”. The light guide is positioned in the hollow core and has a first end in operative relation with the plurality of LEDs and a second end projecting beyond the hollow core. The thickness “T” is at least large enough to encompass the emitting area of the LEDs that are employed with it.

Abstract: A homogenizer for collimated light limits the angular distribution of the light by passing the light through a mild diffuser followed by a slab light guide which has top and bottom surfaces covered with optical constraining layers and optical absorbing layers where the optical absorbing layer has a higher refractive index than the optical constraining layer and the optical constraining layer has a lower refractive index than the slab light guide.

Abstract: An apparatus and method for generating a lamina of light. The apparatus includes an optically transparent member having an input configured to receive light and one or more facets formed in the optically transparent member. As light enters and travels through the member, a lamina of light is created by the light reflecting off the facets. In one application, the lamina of light is provided in the free space adjacent a touch screen display. When the lamina is interrupted during a data entry operation to the screen, an optical position detection device is used to determine the data input based on the location of the interrupt in the lamina. In various other embodiments, the position and uniformity of the lamina may be controlled by selecting the angle, depth and tilt of a reflective surface of the facets in the optically transparent member.

Abstract: At the time of forming irregularities on at least one of a reflection face and an emitting face of a light-guide plate, irregularities are formed as a plurality of linear grooves formed in a direction perpendicular to the entrance face. When the grooves are formed by means of grinding, surfaces of the grooves are made rough. Therefore, light can be appropriately condensed and diffused by the grooves, and the luminance can be enhanced and the unevenness of the luminance can be reduced.

Abstract: An integrated optical assembly including a light management component with an entry surface and a light delivery component having an exit surface attached to the entry surface of the light management component is disclosed The light management component and the light delivery component are attached together in a manner that defines voids between the entry surface of the light management component and the exit surface of the light delivery component. The voids between the light management component and the light delivery component may provide an air interface over substantial portions of the entry surface of the light management component.

Abstract: A planar light device (30) for emitting light beams, including a light guide plate (31) having a plurality of diffraction grating units (33). The light guide plate includes a light-emitting surface (313), an opposite bottom surface, and a light incident surface (311) disposed therebetween. A light source (32) is disposed adjacent to the light incident surface. The diffraction grating units cover the bottom surface of the light guide plate. Each diffraction grating unit is divided into a first part (A) and a second part (B), the first and second parts having different alignment directions from each other.

Abstract: According to one aspect, the invention relates to a light guide which may include a first surface which receives light, a second surface which emits light, wherein the second surface is parallel to the first surface and the second surface has a smaller area than the first surface, at least one edge surface which extends between the first surface and the second surface, and a light barrier which extends between the first surface and the second surface, wherein the light barrier divides the light guide into separate regions and reduces the propagation of light between the separate regions. The light guide can be used in a positron emission tomography scanner.

Abstract: A surface light source unit (2) includes a light source (21), a light guide plate (22), a reflective plate (23) and a diffusing plate (24). The light guide plate includes a light incidence surface (221) adjacent to the light source for receiving light beams, an emission surface (222) for emitting the light beams, a light reflection surface (223) opposite to the emission surface and a plurality of diffusion dots (224) formed on the light reflection surface. The diffusion dots contain a plurality of light scattering particles (225) having substantially global surfaces. The surface light source unit provides high uniform illumination for a liquid crystal display panel.

Abstract: A surface light source (100) includes a light guide plate (20) and a pair of point light sources (10). The light guide plate has an incident surface (201) and an emitting surface (202). The point light sources are adjacent the incident surface of the light guide plate, for radiating light beams into the light guide plate through the incident surface. The emitting surface defines a plurality of polygonal cells (2020). Each of the polygonal cells define a plurality of grooves regularly therein. By the cooperation of the polygonal cells and the point light sources, the surface light source has uniform luminance over the whole emitting surface.

Abstract: A lower cladding layer is laminated on a substrate and constituted of at least one layer. A light absorption layer is laminated on the lower cladding layer. An upper cladding layer is laminated above the light absorption layer and constituted of at least one layer. A light incident end surface is provided on at least one of the substrate and the lower cladding layer, and, when a light is made incident at a predetermined angle, enables the light to be absorbed in the light absorption layer and to be output as a current. An equivalent refractive index of the at least one of the substrate and the lower cladding layer is larger than that of the upper cladding layer. The predetermined angle is an angle enabling a light incident into the light absorption layer to be reflected at a lower surface of the upper cladding layer.

Abstract: Disclosed is an optical probe for obtaining a micro spot light, comprising a rod-like glass body having a rectangular cross section as a core for propagating an light wave. The distal end portion of the glass body is gradually diminished toward the distal end so as to form a micro distal end face having a small diameter. The side surface of the distal end portion of the glass body in a direction perpendicular to the polarized direction of the light wave is coated with a light absorber formed of a metal film.

Abstract: The present invention relates to a light generating device comprising a slab light guide (1), at least one light input unit (2) arranged on at least one side (10) of said light guide (1) comprising at least one light source (20) and a light incoupling means (21) for coupling light into said light guide (1), and at least one light output unit (3) arranged on at least one side (11) of said light guide (1). In order to provide a device that provides polarized light of a high homogeneity the light output unit (3) according to the present invention comprises a polarized light emitting waveguide plate (31) for selectively coupling light of a first polarization state out of said light guide (1). The present invention further relates to a display device, in particular an LCD, comprising a light generating device according to the invention.

Abstract: An optical transmission device improved in optical coupling loss between light guides and optical elements and excelling in efficiency of light utilization is provided with light guides having light incidence/emission sections on plural stepped portions, a substrate that fixes the light guides, and light receiving elements and light emitting elements arranged on the substrate to match the light incidence/emission sections of the light guides. The light receiving elements and the light emitting elements are arranged on the substrate by use of optical connectors. Coefficients of linear expansion and the rates of dimensional variation due to water absorption (or alternatively due to water absorption rates) of the light guides and the substrate here are substantially equalized.

Abstract: A temperature resistant waveguide is mounted to an SMT LED package to provide a complete module that can withstand temperatures found in a solder reflow process without deformation or damage. The waveguide is composed of a high temperature thermoplastic and is coupled to the LED using automated equipment with optical markings for precise positioning and construction. The SMT LED module is automatically located on a printed circuit board and exposed to temperatures for a solder reflow process. The high temperature thermoplastic does not deform during the solder reflow process, thereby providing a robust SMT LED module that can be automatically manufactured and placed on a printed circuit board, without additional steps or human intervention.

Abstract: A compact light source module includes a compact light source and a collimator that includes a parabolic first reflective surface to reduce a radiation angle at which a light beam radiates from the compact light source, so as to emit the light beam through a side aperture and a plane second reflective surface which is located under the first reflective surface and comprises an incident portion through which the light beam radiates from the compact light source. The compact light source is located in the vicinity of a focal point of the first reflective surface.

Abstract: A backlight system comprising a light-guiding plate (1), a light emitting source (2) disposed to face a light-entrance surface (1c), which is a side surface of the light-guiding plate (1), a prismatic sheet (3) disposed at a position facing an upper surface (1a) of the light-guiding plate (1), and a reflecting sheet (4) disposed to face a lower surface (1b) of the light-guiding plate (1), light emitted from the light emitting source (2) enters the light-guiding plate (1), and the light being adapted so as to change the path thereof in the light-guiding plate (1) and then, the light is emitted from the upper surface of the light-guiding plate and enters the prismatic sheet (3), and the light is adapted to arrange a direction thereof in the prismatic sheet (3) to irradiate illumination light emitted from a from exit surface which is the upper surface (1a) of the prismatic sheet to an object, and the prismatic sheet (3) including a lens mechanism provided on the final exit surface and configured to refract the l

Abstract: The present invention is to provide a light guide pillar disposed on a circuit board of an electronic apparatus having a light emitting element disposed thereon, where the light guide pillar includes a bulk opaque and disposed on the circuit board for covering the light emitting element and a pillar with one end inserted into the bulk while the other end thereof extended outside of the electronic apparatus, enabling the light source generated from the light emitting element to be guided and displayed outside of the electronic apparatus via the light guide pillar and enabling the bulk to stop the light source emitted from the light emitting element from dispersing. Therefore, the light source can be guided to outside of the electronic apparatus without interference.

Abstract: The present invention relates to a light-guide body, which has at least one light-entry surface and at least one light-exit surface, the ratio of the light-exit surface area to the light-entry surface area being at least 4, comprising at least one light-guiding layer with a thickness of at least 2 mm, characterized in that the light-guiding layer comprises at least 60% by weight, expressed in terms of the weight of the light-guiding layer, of polymethyl methacrylate and from 0.001 to 0.08% by weight, expressed in terms of the weight of the light-guiding layer, of spherical barium sulphate particles with an average diameter in the range of from 0.3 to 20 ?m.

Abstract: A backlight includes a lightguide, a light source disposed with respect to the lightguide to introduce light into the lightguide and a turning film. Optical structures are formed in one of an output surface and a back surface of the lightguide. The optical structures are arranged to extract light from the lightguide. A back reflector is disposed adjacent the back surface. The optical structures are formed to include a varying pattern arranged to mask non-uniformities in the output of the lightguide.

Abstract: This application describes examples and implementations of optical devices and techniques based on use of whispering gallery mode (WGM) optical resonators that have nonlinear optical materials in multiple sectors where nonlinear coefficients of two adjacent sectors are oppositely poled.

Abstract: A light guide module (10) for use in a flat panel display (21) comprises a light guide pipe (20) having a light emitting surface (21), and a light incident surface (25) orthogonal to the light emitting surface. A light diffusion arrangement (30) is deployed over the light emitting surface and includes organic scattering balls (31) homogenously mixed within a bonding agent (33). At least a light source (60) is arranged adjacent the light incident surface to project light beams into the light guide module.

Abstract: A vehicular lamp including, within a lamp chamber s defined by a lamp body 10 and an outer cover 20, an led 28 which is the light source, and a light guide 24 which guides light emitted from the led 28 by internal reflection so as to emit light at a plurality of locations. the light guide 24 is constructed of a coupling unit u1 that extends along the outer cover 20 and is made of a plurality of light guiding members 25, the surface of each light guiding member 25 formed in an elliptical surface 25a that has a pair of focal points f, are coupled in series while sharing the focal points with each other at coupling portions 26, and the focal points f at both end portions of the light guide 24 (coupling unit u1) are near the light-emitting portion 29 of the led 28.

Abstract: A side-lit illumination arrangement comprises a polarized-light-emitting waveguide comprising a polarization-selective beam-splitting interface formed at an interface of a waveguiding layer and a polarization-selection layer. In order to avoid alignment problems occurring during the manufacture of the waveguide which impair the proper functioning of the polarization-selective beam-splitting interface, the polarization-selective beam-splitting interface is planar. Waveguided light polarized and transmitted by the polarization-selective beam-splitting interface into the polarization-selection layer is coupled out by a relief-structured surface via an exit surface. Display devices having such waveguides, in particular if used in a front light, have a high brightness and efficiency.

Abstract: An optical device is for spatially displacing the output of a light-emitting diode (LED) and coupling the output to a predominantly spherical emission pattern produced at a useftul height above the LED. The device is made of a transparent dielectric material, such as an injection-molded plastic. It comprises a lower transfer section that receives the LED's light from below and an upper ejector section that receives the transferred light and spreads it spherically. One or more LEDs. are optically coupled to the bottom of the transfer section, which operates by total internal reflection upon their entire hemispherical emission. One embodiment operates as a flashlight-bulb substitute with the ejector section radiating onto a parabolic reflector, which forms the beam. Thus hemisphencally emitting LEDs can be used in parabolic-mirror flashlights wherein these LEDs by themselves may be unsuitable for that role.

Abstract: An integrated optical assembly including a light management component with an entry surface and a light delivery component having an exit surface attached to the entry surface of the light management component is disclosed The light management component and the light delivery component are attached together in a manner that defines voids between the entry surface of the light management component and the exit surface of the light delivery component. The voids between the light management component and the light delivery component may provide an air interface over substantial portions of the entry surface of the light management component.

Abstract: A large diameter D-shaped optical waveguide device 9, includes an optional circular waveguide portion 11 and a D-shaped waveguide portion 10 having at least one core 12 surrounded by a cladding 14. A portion of the waveguide device 9 has a generally D-shaped cross-section and has transverse waveguide dimension d2 greater than about 0.3 mm. At least one Bragg grating 16 may be impressed in the waveguide 10 and/or more than one grating or pair of gratings may be used and more than one core may be used. The device 9 provides a sturdy waveguide platform for coupling light into and out of waveguides and for attachment and alignment to other waveguides, for single and multi-core applications. The core and/or cladding 12,14 may be doped with a rare-earth dopant and/or may be photosensitive. At least a portion of the core 12 may be doped between a pair of gratings 50,52 to form a fiber laser or the grating 16 or may be constructed as a tunable DFB fiber laser or an interactive fiber laser within the waveguide 10.

Abstract: A three-dimensional periodic structure exhibiting a complete photonic band gap in a wide wavelength range and being readily produced, as well as a functional element including the same, is provided. In the three-dimensional periodic structure exhibiting a photonic band gap according to the present invention, layers composed of a plurality of columnar structures spaced at predetermined intervals are stacked sequentially with additional layers therebetween. Discrete structures contained in the additional layers are disposed at the positions corresponding to the intersections of the columnar structures, and the area of the discrete structure is larger than the area of the intersection region of the above-described columnar structures.

Abstract: An optical device for collecting light and selectively outputting or concentrating the light. A layer has an optical index of referaction n1, and top, bottom and side surfaces defining an angel of inclination ?. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n2. The first layer index n2 causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such as alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of diffuse light having passed through the LCD layer to enhance viewing of the output light.

Abstract: A plug device for use during manufacturing and/or testing processes for optoelectronic (OE) devices is described. The plug device has a handle and structures that extend off of the handle to cover “barrels” of an OE device. The plug device prevents contaminating particulates from reacting the lenses and/or the photonic devices within the OE device. The plug device can also be made of a material that transmits light signals so that testing of the OE devices can be easily performed. The plug device can also have a surface to which a pick and place machine can attach itself so that the plug device and a respective optoelectronic device can be easily transported. Overall, the plug device can simplify both the manufacturing and testing processes for OE devices.

Abstract: An optical element (1) for reflecting and/or redirecting light rays (L1) entering therein and again emerging therefrom consists of a transparent base body (2) which is so structured and/or formed that, with the formation of reflection surfaces (8) bounding the base body (2), at least a part of the light rays (L1) impinging upon the reflection surfaces (8) upon emergence from the transparent base body (2) are totally reflected, and at least one cover body (9) arranged behind the reflection surfaces (8). The reflection surfaces (8), and the surfaces of the cover body or bodies (9) towards the reflection surfaces, are adapted to one another such that between them there remains a thin gap (10) or only point contacts exist.

Abstract: The present invention involves a light channel communication component for a vehicle interior member. The light channel communication component comprises an integral polymeric body being a signal-conductive integral medium for transmitting light signals therethrough. The integral polymeric body has a predetermined index of refraction through which the light signals are transmitted. The integral polymeric body further includes a structure of the vehicle interior member to support a shape of the vehicle interior member.

Abstract: A rod lens with one or more optically active surfaces and one or more inactive surfaces, in which one part of the optically inactive surface or surfaces, especially a lens facet and/or radial peripheral surface of a lens, is smooth, and a method for smoothing one part of one or more optically inactive surfaces of a lens, especially of a lens facet and/or radial peripheral surface of a lens. As a result, the occurrence of fissures in the lens is prevented or reduced.

Abstract: An optical element that realizes light path conversion of transmitting light at low loss, allows easy incorporation of functions such as light convergence or the like, and can be easily made into a compact size includes upper and lower main surfaces of a light path converting element of a plane shape are facing each other, and a light incoming surface and a light outgoing surface are adjacent surfaces at about 90 degrees. A curved light path converting surface is formed so as to face the light incoming surface and the light outgoing surface. Light coming in from the light incoming surface repeats full reflection between the upper main surface and the lower main surface and goes on, and is reflected by the light path converting surface, thereby the light path thereof is converted, and light is ejected from the light outgoing surface.

Abstract: The present invention provides a light emitting head which has high utilization efficiency of light and facilitates alignment with other heads and which facilitates fabrication, information storage device which provides high volume access to information with such a light emitting head, and composite head manufacturing method suitable to fabricate a composite head having such a light emitting head.

Abstract: Fibers, including fiber lasers and fiber amplifiers, and systems containing such fibers are disclosed.

Abstract: An optoelectronic coupler includes two photodiodes and an optic light guide, where one of the two photodiodes serves as the transmitting diode and the other as the receiving diode and the light guide serves to guide the light emitted by the transmitting diode to the receiving diode. The transmitting diode and the receiving diode are mounted on a circuit board at a distance from each other and the light guide is constituted of a plastic or glass element mounted on the same circuit board. This arrangement provides for a simple optoelectronic coupler design that permits safe operation even from the perspective of explosion protection.

Abstract: A front light (100) and a reflecting liquid crystal display of the present invention includes a dot light emitting source (101), and a light guiding body (104) having a light incident surface (104a) to which light from the dot light emitting source (101) is incident and a light outgoing surface (104b) from which the incident light outgoes, and light from the dot light emitting source (101) is in a linearly emitting state at least when incident onto the light incident surface (104a). By so doing, it is possible to provide bright, inexpensive, low-power consuming front light (100) and reflecting liquid crystal display which do not cause shadows or a moire fringe from the dot light emitting source (101), or a light-dark difference in luminance.

Abstract: Disclosed are an optical waveguide that comprises (A) a copolyester carbonate having aliphatic segment(s), and a method for producing it; and an optical waveguide made from a polycarbonate resin composition that comprises (A) a copolyester carbonate having aliphatic segment(s) and (B) an aromatic polycarbonate, and a method for producing it. The polycarbonate resin composition for the optical waveguide has the advantages of high mechanical strength and improved flowability.

Abstract: An electronic device using total internal reflection to guide light from a light source housed within the electronic device to the surface of the device. The electronic device has a cover secured to a protective housing to form a protective enclosure for the electronic device. The cover is adapted to use total internal reflection to guide light through the cover to a plurality of surface portion of the cover. A second surface portion of the cover is adapted to totally internally reflect a first portion of the light to the first surface portion.

Abstract: The supporting structure for a rod integrator 300 includes, for example, holding members 350a, 350b for holding the rod integrator 300, and supporting units 360a, 360b for supporting the holding members. Each holding member 350a contacts by its planar portions (walls) respectively with two side surfaces of the rod integrator 300 adjacent to one another. The holding member 350a has a clearance such that the holding member does not contact with the edge shared by the two side surfaces of the rod integrator 300. The supporting unit 360a includes, for example, a supporting member 361a and screw 362a. The supporting unit 360a supports the rod integrator 300 by pressing of the screw 362a along the direction of the diagonal of the rod integrator 300 via the supporting member 361a. By doing so, chipping and scratching proximate to the edge can be reduced, and soiling of the reflecting plane can be prevented.

Abstract: A surface light source unit (3) includes a light source (31) and a light guide plate (30). The light guide plate includes a light incidence surface (301) for receiving light beams, an emission surface (302) for emitting the light beams, and a bottom surface (303) for scattering and diffusing the light beams. A plurality of diffusion dots (311) is formed on the bottom surface and a plurality of protrusions (312) parallel to the light incidence surface is formed on the emission surface with decreasing an interval between two adjacent protrusions as goes away from the light incidence surface. The amount (N) of the protrusions satisfies a condition of N=R/220, wherein R is a distance from the light incidence surface to an opposite surface of the light guide plate. The surface light source unit provides uniform illumination and high brightness for a liquid crystal display panel.

Abstract: A rod integrator includes a quadrangular prismatic light-guiding member with a rectangular cross-sectional shape. The light-guiding member guides a light beam from a first end surface to a second end surface, opposing the first end surface, while the beam is reflected by the side surfaces so that the beam is output from the second end surface. The rod integrator includes a tube-shape body having the first open end portion tightly surrounding the end portion of the light-guiding member on the side of the second end surface, and having the second open end portion from which the beam is output while causing the beam from the first end portion to be reflected by inner mirror surfaces of the tube-shape body. The tube-shape body is arrangedy in a pinwheel shape. First, second, third, and fourth members, each of which has a plate shape and a mirror surface on one side, are arranged on the light-guiding member, such that the tube-shape body has the mirror surfaces facing inside.

Abstract: An illuminating waveguide having first and second longitudinally-extending unitary portions of differing cross-sectional shape. In use, light is injected into the waveguide at, for example, an end face of the waveguide and the light travels along the length of the waveguide with a portion of the light refracting laterally out of the waveguide along some or all of its length. The second cross-sectional shape can be any of a large number of different conical shapes to help direct the internally reflecting light toward the first portion where it can laterally exit the waveguide. The first cross-sectional shape can take a variety of different forms depending upon the illumination and other aesthetic and functional requirements for a particular application. The surface of the first portion can be treated to control the emission of light from that surface.

Abstract: Illuminators include transparent light emitting members having a pattern of rounded shallow notches or grooves in one or more surfaces of the members for causing internally reflected light to be emitted from the members. The notches or grooves may be cut using a circular cutting tool. The relative speed of the cutting tool and feed rate of the cutting tool relative to the members may be controlled to produce a roughened surface on the notches or grooves.

Abstract: An optical conductor comprising a rod-like part made of a light-conducting material. To accomplish a mechanically durable structure, a side surface of the rod-like part is provided with a groove, at least one side surface of which is arranged to form a surface acting as a reflective or permeable surface for light.

Abstract: Double clad large mode area planar lasers or amplifiers comprising rare-earth or transition metal doped planar core regions are used to generate near-diffraction-limited optical beams of ultra-high power. The amplified light is guided in the core using different guiding mechanisms in two orthogonal axes inside the core. Waveguiding along a first long core axis is obtained substantially by gain-guiding or thermal lensing. Waveguiding along a second short core axis is obtained by index guiding. This is accomplished by surrounding the planar core region with regions of different refractive index. The long sides of the planar core region are surrounded with a depressed refractive index cladding region. The short sides of the planar core region are surrounded with a cladding region substantially index-matched to the core region. The whole structure is surrounded by an outer cladding region with a low refractive index to enable cladding pumping of the planar waveguide with high-power diode lasers.

Abstract: An optical waveguide for emitting light of uniform intensity distributed over the light emitting surface so as to suppress the occurrences of bright lines includes an optical waveguide and surface light emitting apparatus that has a light emitting plane and a reflecting plane that oppose each other. The reflecting surface has a plurality of dots formed thereon so that light entering from the light source, provided on one end face or two opposing end faces, is output through the light emitting surface with uniform intensity, wherein the dots are arranged so as to form band regions each being defined as a region that has a constant density of distribution. A plurality of vertical lines of the dots are formed at substantially equal intervals in each of the band regions in the direction toward adjacent bands, and the interval between the vertical lines of dots is made different in different bands.

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.