Abstract: A light guide plate (30) has a light incident surface (305) for receiving light, a light emitting surface (301) for emitting light, a bottom surface (303) opposite to the light emitting surface, and side surfaces (307, 309, 311). A subwavelength grating (302) is formed on the light incident surface for diffracting the light. The subwavelength grating is a zeroth-order grating which covers a wide wavelength band and diffracts the light into zeroth-order waves. So that the light guide plate has a high light utilization efficiency and yields high uniformity of outgoing light.

Abstract: An optical diffraction element (1) comprises a diffraction layer (4) which is divided into diffraction strips (6) alternating with intermediate strips (8). The diffraction strips comprise nano-elements (10) which are aligned in one direction and absorb radiation (b) which is linearly polarized in this direction. The diffraction element may be a linear or two-dimensional grating (1) or a Fresnel lens (160). The polarization-sensitive grating can be used in optical systems in which only radiation with a specific polarization direction should be diffracted, or in an optical record carrier to allow reading of an information structure with high spatial frequencies.

Abstract: A diffraction grating generates even-order, odd-order, and 0th-order exit-pupil images. The even-order exit-pupil images have brightness levels within a first range and the odd-order exit-pupil images have brightness levels within a second range that is different from the first range. In one example, the even-order exit-pupil images are virtually invisible, i.e., missing, the odd-order exit-pupil images have the same or approximately the same intensities, and the 0th-order exit-pupil image has an intensity greater than the respective intensities of the odd-order exit-pupil images.

Abstract: An image display apparatus includes an indicating element which modulates or emits light as a pixel in accordance with image information. A displacement unit optically displaces a position of the pixel for each of two or more sub-fields constituting an image field corresponding to the image information. A projection unit enlarges the pixel and projects an enlarged pixel on a screen. A pixel-profile deformation unit changes an optical intensity profile of the pixel.

Abstract: The invention relates to a new light pipe (313) for providing backlighting (312) of a flat-panel display (311) by means of at least one light source so that the light pipe has at least one surface which comprises patterns. The patterns have diffraction properties for conducting the light in the direction of the display, and the patterns comprise uniform, mutually different areas having a certain distribution on the surface of the light pipe. The local outcoupling efficiency of the light pipe depends on the characteristic properties of the patterns, which are dependent on the distance to the light source or its wavelength.

Abstract: The present invention provides improved Wavefront Coding imaging apparatus and methods composed of optics, a detector, and processing of the detected image. The optics are constructed and arranged to have the characteristic that the transverse ray intercept curves form substantially straight, sloped lines. The wavefront coding corrects for known or unknown amounts of “misfocus-like” aberrations by altering the optical transfer function of the imaging apparatus in such a way that the altered optical transfer function is substantially insensitive to aberrations. Post processing then removes the effect of the coding, except for the invariance with regard to aberrations, thereby producing clear images.

Abstract: The present invention provides a diffraction grating element that allows the temperature control mechanism to be dispensed with or simplified. The diffraction grating element of the present invention comprises a transparent plate having a first surface and a second surface that are substantially parallel with one another; and a diffraction grating which is formed on a first surface side with respect to the second surface and is substantially parallel with the first surface. At any temperature within a temperature range ?20° C. to +80° C., the sum of the rate of change in the period per unit length of the diffraction grating with respect to a temperature change, and the temperature coefficient of the refractive index of a medium that surrounds the diffraction grating element is 0.

Abstract: An optical waveguide to fiber coupler comprises a substrate, a first waveguide and a second waveguide. The first and second waveguides are formed on the substrate and intersect at a right angle. A diffraction grating structure is formed at the intersection of the first and second waveguides, such that, when the coupler is physically abutted with a single mode optical fiber, in operation, a polarization split is obtained that couples orthogonal modes from the single-mode optical fiber into single identical modes in the first and second waveguides. Also, employing the coupler in optical polarization diverse applications provides for implementing a polarization insensitive photonic integrated circuit using such diffraction grating structures, such as, for example, photonic crystals.

Abstract: A novel Bragg grating filter in optical waveguiding fiber with suppressed cladding mode coupling and method of producing same is disclosed. The novel grating structure is induced in both the core and the cladding of the optical fiber irrespective of the photosensitivity of the core or cladding to actinic radiation. Such core and cladding of the optical fiber need not be chemically doped to support the grating. The method incorporates an ultra short duration pulse laser source. Electromagnetic radiation provided from the laser propagates to a diffractive element positioned a specific distance to the target material such that the diffracted electromagnetic radiation forms a 2-beam interference pattern, the peaks of which are sufficiently intense to cause a change in index of refraction.

Abstract: An optical element of which diffraction efficiency hardly varies with wavelength is provided by using an optical material satisfying the conditions that nd>?6.667×10?3?d+1.70 and ?g,F??2×10?3?d+0.59 where nd is a refractive index at d-line, ?d is an Abbe number at the d-line, and ?g,F is a second order dispersion at d-line, whereby diffraction efficiency is improved in any working visible wavelength region and more precise chromatic aberration correction is obtained.

Abstract: An optical element is disclosed which is resistant to changes in environmental characteristics such as temperature and humidity and achieves a stable and favorable reflection suppressing effect. The optical element has a base member and a resin layer which is formed on the base member and has a linear expansion coefficient different from that of the base member. The resin layer has a minute periodic structure which has a period smaller than the wavelength of incident light on the optical element.

Abstract: A grating coupled surface plasmon resonance optical modulator is disclosed. A electro-optic polymer dielectric is deposited on the metallic surface of a diffraction grating to provide a metal/dielectric interface. A surface plasmon will propagate at the metal/dielectric interface in a resonant condition, e.g., when the metal surface is illuminated by transverse magnetic (TM) polarized light of the appropriate wavelength, angle of incidence and phase velocity. In the present invention, phase velocity is controlled by the diffraction grating. A transparent electrode deposited on the electro-optic layer allows an electrical potential to be applied across the electro-optic polymer. The applied electrical potential (voltage) changes the index of refraction of the electro-optic polymer, thereby disrupting the resonant condition to produce an optically detectable change in reflectance of incident light from the metal layer.

Abstract: The present invention relates generally to a diffractive light modulator using cantilevers. The diffractive light modulator reflects and diffracts incident beams depending on a height difference formed when neighboring cantilevers, which are constructed in such a way that the first ends thereof are supported by one or more support units and the second ends thereof are free, bend (curve) in the same direction or opposite directions.

Abstract: A DOE homogenizer including a plurality of parallel lasers emitting Gaussian beams of a diameter d along beam lines extending in a z-direction and aligning at a pitch p in an x-direction, and off-axis DOEs diffracting the Gaussian laser beams at inclining diffraction angles, making quasi-uniform density q×w (q>w) stripe-sectioned beams on an image plane I (xy-plane) which is distanced by a focal length f from the DOEs and aligning at the pitch p on an x-direction extending base line K vertical to the beam lines in an order of larger inclining diffraction angles outward and smaller inclining diffraction angles inward on extensions of the beam lines of the lasers, the DOEs diffracting the laser Gaussian beams into the quasi-uniform density stripe-sectioned beams, superposing the diffracted beams partially at edges and making a unified x-direction extending quasi-uniform beam on the image plane I.

Abstract: A method of projecting a pattern from a mask onto a substrate comprises providing an energy source, a substrate, and a mask containing a pattern of features to be projected onto the substrate, and projecting an energy beam from the energy source though the mask toward the substrate to create a projected mask pattern image. The projected mask pattern image is created by zeroth and higher orders of the energy beam. The method then includes diffracting zeroth order beams of the projected mask pattern image to an extent that prevents the zeroth order beams from reaching the substrate, while permitting higher order beams of the projected mask pattern image to reach the substrate. Preferably, the zeroth order beams of the projected mask pattern image are diffracted at an obtuse angle.

Abstract: The present invention provides a diffraction grating element that allows the temperature control mechanism to be dispensed with or simplified. The diffraction grating element of the present invention comprises a transparent plate having a first surface and a second surface that are substantially parallel with one another; and a diffraction grating which is formed on a first surface side with respect to the second surface and is substantially parallel with the first surface. At any temperature within a temperature range ?20° C. to +80° C., the sum of the rate of change in the period per unit length of the diffraction grating with respect to a temperature change, and the temperature coefficient of the refractive index of a medium that surrounds the diffraction grating element is 0.

Abstract: A diffraction grating device operable as a reflection or transmission grating, and a method of manufacturing and using any number of such grating devices so that each device is individually electrically addressable to diffract radiation of different wavelengths. The grating device comprises first and second sets of interdigitated elements so that each element of the first set defines an element pair with an immediately adjacent element of the second set, a first gap is defined between the elements of each element pair, and a second gap is defined between each adjacent pair of element pairs. The elements of an element pair are selectively movable toward and away from each other. As such, the widths of the gaps can be selectively sized to diffract radiation of a desired wavelength.

Abstract: Optical properties with high non-linearity such as a modulation transfer function (MTF) are efficiently optimized at high speed compared to conventional methods. An optimal solution of an optical system is obtained in a first optimization unit using a merit function on aberration. Weights or target values of the merit function on aberration is automatically adjusted in a second optimization unit in a manner that an evaluated value of the MTF or the like approaches a desired value. The first optimization unit re-optimizes the optical system using the weights or target values which have been automatically adjusted. Thus, automated is a function equivalent to the operation which has been conducted by a designer such as adjustment to weights or target values.

Abstract: There is disclosed an optical device in which a first light source for outputting a first wavelength light is apart from a second light source for outputting a second wavelength light by a predetermined distance. An information recording medium is irradiated with the first and second wavelength lights transmitted through a holographic optical element having first and second diffraction areas. The first and second diffraction areas are provided with grating arrangements in which grating axis directions are parallel to each other and grating pitches are different from each other. The first and second wavelength lights reflected by the information recording medium are transmitted through the holographic optical element and diffracted by the first and second diffraction areas.

Abstract: A waveguide having a periodic structure and the excitation of exciton polariton as one form of interactions between radiation fields and matter systems are applied to light switching to provide an optical switch that is excellent in light intensity extinction ratio and operable at a speed in the terahertz order. The optical switch includes a polariton and photon interacting region (5) made of a grating (3) formed on a top face of a transparent substrate (2) and a semiconductor layer (4) with which the grating (3) is covered. The polariton and photon interacting region (5) is irradiated from a free space with a controllable light (7) having a preestablished wavelength and also from a free space with a control light (6) having a preselected wavelength to control the transmissivity of the controllable light (7) through the polariton and photon interacting region (5).

Abstract: [Problem] Provided is a diffraction grating element that allows the temperature control mechanism to be dispensed with or simplified.

Abstract: A modulator for modulating an incident beam of light. The modulator includes a plurality of elements, each element including a first end, a second end, a first linear side, a second linear side, and a continuous or non-continuous light reflective planar surface plurality of elements are arranged parallel to each other and further wherein the light reflective planar surface of each of the plurality of elements includes a first non-linear side and a second non-linear side. The modulator also includes a support structure coupled to each end of the plurality of elements to enable movement between a first modulator configuration wherein the plurality of elements act to reflect the incident beam of light as a plane mirror, and a second modulator configuration wherein the plurality of elements act to diffract the incident beam of light.

Abstract: An imaging system is disclosed that includes an illumination source, a modulator and a variable Fourier diaphragm. The illumination source produces a first illumination field having a first frequency and a second illumination field having a second frequency. The modulator receives the first illumination field and the second illumination field, and produces a first modulated illumination field and a second modulated illumination fields. The variable Fourier diaphragm selectively passes one of the first modulated illumination field and the second modulated illumination field.

Abstract: A method for tailoring properties of high k thin layer perovskite materials, and devices comprising such insulators are herein presented. The method comprise the steps of, first, substantially completing the manufacture of a device, which device contains the high k insulator in a polycrystalline form. The device, such as a capacitor, or an FET, went through the typically high temperature manufacturing process of a fabrication line. In the next step, the device is in situ ion implanted with such a dose and energy to convert a fraction of the polycrystalline material into an amorphous material state, hereby tailoring the properties of the insulator. The fraction of polycrystalline material converted to amorphous material might be 1. This process can be applied to many electronic devices and some optical devices. The process results in novel perovskite thin layer materials and novel devices fabricated with such materials.

Abstract: In order to provide a noise-free reliable projection type display apparatus which has no movable portion and can display a high quality full-color image, the following arrangement is proposed. In a projection type display apparatus which has an optical modulation device for displaying an image by controlling the reflected state of light, an illumination unit for irradiating the optical modulation device with light, and a projecting optical system for projecting reflected light components of the light components with which the optical modulation device is irradiated, and projects and displays an image formed by the optical modulation device, as the optical modulation device, a mirror array device for modulating light by controlling the tilt amounts of mirrors that form pixels is used.

Abstract: Embodiments of the present invention provide methods and systems of temporally smoothing the distortion of a light beam caused by imperfections of an optical element or optical system through which the light beam passes. The optical element is moved relative to the light beam to change a position of the imperfections in the path of the light beam to distribute the distortion of the light beam caused by the imperfection without substantially changing the path of the light beam. In some embodiments, the optical element is axially symmetric with respect to its optical axis, and the distortion of the light beam is distributed by rotating the optical element around its optical axis. In some embodiments, the optical element has geometric uniformity relative to a plane or along a line in a plane, and the distortion of the light beam is distributed by moving the optical element along the plane, or along the line of symmetry in the plane.

Abstract: An optical element including a binary blaze grating formed thereon, wherein the binary blaze grating is formed so as to have step differences formed by a number of levels produced by mechanical processing. The number of levels is equal to or more than 5 and the height of the step difference is greater than or equal to 1 &mgr;m.

Abstract: A SiO2 thin film is formed on a SiO2 substrate provided with a binary-type diffractive element by a radiofrequency sputtering process so as to cover the fine irregularities formed on the substrate caused by misalignment of masks in the production process. This film planarizes the surface having the fine irregularities and thus prevents a decrease in diffraction efficiency.

Abstract: A small-sized and low-cost wavelength division multiplexer having little insertion loss, little polarization dependence and a broad wavelength bandwidth, the wavelength division multiplexer adopting a grating configuration in which an incident light is retroreflected, exit lights from respective grooves are enhanced by interference effect in the incident direction of the light, wave surfaces of evanescent waves in the grooves are parallel to the normal direction of the grating and phases of the evanescent waves in the respective grooves agree with each other. The wavelength division multiplexer has high diffraction efficiency in each of TM and TE polarized lights at a several-order diffraction order and accordingly has a broad wavelength bandwidth and remarkably low polarization dependence.

Abstract: A method and apparatus for transferring a fine pattern (12) on a mask (11) onto a substrate (17) by a projection exposure apparatus including an illumination optical system (1-10) for irradiating an illuminating light on the mask (11), and a projection optical system (13) for projecting an image of the fine pattern (12) on the illuminated mask onto the substrate (17).

Abstract: A beam splitting element having a diffraction grating improves the reduction and polarization dependence of a diffraction efficiency while achieving a desired splitting angle.

Abstract: A method for writing a Bragg grating in a waveguide comprises the steps of placing the waveguide in a writing position in which the waveguide extends essentially along one axis; generating a beam of ultraviolet radiation; executing a first and a second scan with the said beam along the waveguide through a phase mask, in such a way as to generate interference fringes capable of modifying the refractive index along the said waveguide in a predetermined way; moving the phase mask, during the first or the second scan, with an oscillatory motion about one of its equilibrium positions and along a direction lying at an angle of less than 90° to the axis of the said waveguide, in such a way as to produce, in this scan, an essentially zero envelope of the refractive index; and varying the intensity of the energy of the ultraviolet radiation in a controlled way along the waveguide during the first and the second scan, for example by controlling the scanning velocity.

Abstract: The invention provides an optical instrument including means (1, 2) to produce an optical image to be viewed by an observer including a diffractive element (7) located at an intermediate focal or image plane (4) of the optical instrument and comprising a pattern of a plurality of areas effective to cause diffraction interference in light passing through the optical instrument and thereby produce an expanded exit pupil (6) comprising a combination of a multiplicity of exit pupils displaced relative to one another transverse to an optical axis (3) of said instrument.

Abstract: The invention provides a planar waveguide diffractive 1×N beam splitter/coupler. It utilizes an integrated circuit fabrication process to fabricate an integrated optic. A Fourier transform diffractive optical element (DOE) is formed on one end of a planar waveguide (planar lightwave circuit; PLC). Thus, an incident beam coming from one end of the planar waveguide can be diffracted into a plurality of output beams. On the other hand, a plurality of incident beams coming from one end of the planar waveguide can be coupled into one output beam. The beam splitter/coupler is easy to fabricate, small in size and more flexible for applications.

Abstract: A metrology for determining bias or overlay error in lithographic processes. This metrology includes a set of diffraction test patterns, optical inspection techniques by using spectroscopic ellipsometer or reflectometer, a method of test pattern profile extraction. The invention uses a set of diffraction gratings as the test patterns, and thin film metrology equipment, such as spectroscopic ellipsometer or spectroscopic reflectometer. The profiles of the test patterns in the two successive layers are analyzed. Overlay information are obtained after processing the profile data. In a first aspect of the invention, a line-on-line overlay grating test patterns structure is disclosed in which a second layer mask is placed in the center of a clear line in a first layer mask. In a second aspect of the invention, a line-in-line overlay grating test patterns structure is disclosed in which a second layer mask is placed in the center of a dark line in the first mask.

Abstract: Disclosed is a laser diode unit for an optical pick-up apparatus capable of applying a laser beam emitted from a laser diode to an optical disc and a monitor photodiode (PD) using an integral optical system. The laser diode unit includes a laser diode for emitting a laser beam, a monitor PD for controlling recording optical power, an optical disc on which data is written by the laser beam or from which data is read by the laser beam, and a lens module for reflecting a part of the light beam emitted, in the form of a divergent light beam, from the laser diode, thereby focusing the light beam onto the optical disc, the lens module also serving to transmit the remaining part of the light beam therethrough, thereby allowing the transmitted light beam to be converged by the monitor photodiode.

Abstract: Novel methods are disclosed for designing and constructing miniature optical systems and devices employing light diffractive optical elements (DOES) for modifying the size and shape of laser beams produced from a commercial-grade laser diodes, over an extended range hitherto unachievable using conventional techniques. The systems and devices of the present invention have uses in a wide range of applications, including laser scanning, optical-based information storage, medical and analytical instrumentation, and the like. In the illustrative embodiments, various techniques are disclosed for implementing the DOEs as holographic optical elements (HOEs), computer-generated holograms (CGHs), as well as other diffractive optical elements.

Abstract: Phase masks which can be used to make both linear and curved gratings of single or multiple submicron pitches, with or without any abrupt quarter-wavelength shifts (or gradually varying finer phase shifts) simultaneously on the wafer/substrate. The phase masks are made using direct write electron or ion-beam lithography of two times the required submicron pitches of linear and curved gratings on commercially available &pgr; phase-shifting material on a quartz substrate and wet or dry etching of the &pgr; phase-shifting material. The phase masks can be used in connection with making multi-wavelength laser diode chips. The laser diodes have a ridge structure with metal shoulders on either side of the ridge. The laser diode chip, with different wavelength lasers, is bonded and interfaced to a novel microwave substrate that allows for high signal-to-noise ratio and low crosstalk. The substrate is packaged in a low loss rugged housing for WDM applications.

Abstract: A method for forming a diffraction grating in an optical fiber. First and second ultrashort laser pulses are generated. The first and second ultrashort laser pulses are directed to intersect and form an interference pattern. The interference pattern includes periodic intensity variations which cause corresponding periodic changes in an index of refraction of the optical fiber. The ultrashort laser pulses and the optical fiber are configured to be self-focused by the cladding and core of the optical fiber.

Abstract: An optical system and, more specifically, an image pick-up optical system having a small size and satisfactory aberration, in which an optical system includes an optical unit having a light incident surface on which light is incident, a light reflecting surface having a curvature to reflect the light incident from the light incident surface, and a light exit surface from which the light reflected by the light reflecting surface emerges, and has a refractive index distribution, is disclosed.

Abstract: A diffractive homogenizer is provided for receiving a beam of laser energy and producing a desired illumination pattern in a target plane. The homogenizer is made up of a plurality of diffractive sub-elements, each of which contributes to all or a portion of the desired image. By combining the contributions of many sub-elements to form the final image, a homogenizing effect is realized. In preferred embodiments, the sub-elements are designed to compensate for the finite spatial coherence of the incident laser beam and to control the numerical aperture distribution of the transmitted light. Each sub-element is composed of a large number of discrete pixels, each of which alters the phase of radiation passing therethrough by a selected amount. The pixel arrangement is chosen, using computer modeling and optimization techniques, such that the interference pattern created by the collective pixels in a sub-element makes up the desired image (or a portion thereof).

Abstract: A compact illumination device intended especially for illuminating an active matrix in a monochromatic or trichromatic display device. This device includes a source and collimating device in order to deliver a lighting direction from the source along a direction (Dy) and two optical components (M1) and (M2) which anamorphose the lighting in a direction parallel to the direction (Dy) and in a direction (Dz) perpendicular to the direction (Dy), respectively. These components may typically be of the holographic grating type operating in transmission or in reflection.

Abstract: An optical arrangement, in particular for use as a transmitting and/or receiving optical system in optoelectronic sensors, comprises at least one diffractive optical element integrated into transparent material, with the unit formed by the transparent material and the diffractive optical element having at least two different functions such as, for example, image forming functions, polarization, beam division, beam forming, beam shaping and/or the provision of a subaperture.

Abstract: An optical device reads the information such as bar codes on an object. A light-emitting element emits a read-beam. A lens cover has an inclined surface that is at an angle with the read-beam and reflects the read-beam toward a bar code, the read-beam emerging as a reflected-beam after reflection from the surface of the bar code. The reflected-beam contains a component directly reflected from the bar code and a component randomly reflected by the white and black areas of the bar code. An optical system in the form of a lens is arranged between the lens cover and the light-emitting element, and converges the read-beam to the bar code. The inclined surface is also at an angle with the reflected-beam and reflects the reflected-beam toward a second optical system in the form of a lens which in turn converges the reflected-beam emerging from the inclined surface to a light-sensing element. The light-sensing element detects the reflected-beam.

Abstract: An advanced design for a phase plate enables the distribution of spots in arbitrarily shaped patterns with very high uniformity and with a continuously or near-continuously varying phase pattern. A continuous phase pattern eliminates large phase jumps typically expected in a grating that provides arbitrary shapes. Large phase jumps increase scattered light outside of the desired pattern, reduce efficiency and can make the grating difficult to manufacture. When manufacturing capabilities preclude producing a fully continuous grating, the present design can be easily adapted to minimize manufacturing errors and maintain high efficiencies. This continuous grating is significantly more efficient than previously described Dammann gratings, offers much more flexibility in generating spot patterns and is easier to manufacture and replicate than a multi-level phase grating.

Abstract: A system for writing a Bragg grating point-by-point in an optical waveguide includes an illumination system for producing a primary beam. It further includes a diffraction grating to receive the primary beam and to produce a zero order secondary beam and two symmetrical secondary beams of higher order and a focusing optical device for focusing the secondary beams onto a writing area of the waveguide. The diffraction grating and the focusing optical device define an intensity function of writing in the area of the guide including a central peak and two secondary peaks spaced from the central peak by a distance equal to the pitch of the grating.

Abstract: A data encoding system for encoding input color pixel data and outputting encoded data. The data encoding system includes a reference pixel generating device which outputs reference pixel data corresponding to the input color pixel data to be encoded; a predictor having a color order table which sets the color ranks of color codes for every reference pixel pattern, reads and outputs the color rank of the corresponding color code from the color order table on the basis of the color pixel data to be encoded and its reference pixel data; and an entropy encoding device which converts the color ranking data into encoded data and outputs the encoded data.

Abstract: An apparatus for, and method of, decreasing a temporal duration of an optical input pulse having an input power spectrum associated therewith, the apparatus and method operative on at least unchirped optical input pulses. The apparatus comprises: (1) a zero-dispersion pulse shaper for receiving the optical input pulse and spectrally spreading the input pulse to produce a spectrally-spread pulse and (2) a modulator array interposed within the zero-dispersion pulse shaper for receiving the spectrally-spread pulse and selectively attenuating a portion of the power spectrum of the spectrally-spread pulse by a predetermined amount to produce a selectively-attenuated spectrally-spread pulse, the zero-dispersion pulse shaper focusing and recombining the selectively-attenuated spectrally-spread pulse to produce an output pulse having a broader power spectrum than the input pulse, the output pulse further having a temporal duration less than the input pulse, regardless of whether the input pulse is chirped.

Abstract: A method and device for shaping both the temporal and spatial profiles of an input optical pulse to generate an output optical waveform are described. The method includes the step of dispersing the spectral frequencies of the input pulse. These frequencies are then focused with a cylindrical lens to form a two-dimensional optical field. The field is imaged on a mask featuring a two-dimensional array of pixels. The amplitudes, phases, or phases and amplitudes of the two-dimensional optical field are then filtered with the mask. The filtered spectral frequencies are then recombined to form the collective temporal profile of the output waveform. The two-dimensional optical field is then imaged in a sample plane to form the spatially coherent regions.

Abstract: A method and apparatus for transferring a fine pattern (12) on a mask (11) onto a substrate (17) by a projection exposure apparatus including an illumination optical system (1-10) for irradiating an illuminating light on the mask (11), and a projection optical system (13) for projecting an image of the fine pattern (12) on the illuminated mask onto the substrate (17). The illuminating light is irradiated at least in the form of a pair of light beams opposedly inclined with respect to the mask through a pair of transparent windows (6a, 6b) of a spatial filter (6) whereby either one of the .+-.