Abstract: An optical element has a quarter-wave plate formed on the X-Y plane and laminated in the Z-axis direction in three-dimensional space X, Y, Z. The groove in the wave plate is curved, and the angle relative to the Y-axis varies continuously in the range of 0° to 180°. The optical element separates and converts incoming circularly polarized light into light passing therethrough and circularly polarized light reversely rotating a given angle toward the X axis from the Z axis, and outputs the light.

Abstract: To provide a volume-type optical element in which a self-cloning photonic crystal is used. An optical element is provided with half-wave plates of photonic crystals formed on the xy plane and laminated in the z-axis direction in a three-dimensional space x, y, z. The groove direction of the photonic crystals is a curved line, and the angle in relation to the y-axis direction changes continuously in the range of 0°-180°. Light entering the optical element in the axial direction is emitted from the optical element upon being divided and converted into clockwise circularly polarized light in the direction facing the x-axis by a given angle from the z-axis and anticlockwise circularly polarized light in the direction facing the ?x-axis by a given angle from the z-axis. Laminating or placing a quarter-wave plate comprising a photonic crystal on one or both surfaces makes it possible to divide light entering from the z-axis direction of the optical element into two orthogonal linearly polarized lights.

Abstract: To provide an optical element and an optical circuit enabling easy integration. An optical element has a quarter-wave plate formed on the X-Y plane and laminated in the Z-axis direction in three-dimensional space X, Y, Z. The groove in the wave plate is curved, and the angle relative to the Y-axis varies continuously in the range of 0° to 180°. The optical element separates and converts incoming circularly polarized light into light passing therethrough and circularly polarized light reversely rotating a given angle toward the X axis from the Z axis, and outputs the light.

Abstract: To provide a volume-type optical element in which a self-cloning photonic crystal is used. An optical element is provided with half-wave plates of photonic crystals formed on the xy plane and laminated in the z-axis direction in a three-dimensional space x, y, z. The groove direction of the photonic crystals is a curved line, and the angle in relation to the y-axis direction changes continuously in the range of 0°-180°. Light entering the optical element in the axial direction is emitted from the optical element upon being divided and converted into clockwise circularly polarized light in the direction facing the x-axis by a given angle from the z-axis and anticlockwise circularly polarized light in the direction facing the ?x-axis by a given angle from the z-axis. Laminating or placing a quarter-wave plate comprising a photonic crystal on one or both surfaces makes it possible to divide light entering from the z-axis direction of the optical element into two orthogonal linearly polarized lights.

Abstract: It is an object of the present invention to provide an optical module which can extract only light components satisfying predetermined conditions, and an imaging device comprising the optical module. The optical module (10) comprises a first plate-like optical element (4) formed with a ¼ wavelength plate portion (1) and a ?¼ wavelength plate portion (2) alternately jointed together at a joint portion (3), and a second plate-like optical element (8) formed with a ¼ wavelength plate portion (5) and a ?¼ wavelength plate portion (6) alternately jointed together at a joint portion (7), wherein the first plate-like optical element (4) and the second plate-like optical element (8) are parallel, and the ¼ wavelength plate portion (1) of the first plate-like optical element (4) and the ?¼ wavelength plate portion (6) of the second plate-like optical element (8) are overlapped across a gap (9).

Abstract: It is an object of the present invention to provide an optical module which can extract only light components satisfying predetermined conditions, and an imaging device comprising the optical module. The optical module (10) comprises a first plate-like optical element (4) formed with a ¼ wavelength plate portion (1) and a ?¼ wavelength plate portion (2) alternately jointed together at a joint portion (3), and a second plate-like optical element (8) formed with a ¼ wavelength plate portion (5) and a ?¼ wavelength plate portion (6) alternately jointed together at a joint portion (7), wherein the first plate-like optical element (4) and the second plate-like optical element (8) are parallel, and the ¼ wavelength plate portion (1) of the first plate-like optical element (4) and the ?¼ wavelength plate portion (6) of the second plate-like optical element (8) are overlapped across a gap (9).

Abstract: A small and high-speed polarization analysis device and ellipsometer having no driving section are provided by overlapping one polarizer array rendered by arranging a plurality of polarizer regions of mutually different optical axis directions in the form of stripes and one wavelength plate array rendered by arranging a plurality of wavelength plate regions of fixed retardation and mutually different optical axis directions in the form of stripes so that the respective stripes of the plurality of polarizer regions and of the plurality of wavelength plate regions intersect one another and by disposing a light-receiving element array so that the intensities of light that has passed through the matrix-like intersection parts can be individually measured.

Abstract: A small and high-speed polarization analysis device and ellipsometer having no driving section are provided by overlapping one polarizer array rendered by arranging a plurality of polarizer regions of mutually different optical axis directions in the form of stripes and one wavelength plate array rendered by arranging a plurality of wavelength plate regions of fixed retardation and mutually different optical axis directions in the form of stripes so that the respective stripes of the plurality of polarizer regions and of the plurality of wavelength plate regions intersect one another and by disposing a light-receiving element array so that the intensities of light that has passed through the matrix-like intersection parts can be individually measured.

Abstract: A thin polarizer array and a wavelength plate array that are composed of micro regions having different optical axis directions and wavelength characteristics and having a high extinction ratio and a low insertion loss, and a polarization analyzer using them. An array of micro periodic grooves is formed on a substrate, with the directions changed from one region to another. An alternating multilayer film formed by bias sputtering alternating a layer of high refractive index material such as Si or Ta2O5 and a layer of low refractive index material such as SiO2. By selecting a condition that each layer maintains its periodic projecting/recessed shape, an array of photonic crystal polarizer is formed. By mounting this array of photonic crystal polarizer in a photodetector array, a polarization analyzer that is small, has no movable part, has a small number of components, and enables high-precision measurement is constituted.

Abstract: The optical element includes photonic crystals respectively having different optical characteristics. These photonic crystals are formed in a plurality of regions on a single substrate. The optical element has a structure in which two or more kinds of media are nearly periodically deposited on one-dimensionally periodical grooves. Further, the grooves are different in direction according to locations on the deposited surface. A variety of optical elements each having different dependencies on polarization according to locations can be obtained. That is, portions or zones different in optical characteristics can be integrated on a single substrate.

Abstract: A thin polarizer array and a wavelength plate array that are composed of micro regions having different optical axis directions and wavelength characteristics and have a high extinction ratio and a low insertion loss, and a polarization analyzer using them are disclosed. An array of micro periodic grooves is formed on a substrate, with the directions changed from one region to another. An alternating multilayer film formed by alternating a layer of high refractive index material such as Si or Ta2O5 and a layer of low refractive index material such as SiO2 is formed by bias sputtering. By selecting a condition that each layer maintains its periodic projecting/recessed shape, an array of photonic crystal polarizer is formed. By mounting this array of photonic crystal polarizer in a photodetector array, a polarization analyzer that is small, has no movable part, is composed of a small number of components, and enables high-precision measurement is constituted.

Abstract: A polarizer which has and regularly arranged two-dimensional structure which has a pitch of 1 mm or so or less. The polarizer has structure in which two or more film-shaped materials which have a substantially regularly arranged one-dimensional undulation. The polarizer also has a substantially regularly arranged two-dimensional structure. For example, the polarizer consist of materials 1 and 2 which have different refractive indexes. A regularly arranged two-dimensional structure which has a pitch of 1 mm or less can be obtained by a simple method. Because of this structure, the polarizer transmits the incident light which has a specific polarized plane and reflects the incident light which has a polarized plane which is orthogonal to the plane.

Abstract: A three-dimensional periodical structure whose period is about 1 ?m or smaller is provided. At least two kinds of films which have two-dimensionally substantially periodical projections are successively formed in layers substantially periodical to construct structure which is substantially three-dimensionally periodical. For instance, the films are made of materials different in refractive index. The three-dimensional periodical structure whose period is about 1 ?m or smaller can be obtained by a simple fabricating method. By this structure, the propagation of a wave with a specific wavelength in many solid angular directions including several axial directions parallel to the plane and the thickness direction of the layers can be cut off.

Abstract: The invention provides a structure where photonic crystals respectively having different optical characteristics are formed in a plurality of regions on a single substrate and a method for making the same.

Abstract: Disclosed herein is a self-waveguide optical circuit for forming optical paths by propagating rays or electromagnetic waves comprising: photonic crystals having a dielectric constant periodic structure or a dielectric constant semi-periodic structure having a period substantially corresponding to a wavelength of propagation rays, and optical paths formed by establishing a crystal direction of the photonic crystal to level the dispersion surface of the photonic crystal for obtaining a bundle of parallel rays. In accordance with the present invention, elevation of characteristics such as miniaturization, high integration, high speed operation and transmission efficiency can be obtained because a bundle of parallel rays can be obtained without forming crooked parts having an excessive curvature radius.

Abstract: A wavelength dividing circuit which realizes improved device characteristics and performance, such as a small size, high speed and high transmission efficiency and which lends itself to improved integration degree. A wavelength dividing circuit in which materials of different refractive indices are arrayed periodically, without forming individual waveguides as in conventional AWG, in order to create strong wavelength dispersion characteristics not possible with an ordinary optical crystal to control wavelength deviation. A substrate 1 having atomic mediums 5 buried in a background medium 4 in a two-dimensional triangular array has its both sides sandwiched by a first clad 2 and a second clad 3. Optical signals fall on an incident surface inclined at a certain angle relative to the light incident direction and is radiated from a light outgoing surface 7.

Abstract: An optical isolator for preventing reflection-returned light from entering back into the emitter of an optical system such as an optical fiber communication or an optical disc input/output device, using semiconductor laser. The polarization-independent optical isolator includes a light-emitting side optical fiber having a diameter of a core expanded to give a mode field diameter at an end face of 20 to 50 .mu.m, a light-incident side optical fiber having a diameter of a core expanded to give a mode field diameter at an end face of 20 to 50 .mu.

Abstract: A method of manufacturing an optical isolator which has a rotator capable of rotating a plane of polarization by the Faraday effect, and a polarizer of multilayer structure formed of alternately superposed transparent dielectric films and films having a complex dielectric constant, includes the steps of: forming the rotator as a plate having a large area and the polarizer as an array having a large area; forming an optical isolator array by attaching the polarizer array at least to one surface of the rotator plate in such a manner that the layers of the polarizer array extend perpendicularly to the surface of the rotator plate; and cutting the optical isolator array into a plurality of optical isolator chips.

Abstract: There is disclosed an optical switch comprising an optical fiber, a block of PLZT, and two polarizers disposed on opposite sides of the block. The fiber has one or more grooves in which the block and the polarizers are received. The block of PLZT induces an electric field perpendicular to the axis of the core of the fiber. The groove or grooves extend across the core of the fiber such that the block covers the whole cross section of the core. Each polarizer consists of alternate laminations of a metal and a dielectric. The laminations are stacked in a direction perpendicular to the axis of the core. Each dielectric lamination is thicker than each metal lamination. If incident light is polarized, one of the polarizers is omitted.

Abstract: An optical waveguide for optical communication transmitting light wave energy in a single mode composed of a core of a first transparent dielectric material and successive layers of a second and a third transparent dieletric material coaxially covering the core, the refractive index of the first dielectric material being higher than that of the third dielectric material and the refractive index of the second dielectric material being lower than that of the third dielectric material.