Abstract: A zoom lens comprising, in the order of an increasing distance from an object; a fixed first lens group (1) having a positive refractive power; a second lens group (2) containing an aspherical surface, having a negative refractive power and being in charge of a variable power action by being moved; a fixed third lens group (3) containing an aspherical surface and having a positive refractive power; and a fourth lens group (4) containing an aspherical surface, having a positive refractive power and moving while following up a moving object point; wherein the surface on the image plane side of a lens positioned closest to the image plane in the third lens group (3) has a concave plane having a strong refractive power with respect to the image plane and a relation, 2.0<L/CL1<2.

Abstract: An antiglare optical device for selectively attenuating bright light sources in an object field. This device comprises at the object end, the optics necessary for focusing incoming rays onto a focal plane, at the eyepiece end, the optics necessary to view the image of the object field, and at the focal plane, a photochromic layer for moderating rays originating from intense objects in the object field. A sharp focusing of the object field on the photochromic layer is achieved by means of asymmetrical optical components such as polarizing beam splitter and half lenses.

Abstract: An apparatus for generating a pattern on a photomask includes a beam generator generating a row of spaced apart optical beams, a blocking element downstream from the beam generator in a path of at least one of the optical beams, and a refracting element downstream from the blocking element for aligning optical beams closer together and while leaving an enlarged beam spacing downstream from the at least one blocked optical beam. The apparatus further includes a modulator downstream from the refracting element for defining the pattern to be generated on the photomask. The apparatus generates the row of spaced apart optical beams with an enlarged beam spacing between the two central beams without using high precision mirrors that are expensive to produce and requires precise alignment with respect to one another.

Abstract: A system that optically performs complex transforms, such as Fourier transforms. The system includes a pixel addressable spatial modulator that, in parallel, adjusts the phase of the light of each pixel. The modulator can be a reflective or transmissive type device. A transform lens, such as a Fourier lens, performs a two dimensional transform of the pixels outputs. This operation is repeated for the characteristic function (real and imaginary) of the function. The transformed outputs of the characteristic functions are sampled by a light detector and processed by a computer using simple fast operations, such as addition, into the final transform.

Abstract: A luminous intensity sensor element having a flat disk-shaped element (2) made of material with a high thermal expansion coefficient and of low thermal conductivity, and in turn having, on opposite faces (3, 5), an optically absorbent layer (4) and a reflecting layer (6). On receiving excitation radiation (R), the optically absorbent layer (4) is heated and transmits heat to the flat disk-shaped (2), which in turn is heated internally in spatially nonuniform manner and is deformed together with the superimposed reflecting layer (6). The reflecting layer (6) receives an incident reference layer beam (S) to generate a reflected light beam having optical characteristics (&Dgr;&phgr;) depending on the aforementioned deformation (&Dgr;d) and varying in response to the excitation radiation.

Abstract: A variable magnification optical system includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power arranged to move along an optical axis during variation of magnification, the second lens unit including, in order from the object side to the image side, a first lens (L21) of negative refractive power and of meniscus form having a concave surface facing the image side, a second lens (L22) of negative refractive power, a third lens (L23) of positive refractive power and a fourth lens (L24) of negative refractive power, a third lens unit of positive refractive power, at least a part of the third lens unit being moved in such a way as to have a component perpendicular to the optical axis to displace an image formed by the variable magnification optical system, and a fourth lens unit of positive refractive power arranged to move along the optical axis during the variation of magnification, wherein the following condition

Abstract: An objective lens for use in an optical pickup apparatus to record or reproduce information in an optical information recording medium, comprises an aspheric surface, wherein the following conditional formula is satisfied: 1.1≦d1/f≦3 where d1 represents axial lens thickness and f represents a focal length.

Abstract: An optical system comprising a first array of individual beam shaping elements and a second array of beam shaping elements placed between a light source, e.g., a linear array of individual laser diodes and a reshaped beam receiver, e.g., an optical fiber cable. The inhomogeneous beams emitted from the laser diodes are passed in sequence through the first and second stages so that the first stage reshaped the cross section of the beam, e.g., in the fast-axis direction and the second stage reshapes the cross section of the beam, e.g., in the slow-axis direction. As a result, the output beams of the system may have a cross section reshaped to any desired configuration, e.g., suitable for inputting into the optical fiber cable and having divergences individually adjusted in mutually perpendicular directions.

Abstract: A cross dichroic prism comprises four triangular prisms having isosceles right triangular cross sections identical in shape, opposing side faces thereof being bonded and secured together with rectangular portions thereof facing each other; and a dichroic film having an X-shaped cross section formed between the bonding faces of the triangular prisms; wherein, of the four triangular prisms, a given prism and at least one of the prisms adjacent thereto have a refractive index difference therebetween of 0.00005 or less, and the remaining two prisms opposed thereto have a refractive index difference therebetween of 0.00005 or less.

Abstract: This invention discloses an optical system which comprises first positioning and connecting portions which are formed by an integral molding on left and right side surfaces of an incidence surface of a second prism while having steps above an incidence surface and includes small bolt holes and positioning pins and second positioning and connecting portions which are formed by an integral molding at both left and right sides of a projection surface of the first prism such that they extend from the both left and right sides from the projection surface and includes small bolt holes and small bolt fitting holes, wherein the positioning pins are fitted into the positioning pin fitting holes and the lower surfaces of the second positioning and connecting portions are brought into contact with the upper surfaces of the first positioning and connecting portions, and thereafter, small bolts are made to pass through and are threaded into the small bolt holes thus integrally connecting the first prism and the second pri

Abstract: An optical pickup device includes a light source for generating light, a light path changing means for changing the traveling path of incident light, an objective lens for focusing incident light to form a light spot on a recording medium and having an incidence region of a predetermined size, a tracking mirror disposed on the light path between the light path changing means and the objective lens, for reflecting incident light emitted from the light source so that the light spot traces proper track positions of the recording medium, a lens unit consisting of at least two lenses which allow the light reflected from the tracking mirror to be incident on the incidence region of the objective lens, and a photo detecting unit for receiving light reflected from the recording medium and having passed through the objective lens and the light path changing means.

Abstract: A rear focus type zoom lens has, in succession from the object side, a first lens unit L1 of positive refractive power, a second lens unit L2 of negative refractive power, a third lens unit L3 of positive refractive power and a fourth lens unit L4 of positive refractive power. The second lens unit is moved toward the image plane side to effect a focal length change from the wide angle end to the telephoto end. The fourth lens unit is moved to correct the fluctuation of the image plane resulting from a focal length change and the fourth lens unit is moved to effect focusing. The third lens unit has a stop most adjacent to the image plane side. The surface thereof adjacent to the stop is convex toward the image plane side and aspherical.

Abstract: A zoom lens of the rear-focus type includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power. The variation of magnification from a wide-angle end to a telephoto end is effected by moving the second lens unit toward the image side. Shifting of an image plane caused by the variation of magnification is compensated for by moving the fourth lens unit. Focusing is effected by moving the fourth lens unit. The second lens unit consists of, in order from the object side to the image side, a negative lens, a negative lens, a positive lens and a negative lens, the third lens unit comprises a plurality of positive lenses and a negative lens, and the fourth lens unit consists of a negative lens and a positive lens, and wherein the following condition is satisfied: 0.25<(Fm−Fw)/(Ft−Fw)<0.

Abstract: The present invention pertains to an optical shutter comprising an organic free compound, preferably a radical cation or a radical anion, wherein the organic free radical compound forms a reaction product having a change in absorption in a near-infrared or a wavelength region as a result of a photo-induced reaction of the free radical compound. Preferably, the photo-induced reaction occurs in less than 0.1 nanoseconds after absorption of photons by the free radical compound. Also, preferably, the change in absorption is reversible, and the optical shutter is reversibly imaged in less than 10 milliseconds to regenerate the free radical compound. Provided is an optical shutter for use as an optical switch in fiber optic communications, and, alternatively, for use in a laser protection device, a security protection system, and an eyewear device. Also provided are optical switch arrays, optical buffers, optical routers, and tunable optical gain filters comprising such optical shutters.

Abstract: An apparatus for retaining and protecting spliced optical fibers that are part of cables that have ultra-high strength steel wires, in which the optical fibers are free to move within a sleeve inside of the wires. The apparatus includes a joint box having opposing longitudinal cable termination ends. The high-strength steel wires of each cable are attached to a respective cable termination end. At least one optical fiber from each cable extends through its respective cable termination end and is spliced together to form a continuous optical fiber. The fiber or fibers are restrained at locations on the continuous optical fiber spaced from the splice by winding portions of the fibers around a friction imparting element, such as a drum, that includes a curved outer surface. Tension forces applied to the fiber or fibers are transferred to the drum.

Abstract: A lens assembly is provided to adjust the path of an optical beam. The lens assembly includes a lens positioned along the path of the optical beam. The lens is also positioned for movement in directions parallel to a plane traversing the path of the optical beam. The lens is configured to adjust the path of the optical beam upon movement of the lens in a direction parallel to the plane.

Abstract: The invention concerns an electrochromic glazing system, with an electrochromic pane unit and at least one other pane, which are joined to one another in the edge area by means of a spacer frame, forming an interspace, and with a temperature sensor for detection of the temperature of the electrochromic pane unit. To optimize its location, according to the invention the temperature sensor is arranged in the region of the spacer frame, between the electrochromic pane unit and the other pane. The invention takes advantage of the fact that the spacer frame area represents a thermal bridge between the panes of a double-glazing unit which is especially suitable for the arrangement of a temperature sensor.

Abstract: In an optical element composed of an entrance refractive surface, an exit refractive surface and a plurality of internal reflective surfaces provided between the entrance refractive surface and the exit refractive surface, a structure is provided for enabling the optical element to turn around a reference axis of the entrance refractive surface. Further, in such an optical element, an diaphragm member is disposed adjacent to the entrance refractive surface and is arranged to vary an aperture diameter thereof according to a movement thereof.

Abstract: The invention relates to a zoom lens system of two-group construction, one lens for each group, which is less susceptible to aberration variations even upon zooming and can be much more increased in terms of lens aperture and zoom ratio. The zoom lens system of two-group construction comprises, in order from an object side thereof, a first lens group G1 having negative refracting power and a second lens group G2 having positive refracting power and in which a focal length thereof is varied by moving both the lenses while an optical axis separation therebetween is varied. The first lens group G1 consists of one concave lens having a strong concave surface directed toward an image plane side of the zoom lens system and formed of a homogeneous medium, and the second lens group G2 consists of one convex lens formed of a homogeneous medium. A stop S is located between the first lens group G1 and the second lens group G2.

Abstract: A method is supported for aligning the height of a polymer waveguide to the height of a core layer of a semiconductor element in an optical module composed so as to mount the semiconductor element on its polymer waveguide substrate. In order to achieve the method, at first a waveguide is formed on the silicon substrate coated with an oxide film using a polymer whose refractive index is larger than that of the oxide film. The waveguide consists of a lower cladding layer, a core layer, and an upper cladding layer. The lower cladding layer is formed to be thinner than the conventional one and the height of the core layer is set to 5 to 10 &mgr;m. In this way, it is possible to fabricate an optical module in less process steps and at a lower cost than the conventional one.