Abstract: An imaging optical apparatus comprising a gradient-index rod lens array and two transparent or light transmitting optical elements that are substantially identical in shape and imaging characteristics and which are provided in the object space and the image space in the optical path of said gradient-index rod lens array in such a way that they are symmetrical with respect to said gradient-index rod lens array.

Abstract: A color image scanner is constructed by a three primary color LED array (4) for illuminating an original (2) to be read out, a monochromatic image sensor array (3) and a rod lens array (1) disposed between the original (1) and the image sensor array (3). The focusing parameters of the three kinds of refractive index distribution type rod lenses (11, 12, 13) constituting the rod lens array (1) are set so that each of the operating wavelength band and the predetermined wavelength is different among the kinds, the lens length Zo is equal among the kinds, and the conjugate length TC at each predetermined wavelength is substantially equal among all the kinds. Accordingly, when a color image reading operation is carried out by using the rod lens array which is effective in compactness and brightness, the chromatic aberration of the rod lens array can be sufficiently reduced and high-resolution can be implemented at low cost.

Abstract: A rod lens for an optical communication module is not easily damaged An input side end surface of the rod lens has an inclined surface The inclined surface is inclined by a predetermined angle with respect to a central axis of the rod lens to reduce the reflection loss. A flat contact surface, which is perpendicular to the central axis, is formed on the distal end of the rod lens. By simply arranging two of the rod lenses to contact each other, the rod lenses are optically coupled in the optimum manner without being damaged.

Abstract: Disclosed is a lens of gradient dielectric constant and methods for the production of same. The lens includes an inner core comprising a cured or fused substantially homogenous blend of glass spheres, curable or fusible binder and, as needed to increase dielectric constant, a low-loss dielectric material. The inner core preferably has a dielectric constant of about 2.0, and an interstitial void volume (representing trapped air space between elements of the cured or fused material) of from about 30% to about 50%. The lens also includes an outer shell layer comprising a cured or fused substantially homogenous blend of hollow glass spheres and curable or fusible resin. The outer shell layer preferably has a dielectric constant of about 1.0, and an interstitial void volume of from about 30% to about 50%. In addition, the lens includes a minimum of one, and preferably two or more intermediate layers, the intermediate layers having a dielectric constant falling between 1 and 2.

Abstract: A method of manufacturing a collimating assembly includes the following steps: preparing a GRIN lens subassembly; preparing a dual-fiber (DF) pigtail subassembly; fitting the GRIN lens subassembly and the DF pigtail subassembly together; applying epoxy onto a junction zone between the GRIN lens subassembly and the DF pigtail subassembly; and baking the junction zone for curing the epoxy thereof until the epoxy spreading uniformly over the junction zone due to the so-called capillarity phenomenon.

Abstract: A single element objective lens for an optical disc drive converges a laser beam, which is emitted by a laser source, on a data recording surface of an optical disc through a protective layer of the optical disc. One surface of the objective lens is divided into a central area including an optical axis thereof and a peripheral area surrounding the central area. The peripheral area is provided with a diffraction lens structure formed by a plurality of concentric annular zones including minute steps. The central area is a continuous surface having no stepped portions. The diffraction lens structure compensates for variation of converging characteristic of the objective lens due to a change of a temperature.

Abstract: In an objective lens for use in an optical pickup device, when NA1 and N2 (NA2 <NA1) represent a needed numerical aperture of the objective lens on an image side, a first spot and a second spot represent a spot formed by the light flux having passed through the central region, a mth order diffracted ray and a nth diffracted ray represent a diffracted ray having the maximum diffraction efficiency among diffracted rays, the central region nearly corresponds to a region through which the light flux in the inside of the numerical aperture NA2 passes, the light amount of the nth order diffracted ray which reaches the inside of the second spot is less than that of the mth order diffracted ray which reaches the inside of the first spot, and the mth order diffracted ray and the nth order diffracted ray satisfy the relationship of m=n.

Abstract: An aligning tool having a plurality of grooves formed side by side is provided; gradient index rod lenses are placed in alignment within the grooves at an average spacing of 1 &mgr;m-5 &mgr;m; the gradient index rod lenses are fixed to form an integral unit as they maintain the aligned state; thereafter the end faces of each rod lens are polished.

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: A method of producing a collimator or collimator array is constituted by the steps of: fixing long-size gradient index rod lens raw materials on a substrate having end surfaces each forming a plane so that the long-size gradient index rod lens raw materials are arranged side by side at intervals of the predetermined pitch while optical axes of the gradient index rod lens raw materials are parallel to one of the end surfaces of the substrate cutting the substrate provided with the gradient index rod lens raw materials at a predetermined position in a plane perpendicular to the optical axes of the gradient index rod lens raw materials to thereby divide the substrate provided with the gradient index rod lens raw materials into lens array parts; adjusting the divided lens array parts so that each of the gradient index rod lens raw materials in the lens array parts has a defined lens length; and arranging the lens array parts so that the cut end surfaces of the lens array parts are made to face each other while op

Abstract: Disclosed herein is a method of producing an object having a refractive index which varies radially from the central portion of the object toward the peripheral portion thereof. Also, an object produced by the method and an apparatus for carrying out the method are disclosed. The method comprises the steps of mounting in a rotatable reactor a solid central rotating body formed by polymerizing a first component; filling a liquid second component in the rotatable reactor around the central rotating body; rotating the central rotating body and/or the rotatable reactor to subject the first component to a dissolution, diffusion, and radial mixing into the second component; and polymerizing the dissolved first component and the second component.

Abstract: A set of lens systems consisting of a plurality of different kinds of lens systems each comprising a radial type gradient index lens element(s), wherein the radial type gradient index lens elements have a common refractive index distribution.

Abstract: A high refractive index composition comprising a core resin mixture comprising a mixture of ethoxylated bisphenol A di(meth)acrylates and/or their derivatives having variable degrees of ethoxylation to provide enhanced impact resistance and refractive index.

Abstract: An imaging optical element is comprised of a gradient index rod lens 12 of which external peripheral surface is a smooth surface without being processed by means of a flare-cut treatment and a field limitation stop member 14 mounted on the lens surface at the incidence side thereof. As for the stop member, the length t thereof is: t>lo·D/2X (where, lo: a lens working distance, D: a rod lens diameter, X: a radius of field of view), whereby the angle of incidence of beam &thgr; at the center of the lens satisfies &thgr;<tan−1(X/lo). It is effective especially when an application thereof is made to a rod lens array comprised of a plurality of rod lenses arranged into an array.

Abstract: An imaging optical apparatus comprising a gradient-index rod lens array and two transparent or light transmitting optical elements that are substantially identical in shape and imaging characteristics and which are provided in the object space and the image space in the optical path of said gradient-index rod lens array in such a way that they are symmetrical with respect to said gradient-index rod lens array.

Abstract: An objective optical system comprising, in order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and a third lens unit having a positive refractive power, wherein the second lens unit is moved along an optical axis for changing a magnification. This objective optical system is configured to be compact and have favorable optical performance by adequately selecting an airspace between the first lens unit and the second lens unit as well as a power for the first lens unit.

Abstract: The transparent article with radial gradient index, according to the invention, comprises a matrix made of a first transparent polymer having a first refractive index n1 and a first Abbe number &ngr;1, a second transparent polymer, diffused into the first polymer in order to produce the radial gradient index and having a second refractive index n2, different than the first refractive index, and a second Abbe number &ngr;2, characterized in that it furthermore comprises an effective amount of an Abbe number modifier agent which reduces by at least 10%, preferably by at least 15%, and more preferably by at least 20%, the value of the Abbe number of that of the first or second polymer which has the refractive index with lower value.

Abstract: A non-phase separable glass material for fabricating a GRIN lens comprises 5-20 mole % boron oxide and ratio R of network modifiers in mole % to the network former boron oxide in mole % is in the range of about 1-1.5. The melted preform of such glass material is extruded through an opening to form a glass rod where the extrusion process eliminates bubbles that may be present in the preform. Neodymium oxide may be added in the frit material for forming the preform to reduce friction forces in the extrusion process and reduces the stress in the glass rod. Centerless grinding may be performed to control the diameter and roughness of the surface of the rod to control the diffusion parameters during the subsequent ion-exchange.

Abstract: A designing method of a zoom optical system wherein each zoom unit is formed of one optical element has steps of: selecting a spherical system, a gradient index system or a diffractive optical system and at least one more system as systems constituting the degree of design freedom of each zoom unit, optimizing each zoom unit with respect to third-order aberrations and chromatic aberration; and using an optical solution obtained by said optimizing step as the design start data.

Abstract: The invention relates to an optical array for symmetrization of the beam of multiple sequentially fixed adjacent laser diodes, their respective output radiation being asymmetrical in relation to a first and a second direction that are perpendicular to each other. A cylindrical lens with sufficient isoplanacy is mounted on the tilted optical axis (z axis), which is perpendicular to the plane predetermined by the two directions (x, y). The lens collimates and displaces the output beam bundle of the individual laser diodes in the first direction (x). The cylindrical lens is mounted downstream a directional element that deflects the beam bundle of the individual laser diodes in the second direction (y) with different deflecting angles respectively in such a way that the centers of gravity of the individual beam bundles converge at a predetermined spacing.

Abstract: A process for correcting optical aberration of a lens by depositing a coating on at least one of the face of the lens. The process varies a composition of the coating depending on its thickness, using at least two optical materials having different refractive indices and dispersion indices, the mutual proportions of which are varied during the deposition. Further, the coating is shaped in order to give it the shape of a lens. Such a process may find particular application in the manufacture of objectives.

Abstract: A refractive index distribution type optical element has a core/cladding structure produced with the ion exchange method. The element includes colorant of metal oxides in cladding glass thereof. The cladding glass consists of base glass and the colorant of the metal oxides comprising: 0.3 to 4.0 wt. % CoO; 1.0 to 12.0 wt. % Fe.sub.2 O.sub.3 ; 0.0 to 2.0 wt. % NiO; and 0.0 to 0.2 wt. % Cr.sub.2 O.sub.3 when the total amount of the base glass except for the colorants is taken as 100 wt. %. The refractive index distribution type optical element is prevented from deterioration of the optical properties occurring at portions having the refractive index departing the regular parabolic distribution and also is prevented from entrance of the flare light. The element is provided with good resolution even when employed for an optical device using a white light, and a rod lens array formed with the refractive index distribution type optical element is provided.

Abstract: A method for producing a spatially stratified Optical System includes the steps of a) selecting a suitable, spatially stratified profile of index of refraction to achieve an optical system having a desired performance; b) selecting an atomic/molecular species having a suitable index of refraction in a desired operational wavelength band; c) forming sub-micron pellets of the species; and d) placing the pellets into a host material while controlling the density of the placement. The density is varied to achieve a local index of refraction value for the optical system in accordance with the selected stratified profile. The wavelength regime the optical system is designed for is much greater than the characteristic scale of stratification, which in turn is much greater than the spatial size of the pellets. The optical system is much greater than the wavelengths in the wavelength regime.

Abstract: An optical system comprising a radial type gradient index lens element which has a negative refractive power of medium and a negative refractive power as a whole, and a radial type gradient index lens element which has a negative refractive power of medium and a negative refractive power as a whole; the optical system having favorable imaging performance: and an optical module using the optical system which is suited for stereoscopic photography and automatic focusing.

Abstract: A radial gradient contact lens is provided. The methodology described above allows the parameters of the lens and of the radial gradient profile to be chosen to improve the vision and the comfort of the wearer. The lens can be made thinner and the optical performance remains improved as the CL moves around in the eye. The improved vision leads to higher contrast when the iris of the eye is fully open as it is under low light level conditions. The use of an anamorphic lens consisting of an elliptical index profile for use in correcting astigmatism is described.

Abstract: GRIN lenses are made by an ion/exchange process. In order to make a GRIN lens whose gradient index varies slowly radially, a cylindrical glass rod of a sufficiently large diameter is immersed in a salty bath. The size of the lens may be reduced by grinding, polishing or chemically etching away a peripheral optically dispensable portion of the lens away from the axis of the lens so that the outer diameter of the lens is as small as 0.8 millimeters. When such a smaller lens is used in optical components such as circulators, switches, WDM's and isolators, such optical devices would also be reduced in size to fit within a limited space.

Abstract: A rod lens made of a transparent cylindrical medium having a refractive index distribution in the radial direction is used as a graded index lens. An object surface and an image surface are arranged on both sides of the rod lens. A first surface of the lens is a convex spherical surface, and a second surface of the lens is a planar surface, and the lens is arranged so that the convex spherical surface faces the object surface, and the planar surface faces an image surface. The equations1.0.ltoreq.R/r.sub.0 .ltoreq.1.6, andR/f.ltoreq.1.2are satisfied, wherein r.sub.0 is a radius of a portion of the rod lens that operates as a lens, measured from an optical axis of the lens, R is a curvature radius of the convex spherical surface, and f is a focal length of the rod lens. Thus, an object lens system with a large NA, that is smaller and lighter, while keeping the number of parts to a minimum, can be provided.

Abstract: A multi-pass optical filter using two identical filters provides narrower band filtering by double filtering an optical signal passing therethrough. Although passing a beam of light at an optical filter having a substantially thick optical thickness is known to have significant coupling losses due to angular misalignment of the output beam and the receiving optical fibre, it has been found that twice filtering in the conventional manner by serially coupling two same filters increases coupling losses. However, this invention provides a coupling arrangement wherein losses are significantly lessened by offsetting the axes of the lensed filters such that the beam exiting the first filter couples into the second filter as it would be reflected backward into the first filter.

Abstract: A vari-focal lens system which comprises a plurality of lens units including a final lens unit having a positive refractive power, and uses at least a gradient index lens element which has a planar surface and another surface having curvature. This vari-focal lens system has a nearly telecentric composition, uses a small number of lens element in the final lens unit and is suited for use in electronic image pickup optical systems.

Abstract: An optical imaging system includes a rod lens array, whose individual lenses have a refractive index distribution optimized for high resolving power, which can be expressed byn(r).sup.2 =n.sub.0.sup.2 .multidot.{1-(g.multidot.r).sup.2 +h.sub.4 .multidot.(g.multidot.r).sup.4 +h.sub.6 .multidot.(g.multidot.r).sup.6 }(Eq. 93)wherein r is a radial distance from an optical axis of said rod lenses, n.sub.0 is the refractive index at the optical axis of said rod lenses, and g, h.sub.4 and h.sub.6 are coefficients of the refractive index distribution. The refractive index distribution coefficients h.sub.4 and h.sub.6 are defined, using parameters a, b, c, and d, asc-d.ltoreq.h.sub.4 .ltoreq.c+d (Eq. 94){(h.sub.4 -c)/d}.sup.2 +[{h.sub.6 -(a.multidot.h.sub.4 +b)}/e].sup.2 .ltoreq.1. (Eq.

Abstract: Disclosed are (1) an optical resin composition comprising Component A: a thiourethane prepolymer compound prepared by reacting a polythiol compound having at least 3 functional groups and an intramolecular sulfide bond, with a polyisocyanate compound in a molar ratio of --SH to --NCO ranging from 3.0 to 7.0; Component B: at least one (meth) acrylate compound having at least 2 functional groups; and Component C: a compound radically polymerizable with Components A and B, in 10 to 50% by weight, 35 to 70% by weight, and 5 to 30% by weight, respectively; (2) a preparation process for an optical resin by photopolymerization; (3) an optical resin; and (4) a prepolymer suitable for Component A. The composition is a novel, rapidly polymerizable composition for an optical resin. Furthermore, a resin prepared by curing the composition not only has a high refractive index and a high Abbe number, but also is excellent in transparency and optical homogeneity.

Abstract: A process for producing a polymer or a crosslinked article having a region in which the polymerization rate or crosslinking rate is varied is disclosed, comprising irradiating a photopolymerizable substance or photo-crosslinkable substance with laser light having an uneven distribution of intensity. The process is suitable for mass production of polymerization rate- or crosslinking rate-distributed articles. An arbitrary distribution pattern can be designed and formed under good control, and distribution regions having a fine shape can be formed with excellent precision. A plurality of distribution regions having a regular shape can be formed at a high density with high precision.

Abstract: A gradient index lens which reflects light and focuses a corresponding image. The reflector can be easily incorporated to optical devices, and is particularly suitable for encoders position detectors, or other instrumentation utilizing line gratings.

Abstract: In a rod lens array in which a plurality of rod lenses each having a refractive-index distribution in the radial direction are arranged in one row such that the optical axes are parallel to each other, and in a life-size imaging optical apparatus using the rod lens array, the outside diameter of each rod lens is such that 0.05 mm.ltoreq.R.ltoreq.0.25 mm and 0.5R.ltoreq.r.sub.0 .ltoreq.1.0R (2R: the distance between the optical axes of adjacent rod lenses and r.sub.0 : the radius of the effective area of each rod lens that provides a lens action) and the degree of overlap m defined by m=x.sub.0 /2R is such that 1.61.ltoreq.m.ltoreq.1.80 or 2.06.ltoreq.m.ltoreq.2.50 where X.sub.0 is the view radius of a single rod lens which is given by X.sub.0 =-r.sub.0 /cos(Z.sub.0 .pi./P).

Abstract: This invention proposes the fabrication of a polarization-independent air-path isolator based on a beam aperture method. The isolator includes a micro Grin lens (MGL) and three small Grin lenses (SGLs). These lenses focus and collimate the forward and backward beams from the input and output ends of the isolator. In addition, one of the small Grin lenses (SGLs) also acts as a beam expander for the backward beam. Due to the significant difference in widths between the forward and backward collimated beams, the optical power of the forward beam is almost completely collected by the output small Grin lens (SGL) at the output end, while only a very small percentage of the optical power of the backward beam is collected by the small Grin lens (SGL) at the input end. Since a laser beam, in general, has a Gaussian beam-intensity distribution, positioning the micro Grin lens (MGL) at an off axis position will significantly enhance the isolation characteristic of the isolator.

Abstract: An image bar printing system, which, in a preferred embodiment, utilizes a plurality of LED arrays to provide a plurality of color images. The print bars are used in conjunction with a plurality of gradient index lens arrays which optically couple and focus the LED outputs onto a photosensitive surface. In order to maintain image-to-image registration, out of spec deviations in active write length of the image bar and scan line bow are identified and compensated for by selective deformation of one or more lens arrays in a specified manner. The lens deformation serves to reorient the position of certain of the lens elements, redirecting the transmitted LED outputs so as to shorten or lengthen the active write length, or to eliminate bow in the scan line.

Abstract: In a rod lens array in which a plurality of rod lenses each having a refractive-index distribution in the radial direction are arranged in two rows such that the optical axis for one row is parallel to that for the other row, and in a life-size imaging optical apparatus using the rod lens array, the outside diameter of each rod lens is such that 0.05 mm.ltoreq.R.ltoreq.0.25 mm and 0.5R.ltoreq.r.sub.0 .ltoreq.1.0R (2R: the distance between the optical axes of adjacent rod lenses and r.sub.0 : the radius of the effective area of each rod lens that provides a lens action) and the degree of overlap m defined by m=X.sub.0 /2R is such that 1.46.ltoreq.m.ltoreq.1.64 (where X.sub.0 is the view radius of a single rod lens which is given by X.sub.0 =-r.sub.0 /cos(Z.sub.0 .pi./P).

Abstract: A segmented GRIN anamorphic lens and a lens array using such lenses are provided. The lens has an optical axis and is composed of a plurality of segments. The interfaces between the segments are planes or wedges inclined at an angle to the optical axis. At least one segment has a predetermined axial index of refraction profile while the other segment may have either a predetermined homogeneous index of refraction or a predetermined radial index of refraction profile. The planar interface geometry and the index of refraction profiles are chosen to provide lenses with desirable optical properties. Spherical and cylindrical aberrations can be reduced or eliminated by appropriate choice of the index of refraction profile. The front and rear surfaces of the lens assembly can also be ground and polished into spherical shapes which act with the axial gradient interface to yield an anamorphic lens functionality.

Abstract: Optics using a graded-index lens, comprising: a single graded-index lens and a homogeneous plano-convex lens. The single graded-index lens has a refractive index distribution in a radial direction, wherein the graded-index lens has a plane or convexo-spherical lens surface and when its refractive index distribution is expressed byn(r).sup.2 =n.sub.0.sup.2 .multidot.{1-(g.multidot.r).sup.2 +h.sub.2 (g.multidot.r).sup.4 +h.sub.6 (g.multidot.r).sup.6 +h.sub.8 (g.multidot.r).sup.8 +.multidot..multidot..multidot.}the following conditions are satisfied,1.45.ltoreq.n.sub.0 .ltoreq.1.80, and0.45.ltoreq.n.sub.0 .multidot.r.sub.0 .ltoreq.0.90,where r is the distance from the optical axis, n(r) is the refractive index at the position distant by r from the optical axis, n.sub.0 is the refractive index on the optical axis, r.sub.0 is the radius of the graded-index lens, g is an index distribution coefficient, and h.sub.4, h.sub.6 and h.sub.8 are index distribution coefficients.

Abstract: A scanning optical system which includes a light source for emitting a beam of light, a light deflector for deflecting the beam of light in a main scanning direction, and a scanning lens which receives a beam of light deflected by the light deflector for focusing the deflected beam of light onto a scanning surface. The scanning lens includes a lens having a refractive index distribution in either the main or the sub-scanning direction.

Abstract: An achromatic lens system which comprises a radial type gradient index lens which has a refractive index varying in a direction perpendicular to an optical axis and a diffraction type lens, and sufficiently corrects the secondary spectrum with a small number of optical elements.

Abstract: A progressive optic has an optical preform wherein the radius of curvature of the surface is altered by forming discrete spherical portions across the surface. A thin intermediate layer, having a different refractive index from the optical preform, is then cast over the formed optical preform surface. The optical preform having the thin intermediate layer is then cast with a resin superstrate layer which restores the curve of the optic. Each spherical section, defined by the spherical portions and corresponding portions of the outer surface of the superstrate layer, alters the spherical power of the adjacent spherical section by about 0.03 D to 0.05 D.

Abstract: An optical low pass filter having an optical axis common to an imaging optical system or configured as a portion of an imaging optical system for contribution to formation of an image, functioning to image components in a longitudinal direction of the image pickup device onto a desired imaging location and having refractive powers, for components in different directions, which are different from that for the components in the longitudinal direction. This optical low pass filter is suited for use with line sensors.

Abstract: A graded-index microcylindrical lens functioning in combination with a laser diode beam to change the divergence of the fast axis on an incoming laser beam from one divergence to another, but not to collimate the beam. In one embodiment of the present invention, the graded-index microcylindrical lens changes the divergence of one axis of the laser beam to be substantially equal to the divergence of the slow axis.

Abstract: A gradient index lens component composed of a single radial type gradient index lens element which has planar surfaces on both side and a positive refractive power and comprising an aperture stop which is disposed in the vicinity of an object side surface of the radial gradient index lens element for restricting a light bundle. And an image pickup apparatus composed by integrating the gradient index lens component with an image pickup device.

Abstract: A lens having a variable index of refraction and a point of symmetry is fabricated from a plurality of substantially identically shaped parts. Each of the parts is pyramidal in configuration and has a base and a plurality of sides extending from the base to an apex. Each of the parts has a coefficient of refraction which varies from the base to the apex.

Abstract: A scanning optical system which includes a light source for emitting a beam of light, a light deflector for deflecting the beam of light in a main scanning direction, and a scanning lens which receives a beam of light deflected by the light deflector for focusing the deflected beam of light onto a scanning surface. The scanning lens includes a lens having a refractive index distribution in either the main or the sub-scanning direction.

Abstract: An axially-based lens is provided, comprising two biaxial elements, each having entrance and exit surfaces. The exit surface of one of the elements is joined to the entrance surface of the other element, with one of the elements rotated at an angle with respect to the other. In a preferred embodiment, the angle of rotation is 90.degree.. The axially-based lens thus comprises four axial sub-elements, and is called a "quadaxial" lens herein. The axially-based lens element has the ability to gather and focus light to a spot with a minimum of spherical aberration and with a substantially uniform distribution of light intensity from center to periphery of the spot. In a preferred embodiment, the lens element focuses light to a square spot size.

Abstract: A high purity ball-shaped optical article formed of silica glass useful in optical systems employed in photolithography applications. The optical article is characterized by end faces and a side face positioned between the end faces. The side face is externally projected beyond the outline of the end faces and has a spherical configuration. The optical article is uniquely characterized by a smaller number of cords per unit area, viewed in a direction perpendicular to a line connecting the end faces, than the number of cords per unit area viewed in a direction along the line connecting the end faces. The article is also defined by optical homogeneity in a direction perpendicular to the line connecting the end faces.

Abstract: An optical device is disclosed wherein a first GRIN lens and a second GRIN lens having their optical axes offset. The first GRIN lens has one or more input ports at an input end. The second GRIN lens is disposed to receive light from the first GRIN lens. A reflecting surface is coated onto a second end face of the second GRIN lens or alternatively is disposed adjacent to the second end face and positioned to reflect an input beam of light launched into the input end face of the first GRIN lens. The reflective surface is at a location where light incident upon it to be returned to the first GRIN lens is collimated. By placing a filter and third GRIN lens between the first and second lenses double filtering may be achieved at the pass band or pass wavelength of the filter. Furthermore, the more simple arrangement including only first and second lenses provides a means of directing light into and out of the device at different angles or directions with respect to the optical axis of the first lens.