Abstract: Provided is an optical device through which the angle of light passing and going out has little wavelength dependency and which is well applicable to Fresnel lenses with little coloration of light passing through it. The optical device has a diffraction grating formed on one surface and capable of diffracting rays of light incident thereon, and has a refracting member (e.g., a Fresnel lens) formed on the other surface opposite to the diffraction grating and capable of refracting the diffracted rays of light from the diffraction grating to make the refracted rays of light go out of it, in which the wavelength dependency of the diffractive angle of the main rays diffracted by the diffraction grating compensates for the wavelength dependency of the refractive angle thereof refracted by the refracting member, or that is, the former wavelength dependency is opposite to and cancels out the latter one.

Abstract: A discontinuous light-beam condenser lens which features excellent light-beam permeability and little loss of solar energy, and can precisely condense incident light beams onto a condensing line, and is formed by a combination of a plurality of lens segments, each of which comprises a stair-like incident-light surface and a refractive surface functioning as a condensing curved surface being so formed that light beams passed through the refractive surface are condensed as refractive light beams onto a single line when parallel light beams are incident from incident-light surface.

Abstract: A monolithic element has a substrate body and at least one macro-optical characteristic integral in a first portion of the optical element. A plurality of surface micro-structures are integral in a portion of the optical element. The micro-structures are designed to homogenize light passing through the optical element to produce a predetermined pattern of smoothly varying, non-discontinuous light exiting the optical element. The light exiting the optical element is therefore altered according to both the macro-optical characteristic of the optical element as well as the homogenizing characteristics of the micro-structures.

Abstract: Disclosed is a photovoltaic module including a plurality of concentrators each having a light-incident plane and a reflection plane, and photo detectors each being in contact with one of the concentrators, which is capable of effectively trapping light and effectively generating power throughout the year even if the module is established such that sunlight at the equinoxes is made incident on the light-incident planes not perpendicularly but obliquely from the right, upper side, for example, in the case where the module is established in contact with a curved plane of a roof or the like.

Abstract: The invention relates to a method for producing a Fresnel lens having a staged entrance surface, reflecting surfaces and an exit surface. The entrance surface is subdivided into outer concentric stages and a central part. The central part is aspherically curved on an entrance side and plane on an exit side by satisfying the eikonal condition. Every stage has a top side, underside and outer side, top sides and undersides being of plane design, and the outer sides having curvatures appropriate for satisfying the eikonal condition.

Abstract: There is disclosed a Fresnel lens, adapted to be placed in front of a display screen of a computer or a television set in order to magnify images for observation, which does not cause a rainbow-like pattern to appear even when annular prism elements as the constituent elements of said Fresnel lens are arranged at a fine pitch. A spherical surface having a radius of curvature corresponding to the focal distance of the lens formed by said annular prism elements of said Fresnel lens is formed within a circular area defined by a predetermined radius around the optical axis, where the rainbow-like pattern would otherwise appear due to diffraction. The predetermined pitch in arranging a plurality of annular prism elements of the Fresnel lens is equal to or less than 0.25 mm and the height of the annular prism elements in the circular area is equal to or less than 5 &mgr;m and preferably equal to or less than 7 &mgr;m.

Abstract: An optical device for focusing a light beam. The device includes a Fourier diffractive element that can separate an incident beam into n beams along n directions which are symmetric about an optical axis. The device also includes a diffractive element including n Fresnel lenses capable of refocusing the n beams onto the optical axis. The device may be used with lasers and laser cutting devices.

Abstract: An optical combiner with a Fresnel lens having a Fresnel surface coated with a thin film spectrally selective reflective coating configured to reflect light within a first wavelength range, and transmit light within a second wavelength range is provided. The optical combiner also includes a covering which covers the Fresnel surface and the reflective coating to provide a generally planar surface which is substantially parallel to a similarly planar exterior surface of the Fresnel lens. The covering may take the form of an optical adhesive (or of a second Fresnel lens) with an index of refraction which substantially matches the index of refraction of the Fresnel lens.

Abstract: A zoom lens system has the first and second lens units. During zooming from a wide-angle end to a telephoto end, the lens units are moved to decrease a distance therebetween. The first lens unit has a positive refractive power. The second lens unit has a negative refractive power. The zoom lens system is provided with at least one surface having a power to diffract light.

Abstract: A headlight for a vehicle has a reflector, a light source, a lens through which a light reflected by the reflector passes, and at least one element which surrounds the lens at least over a part of its periphery and is at least partially light permeable so that the light emitted by the light source and not engaged by the reflector passes through the element and is collected, the element being provided with ring-shaped optical profiles which form a Fresnel lens.

Abstract: The eyewear of the invention causes a person to perceive nearby objects as being distorted such that the person cannot perform simple tasks. The eyewear comprises a goggle with an opening that spans both eyes of the person. A fresnel lens is used to produce an eyepiece that fills the goggle opening. Different distortion effects are perceived depending on the particular area of the fresnel lens from which the eyepiece is produced. The eyewear is particularly useful as an educational tool that simulates intoxication and other bodily impairments.

Abstract: In a device for directing light longitudinally forwardly, the combination comprising a light source, and a protective, transparent envelope extending about the light source; a drum lens having a body extending about the light source and envelope, for refracting light from the source; a light reflector extending about the drum lens body, for forwardly and convergently re-directing refracted light received from the drum lens body; and a correcting lens for receiving a collimating re-directed light screened from the reflector.

Abstract: A projection display apparatus includes a scrambler for making a distribution of light intensity uniform and a Fresnel lens positioned between the scrambler and a lamp, for converting the light incident from the lamp into light parallel to the optical axis of the scrambler. The angle of divergence of the light emerging from the scrambler is reduced by means of the Fresnel lens. Accordingly, the angle of divergence of the light incident to the LCD panel also becomes small. Thus, the light incident to the surface of each pixel in the LCD panel increases, with a result that contrast increases and resolution heightens to improve picture quality. Also, as the angle of divergence of the light at the incident side of the LCD panel decreases, the aperture of the projection lens positioned in front of the LCD panel also decreases which enables the whole optical system to be compact and lowers production cost.

Abstract: An imaging optical system (10) having a focal length (f) and a maximum imagewise numerical aperture. The system combines diffractive and refractive optical elements such that aberrations, including axial chromatic aberration, are well-corrected over a large wavelength range from the visible into the infrared. The system comprises, objectwise to imagewise along an optical axis (A), a front lens group (G.sub.F) having at least one refractive optical element, a diffractive optical element (DOE) provided with a diffractive surface (D) having positive diffractive power and a focal length (f.sub.DOE). The system also includes a rear lens group (G.sub.R) having at least one refractive optical element. The system has an amount of spherical aberration at the maximum imagewise numerical aperture, is measured with respect to e-line wavelength light, in the limit as the positive diffractive power of the diffractive surface approaches zero, of RSA.

Abstract: A novel, high-efficiency, extremely light-weight, inflatable refractive solar concentrator for space power is described. It consists of a flexible Fresnel lens, flexible sides, and a back surface, together enclosing a volume of space which can be filled with low pressure gas to deploy the concentrator on orbit. The back surface supports the energy receiver/converter located in the focal region of the Fresnel lens. The back surface can also serve as the waste heat radiator. Prior to deployment, the deflated flexible lens and sides are folded against the back surface to form a flat, low-volume package for efficient launch into space. The inflatable concentrator can be configured to provide either a line focus or a point focus of sunlight. The new inflatable concentrator approach will provide significant advantages over the prior art in two different space power areas: photovoltaic concentrator arrays and high-temperature solar thermal conversion systems.

Abstract: A planar solid immersion lens has flat surfaces on both the top and bottom. The planar structure is made to function as a solid immersion lens by including compensation for the refraction of light rays entering the top surface of the solid immersion lens other than normal to the top surface. Compensation can be provided by using a radial graded index lens material or by including on the top surface a surface relief diffraction grating. The planar solid immersion lens can be included in a slider or flying head used in an optical disk drive data recording system.

Abstract: A Signal Viewing Device is comprised of a fresnel lens of a vinyl material to be applied to the inside top edge of a vehicle windshield to provide an enhanced field of view to the driver thereof.

Abstract: A side-viewing optical system that provides wide-field viewing of image scenes on both sides of a vehicle, particularly in blind areas between the driver's direct peripheral vision and a image scene normally viewed using the rear view mirror. A projected demagnified image from both sides of the vehicle is directed into the driver's eyes from a position straight forward and angled downward so that the forward viewing direction is not blocked while driving the vehicle or requiring driver head motion. The system has left and right side viewers having prisms and Fresnel relay lenses. A roof mirror having left and right mirror surfaces respectively reflect image scenes observed by the side viewers toward the driver. A relay is disposed between the right side viewer and the right mirror surface of the roof mirror. A projector having a Fresnel lens finally projects the image scenes toward the driver for viewing.

Abstract: A zoom lens system has the first and second lens units. During zooming from a wide-angle end to a telephoto end, the lens units are moved to decrease a distance therebetween. The first lens unit has a positive refractive power. The second lens unit has a negative refractive power. The zoom lens system is provided with at least one surface having a power to diffract light.

Abstract: Method for the preparation of diffractive lens with one single etching step and using one single etching mask. While the widths and intervals of the masked areas of the photo masks are decided under a geometric relation, an etching mask can be prepared on the substrate of the lens where the widths and the intervals of the masked areas can be determined. As the included angle between the etching mask and the plan of the material of the lens is in a certain ratio to the etching efficiency of the etchant to the substrate of the lens, a one step etching process can be developed whereby multilevel diffractive lens with required number, widths and heights of the levels can be obtained. This invention also provides an oxidation-isotropic etching process on the diffractive lens so prepared.

Abstract: A free space imaging system utilizing a doublet form of optic. The doublet is configured with two large Fresnel lenses configured such that their echelon groove components are mutually oppositely disposed within the optical path of the system. The method includes an arrangement wherein the output focal plane deliberately is curved and generated with a relatively wide field of view to evoke an emulation of three-dimensionality.

Abstract: An optical system that can be used in an optical imaging system and displays good imaging performance with corrected chromatic aberration without increasing the number of lenses is provided by employing a lens surface with a diffractive effect. The optical system uses a lens with a concave incident surface and positive refractive power. A grating element surface 40 with positive refractive power is formed on at least one surface of the lens. The surface on which the grating element is formed is an aspherical surface with a radius of curvature that becomes bigger with increasing distance from the optical axis.

Abstract: A segmented aperture lens having multiple lens segments having predetermined patterns. Each lens segment may be a fresnel lens. The lens segments may be arranged in a two-dimensional array or a one-dimensional array.

Abstract: A Fresnel lens sheet (11) used in combination with a lenticular lens sheet (12) to form a rear projection screen of a TV set, has Fresnel lens elements (15) on a front surface thereof. The Fresnel lens elements (15) include a first group of Fresnel lens elements (15a) and a second group of Fresnel lens elements (15b). The first group of lens elements (15a) has a first focal length (f.sub.1) which is greater than a second focal length (f.sub.2) of the second group of lens elements (15b). The first group lens elements (15a) and the second group of lens elements (15b) are disposed alternately. The above configuration provides an increased vertical angular range of a viewing region from which pictures displayed on the rear projection screen can be viewed satisfactorily, as well as an increased luminance of the rear projection screen.

Abstract: A method for precise design of light distribution for lighting equipment that use light-emitting devices, and for subsequently producing such equipment. By modeling the internal structure of an LED device with respect to the geometry and characteristics of a chip portion, chip reflector and lens portion, illuminating light from an LED device is classified into direct light from the chip portion and the reflected light from the chip reflector. The unknown values necessary for the modeling are specified preliminarily by actual measurements. Subsequently, the original geometry of the lens step is determined roughly based on the target direction and the diffusion angle of the light transmitted through the step. The manner in which the direct light from the chip portion and the reflected light from the chip reflector are transmitted through the lens portion and the lens step is simulated by ray tracing.

Abstract: A color-mixing lens for use in a concentrator system and methods of manufacture and operation thereof. The color-mixing lens includes: (1) a light-transmissive substrate that receives broad spectrum light from a source, (2) a first plurality of prisms, located on the substrate, that refract and chromatically disperse the light received therein toward a first plurality of locations on an active region of a target cell, and (3) a second plurality of prisms located on the substrate that refract and chromatically disperse the light received therein toward a second plurality of locations on the active region. Relative dimensions of the first and second pluralities of prisms are preselected to cause the chromatically-dispersed light to mix and thereby increase a power output of the target cell by reducing inter-junction currents therein.

Abstract: A modular solar energy collector having elongated V-shaped side walls formed by a pair of coplanar panels for each side wall. The upper panels, occupying most of the wall area are diffusely reflective, but the lower panels are specularly reflective. A Fresnel lens, having a snap fit relation to the side walls focuses some light on the lower specularly reflective panels which direct light to the solar cells at the base of the V-shaped walls. A heat sink provides support for the two panels with two opposed, upwardly extending wings terminating in opposed linear clips located near the lengthwise seam of the coplanar panels, each clip holding two coplanar panels in parallel alignment. The clips not only provide support for the panels, but also transfer heat to the remainder of the heat sink. The clips are shaped so that edges of the panels engage each clip by a snap fit, outside of the clip in one embodiment and inside of the clip in another embodiment.

Abstract: A solar energy conversion system, in which two separated arrays of refracting elements disperse incident sunlight and concentrate the sunlight onto solar energy converters, such that each converter receives a narrow portion of the broad solar spectrum and thereby operates at higher efficiency.

Abstract: Disclosed is a fresnel magnifying lens card holder dimensioned to fit standardized cards, for example, all credit card sized cards. The card holder features a pair of parallel tracks, for example, J-shaped tracks which face each other, and a raised narrow strip on a base plate thereby facilitating the slipping on and off all such cards and, at the same time, using the cards themselves as a carrier, as a storage place and as a delivering vehicle of the fresnel lens. That is, the holder can take advantage of the popularity of the standardized cards, using them as its carriers in delivering a fresnel magnifying lens and a data stripe shield to the credit card users. Since keeping the data stripe from damage and helping to see small print clearly make the card friendlier to the user, providing these benefits could be of significant importance to both the card using public and to those who are marketing products and services.

Abstract: An optical system has a diffractive optical element. A diffractive optical surface of the optical element has a blaze-shaped diffraction grating. The grating heights are smaller in the peripheral region of the grating than in the central region of the grating around its optical axis. The optical element acts as a lenses a result of light rays being deflected by the light-diffracting action of the diffractive optical surface.

Abstract: A display adapted for use in head mounted display systems. The display includes an array of reflecting pixels, a first light source for illuminating the array of reflecting pixels, and a mask screen located between the light source and the array of reflecting pixels. The mask screen includes a plurality of mask elements, one mask element corresponding to each of the pixels. The mask elements have a first state in which the mask element is transparent and a second state in which the mask element is opaque. The state of the mask element is determined by a potential generated by the corresponding pixel. Each of the pixels includes a reflector for reflecting light from the first light source into a cone having an opening angle and an axis which depends on the position of the pixel in the display and on the telecentricity of the imaging optic. In the preferred embodiment of the present invention, each of the reflectors is an off-axis portion of a diffractive micro Fresnel mirror.

Abstract: The invention makes the size of the apparent image of the display screen of the display screen larger than the real size. A flat optical magnifier such as a lens of the fresnel type is positioned in an optically enhancing location between the operator and the display screen so that the apparent image at the operator side of the magnifier is greater than the actual image that is present on the display screen. A mechanism is provided for a notebook type portable computer that is passive to a user, folds into the case when the display screen closes over the keyboard and positions a fresnel lens, coplanar with and at a fixed distance from the display screen, when the notebook computer is opened and remains at that fixed distance as the display screen moves to maximum travel.

Abstract: A fresnel magnifying lens for forming a hand-held, pocket-sized hybrid assembly of the lens and another object or objects. The lens is provided with at least one hole for use with a fastener to detachably or permanently couple the lens to the other object in a manner which allows a selective magnified hand-held viewing, through the lens, of both the other object, as well as different objects. The coupling of the lens to the other object is such that the lens can be slidably moved, using the fastener which couples the lens to the other object as a pivot point, to permit the lens to be used to view different objects which are not part of that hybrid assembly. The pocket-sized fresnel magnifying lens can thereby be attached onto a variety of objects, for example, marketing objects, such as credit cards, debit cards, ID cards, pocket calenders, schedules, telecards, magnetic note holders, key rings, etc.

Abstract: A zoned lens comprises at least two adjacent zones (16) formed such that the differences between the optical path lengths between an object point and a pixel of light beams extending through these two adjacent zones (16) of the lens (15) are at least equal to half the coherence length of the light used, preferably at least equal to the coherence length of the light used.

Abstract: For the purpose of providing a solar module which has a fixed type solar concentrator of high converging magnification, a solar cell 12 is installed on the bottom face of an extension 30 which is extended further from the apex of a V shape formed by a pair of prisms having a refractive index larger than that of air, and a mirror surface 18 is formed on the back side of an incident surface 20 on which sunlight 10 falls. The mirror surface 18 and the incident surface 20 are formed in such a manner that their distance widens toward the apex of the V shape. The sunlight 10 incident on the prisms 16 performs reflection on the mirror surface 18 and total internal reflection on the incident surface 20, respectively. After repeating such reflection, the sunlight 10 reaches the bottom of the extension 30, where it emerges as outgoing light 22 to the solar cell 12.

Abstract: An active energy ray-curable composition comprising(A) 20 to 80 parts by weight of a compound represented by the following general formula I: ##STR1## wherein R.sup.1 represents hydrogen or methyl, X and Y may be the same or different and represent methyl, chlorine, bromine or iodine, and t and u each independently represent an integer of 0-2,(B) 20 to 80 parts by weight of at least one compound having at least one acryloyl or methacryloyl group in the molecule, or (B-1) 10 to 90 parts by weight of at least one compound having at least two acryloyl or methacryloyl groups in the molecule and (B-2) 1 to 90 parts by weight of at least one monoacrylate or monomethacrylate compound having one acryloyl or methacryloyl group in the molecule, and(C) 0.

Abstract: A wide-angle lens has a three-group configuration in which a plastic aspherical lens is used in the first lens group on the enlargement side, and predetermined conditional expressions concerning focal lengths of individual lenses constituting the first lens group are satisfied, whereby image quality is restrained from deteriorating due to changes in temperature, and a telecentric characteristic is attained such that no vignetting occurs in marginal luminous fluxes, thus making various kinds of aberration favorable and allowing the cost to be cut down. The first lens group G.sub.1 disposed on the enlargement side has a three-lens configuration in which the first lens L.sub.1 on the enlargement side and the third lens L.sub.3 on the reduction side are constituted by a plastic aspherical lens having a negative refracting power and a plastic aspherical lens having a positive refracting power, respectively. Letting the focal length of the first lens group G.sub.1 be F.sub.

Abstract: An objective lens for a pickup optical system for optically reading out information recorded in a recording medium , includes a first lens body and a second lens body integrally attached to a surface of the first lens body and having a micro Fresnel portion for focusing light to a predetermined position of the recording medium. When the objective lens is used for a pickup optical system, the micro Fresnel portion faces away from an accommodation region for accommodating the recording medium to prevent dust from attaching to the micro Fresnel portion.

Abstract: A new optical system capable of correcting aberrations well by using a refracting optical element and a diffracting optical element in combination, and of increasing the aperture and the field angle. The optical system includes a first refracting optical unit placed on the object side with respect to a stop, a diffracting optical unit placed adjacent the stop to correct chromatic aberration, and a second refracting optical unit placed on the image side with respect to the stop. The first and second refracting optical units are substantially symmetrical with respect to the stop.

Abstract: UV-curable Fresnel lens resin compositions ?a! comprising a (meth)acrylate containing hydroxyl group and aromatic ring (A1), a urethane group-contining (meth) acrylate (A2) comprising an aromatic diol, an aromatic ringcontaining monofunctional (meth)acrylate (A3), and a photopolymerization initiator (B) and ?1b! comprising (A1), a mono- or di(meth)acrylate monomer (A4), and (B), further supplemented with a polyester (C1) comprising an aromatic diol and a phosphate (C2) for the formation of a Fresnel lens on a sheet or plate made of a methyl methacrylate (co) polymer; a Fresnel lens formed by UV cure of composition ?1a! or ?1b!; and a rear projection screen including a sheet or plate carrying said Fresnel lens. The Fresnel lens has high refractive index, antistatic properties and is satisfactory in adhesion-to a sheet or plate.

Abstract: Method of assembling a large, lightweight, composite optical device such as a mirror or lens, includes providing a plurality of flat, lightweight optical element sections, fastening each optical element section to an associated frame segment to provide a plurality of optical elements and detachably fastening a plurality of the optical elements together in a manner causing all of them to lie in a single plane. After use, the device is disassembled and the optical elements are stacked in a compact mass to make them readily portable.

Abstract: A composite Fresnel lens useful in an infrared passive detection system includes an array of Fresnel lens segments having a given vertical centerline and a curvature of a given radius. The Fresnel lens segments fall in first and second groups. Each Fresnel lens segment in the first group has a long detection range and a width less than one-third of the diameter of an original whole Fresnel lens from which the segment was taken. Also, each lens segment of the first group has a geometrical center located horizontally from the vertical centerline of the array along the curvature of the array through a circumferential distance less than one-fourth of the radius of curvature of the array. Each Fresnel lens segment in the second group has a short detection range less than the long detection range by a predetermined amount and a width less than one-third of the diameter of an original whole Fresnel lens from which the segment was taken.

Abstract: Variable focal length lens system comprises two adjacent lens units, one stationary, the other movable. These lens units are in order from an object side towards an image side(i) A first lens unit possessing divergent refractive power. The first lens unit is the front most lens unit. It consists of a single negative lens component.(ii) A second lens unit possessing convergent refractive power. The second lens unit, includes at least two positive power lens components and an aperture stop.

Abstract: A zoom lens system includes, from the object to image side, a first lens unit of a positive refractive power having a first lens element with a power to both diffract and refract light. A second lens unit has a negative refractive power and may include a second lens element having both the power to diffract and refract light, and it least a third lens unit is included. A zooming operation is performed by varying the distances between the respective first, second, and third lens units.

Abstract: A process for the extrusion of plastic plates with very finely structured surface using an extrusion system which is equipped with an extruder and a three roll polishing stack containing a roller with the structuring surface. The system is designed for coextrusion and the plastic plates are produced via two extruders as a coextrudate CX from a highly viscous basic molding compound BF and a low viscosity molding compound NF which is extruded on BF. The surface of said plates is structured via the three roll polishing stack. Fresnel lenses produced by the process may be used in solar collectors.

Abstract: A light transmission screen having strong mechanical strength, enhanced image resolution, extremely narrow joints between screens and the like, consisting of a light transmissive panel, a lenticular lens sheet stacked on the light incident side of the light transmissive panel, a Fresnel lens sheet stacked on the light incident side of the lenticular lens sheet and optionally a light transmissive film stacked on the light incident side of the Fresnel lens sheet. The periphery of the light transmissive film or the periphery of the Fresnel lens sheet is joined to the light transmissive panel, resulting in the light transmissive panel, lenticular lens sheet, Fresnel lens sheet and light transmissive film being formed into a single-piece construction.

Abstract: Targets for use with scanning light beam leveling/marking devices, are constructed with their elements assembled as unitary target structure. The lens and beam divider functions are provided by optical quality fresnel lenses attached to or formed on a polycarbonate block, these parts thus can be made essentially an integral element. These special fresnel lens which are optically equivalent of the input lens and beam dividing axicon, and the viewing screen diffuser function provided by a frosted viewing plate. A separate fresnel lens is mounted alongside the beam dividing lenses and functions to provide a reference image on the viewing screen. The optical path for the impinging light beam (after it is divided) may be transmitted directly through the body block, from the input to the view window, or through a reflector surface at a side of the block, the block body of the target functioning as a waveguide.

Abstract: A method for making a fresnel lens on a substrate by forming a plurality of annular rings. Each ring has a plurality of steps, with each step having an inner wall and an outer wall, and an upper surface.

Abstract: A wide angle lens is made of three groups so as to satisfy a predetermined conditional expression concerning abbe number, thereby making it telecentric and yielding no eclipse in its peripheral luminous flux. Also, an apparatus accommodating it is made compact as a whole. This wide angle lens comprises, arranged in the following order from the screen side toward the liquid crystal side, a first lens group composed of a concave lens (L1), whose concave surface having a large radius of curvature is directed toward a smaller conjugate side (liquid crystal panel), and a convex lens (L2); a second lens group composed of one concave lens (L3) and two convex lenses (L4) and (L5); and a third lens group composed of a Fresnel lens (L6) which is disposed near a liquid crystal panel (L7; 4). The abbe number .nu. 1 of the lens L1 which is the concave lens in the first lens group is 57.8, whereas the abbe number .nu. 2 of the lens (L3) which is the concave lens in the second lens group is 25.

Abstract: The method utilizes high resolution lithography, mask aligning, and reactive ion etching. In particular, at least two binary amplitude masks are generated. A photoresist layer on an optical element substrate is exposed through the first mask and then etched. The process is then repeated for the second and subsequent masks to create a multistep configuration. The resulting optical element is highly efficient.