Abstract: A diffractive optical element capable of further reducing zero-order diffraction light includes a diffraction layer including: a high refractive index part in which a plurality of projections are arranged side by side in a cross-sectional shape; and a low refractive index part that has a lower refractive index than the high refractive index part and that includes a recess formed at least between the projections. The projections have a sawtooth shape or a shape that imitates a sawtooth shape by a multi-stage outline shape. An inclined plane that is inclined with respect to a sheet surface of the diffractive optical element, which has a sawtooth shape or a sawtooth shape imitated by a multi-stage outline shape, has a concave curved plane that is concave toward the projections.

Abstract: Blazed diffraction gratings provide optical elements in head-mounted display systems to, e.g., incouple light into or out-couple light out of a waveguide. These blazed diffraction gratings may be configured to have reduced polarization sensitivity. Such gratings may, for example, incouple or outcouple light of different polarizations with similar level of efficiency. The blazed diffraction gratings and waveguides may be formed in a high refractive index substrate such as lithium niobate. In some implementations, the blazed diffraction gratings may include diffractive features having a feature height of 40 nm to 120 nm, for example, 80 nm. The diffractive features may be etched into the high index substrate, e.g., lithium niobate.

Abstract: A spectral resolution enhancement device including a preliminary dispersion unit, a two-grating angular dispersion amplification unit, and a detection unit is provided. The preliminary dispersion unit is configured to receive collimated incident light and emits light of different wavelengths in the incident light at different angles. The two-grating angular dispersion amplification unit is configured to diffract the light of different wavelengths and emitted from the preliminary dispersion unit multiple times, such that angular dispersion the light of different wavelengths is enhanced, and emergent angle deviations between the light of different wavelengths are increased. The detection unit is configured to detect light of different wavelengths and emitted from the two-grating angular dispersion amplification unit. Since the emergent angle deviations of light of different wavelengths are increased, resolution of the detection unit for the light of different wavelengths is increased.

Abstract: Embodiments of the present application generally relate to methods for forming a plurality of gratings. The methods generally include depositing a material over one or more protected regions of a waveguide combiner disposed on a substrate, the material having a thickness inhibiting removal of a grating material disposed on the waveguide combiner when an ion beam is directed toward the substrate, and directing the ion beam toward the substrate. The methods disclosed herein allow for formation of a plurality of gratings in one or more unprotected regions, while no gratings are formed in the protected regions.

Abstract: The present invention relates to a diode laser with external spectrally selective feedback. It is an object of the invention is to provide an external cavity diode laser with wavelength stabilization which allows an increased overall output power in the desired wavelength range.

Abstract: A directional backlight, backlit display and method of directional backlight operation employ diffraction grating to provide emitted light collectively scattered out by diffraction gratings having a uniform intensity and angular spread. The directional backlight includes a light guide configured to guide plurality of guided light beams and a light source configured to provide the guided light beam plurality having the different radial directions. The directional backlight further includes an array of diffraction gratings configured to configured to scatter out a portion of a guided light beam of the guided light beam plurality as emitted light having an intensity and an angular spread that is uniform across the light guide surface. The backlit display further includes an array of light valves configured to modulate the emitted light to provide a displayed image.

Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.

Abstract: There is provided a chirped diffractive element (20) in the form of a grating (22) configured for supporting a plurality of guided mode resonances (54), which resonances (54) may be considered to comprise a standing wave. Chirping the grating (22) may allow guided mode resonances (54) to be distinguishable in terms of position within a section (34) the grating (22). An incident electromagnetic field may be coupled into at least one of the sections (34) when the electromagnetic field has a wavelength value within a predetermined wavelength range and a sample has a refractive index value within a predetermined index range. The incident electromagnetic field may be reflected by at least one of the sections (34) of the grating (22) exhibiting a guided mode resonance (54).

Abstract: A naked eye 3D display device is provided. The naked eye 3D display device includes a directional projection screen, a laser light source, a red monochromatic laser light source, a green monochromatic laser light source and a blue monochromatic laser light source. Lights emitted by the three monochromatic laser light sources emit incident light on the directional projection screen with nano-grating pixels at specific angles and specific positions, and the same emergent light fields are formed. The laser light source provides multi-perspective image pixels. The multi-perspective image pixels match a nano-grating pixel array on the directional projection screen. By a direct spatial modulation for the laser projection light, colorful 3D display is achieved. There is no crosstalk between various viewpoints. The naked eye 3D display device has no visual fatigue and has a low cost.

Abstract: A diffractive backlight system includes a light source and a plate light guide. A surface of the plate light guide is configured with a diffraction grating that couples light out of the plate light guide and concentrates the light into a localized region of space. The diffractive backlight system may be used with at least one light valve array to form a display that generates images for viewing in the localized region of space. The display may be incorporated in head-mounted displays in order to generate focused augmented or virtual reality images for wearers.

Abstract: The invention relates to a display device for displaying an image over a field of view. The device comprises: an optical arrangement for directing image bearing light from an image source so that the light has rays at a range of angles relative to an injection axis; and an optical waveguide having an input grating for diffracting into the waveguide said light over said range of angles such that all of the diffracted light is totally internally reflected within the waveguide and so that image bearing light output from the waveguide has a field of view corresponding to said range of angles, wherein the input grating is a surface relief grating having a profiled reflective surface and at least one layer of dielectric material conforming to the surface for diffracting light over said range of angles into the waveguide.

Abstract: An apparatus, method and computer program wherein the apparatus includes an optical arrangement including an image source and an exit pupil wherein the exit pupil is configured to be positioned proximate to an eye of a user to enable a user to view an image from the image source; and wherein the apparatus is configured to control a size and location of the exit pupil of the optical arrangement in response to a determination of a size and location of a pupil of the eye.

Abstract: A diffractive optical beam shaping element for imposing a phase distribution on a laser beam that is intended for laser processing of a material includes a phase mask that is shaped as an area and is configured for imposing a plurality of beam shaping phase distributions on the laser beam incident on to the phase mask. A virtual optical image is attributed to at least one of the plurality of beam shaping phase distributions, wherein the virtual image can be imaged into an elongated focus zone for creating a modification in the material to be processed. Multiple such elongated focus zones can spatially add up and interfere with each other, to modify an intensity distribution in the material and, for example, generate an asymmetric modification zone.

Abstract: A backlight module, a display device and a method for driving the same are disclosed, such that brightness of display device can be increased when rendering 3D display. The backlight module includes a light guide plate, a light-splitting structure and an edge light source, wherein the light-splitting structure includes a plurality of strip-shaped first light-splitting units and a plurality of strip-shaped second light-splitting units, the first light-splitting unit and second light-splitting unit are alternately disposed on the light output surface of the light guide plate, each of first light-splitting unit and second light-splitting unit comprises at least one grating strip, the first light-splitting unit is configured for directing light to output towards a first position external to the backlight module, and the second light-splitting unit is configured for directing light to emit towards a second position external to the backlight module.

Abstract: An optical system and photo sensor pixel are provided. The photo sensor pixel includes a substrate including an active region and a peripheral region that is peripheral to the active region, an optical sensor disposed at the active region of the substrate and configured to receive light and output a measurement signal based on the received light, and an encapsulation layer disposed over the active region and the first peripheral region of the substrate. The encapsulation layer includes at least one subwavelength-based graded index structure provided over the peripheral region of the substrate, and the subwavelength-based graded index structure is configured to redirect the light from a region over the peripheral region onto the optical sensor.

Abstract: An optical fiber launcher assembly can include a low precision fiber array that outputs a plurality of optical signals from a given side that are input into an opposing side. The optical fiber launcher assembly can also include a corrective optic aligned with and spaced apart from the low precision fiber array. The plurality of optical signals output from the low precision array to the corrective optic have a given trajectory and optical signals output from the corrective optic have a substantially parallel trajectory different from the given trajectory.

Abstract: A diffractive optical element (1) includes a first diffraction grating (21) including a first grating surface (21a) and a first grating wall surface (21b), a second diffraction grating (31) including a second grating surface (31a) and a second grating wall surface (31b), and a thin film (11) provided between the first grating wall surface and the second grating wall surface and being in contact with both of the first and second grating wall surfaces, an extinction coefficient of the thin film with respect to a wavelength ? in a use wavelength band is not greater than 0.0005, and with respect to the wavelength ?, refractive indices of materials of the thin film, the first diffraction grating, and the second diffraction grating, a relative diffractive index difference of the thin film and the first diffraction grating, and a width of the thin film satisfy predetermined conditions.

Abstract: An optical system and photo sensor pixel are provided. The photo sensor pixel includes a substrate including an active region and a peripheral region that is peripheral to the active region, an optical sensor disposed at the active region of the substrate and configured to receive light and output a measurement signal based on the received light, and an encapsulation layer disposed over the active region and the first peripheral region of the substrate. The encapsulation layer includes at least one subwavelength-based graded index structure provided over the peripheral region of the substrate, and the subwavelength-based graded index structure is configured to redirect the light from a region over the peripheral region onto the optical sensor.

Abstract: A PCA is provided including: a semiconductor substrate; a metallic antenna, formed on one surface of the semiconductor substrate; and a first pattern structure, formed on the same surface of the semiconductor substrate as the surface on which the metallic antenna is formed, to obstruct surface waves and/or back-scattered waves.

Abstract: Compact photonics platforms and methods of forming the same are provided. An example of a compact photonics platform includes a layered structure having an active region along a longitudinal axis, a facet having an angle no less than a critical angle formed at least one longitudinal end of the active region, and a waveguide having at least one grating coupler positioned in alignment with the angled facet to couple light out to or in from the waveguide.

Abstract: A vehicle cup holder includes a console substrate defining a cup well. A light source is positioned proximate the cup well. An insert is positioned within the cup well and defines a base wall and a side wall, wherein at least one of the base wall and the side wall defines a diffraction grating.

Abstract: Dual-sided optical films have extended split spreading structures formed on one major surface, and extended prisms formed on an opposite major surface. One portion of each split spreading structure has a low light spreading characteristic, and another portion has a high light spreading characteristic. For each split spreading structure, the low light spreading portion may be disposed alongside the high light spreading portion. The split spreading structures may be arranged in a one-to-one correspondence with the prisms. Light that enters a given prism from one inclined surface thereof can be associated primarily with light transmitted through the low light spreading portion of the split spreading structure, and light that enters the given prism from the other inclined surface thereof can be associated primarily with light transmitted through the high light spreading portion.

Abstract: A grating out-coupler assembly is provided. The grating out-coupler assembly includes a substrate, a tiltable surface suspended above the substrate, an actuator configured to selectively control a pitch of the tiltable surface, and a grating out-coupler supported by the tiltable surface.

Abstract: A method for manufacturing a blazed diffraction grating made of a crystalline material comprising zinc selenide (ZnSe) or zinc sulfide (ZnS) includes forming the blazed diffraction grating by forming a plurality of grating grooves on a machined surface of a workpiece by machining, wherein the grating grooves are formed so that a surface comprising a (110) plane is arranged to receive the most incident light among the surfaces that constitute each grating, where (110) describes a crystal orientation of the crystalline material.

Abstract: An optical device that is capable of producing an image in the air includes a substrate having a reflective diffraction region formed into a net structure, and a light radiation unit which radiates a light beam onto one surface of the substrate. The diffraction region is capable of collecting light beams that are diffracted in the upper space of one surface of the substrate by diffracting the light beam which is incident on one surface of the substrate. Here, the light radiation unit may have a display source that generates the light beams which form the image, and a lens portion that radiates the generated light beams onto the substrate.

Abstract: A laminated diffraction optical element includes a substrate, and a resin layer provided on the substrate and including an optically effective portion and an optically non-effective outer portion adjacent to the optically effective portion. The optically non-effective outer portion in the resin layer has a continuous shape such that a layer thickness decreases when extending toward an outer periphery of the substrate. An angle formed between a straight line connecting both ends of the continuous shape and a tangent to a surface of the substrate at a point opposite to an end closer to the surface of the substrate is within a range of 20 to 60 degrees.

Abstract: A tunable laser comprises a first tuner configured to select an emission wavelength of the laser; a second tuner configured to adjust a cavity mode of the laser by modifying the cavity optical path length. The second tuner is constrained by a finite tuning range. The tunable laser also comprises a controller configured to control the first and second tuners to select the emission wavelength and adjust the cavity mode in synchronization to perform phase-continuous tuning across a range larger than supported by the finite tuning range of the second tuner.

Abstract: A method of manufacturing a blazed diffractive grating includes a first step of forming a first groove having a first surface and a second surface by moving, in the first direction at a first position in the second direction, a cutting tool having a first cutting blade and a second cutting blade to cut the object; a second step of forming a second groove by moving, in the first direction at a second position separated from the first position in the second direction by a grating pitch, the cutting tool to cut the object; and a third step of forming a blazed surface of the first groove using the first cutting blade by moving, in the first direction at a third position between the first position and the second position, the cutting tool to cut the first surface of the first groove.

Abstract: Provided are an illumination unit and a display capable of achieving size reduction in a case where a plurality types of light sources emitting light with various different wavelengths are in use. An optical-path conversion member 12 is provided for performing optical-path conversion to light (red laser light Lr, green laser light Lg, and blue laser light Lg) coming from three types of light sources (a red laser 11R, a green laser 11G, and a blue laser 11B) in a light source unit 11 in such a manner that, compared with an angle formed by center rays in the light, an angle formed by center rays in outgoing light becomes much smaller. Such optical-path conversion is performed without using a large-scale optical system (optical members).

Abstract: A variable focal length achromatic lens includes a flat liquid crystal diffractive lens and a pressure-controlled fluidic refractive lens. The diffractive lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive lens' focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive lenses at a number of selected focal lengths.

Abstract: A manufacturing method for an excimer laser that includes a reflective Echelle diffraction grating includes obtaining information of a wavelength of a light source, a blazed order, a repetitive pitch of the grating, a material of the grating, and a predefined orientation ratio B/A that is a ratio between that a diffraction efficiency A of the blazed order and a diffraction efficiency Bb of an order lower by one order than the blazed order, and determining an initial value of a blaze angle based upon these pieces of information.

Abstract: Methods of forming microelectronic structures are described. Embodiments of those methods may include forming a photomask on a (110) silicon wafer substrate, wherein the photomask comprises a periodic array of parallelogram openings, and then performing a timed wet etch on the (110) silicon wafer substrate to form a diffraction grating structure that is etched into the (110) silicon wafer substrate.

Abstract: A projection display 210 arranged to display an image to an observer 212 use waveguide techniques to generate a display defining a large exit pupil at the point of the observer 212 and a large field of view, while using a small image-providing light source device. The projection display 210 uses two parallel waveguides 214, 216 made from a light transmissive material. One waveguide 214 stretches the horizontal pupil of the final display and the other waveguide 216 stretches the vertical pupil of the final display and acts as a combiner through which the observer 212 views an outside world scene 220 and the image overlaid on the scene 220. In a color display, each primary color is transmitted within a separate channel R, G, B.

Abstract: A manufacturing method for a grating is disclosed for the angular dispersion of light impinging the grating. The grating comprises tapered structures and cavities. A cavity width and/or corrugation amplitude is varied for achieving a desired grating efficiency according to calculation. A method is disclosed for conveniently creating gratings with variable cavity width and/or corrugation amplitude. The method comprises the step of anisotropically etching a groove pattern into a grating master. Optionally a replica is produced that is complementary to the grating master. By variation of an etching resist pattern, the cavity width of the grating may be varied allowing the optimization towards different efficiency goals.

Abstract: A diffractive optical element includes a first diffraction grating and a second diffraction grating which are made of materials different from each other and are stacked in an optical axis direction, and a thin film which is arranged at least part of an interface between the first diffraction grating and the second diffraction grating, includes a single layer or multiple layers made of a material different from that of each of the first and second diffraction gratings, and is transparent to light of a working wavelength range. nd1<nd2 and 0.5<nd3?nd2<0.8 are satisfied, where nd1 is a refractive index of the material of the first diffraction grating to d-line, nd2 is a refractive index of the material of the second diffraction grating to the d-line, and nd3 is a maximum refractive index of the material of one layer of the thin film to the d-line.

Abstract: The laminated diffractive optical element includes plural diffraction gratings 21, 22 and 23 laminated with each other, the respective diffraction gratings being formed of a same light-transmissive material. In the element, reflective films are formed on grating surfaces 11 and 12 of the respective diffraction gratings, each of the reflective films being disposed between the diffraction gratings. Each of the reflective films reflects light in a specific wavelength range and transmits light in a wavelength range different from the specific wavelength range, the specific wavelength ranges of the respective reflective films being different from each other. The grating surfaces of the respective diffraction gratings are formed in shapes different from each other according to the specific wavelength ranges corresponding to the respective reflective films.

Abstract: An optical de-multiplexer (de-MUX) that includes an optical device that images and diffracts an optical signal using a reflective geometry is described, where a free spectral range (FSR) of the optical device associated with a given diffraction order abuts FSRs associated with adjacent diffraction orders. Moreover, the channel spacings within diffraction orders and between adjacent diffraction orders are equal to the predefined channel spacing associated with the optical signal. As a consequence, the optical device has a comb-filter output spectrum, which reduces a tuning energy of the optical device by eliminating spectral gaps between diffraction orders of the optical device.

Abstract: To provide a highly workable diffractive optical element which realizes a high refractive index and a low wavelength dispersiveness well balanced with each other and which exhibits high heat resistance and high endurance against temperature changes, a diffractive optical element includes a base member including a diffraction grating formed on a surface thereof and a protective film provided on the surface of the base member where the diffraction grating is formed, wherein the base member is composed of a silsesquioxane resin material or a dendrimer material which has a first refractive index and a first Abbe number and wherein the protective film is composed of a silicone resin material which has a second refractive index smaller than the first refractive index and a second Abbe number smaller than the first Abbe number.

Abstract: Described is a security document with a transparent security element (12) which is arranged in a window or in a transparent region of the security document and has a structure layer, in which a first region (12f) of the structure layer has an asymmetrical diffractive relief structure, wherein the first region (12f) has an optical effect which is unexpectedly different in a front view and in a rear view of the security document.

Abstract: The specification and drawings present a new apparatus and a new apparatus for compensation of the optical aberrations caused by a non-planar window (or windows in general, for example windows having a curved surface) using a diffractive (optical) element such as a diffractive foil in electronic/camera devices such as electronic devices with displays. According to an embodiment, an optical window of an electronic device/camera may have at least a non-planar front surface which causes an aberration of an input image. This aberration can be corrected to be below predefined one or more parameters (such as a circle with a predefined maximum radius and/or a directional shift by a predefined maximum value) using a diffractive element/foil located on/near a back surface of the optical window or between the back surface of the optical window and a sensor/camera image plane where the input image is focused on.

Abstract: A method producing a refractive or diffractive optical device, including: production, in a first layer, of at least one inclined general profile approximated by a staircase profile including plural stairsteps; production of the profile including: forming buffer patterns on the first layer and at least one sequence including: forming masking patterns, so each masking pattern includes at least one edge situated above a buffer pattern and covers at least one area of the first layer not masked by the buffer patterns, the forming the masking patterns also defining, for the first layer, plural free areas not masked by the masking patterns or by the buffer patterns; etching the free areas to form trenches in the first layer. The production of the profile also includes: removing the masking patterns, removing the buffer patterns revealing walls previously covered by the buffer patterns, and then an isotropic etching to remove the walls.

Abstract: An objective lens (101) is configured to converge laser light of a first wavelength ?1 (390 [nm]??1?430 [nm]), laser light of a second wavelength ?2 (630 [nm]??2?680 [nm]), and laser light of a third wavelength ?3 (750 [nm]??3?810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.

Abstract: An objective lens element which has excellent compatibility with optical discs having different base material thicknesses is provided. An objective lens element 141 has optically functional surfaces on an incident side and an exit side. Either one of the optically functional surfaces is divided into an inner part 131B including a rotational symmetry axis and an outer part 131F which is a ring-shaped region surrounding the inner part 131B. On the inner part 131B, a plurality of discontinuous steps are provided. The plurality of steps change in height in the same direction from the optical axis toward the outer part, and each of the steps causes a constant optical path difference longer than the wavelength ?1 to the first incident light beam 61 and causes a constant optical path difference shorter than the wavelength ?2 to the second incident light beam 62.

Abstract: Provided are an organic-inorganic composite resin composition and an organic-inorganic composite resin material made of a cured product thereof, containing at least an organic compound having a polymerizable functional group, metal oxide fine particles, and a polymerization initiator. The cured product obtained by curing the organic-inorganic composite resin composition through application of an active energy has a refractive index nd of 1.61 or more and 1.65 or less, Abbe's number ?d of 13 or more and 20 or less, and an anomalous dispersion characteristic ?g,F of 0.42 or more and 0.54 or less. Further provided is an optical element comprising a transparent substrate and the organic-inorganic composite resin material formed on the transparent substrate.

Abstract: Films for optical use, articles containing such films, methods for making such films, and systems that utilize such films, are disclosed.

Abstract: An Al film is formed so that film forming particles are incident at normal incidence to grating wall surfaces of a diffraction grating having multiple grating portions and are incident at oblique incidence to optical effective surfaces. After that, oxidation treatment is performed from a direction to be incident at normal incidence to the optical effective surface so that the Al layer on the optical effective surface is changed to Al2O3 layer. Hence, in the diffraction grating having the multiple grating portions, the Al2O3 layer is formed on the optical effective surface for transmitting light, and the Al layer is formed on the grating wall surfaces as a light shielding layer. Thus, flare of the diffractive optical element can be suppressed.

Abstract: An element includes a first resin layer and a second resin layer disposed between a first glass lens substrate and a second glass lens substrate, a boundary surface between the first resin layer and the second resin layer having a diffraction grating shape including a plurality of inclined surfaces and wall surfaces. The second resin layer is composed of a fluororesin in which fine metal oxide particles are dispersed. Since a refractive index distribution easily occurs in this material during curing by application of ultraviolet light, by applying ultraviolet light substantially perpendicular to the inclined surfaces of the diffraction grating shape, a refractive index distribution is formed in the thickness direction perpendicularly to the inclined surfaces.

Abstract: A diffractive light outcoupling unit for forming a part of a directive light outcoupling system of a lighting device including a plurality of diffractive outcoupling units. The diffractive light outcoupling units each include a carrier element for accommodating a diffractive surface relief pattern, and a diffractive surface relief pattern including a plurality of consecutive diffractive surface relief forms defined on a surface area of the carrier element arranged to couple light incident on the diffractive surface relief pattern outside the carrier element via interaction involving at least two surface relief forms of the plurality of surface relief forms of the diffractive surface relief pattern so as to enhance the directivity of the coupled light. A diffractive light outcoupling system includes a plurality of diffractive light outcoupling units. A lightguide includes the outcoupling system.

Abstract: An optical element has at least one surface divided into a plurality of regions and includes: a first region configured to converge light with a wavelength ?1 onto a storage surface of a first optical disc and converge light with a wavelength ?2 onto a storage surface of a second optical disc; and a second region formed around the outer circumference of the first region and configured to converge light with the wavelength ?1 onto the storage surface of the first optical disc. The second region has a concave-convex structure concentrically formed on an aspheric surface and having a cross section being a saw teeth shape. The concave-convex structure is formed by a plurality of different saw teeth shapes, and the plurality of different saw teeth shapes respectively give different phase differences corresponding to substantially integer multiples of the wavelength ?1, for light with the wavelength ?1.

Abstract: A lens in accordance with the present invention includes an switchable cell consisting of optical substrate with diffraction surface, elastic film in contact with the diffraction surface of the substrate, optical fluid that fills the space between the film and diffraction surface and the mean to transfer the optical fluid in and out of the space between the film and diffraction surface. The refractive index of the optical fluid matches the refractive index of the optical substrate. The switchable cell changes focus positions between refractive focus in relaxed state when the pressure at both sides of the film is the same and diffraction focus when the optical fluid is transported from the space between the film and optical substrate for the film to largely conform to the diffraction surface shape of the optical substrate.