Abstract: Light management film constructions contain a first optical film having a first major surface and a second major surface opposite the first major surface. The first major surface is a micro structured surface with asymmetrical structures. The asymmetrical structures form an ordered arrangement of a plurality of multi-sided refractive prisms, with the multi-sided refractive prisms having a cross section of 3 or greater sides. A second optical film contacts and is bonded to substantially all of the structures of the first major structured surface of the first optical film. The light management constructions can be incorporated into optical articles such as windows.

Abstract: An optical device includes a first prism unit, a second prism unit spaced apart from the first prism unit, and a spacer unit disposed between the first and second prism units. Each of the first and second prism units includes a substrate, an anti-reflection coating, and a prism. The substrate has a first surface disposed to face the other one of the first and second prism units, and a second surface opposite to the first surface. The anti-reflection coating is disposed on the first surface of the substrate. The prism is disposed adjacent to the second surface of the substrate. The spacer unit is disposed between the anti-reflection coatings of the first and second prism units.

Abstract: An optical sheet capable of enhancing contrast is provided. The optical sheet includes a layer configured to control light incident on the layer and then allow the light to exit towards the observer side. The optical sheet includes: an optical functional sheet layer having multiple prisms capable of transmitting light and multiple light-absorbing parts capable of absorbing light, the multiple prisms and multiple light-absorbing parts being arranged alternately along a sheet plane of the optical sheet; and an electromagnetic-wave shield layer. The electromagnetic-wave shield layer is positioned on a side opposite to the observer side relative to the optical functional sheet layer.

Abstract: A biochip reader wherein spectroscopic information of a sample under analysis is arranged in spaces between images of the sample arranged on a biochip. The reader comprises a confocal microscope and the biochip comprises a transparent substrate to allow passage of the excitation light and fluorescent light from the sample with the excitation light being applied from the side opposite that on which the samples are arranged so that noise from dust and the like is avoided by the transmitted light avoiding contact with the dust. Another aspect is an electrophoresis system wherein different coloring material are used for each of a variety of target substances, so that the same lane and area are utilizable to concurrently detect a polychrome fluorescent pattern of the different targets. A confocal scanner or fluorescence imaging system is used with a plurality of filters to detect the multi-colored fluorescences of the target substance.

Abstract: A system for equalizing pulse to pulse energy of a light beam includes a group of optical devices including an optical device configured to exhibit nonlinear properties, e.g., higher order or third order nonlinear properties. Transmission properties of an unequalized light beam passing through the group of optical devices change such that an output intensity of a resulting light beam output from the optical devices is equalized. One example configuration includes at least first and second prisms having nonlinear properties, i.e., higher order or third order, and configured as a beam steering system.

Abstract: An adjustment device including an enhanced underwater viewfinder having, in use, a substantially watertight body and including a plurality of prisms within the body, at least one of the prisms being moveable by element of a control mechanism operable from a position exterior of the body.

Abstract: An optical pickup apparatus comprising: a collimating lens configured to convert laser light emitted from a laser diode, from diffused light into parallel light; an objective lens; and a prism configured to guide the laser light emitted from the collimating lens to the objective lens, the prism including: a first face that the laser light emitted from the collimating lens enters; a second face that reflects the laser light entering the first face; and a third face that reflects the laser light reflected from the second face in a direction of the second face, and emits the laser light reflected again from the second face in a direction of the objective lens.

Abstract: The invention discloses a projecting system. The projecting system includes two sets of lens. The first set of lens has a first focal length for focusing an incident ray of light to form a first image. The second set of lens has a second focal length for projecting the first image to form a second image. The two sets of lens are separated by a lens-apex distance relative to the light path between the two sets of lens. The second focal length is smaller than or equal to the lens-apex distance. A difference between the second focal length and the lens-apex distance is smaller than or equal to a half of the first focal length.

Abstract: A spectrometer comprises a detector array and a prism. The prism comprises a first prism element comprising a substantially crystalline crown material, and a second prism element contacting the first prism element, the second prism element comprising a substantially crystalline flint material. The spectrometer further includes optics configured to direct light at least twice through the prism. The prism is configured to disperse light received from the optics at an incident angle therethrough into constituent spectra in visible and infrared wavelength bands that are dispersed from the prism at angles offset from the incident angle. The constituent spectra are directed onto the detector array with approximately equal dispersion across the visible and infrared wavelength bands. Among other things, desirable material selections for the first and second prism elements are also disclosed.

Abstract: A prism monomer for use in a digital light processing projection device includes a plastic triangular prism having a hypotenuse surface and a glass sheet. The glass sheet has two opposite surfaces. One surface of the glass sheet is attached to the hypotenuse surface of the plastic triangular prism and the other surface of the glass sheet is formed with an anti-reflective coating.

Abstract: A prism includes a light incident portion that has first and second convex portions, the first and second convex portions each are a convex portion that refracts rays of light incident to a prism body and reduces a spread angle after incidence to the prism body via the convex portion to be smaller than that before the incidence, the spread angle is an angle between a given two of the rays, a first reflecting surface, provided on the prism body, that can reflect a first ray of light that has entered the prism body via the first convex portion, a first emitting portion, provided on the prism body, that emits, to the outside, the first ray reflected by the first reflecting surface, and a second emitting portion that emits, to the outside, a second ray of light that has entered the prism body via the second convex portion.

Abstract: An illumination system including at least one coherent light source, a light uniforming element, and a prism is provided. The coherent light source is capable of emitting a coherent beam. The light uniforming element is disposed on a transmission path of the coherent beam. The prism is disposed on the transmission path of the coherent beam and between the coherent light source and the light uniforming element. The prism has a light incident end and a light exit end. The light incident end has at least one incident polygonal pyramid portion protruding away from the light exit end. The prism is capable of rotating about an axis, and the axis extends from the light incident end to the light exit end. The illumination system effectively reduces the degree of the speckle phenomenon.

Abstract: To facilitate seeing of the image on a peripheral region which may become difficult to see as the screen size increases. A stereoscopic two-dimensional image display device includes a display unit 1 including an image display plane 1a on which an image is displayed; an image transfer panel 3 arranged apart from the image display plane, for imaging light emitted from the image display plane on an imaging plane 2 in a space, thereby displaying a stereoscopic two-dimensional image; and an optical path changing member (not shown) arranged between the image display plane and the imaging plane, for changing the optical path of the light emitted from the peripheral edge having a predetermined region constituting the image display plane. The optical path of light emitted from the peripheral edge is changed by the optical path changing means so that the light can be reached the eyes of a viewer 100 who sees at a near position.

Abstract: Disclosed herein is a method and apparatus for automatic correction of beam waist position drift in real time, using wafer inspection data taken during normal tool operation. Also disclosed herein is an improved laser astigmatism corrector for use either internal or external to the laser.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the main body. The first surface of transparent main body is flat. The second surface defines a plurality of parallelogram microstructures. Each parallelogram microstructure defines four adjacent triangular pyramid depressions.

Abstract: An illumination system including at least one coherent light source, a light uniforming element, and a prism is provided. The coherent light source is capable of emitting a coherent beam. The light uniforming element is disposed on a transmission path of the coherent beam. The prism is disposed on the transmission path of the coherent beam and between the coherent light source and the light uniforming element. The prism has a light incident end and a light exit end. The light incident end has at least one incident polygonal pyramid portion protruding away from the light exit end. The prism is capable of rotating about an axis, and the axis extends from the light incident end to the light exit end. The illumination system effectively reduces the degree of the speckle phenomenon.

Abstract: An optical element includes a plurality of first beam bodies arranged in a first direction on a first plane and being parallel to each other, and second beam bodies placed between adjacent ones of the first beam bodies and provided parallel to the first beam bodies. The first beam body has side surfaces which face the second beam bodies adjacent thereto and are sloped so that the width in the first direction gradually decreases to the upward direction perpendicular to the first plane, the second beam body has side surfaces which face the first beam bodies adjacent thereto and are sloped so that the width in the first direction gradually increases to the upward direction perpendicular to the first plane, and as viewed in the first direction, the spacing between the first beam body and the second beam body is variable.

Abstract: A pair of optical prisms arranged in a complementary relationship provides for anamorphic magnification and cooperates with a refractive or diffractive cylindrical lens element, the later of which generates an aberration that at least partially compensates an aberration generated by the pair of optical prisms. The refractive or diffractive cylindrical lens element is rotated out of normal with respect to the optic axis of the system so as to provide for reflecting stray light away from the optic axis.

Abstract: An illumination system including at least one coherent light source, a light uniforming element, and a prism is provided. The coherent light source is capable of emitting a coherent beam. The light uniforming element is disposed on a transmission path of the coherent beam. The prism is disposed on the transmission path of the coherent beam and between the coherent light source and the light uniforming element. The prism has a light incident end and a light exit end. The light incident end has at least one incident polygonal pyramid portion protruding away from the light exit end. The prism is capable of rotating about an axis, and the axis extends from the light incident end to the light exit end. The illumination system effectively reduces the degree of the speckle phenomenon.

Abstract: An image fluctuation correcting apparatus rotates a first rotary apex angle prism held in a first prism holding member around a first shaft in a direction for canceling an amount of horizontal fluctuation by electromagnetic force generated between a first drive coil and a first magnet by flowing electric current in the first drive coil. Also, the image fluctuation correcting apparatus rotates a second rotary apex angle prism held in a second prism holding member around a second shaft, which is located 180-degree angle away from the first shaft, in a direction for canceling an amount of vertical fluctuation by electromagnetic force generated between a second drive coil and a second magnet by flowing electric current in the second drive coil.

Abstract: The present invention provides a light redirecting article for redirecting light toward a target angle, the light redirecting article comprising: an input surface comprising a plurality of light redirecting structures each light redirecting structure having a near surface having two slopes, sloping away from normal in one direction as defined by a first inclination base angle ?1, a second inclination angle ?2, and a first half apex angle ?2, for accepting incident illumination over a range of incident angles and a far surface sloping away from normal, in the opposite direction relative to the input surface, as defined by a second base angle ?1 and a second half apex angle ?1. The invention further provides an output surface opposing to the input surface wherein the near and far surfaces are opposed to each other at an angle (?1+?2) that is in the range from 60 to 70 degrees, and the base angle ?1 is in the range from 82 to 87 degrees.

Abstract: A transparent bevel apparatus overlays marginal portions of juxtaposed display devices of a segmented display panel to obscure the visual gap between the display devices. The bevel apparatus at least partially overlaps only marginal pixels of the adjacent display devices, so that light from a given display device that passes through the bevel apparatus is bent toward from the respective display device at an angle with respect to the remainder of the emitted light. Consequently, light emitted from the marginal portions of the juxtaposed display devices is seen by the viewer in the place where the visual gap would otherwise be seen. The bevel apparatus may be constructed in the form of a sheet that overlays an entire display device, or all or a portion of the entire display panel, or a narrow strip that is aligned with the seams and affixed to juxtaposed faces of the display devices.

Abstract: A Risley integrated steering module is disclosed. The beam steering device consists of an outer assembly rotatable about an axis, and an inner assembly rotatable about the axis and positioned radially within the outer assembly. The beam steering device also includes a first prism connected to the outer assembly and a second prism connected to the inner assembly, and a stationary assembly, with the outer and inner assemblies being rotatable about the portion of the stationary assembly. In an alternative embodiment, the inner assembly rotates within the stationary assembly. The beam steering device also consists of beam expansion optics carried by either the inner assembly or the stationary assembly.

Abstract: An optical pickup includes a light emitting device, a prism, and an objective lens. The light emitting device emits a laser beam. The prism has an entrance face and an exit face. In the prism, the laser beam emitted from the light emitting device is perpendicularly incident on the entrance face, is parallel-shifted, is perpendicularly reflected, and is emerged from the exit face. The objective lens focuses the laser beam emerged from the prism on a recording surface of an optical disk.

Abstract: An Abbe prism lens and lens array are disclosed. The lens comprises front lenses disposed on a front surface of the Abbe prism, rear lenses disposed on a rear surface of the Abbe prism, a front bottom reflecting surface, a rear bottom reflecting surface, a left top reflecting surface, and a right top reflecting surface. An aperture cover is positioned over the front surface of the Abbe prism lens and a field cover is positioned over the rear surface of the Abbe prism lens. The aperture cover comprises aperture holes encircling the aspherical front lenses. The field cover comprises field holes encircling the aspherical rear lenses. Light enters the Abbe prism lens and reflects off the front bottom reflecting surface, reflects off the left top reflecting surface and the right top reflecting surface, reflects off the rear bottom reflecting surface, and exits the rear lens of the Abbe prism lens.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the transparent main body. The first surface defines a plurality of micro-depressions. Each micro-depression forms four inner sidewalls connected with each other. A transverse width of each inner sidewall progressively decreases with increasing distance from the first surface. The second surface defines a plurality of parallelogram microstructures. Each parallelogram microstructure defines four adjacent triangular pyramid depressions.

Abstract: Beam steering apparatus is presented having a Risley double-prism pair with first and second double-prisms disposed along an optical path, where one or more of the prisms are made from a chalcogenide glass material.

Abstract: An exemplary prism sheet according to a preferred embodiment includes a transparent main body. The transparent main body includes a light input surface and a light emitting surface opposite to the light input surface. A plurality of curved elongated V-shaped protrusions are formed on the light emitting surface. Each of the curved elongated V-shaped protrusions extends along a circular arc. The circular arcs have a same curvature, and centers of the circular arcs are aligned apart and in a straight line. A liquid crystal display device using the prism sheet is also provided.

Abstract: A full or partial air-to-water de-anamorphoser and method of air-to-water de-anamorphosis is provided. A housing has a planar transparent window in one end thereof adjacent to a defined air space. The housing is placed under the water's surface with an acute angle being formed between the window and the water's surface to thereby define a virtual prism whose center leads its apex. An optical prism having an apex and a center is positioned in the housing's air space and is spaced apart from the housing's window such that the prism's apex leads its center as measured along a line parallel to light exiting the prism. The light exiting the prism was originally incident on the water's surface, subsequently traveled through the water, and then was passed sequentially through the housing's window, the housing's air space and the prism.

Abstract: An image display device projects lights emitted from each of two two-dimensionally light emitting type photoelectric devices onto first and second light diffusing bodies, and projects and images transmitted images of the light diffusing bodies onto the retina in the respective eyeballs of the user. The display device includes one light source, a first polarization beam splitter dividing light emitted from the light source into P-polarized light and S-polarized light, and an optical system which leads each of the P-polarized light and S-polarized lights respectively to the two photoelectric devices thereby illuminating the two photoelectric devices. The optical system leads polarized light to each of the two photoelectric devices via a second polarization beam splitter and a ?/4 plate, and leads reflected lights to the relay optical system via the ?/4 plate and the second polarization beam splitter.

Abstract: A radiant energy trap. This diffuse and direct radiant energy concentrator comprises at least one reflector, a refractor substantially prism shaped and a receiver interfaced with the refractor. The invention is capable of a solid angle of acceptance of radiant energy, equivalent to that of a flat panel collector, while maintaining a relatively high concentration ratio of diffuse light. The invention can be embodied as an effective hybrid solar electric and thermal collector. A unique yet simple geometry results in relatively high optical and thermal efficiency. The invention can be embodied as a low profile 3-D diffuse light concentrator, combining reflection, refraction, and total internal reflection to approach the thermodynamic limit. It minimizes materials cost to the limits of cost reduction with relatively high efficiency PV cells. The invention increases the utilization of available solar energy and greatly reduces installed system payback periods, compared to prior art.

Abstract: A system for multidirectional electromagnetic wave irradiation of an object to be processed has at least one of a side face irradiation prism system capable of irradiating a top face and one, two or more side faces of the object, and a bottom face irradiation prism system capable of irradiating a bottom face of the object. The side face irradiation prism system has an optical path direction changing prism placed so that each of the optical paths through which electromagnetic waves entering the optical path from above travel extends via the optical path direction changing prism to reach the side face of the object, without being obstructed. In this way, a laser machining apparatus or the like can be implemented which can simultaneously irradiate the faces of the object to be processed with electromagnetic waves with accuracy without moving the object to be processed.

Abstract: The light redirecting films have a thin optically transparent substrate having a light entrance surface and an opposite light exit surface, at least one of the surfaces including a pattern of individual optical elements of well defined shape having two differently curved surfaces. The individual optical elements are quite small in size relative to the length and width of the substrate, and redistribute light passing through the substrate in a predetermined angular distribution. The individual optical elements may be distributed on the surface of the substrate such that some intersect each other, or the placement may be randomized.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the main body. The first surface of transparent main body defines a plurality of first elongated arc-shaped grooves and a plurality of second elongated arc-shaped grooves. The first elongated arc-shaped grooves intersect with the second elongated arc-shaped grooves. The second surface defining a plurality of rectangular structures. Each rectangular structure defining four adjacent triangular pyramid depressions.

Abstract: In a retroreflective sheeting, and methods of formation thereof, the sheeting comprises a body of material, the body having a first surface and a second surface. A plurality of first full-square-sided corner-cube structures are on the first surface of the body, the first full-square-sided corner-cube structures each having three facets that lie along planes that are orthogonal to each other. A plurality of second full-square-sided corner-cube structures are on the second surface of the body, the second full-square-sided corner-cube structures each having three facets that lie along planes that are orthogonal to each other.

Abstract: A prismatic joint for an optical swiveling device has a first prism rotatably mounted about a first rotation axis and a second prism, rotatably mounted about a second rotation axis with respect to the first prism. The first rotation axis and the second rotation axis intersect one another at an intersection angle of 45°. The first prism and the second prism have a respective first side surface and a second side surface, as well as a base surface. The first side surface is inclined through the intersection angle with respect to the base surface, and the second side surface is inclined through half the intersection angle with respect to the base surface. The first and second prisms project substantially mirror-image symmetrically along the first rotation axis, and a third prism is disposed with its side surfaces adjoining, the first and the second prisms.

Abstract: An image display apparatus includes an image generation source, optics for projecting in an enlarged form the image generated by the image generation source, and a transmissive screen for displaying the image projected from said optics. The transmissive screen includes a Fresnel lens sheet disposed at an image generation source side, and a diffusing sheet disposed at an image-watching side in order to diffuse image light at least in a horizontal direction of the screen. The Fresnel lens sheet has a plurality of entrance-side prisms formed at the image generation source side, and a plurality of exit-side prisms formed at the image-watching side, and the Fresnel lens sheet emits lights in a first direction and a second direction. The first direction is almost parallel to a central axis of the Fresnel lens sheet, and the second direction extends toward the central axis.

Abstract: A security document including a substrate of transparent polymeric material, and opacifying layers provided on opposing sides of the substrate, the opacifying layers acting to guide light propagating within the substrate, wherein the substrate is formed with at least one micro-prism for diverting light propagating within or entering the substrate.

Abstract: An optical film with a plurality of micro structures which are capable of collecting incident light to the frontal and normalized view angle of the optical film for reducing the chance of incident light returning to light guild plate so as to enhance light collecting efficiency is provided in the present invention. In an embodiment, the optical film is combined with a flat light source so as to form a backlight system. By means of the merit of the optical film, the quantities of the optical film can be reduced so that the backlight system can have characteristics of thin thickness and low production cost.

Abstract: A Risley integrated steering module is disclosed. The beam steering device consists of an outer assembly rotatable about an axis, and an inner assembly rotatable about the axis and positioned radially within the outer assembly. The beam steering device also includes a first prism connected to the outer assembly and a second prism connected to the inner assembly, and a stationary assembly, with the outer and inner assemblies being rotatable about the portion of the stationary assembly. In an alternative embodiment, the inner assembly rotates within the stationary assembly. The beam steering device also consists of beam expansion optics carried by either the inner assembly or the stationary assembly.

Abstract: An exemplary optical plate includes a transparent layer and a light diffusion layer. The transparent layer includes a light input interface and a light output surface opposite to the light input interface. A plurality of micro-protrusions formed on the light output surface. The micro-protrusions are arranged along a plurality of separate, circular arcs. Each micro-protrusion has four side surfaces connected to each other, and a transverse width of each side surface decreases along a direction away from the light diffusion layer. The light diffusion layer is integrally formed in immediate contact with the light input interface of the transparent layer, and free of air or gas pockets trapped in an interface therebetween. The light diffusion layer includes a transparent matrix resin and a plurality of diffusion particles dispersed in the transparent matrix resin.

Abstract: An optical element includes one or more transparent prisms and a multilayer optical thin-film formed on the transparent prisms. The multilayer optical thin-film includes a transparent substrate and a multilayer optical thin-film formed on the transparent substrate. The multilayer optical thin-film includes a plurality of high refractive index layers having a refractive index of more than 2.1 and a plurality of medium refractive index layers. The medium refractive index layers have a refractive index of one of to 1.79 and 1.81 to 1.86. The medium refractive index layers and the high refractive index layers are laminated in alternating fashion.

Abstract: Apparatus is disclosed for optically steering an optical beam, the apparatus comprising a pair of optical prism components arranged together with a diffraction grating so as to allow efficient coupling of an array of spectrally and spatially offset laser diodes to a common optical fiber. A method of optically steering at least one of a series of optical beams is disclosed, the method comprising providing a pair of optical prism components comprising a thermo-optic material; actuating at least one of the components so as to steer at least one of the series of optical beams received from an array of spatially and spectrally offset lasers.

Abstract: An optical substrate having a structured surface that enhances brightness and reduces moiré effect. The optical substrate has a three-dimensionally varying, structured light output surface that comprises an irregular prismatic structure. The irregular prismatic structure may be viewed as comprising longitudinal prism blocks or rows thereof, arranged laterally defining peaks and valleys. Adjacent peaks, adjacent valleys, and/or adjacent peak and valley may be parallel or non-parallel, in an orderly, semi-orderly, random, or quasi-random manner. The lateral adjacent peaks, adjacent valleys, and/or adjacent peak and valley are not parallel. The adjacent irregular prism blocks may be irregular longitudinal sections having the same length, or random or quasi-random irregular sections having different lengths. The facets of each prism block may be flat, or curved (convexly and/or concavely).

Abstract: A thin lens consists of a first optical element which comprises a first refracting surface, wherein incoming light passes through the first refracting surface on a first optical axis. A reflecting surface changes a direction of the incoming light from the first optical axis to a second optical axis. Incoming light on the second optical axis passes through a second refracting surface. A second optical element comprises a first refracting surface, wherein incoming light passes through the first refracting surface on the second optical axis. A reflecting surface changes a direction of the incoming light from the second optical axis to a third optical axis. Incoming light on the third optical axis passes through a second refracting surface. The third optical axis is approximately parallel to, and in opposite direction from, the first optical axis.

Abstract: There is provided an optical apparatus that provides quick and precise TTL phase difference detection and pupil slicing focus detection. An optical apparatus includes a first optical element for splitting a first polarized light component contained in light that passes an exit pupil of a first optical system and directs to a photoelectric conversion element so that the first polarized light component direct to different light-receiving areas on the photoelectric conversion element. The optical apparatus may further include a second optical element for separating a second polarized light component contained in the light from said first optical element, from the first polarized light component.

Abstract: An exemplary prism sheet includes a main body having a surface. The surface defines a plurality of first V-shaped micro-protrusions and second V-shaped micro-protrusions thereon. Each of the first V-shaped micro-protrusions extends along a first curved direction. Each of the second V-shaped micro-protrusions extends along a second curved direction. The first V-shaped micro-protrusions intersect with the second V-shaped micro-protrusions. The present prism sheet and the liquid crystal display device using the same can efficiently decrease moire pattern interference between the prism sheet and the pixel pitch of LCD panel.

Abstract: A prism assembly including two or more prisms, at least one of which has or more surfaces that are used for total internal reflection or partial spectral reflection of incoming light, wherein at least a part of one of the surfaces used for reflection purposes is covered with an element that is spaced apart from the surface, such that a gap is defined in between the surface and the element, and wherein the gap is sealed with a seal that is applied on one of said prisms in order to prevent contaminants from entering the gap.

Abstract: The present invention may provide a structure capable of obtaining a higher difference in refractive indices between that of a transparent material and that of a cavity, than in the past, and a manufacturing method thereof, and the present invention provides a structure having a transparent material and an internal cavity which is formed by irradiating said transparent material with a pulse laser beam having a pulse width of 10×10?12 seconds or less, and wherein refractive index of said transparent material at d line is nd?1.

Abstract: A lighting device includes a first platform, a light-emitting unit, a second platform and a connecting member. The light-emitting unit is disposed on the first platform for emitting light beams. The second platform is made of transparent material and has a chamber therein. The chamber contains immiscible first and second fluids with different refractive indices. The connecting member is used for interconnecting the first platform and the second platform and transmitting inclination of the second platform. The light beams are refracted by the first and second fluids when the second platform is inclined at a specified inclining angle.