Abstract: The present disclosure discloses a telephoto optical imaging system and zoom camera apparatus. The telephoto optical imaging system includes, sequentially from an object side to an image side along an optical axis, a first lens having positive refractive power, a second lens having negative refractive power, an optical path turning prism, and a triangular prism. A total effective focal length F1 of the telephoto optical imaging system may satisfy F1>40 mm. The zoom camera apparatus includes the telephoto optical imaging system and a short-focus optical imaging system arranged in parallel with the telephoto optical imaging system. A total effective focal length F1 of the telephoto optical imaging system and a total effective focal length F2 of the short-focus optical imaging system satisfy F1/F2>5.

Abstract: This invention is a novel transparent curvilinear prismatic film which eliminates glare and reduces front-surface reflections when applied to solar panels and other surfaces with a transparent adhesive. The new prismatic film comprises an exposed top surface with substantially triangular prisms following a curvilinear path across the top surface and a bottom surface which is substantially flat and smooth. The bottom surface is configured to enable a transparent adhesive bond to the solar panel or other surface beneath the prismatic film to eliminate glare and to reduce front-surface reflections from this solar panel or other surface. The curvilinear prismatic film is configured to be transparent, thin, lightweight, and inexpensive.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: An aspect of the disclosed subject matter includes a method of reducing the laser absorption of a beam reverser prism consisting of at least one of the following: increasing a first distance between a first incident point and a chamfered corner, wherein the first incident point is on a first reflective surface of the prism and the chamfered corner is formed between the first reflective surface and a second reflective surface of the prism, wherein the chamfered corner has a chamfered surface; increasing a second distance between a second incident point and the chamfered corner, wherein the second incident point is on the second reflective surface of the prism; and increasing a reflectivity of the chamfered surface of the chamfered corner of the prism. A method of determining a prime cut for an optical component is also disclosed. A laser including at least one prime cut optical component is also disclosed.

Abstract: A prism assembly includes a first prism, a second prism, a roof prism and an optical multilayer film. The first prism includes a first, a second and a third surface. The second prism includes a fourth, a fifth and a sixth surface. The fifth surface faces the third surface. The roof prism includes a seventh, an eighth and a ridge surface. The seventh surface faces the second surface. The optical multilayer film is disposed between the fifth surface and the third surface. A first light beam and a second light beam entering the first prism are totally reflected from the second surface to the optical multilayer film which reflects the first light beam but allows the second light beam to pass through. The second light beam enters the second prism, is totally reflected on the sixth surface, and exits from the fourth surface of the second prism.

Abstract: Two side-by-side optical paths transmit stereoscopic right side and left side images onto the surface of a single image sensing chip. The single image sensing chip may be placed at various orientations with respect to the lens trains in the optical paths. In some embodiments a single prism is used to turn the light for both the right side and left side images onto the single image sensing chip. In other embodiments one prism is used to turn the light for the right side image and another prism is used to turn the light for the left side image, and the reflective surfaces of the two prisms are substantially coplanar such that the right side and left side images are incident on the single image sensor chip.

Abstract: A reflector array optical device includes two dihedral corner reflector array optical elements each having a substrate and a plurality of prism bodies arranged regularly on and each protruding from one main surface of the substrate. Each prism body includes at least two sides of orthogonal planes. The two optical elements are adhered so that top faces of the prism bodies are directly confronted respectively so as to make two coplanar planes in which the two orthogonal planes exist respectively.

Abstract: An embodiment of the present invention provide for an optical microscope apparatus including a light source, a base unit, a rotary monochromatic dispersion unit, a condenser, a stage, an objective, a tubular assembly and an ocular assembly. In a preferred embodiment, light travels from the light source sequentially through each of these seven components, producing an image of the contents of a slide on the stage to a user looking through the ocular assembly. In the base unit, in place of a standard mirror which would direct the light vertically up into the scope along the z-axis, a right angle piece of single crystal Calcite, known as Iceland Spar is used, which has a birefringent affect upon the light as it passes up through the scope.

Abstract: The universal sphere mount provides a spherically mounted retro-reflector conical nest mount having a base, a body of lesser diameter than the base, and a precise nest in the body that receives a retro-reflector target. The body steps inwardly from the base or has bevel. The body has a lesser diameter than the base so the reflector achieves an orientation below a horizontal plane at any horizontal rotation upon the body. The nest receives a spherically mounted retro-reflector and positions it with high precision over the shank. The nest has at least three oblique clearance areas, equally spaced, that permit a maximum negative acceptance angle for incident light to a mounted spherically mounted retro-reflector without occlusion and at any angle of rotation upon the body. The universal sphere mount achieves tolerances, within 0.0005 inch of the centerline and of the height of a spherically mounted retro reflector placed therein.

Abstract: An array of light valves switch light by enabling and disabling total internal reflection (TIR) on a surface of the light valve. The disabling of the TIR is accomplished by putting another optical element in contact with the surface and then diffusing or changing the direction of the light. The mechanical mechanism to move the optical element is a simple one in that it only moves the optical element a small distance to change the valve from a first position to a second position.

Abstract: An aspect of the disclosed subject matter includes a method of reducing the laser absorption of a beam reverser prism consisting of at least one of the following: increasing a first distance between a first incident point and a chamfered corner, wherein the first incident point is on a first reflective surface of the prism and the chamfered corner is formed between the first reflective surface and a second reflective surface of the prism, wherein the chamfered corner has a chamfered surface; increasing a second distance between a second incident point and the chamfered corner, wherein the second incident point is on the second reflective surface of the prism; and increasing a reflectivity of the chamfered surface of the chamfered corner of the prism. A method of determining a prime cut for an optical component is also disclosed. A laser including at least one prime cut optical component is also disclosed.

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: An optical element with improved deflection of a laser light beam calls for combination of a pentaprism with one or more glass blocks or an afocal optical system. A rotational angle-dependent parallel offset of emerging beams is eliminated for the most part.

Abstract: In a viewfinder for a single lens reflex camera, in which a focused image of an object formed on a ground glass by a photographing lens is transmitted to an ocular optical system through a pentagonal prism or a pentagonal mirror and an information image displayed on an indication surface of an indication block is transmitted to the pentagonal prism or pentagonal mirror, through an indication prism, so that the object image and the information image are indicated in the finder view field of the ocular optical system, the indication surface of the indicator is inclined with respect to a direction perpendicular to an incident surface of the image-erecting optical member toward the incident surface, and an angle between the indication surface of the indicator and the incident surface of the image-erecting optical member is smaller than 90°.

Abstract: This invention provides a system and a method of the optical delay line, wherein the system comprises a source and an array of mirrors, wherein the array of mirrors comprises a first reflective mirror, a second reflective mirror, a third reflective mirror, and a fourth reflective mirror. Beams from the source could be delayed because the beams are multi-reflected by the reflective mirrors.

Abstract: A digital camera module (100) and a lens (20) used therein, the digital camera module includes a holder (10), an image pickup module (30) and a lens (20). The holder has a window (12) defined on a sidewall, the window is configured for receiving light. The image pickup module includes a base (31) and a chip (33) attached to the base, the base is mounted to the holder to cooperatively form a receiving space therebetween. The prism lens is received in the receiving space and formed from a first transmitting surface (22) configured for transmitting light passing through the window, a second reflecting surface (24) configured for reflecting light transmitted from the first surface, and a third transmitting surface (26) configured for transmitting the reflected light to form an image on the chip.

Abstract: A system for determining wire bonding tool placement for use with a wire bonder and an optical imager is provided. The system includes a prism disposed below the optical imager and the wire bonding tool. The system also includes at least one lens positioned between the prism and a lower portion of the wire bonding tool along a first optical axis. The at least one lens and the prism define an object plane between the at least one lens and the lower portion of the wire bonding tool. The at least one lens is positioned between the prism and the optical imager along a second optical axis. The at least one lens and the prism define an image plane between the at least one lens and the optical imager.

Abstract: A device for linear scanning includes a roof prism. The roof prism includes a roof of two mutually perpendicular reflecting surfaces intersecting in a line of intersection. A scanning mechanism moves the roof prism in a direction perpendicular to a plane of bilateral symmetry. The line of intersection is included in the plane of bilateral symmetry; and an incident beam entering the prism and an exit beam exiting the prism are angularly separated by a substantial angle. Preferably, the scanning mechanism generates periodic motion or rotational motion of the roof prism with a radius of motion greater than a dimension of the roof prism.

Abstract: A substantially neutral filter across the white-light spectrum is obtained by minimizing the wavelength-dependent effects of filtering components and of reflective coatings on surfaces. The incoming light is captured by a first prism and directed toward the interface formed by the optical contact of a second prism with a face of the first prism, where the light is partially reflected internally and partially transmitted into the second prism. The reflected light is further reflected internally and directed toward the image surface out of the first prism. The fraction of light transmitted into the second prism is reflected back and redirected out of the system toward the incoming beam. The amount of energy directed toward the image plane is controlled by the judicious selection of the refractive indices in the two materials at the contacting interface of the first and second prisms.

Abstract: A two-corner retroreflector that includes a common face positioned to receive two beams and two corners each positioned to receive one of the beams and retro-reflect it back through the common face.

Abstract: A device for linear scanning includes a roof prism. The roof prism includes a roof of two mutually perpendicular reflecting surfaces intersecting in a line of intersection. A scanning mechanism moves the roof prism in a direction perpendicular to a plane of bilateral symmetry. The line of intersection is included in the plane of bilateral symmetry; and an incident beam entering the prism and an exit beam exiting the prism are angularly separated by a substantial angle. Preferably, the scanning mechanism generates periodic motion or rotational motion of the roof prism with a radius of motion greater than a dimension of the roof prism.

Abstract: Asymmetry of output beams from a laser diode bar is significantly reduced by internally reflecting the beams from an array of roof prisms positioned and oriented to rotate the cross-sectional shape of each beam by 90°. An elongated retro prism is positioned to received all of the reflected beams and to redirect them away from the laser diode bar.

Abstract: A trinocular tube for stereo microscopes with an inclined binocular eyepiece whose angle can be adjusted and with two stereo microscope beam paths. The trinocular tube includes, in the beam paths, a first tube unit which can be connected to the body of the stereo microscope. A connection piece for cameras is arranged at the first tube unit. A second tube unit is arranged at the first tube unit so as to be swivelable around an axis and which is connected to an eyepiece tube unit that is swivelable around the optical axis of the respective beam path. The trinocular tube also includes a roof mirror, a deflecting element and an optical axis that is swivelable around a second swiveling axis.

Abstract: A dual lamp coupling system is provided using a single equilateral 60 degree triangle prism in front of the integrator rod to homogenize the focused light from two lamps, with increased projection brightness. According to one embodiment, the equilateral 60 degree triangular prism is integrated into the end of the rod.

Abstract: A substantially neutral filter across the white-light spectrum is obtained by minimizing the wavelength-dependent effects of filtering components and of reflective coatings on surfaces. The incoming light is captured by a first prism and directed toward the interface formed by the optical contact of a second prism with a face of the first prism, where the light is partially reflected internally and partially transmitted into the second prism. The reflected light is further reflected internally and directed toward the image surface out of the first prism. The fraction of light transmitted into the second prism is reflected back and redirected out of the system toward the incoming beam. The amount of energy directed toward the image plane is controlled by the judicious selection of the refractive indices in the two materials at the contacting interface of the first and second prisms.

Abstract: An erecting prism of a binocular includes a first and a second prism, which are held by a holder, and the holder being supported vertically movable and laterally immobile with respect to a thin plate. The thin plate is supported laterally movable and vertically immobile with respect to a right moving body. A shaft reception means is provided, for rotatably supporting a jig, at the right eyepiece cylinder that is attached to the rear wall 303B of the right moving body. The position of erecting prism is adjusted by using a jig to move the holder vertically with respect to the thin plate, and to move the thin plate laterally with respect to the right moving body. The jig may be supported by the shaft reception means and rotated.

Abstract: An assembly of beam splitters of the invention includes a roof-prism, a triangle prism and a complementary prism; wherein the roof-prism has a first emitting/receiving surface, the triangle prism has a second emitting/receiving surface and the complementary prism has a third emitting/receiving surface and a fourth emitting/receiving surface. A beam of first wavelength enters the assembly of beam splitters through the second emitting/receiving surface, and leaves it through the first emitting/receiving surface. A beam of second wavelength parallel to the beam of first wavelength enters the assembly of beam splitters through the second emitting/receiving surface, and leaves it through the third emitting/receiving surface. A beam of third wavelength enters the assembly of beam splitters through the fourth emitting/receiving surface, and leaves it through the first emitting/receiving surface. Thus, the optical axis of the beam of third wavelength is parallel to the optical axis of the beam of first wavelength.

Abstract: In a luminous display element, a retro-reflector is provided on the back side of an organic EL layer which includes an emission layer whose state changes between an emission state and a non-emission state. The retro-reflector includes a corner cube array, and reflects incident light in the same direction as an incident direction. A unit structure of the corner cube array is a form of a triangular pyramid which is made up of rectangular equilateral triangles having three faces, and a light shielding process is performed on the periphery of a base angle of the rectangular equilateral triangle. Thus, it is possible to prevent an image from being reflected, so that it is possible to provide the luminous display element whose contrast ratio and the utilization efficiency of emission are high.

Abstract: A wavelength router that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input ports and said output ports, and a routing mechanism. The free-space optical train can include air-spaced elements or can be of generally monolithic construction. The optical train includes a dispersive element such as a diffraction grating, and is configured so that the light from the input port encounters the dispersive element twice before reaching any of the output ports. The routing mechanism includes one or more routing elements and cooperates with the other elements in the optical train to provide optical paths that couple desired subsets of the spectral bands to desired output ports. The routing elements are disposed to intercept the different spectral bands after they have been spatially separated by their first encounter with the dispersive element.

Abstract: An erecting prism of a binocular includes a first and a second prism, which are held by a holder, and the holder being supported vertically movable and laterally immobile with respect to a thin plate. The thin plate is supported laterally movable and vertically immobile with respect to a right moving body. A shaft reception means is provided, for rotatably supporting a jig, at the right eyepiece cylinder that is attached to the rear wall 303B of the right moving body. The position of erecting prism is adjusted by using a jig to move the holder vertically with respect to the thin plate, and to move the thin plate laterally with respect to the right moving body. The jig may be supported by the shaft reception means and rotated.

Abstract: The present invention includes time delay devices and time delay systems. The invention also includes machines and instruments using those aspects of the invention. The invention may also be used to upgrade, repair, or retrofit existing machines or instruments, using methods and components known in the art. The present invention comprises a true time device that falls into the free-space category but uses a multiple-pass optical cell with refocusing mirrors that has the advantage of avoiding beam-spreading problems. This approach differs from previous free-space approaches in that it uses only one optical switch or spatial light modulator instead of one or more switches for each bit. In one approach, a microwave signal for each antenna element may be modulated onto an optical beam. After the individual optical beams are delayed by the desired amount of time through the system, the signals may then be down-converted to microwave signals for further processing.

Abstract: A screen mounting device for a projection TV includes a mask for protecting an edge of a screen on which an image is displayed which is arranged to enclose an edge portion of the screen and having a hooking socket formed at a back side thereof, and a holder member for fixing the screen s and the mask to the cabinet. The holder member includes a coupling portion fitting in a front edge portion of the cabinet and fixed thereto, a hooking portion inserted in the hooking socket of the mask and coupled thereto, and a screen fixing portion in which the edge portion of the screen is inserted. Also, the coupling portion, the hooking portion and the screen fixing portion are integrally formed.

Abstract: A light deflector/recombiner is longitudinally symmetrical with respect to an X axis perpendicular to a Z axis. An X and Z vector components inverter longitudinally symmetrical with respect to both the X axis and a Y axis perpendicular to the X and Z axes lies parallel to the deflector/recombiner. A Y vector component inverter longitudinally symmetrical with respect to the X axis lies parallel to and between the deflector/recombiner and the X and Z inverter. The Y inverter has many reflector elements. Light rays incident in the Z direction encounter an element only once during return passage between the deflector/recombiner and the X and Z inverter. The X and Z inverter directionally inverts the rays with respect to the X and Z axes and the reflector element directionally inverts them with respect to the Y axis, such that substantially all incident rays are retro-reflected with respect to the X, Y and Z axes.

Abstract: The invention concerns a microsystem module, in particular for use in microoptical systems, the module consisting of a body on the surface of which at least one functional area and support areas for attachment to adjacent microsystem components are provided. According to the invention, in order to provide a microsystem module of this type which can be connected to adjacent microstructure system components with an extremely good fit and in an exactly reproducible manner and preventing damage to the adjacent components and the sensitive functional areas of the microsystem module, the support areas are disposed in the region of outwardly projecting surface regions of the body which are set back relative to the support areas in the direction towards the interior of the body. The functional areas are disposed with very narrow tolerances in a dimensionally accurate manner relative to the support areas.

Abstract: A projection type display device constructed so that light source beams via a polarization beam splitter are separated of colors by a color separating/synthesizing optical system and enter light valves disposed for every color light, the light beams exiting from the respective light valves are synthesized by the color separating/synthesizing optical system, the synthesized light beams exit, the polarization beam splitter analyzes the synthesized light beams and takes out the analyzed light beams, and the analyzed light beams are projected on a screen through a projection lens. A normal line of an outgoing surface of the polarization beam splitter with respect to the light source beams exiting toward the color separating/synthesizing optical system from the polarization beam splitter, has a predetermined angle larger than zero degree with respect to an optical axis of the light source beams.

Abstract: A viewing optical instrument has a roof prism which is provided with a pair of reflection surfaces intersecting at a nominal face angle of 90°, wherein the pupil is split by an edge line of the reflection surfaces of the roof prism. The reflection surfaces are provided with a multiple-layer coating which does not absorb visible light. A change in the phase difference produced between light incident on one of reflection surfaces located on opposite sides of an edge line of the roof prism and emitted from the other reflection surface, and light incident on the right reflection surface and emitted from the left reflection surface is restricted to reduce wavefront aberrations to thereby improve the quality of an image to be viewed. A roof prism used in the optical instrument is also disclosed.

Abstract: A prism system for image inversion in a visual observation beam path, which uses a roof prism and a reflecting prism. The roof prism has a roof edge inclined with respect to a bottom face, and a gable face which is placed at an angle with respect to the bottom face and which acts as a beam splitter. The reflecting prism has a beam-pass face parallel to the bottom face of the roof prism. The bottom face of the roof prism and the beam-pass face of the reflecting prism have areas separated geometrically from one another for the passage of observation beams and for the passage of a further beam path which reflects a measured-value display into an exit-side observation beam path and/or reflects a rangefinder measuring beam path into an entry-side observation beam path.

Abstract: A convergence tube for stereomicroscopes in which both observation beam paths are inclined relative to one another at an angle of convergence &agr; and image inversion elements are provided in both observation beam paths. Four planar reflectors R1 to R4 are provided in each of the two beam paths and are arranged relative to one another in such a way that the axis beams incident on and emergent from the reflectors R1, R2 lie in a common plane E1,2, the axis beams incident on and emergent from the reflector R3 describe a plane E3 that forms an angle &bgr;=90°+&agr;/4 with the plane E1,2, and the axis beams incident on and emergent from the reflector R4 describe a plane E4 that forms an angle &bgr;2=&agr;/2 with plane E3.

Abstract: A real image type finder optical system includes, in order from the object side, an objective optical system, a first prism, a second prism, and an eyepiece lens. The first prism includes a first face as an entrance surface confronting the exit plane of the objective optical system, a second face making an angle of 22.5° with respect to this first face and a third face for transmitting the finder optical axis bent in order by the second face and the first face. The second prism includes a first face as an entrance surface confronting the third face of the first prism with a space therebetween, a second face opposed to the first face so as to bend the finder optical axis toward the object side within a horizontal plane, a third face for turning the finder optical axis bent in order by the second face and the first face to a direction generally coaxial with the eyepiece lens and a fourth face for transmitting the optical axis turned from the third face.

Abstract: The bottom surfaces of an entering surface-forming portion 1a for forming a light-entering surface 11a of a reflector type prism 11 and of an emitting surface-forming portion 1b for forming a light-emitting surface 11b of the reflector type prism 11 are formed as concave surfaces in a die 1. Even if shrinkage of the reflector type prism 11 occurs during its formation, the light-entering surface 11a and the light-emitting surface 11b are, at least, not formed as concave surfaces, so that a light beam entering the reflector type prism 11 and a light beam emitted from the reflector type prism 11 are prevented from becoming scattered.

Abstract: A stable resonator for a ring-down cavity spectroscopy cell having an optic axis. The resonator includes two Brewster's angle retroreflector prisms, each having a plurality of total internal reflection surfaces, with one of the total internal reflection surfaces of at least one of the prisms having a curved surface (either a ground curved surface or a surface curved by the addition, through optically contacting or gluing, of a plano-convex lens to the surface). The prisms are disposed in alignment along the optic axis of the resonator. A spherical mirror or lens, tilted from normal incidence to produce a desired degree of astigmatism, mode matches the radiation into the resonator. One or both of the prisms can be rotated so that light rays enter and leave a surface of the prism nearly at Brewster's angle to the normal of the prism surface. This feature maintains alignment between the prisms and allows the resonator to be tuned.

Abstract: A stable resonator for a ring-down cavity spectroscopy cell having an optic axis. The resonator includes two Brewster's angle retroreflector prisms, at least one prism having greater than two total internal reflection surfaces. The prisms are disposed in alignment along the optic axis of the resonator. One or both of the prisms can be rotated so that light rays enter and leave a surface of the prism nearly at Brewster's angle to the normal of the prism surface. This feature maintains alignment between the prisms and allows the resonator to be tuned. One of the total internal reflection surfaces of at least one of the prisms may be a curved surface (either a ground curved surface or a surface curved by the addition, through optically contacting or gluing, of a plano-convex lens to the surface).

Abstract: The display device includes an optical cell having a cell front with at least one cell region being capable of an optically transmissive mode and an optically nontransmissive mode with reference to the cell front. The optical cell contains an optically active material responsive to an applied electrical field such that optical properties of the material are controllably changeable. A reflector may be optically coupled to the cell. A prismatic film including a prismatic surface is optically coupled to the optical cell. The prismatic surface preferably comprises a series of prisms. The prisms have first faces and second faces intersecting the first faces. The first faces are oriented to refract light obliquely intercepting the first faces and the second faces are oriented to minimize refractive, reflective, and optical interactions of the light with the second faces.

Abstract: A stable resonator for a ring-down cavity spectroscopy cell having an optic axis. The resonator includes two Brewster's angle retroreflector prisms, each having a plurality of total internal reflection surfaces. The prisms are disposed in alignment along the optic axis of the resonator. One or both of the prisms can be rotated so that light rays enter and leave a surface of the prism nearly at Brewster's angle to the normal of the prism surface. This feature maintains alignment between the prisms and allows the resonator to be tuned. One of the total internal reflection surfaces of at least one of the prisms may be a curved surface (either a ground curved surface or a surface curved by the addition, through optically contacting or gluing, of a plano-convex lens to the surface). Alternatively, an astigmatic lens may be centered in one arm of the resonator and tilted at Brewster's angle with respect to the optic axis of the resonator. In a preferred embodiment, each of the prisms has an apex angle of about 135.

Abstract: A beam reconfiguring device comprises a single prism element that reconfigures a beam input, such as from a semiconductor laser or bar array, having aperture images with major axis aligned abreast along a single axis, into an output comprising multiple segments of the input image with a major axis of each segment aligned perpendicular along the same single axis. The etendue, the aperture-times-divergence product of a beam, in orthogonal directions of the output beam will be more nearly equal than the etendue in orthogonal directions of the input beam. The input beams and reconfigured beams are provided as adjacent inputs to a hypotenuse front edge surface of the prism element. The reconfigured beams are more conducive for converging into a single substantially symmetrical spot for input to an optical handling device or medium such as an optical fiber. An optical handling system is disclosed for achieving straight in-line, beam input/output that is more adaptable for optically aligned delivery applications.

Abstract: An inverting and reversing prism system for a stereo microscope having an optical longitudinal axis and left and right eye viewing systems having left and right longitudinal axes, respectively, along which left and right beam paths are transmitted, respectively, comprising: at least four reflecting surfaces (13, 15, 16, 13A and 13A, 15A, 16A, 13) in each beam path (14, 14A), two of the reflecting surfaces (13, 13A and 13A, 13) in each beam path comprising inlet and outlet surfaces, respectively, for deflecting the beam path by 90.degree., the inlet and outlet surfaces in each beam path being oriented 45.degree. relative to the optical longitudinal axis of the microscope and 90.degree. relative to each other, with a line of intersection (26) of planes containing the inlet and outlet surfaces in each beam path defining an angle of 45.degree.

Abstract: A stable resonator for a ring-down cavity spectroscopy cell having an optic axis. The resonator includes two Brewster's angle retroreflector prisms, each having a plurality of total internal reflection surfaces. The prisms are disposed in alignment along the optic axis of the resonator. One or both of the prisms can be rotated so that light rays enter and leave a surface of the prism nearly at Brewster's angle to the normal of the prism surface. This feature maintains alignment between the prisms and allows the resonator to be tuned. One of the total internal reflection surfaces of at least one of the prisms may be a curved surface (either a ground curved surface or a surface curved by the addition, through optically contacting or gluing, of a plano-convex lens to the surface). Alternatively, an astigmatic lens may be centered in one arm of the resonator and tilted at Brewster's angle with respect to the optic axis of the resonator. In a preferred embodiment, each of the prisms has an apex angle of about 135.

Abstract: A prism has a notch at a lower end of a third reflection plane of a pentagonal roof prism. The notch has a frosted wall, on which a transparent plate is adhered with adhesive. A miniature prism is adhered to the transparent plate with adhesive. The adhesive has photo-transmissibility, so that a transparent plane is formed between the pentagonal prism, the transparent plate and the miniature prism. Information displayed by an indication device is directed to an eyepiece optical system, via a mirror and the miniature prism.

Abstract: An injection-molded roof prism has a roof surface. A positioning portion is provided for a positioning in a direction vertical to both a ridgeline formed at the roof surface and an optical axis bent at the ridgeline. The positioning portion is formed together with the ridgeline by using the same molding plate.

Abstract: A spyhole viewer for a door or wall, includes an objective system for producing a real, inverted image. The objective system is mounted in a tubular member fixedly installable in the door or wall. An erector is provided for inverting the inverted image of the objective system and is located behind at least one of the elements of the objective system. At least one reflector is provided for angularly deflecting the light beams from the objective system, and a housing is fixedly attachable to the tubular member for accommodating at least the erector and the reflector. A viewing lens is provided for magnifying the real image as inverted by the erector means. The viewing lens is adapted to swivel in a substantially vertical plane about an imaginary horizontal axis at a radius of swivel at least approximately equal to the length of the light path from the image-side focal plane of the objective system to the first principal plane of the viewing lens.