Abstract: A method of fabricating an optical waveguide grating having a plurality of grating lines of refractive index variation comprises the steps of: (i) repeatedly exposing a spatially periodic writing pattern onto a photosensitive optical waveguide: and (ii) moving the writing light pattern and/or the waveguide between successive exposures of the writing light pattern, so that each of at least a majority of the grating lines is generated by at least two exposures to different respective regions of the writing light pattern.

Abstract: The electromagnetic wave focusing device has a mirror group consisting of a focal-line type primary reflective mirror and secondary reflective mirror which have a unique parabolic cross-sectional shape. Incident light rays are primarily reflected by the primary reflective mirror and are then secondarily reflected by the secondary reflective mirror, so that solar rays are focused at one point. The electromagnetic wave focusing device can be made extremely thin and light-weight, and can be folded without causing great loss of precision or great increase in mass. Consequently, the mirror bodies can be folded into a compact form and loaded inside the restricted space of a rocket or the like; thus, the device can be transported into aerospace, and a sunlight focusing device having high focusing performance can be reproduced on-site with a high precision.

Abstract: New material useful in miniature, low-cost Faraday rotators, polarizers (analyzers) and magnetic substances; in Faraday rotators and optical isolators that can handle a plurality of wavelengths; and in miniaturizing, and reducing the cost and enhancing the performance of, optical isolators and various optical devices. Optical isolator (60b) as one example is configured by rectilinearly arranging a wavelength-selective Faraday rotator (30), a polarizer (20) and an analyzers (40) formed from a DLC thin film, and a magnetic substance (50) that is transparent to light. Integrally forming these using thin-film lamination technology simplifies the fabrication procedure to enable manufacturing miniature, low-cost optical isolators.

Abstract: A low dispersion comb filter or interleaver assembly has a first interleaver element and a second interleaver element. The first interleaver element is configured so as to provide a dispersion vs. wavelength curve wherein each dispersion value thereof is approximately opposite in value to a dispersion value at the same wavelength for the second interleaver element, so as to mitigate net or total dispersion in the interleaver assembly.

Abstract: A mirror device for a cap for allowing the user to see behind oneself and to either side which is especially useful when the user is riding a bicycle. The mirror device for a cap includes a first panel member having a back side and a front side and being adapted to be securely and pivotally disposed on an underside of a bill of a cap; and also includes a support assembly for supporting the first panel member upon the underside of the bill of the cap; and further includes a second panel member being hingedly attached to the first panel member and having a front side and a back side; and also includes a mirror being attached to the second panel member; and further includes an assembly for hingedly attaching the first and second panel members together. The support assembly allows the user to swivel the mirror left and right which allows the user to view behind oneself and to either side of oneself.

Abstract: A unique reflective surface is employed to compensate polarization dependence of optical taps. Specifically, the reflective surface compensates optical tap induced polarization by employing the intrinsic properties of metals rather than complex thin film stacks. To this end, a reflective thin metal film or a polished reflective metal surface may be employed. In a particular embodiment of the invention, a reflective surface that is coated with a single dielectric thin film can also be employed. In one example, the metal is preferably tungsten because it exhibits a large difference in the spread of reflectance between the s and p polarization states.

Abstract: Various methods, apparatuses, and systems in which a chromatic dispersion compensation module includes a beam spatial orientation device to separate an optical signal into a first polarized light signal and a second polarized light signal. The second polarized light signal has the posited polarization of the first polarized signal. A wavelength-dependant delay path couples to the beam spatial orientation device. A polarization rotator couples to the wavelength-dependant delay path such that the first polarized light signal reflects into the wavelength-dependant delay path in substantially the opposite direction of the second polarized light signal.

Abstract: A polarized lens formed by an injection/coining injection molding process is disclosed. The polarized lens includes a polarizing insert formed from a polarizer sandwiched between two layers of cellulosic material. The polarizing insert is surrounded by high-impact polymer formed by a two-step injection/coining process of injection molding that results in minimal stress in the lens.

Abstract: A recirculating light polarizer utilizes a reflective polarizer on the exit face of a light integrator, such as a light pipe or light tunnel. Light is provided to the light integrator and light of one polarization is transmitted through the polarizer, the remaining light being reflected back into the integrator. The back-reflected light accumulates polarization shift before it eventually is reflected back to the polarizer. The reflected light is further homogenized on its trip back to the polarizer. This process is typically repeated several times to enhance the light output from the light pipe assembly, with some light being lost in each cycle due to various loss mechanisms. A polarization state modifier, such as a retarder plate or phase-shifting coatings, may be included in the recirculating light path to enhance polarization shift.

Abstract: Various embodiments of reinforced mirror microstructures for a surface micromachined optical system are disclosed. Multi-layered and structurally reinforced mirror microstructures are disclosed, including both two and three-layer microstructures. Adjacent structural layers in these multi-layered mirror microstructures may be structurally reinforced and interconnected by a plurality of vertically disposed columns, or by a plurality of at least generally laterally extending rails or ribs, or some combination thereof. Various embodiments of a single layered mirror microstructure with a structural reinforcement assembly that cantilevers from a lower surface thereof is also disclosed.

Abstract: An optical system includes a diffractive optical element having a diffraction grating provided, on a lens surface having a curvature, in a concentric-circles shape rotationally-symmetrical with respect to an optical axis. The sign of the curvature of the lens surface having the diffraction grating provided thereon is the same as the sign of a focal length, at a design wavelength, of a system composed of, in the optical system, a surface disposed nearest to an object side to a surface disposed immediately before the lens surface having the diffraction grating provided thereon, and is different from the sign of the distance from the optical axis to a position where the center ray of an off-axial light flux enters the lens surface having the diffraction grating provided thereon. Further, the apex of an imaginary cone formed by extending a non-effective surface of the diffraction grating is located adjacent to the center of curvature of the lens surface having the diffraction grating provided thereon.

Abstract: An optical device for making light converge produces a convergent light beam with a satisfactorily great numerical aperture and acceptably small aberrations. The optical device has a plurality of diffraction gratings that each make light converge. The light shone into the optical device is passed through one after another of those diffraction gratings in such a way that the light is made to converge to a higher degree every time it passes through one of the diffraction gratings. The diffraction gratings may be all transmissive, all reflective, or a combination of both. The diffraction gratings are formed on a surface of or at an interface inside the optical device, and two diffraction gratings may be formed on a single surface. The light is made to eventually converge on the exit surface of the optical device so that the optical device functions as a solid immersion device.

Abstract: An optical system having a pair of ellipsoidal shaped reflective surfaces or mirrors which receive light from an object and provide wide field view imaging for the object. The optical system directs the light onto a flat detector to a record a wide field of view image of the object on the flat detector.

Abstract: Optical isolators and methods of manufacturing optical isolators are disclosed. The optical isolators are manufactured by directly bonding the parts of the isolators without the use of adhesive or mechanical devices to hold the individual parts together.

Abstract: A multilevel optical phase element is illuminated with a light source having a plurality of wavelengths of interest. The multilevel phase element disperses light from the light source by diffraction and focuses the dispersed light onto an imaging plane. A light modulating display in the imaging plane having a plurality of pixel elements is actuated. Each pixel element is assigned to transmit a predetermined spectral region within the near field region of the multilevel display element so as to receive the dispersed and focused light from the multilevel optical phase element. A system for displaying a color image includes a light source emitting a plurality of wavelengths of interest, a multilevel optical phase element, and a light modulating electronic display.

Abstract: In a polarization beam splitter that allows effective polarization separation in a wide wavelength range with low dependency on angle of incidence, between two prisms is sandwiched a dielectric multilayer film composed of a first and a second multilayer portion that are designed with respect to a first and a second wavelength &lgr;1, and &lgr;2, respectively. Moreover, the formula &lgr;1<&lgr;2≦155·&lgr;1 is fulfilled, and which is greater of the difference between the refractive indices of the high-refractive-index and low-refractive-index layers in the first multilayer portion and the same difference in the second multilayer portion coincides with which is greater differences of the angles &thgr;1 and &thgr;2 from the prism vertex angle &thgr;.

Abstract: Fiber optical interleavers based on a retro-reflective structure are disclosed. The retro-reflective structure includes three stages of optical components. A first stage includes walk-off crystals, at least one of the crystals is used to displace a received optical signal with multiplexed bands or channels therein into a first ray (e.g. an O-ray) and a second ray (e.g. an E-ray). A second stage following the first stage includes at least a pair of birefringent crystals to form an interferometer that create path or phase differences introduced by the birefringent index differences between the first ray and the second ray. A third stage following the second stage includes a pair of half wave plates, a walk-off crystal and a quarter wave plate, wherein the quarter wave plate has a highly reflective coating on one end to retro-reflect light beams back through the same stages. Respective reflected and processed first ray and second ray are then combined in the first stage to output respective demultiplexed beams.

Abstract: In a reflector comprising a reflecting film formed on a surface having depressions and protrusions, wherein each of the depressions and protrusions has a vertex and is composed of a curved surface formed so as to be convex up or convex down and a surrounding portion including a valley or a ridge surrounding the curved surface with an inflection point of the curved surface serving as a boundary between the curved surface and the surrounding portion; and wherein when the curved surface is convex up, the inflection point is on the valley side of the midpoint between the vertex and the valley, whereas when the curved surface is convex down, the inflection point is on the ridge side of the midpoint between the vertex and the ridge.

Abstract: A polarization insensitive tunable optical filter system combines an interference filter or the like with a quarter wave plate and a retro-reflector. The retro-reflector is situated and aligned to intercept light reflected from the filter, and the quarter wave plate is disposed between the filter and the retro-reflector. Hence, the pass signal reflected off the filter a first time passes through the quarter wave plate a first time, reflects off of the retro-reflector, passes through the quarter wave plate a second time, and reflects off of the filter a second time.

Abstract: Various embodiments of reinforced mirror microstructures for a surface micromachined optical system are disclosed. Multi-layered and structurally reinforced mirror microstructures are disclosed, including both two and three-layer microstructures. Adjacent structural layers in these multi-layered mirror microstructures may be structurally reinforced and interconnected by a plurality of vertically disposed columns, or by a plurality of at least generally laterally extending rails or ribs, or some combination thereof. Various embodiments of a single layered mirror microstructure with a structural reinforcement assembly that cantilevers from a lower surface thereof is also disclosed.