Abstract: Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

Abstract: In an optical waveguide grating in an optical fiber having a cladding region around a core region, a periodic refractive index distribution is existed in a predetermined area of the core region along the optical axis. The core region has a composition of GeO2—P2O5—SiO2 based glass, for example, whereas the cladding region is made of SiO2, and the co-doping ratio in the core region is adjusted, so as to lower the temperature dependence of characteristics. The doping amount of P2O5 in the core region is preferably {fraction (1/15)} to 1 times, more preferably 0.6 to 1 times that of GeO2.

Abstract: An optical system for alternative or simultaneous direction of light from two scenes to the eye of a viewer comprising (a) a first lens (42) having a first focal length; (b) a second lens (44) having a second focal length, the first and second lenses being positioned aside one another in front of one of the eyes of the viewer, such that a single light beam from any of the scenes (48, 50) passes only through one of the first and second lenses; and (c) an optical arrangement for directing incident light originating from the first scene and passing through the first lens into the eye of the viewer, and at the same time, for directing incident light originating from the second scene and passing through the second lens into the eye of the viewer, the optical arrangement being positioned between the first and second lenses and the eye of the viewer.

Abstract: The present invention is a fiber optic connection system including a fiber optic plug adapted to mate and lock with a fiber optic connector. The plug includes a housing and mated insert that cooperate to position and secure the plug pre-assemblies with respect to the plug and to structurally affix the cable strengthener to the plug.

Abstract: Embodiments of the invention include an optical communications system including a multimode optical fiber having improved overfill-launch bandwidth performance without disturbing existing laser-launch bandwidth performance. The multimode optical fiber has a characteristic differential mode delay with a first portion associated with lower order modes that behaves conventionally and a second portion associated with higher order modes that deviates from conventional behavior in a way that improves overfill-launch bandwidth performance at one operating window without adversely impacting the laser-launch bandwidth performance at the same and other operating windows. Multimode optical fibers conventionally optimized for operation at 850 nm are configured in such a way that their characteristic differential mode delay, at 1300 nm, initially increases in a conventional manner and then flattens out to approximately zero at the higher order modes.

Abstract: The invention relates to an exposure method for producing a Bragg grating on a photosensitive guide (120) or optical fiber (120), in which method the guide (the fiber) (120) is scanned by a light beam (300) and means (100, 220, 230) are provided for modulating the exposure time along the guide (the fiber) by varying the speed at which the beam (300) moves along the guide (the fiber) (120) so that it is located opposite each location of the guide (the fiber) (120) for a time period that varies with the location, the method including the step of disposing in front of the guide (the fiber) (110) a system (140) adapted to create interference fringes on the guide (the fiber) (120) and to scan the beam (300) over the interference system (140) at a speed that is modulated along the system (140), and furthermore the step of having the beam scan the guide (the fiber) (120) at a modulated speed without the interference system (140) on the path of the beam (300), the scanning with the interference system (140) being eff

Abstract: Disclosed is a system and method for converting modes in an optical network. Briefly described, the system comprises an optical pathway extending from an exit face of a single-mode waveguide to an entrance face of a multimode waveguide. A first ball lens and second ball lens are located in the optical pathway, with an optical link gap located the first and second ball lenses.

Abstract: An arrangement and corresponding method are provided for coupling radiation, preferably laser radiation, into a scanning head with a scanning unit in at least two dimensions. The radiation is focussed on an object via a microscope objective via at least one light-conducting fiber which is coupled with the scanning head. A collimato is arranged downstream of the fiber end at the scanning head for collimatiing the radiation exiting in a divergent manner at the fiber end.

Abstract: A collimating screen simulator comprising a projector and a holographic diffuser screen. The projector is adapted to project a viewable image onto a focal plane that is spaced from the projector. The focal plane has a backside and a viewing side opposite the focal plane backside. In operation, the projector is able to project the image onto the focal plane backside. The holographic diffuser screen is adapted to permit light from a source and incident upon a surface of the diffuser screen to pass through the screen. The holographic diffuser screen has a first surface facing the focal plane viewing side for receiving the incident light. The holographic diffuser screen also has a second surface opposite the first surface. The holographic diffuser screen is spaced from the focal plane viewing side by a distance effective for enabling a viewer facing the second surface of the holographic diffuser screen to see collimated light exiting the holographic screen.

Abstract: A surface-relief transmission diffraction grating which, after having been subjected to a test condition of 85 degrees centigrade and a relative humidity of 85 percent for at least 500 hours, has diffraction efficiency performance within 6 percent of that achieved before being subjected to these test conditions.

Abstract: A multibeam optical system that employs a multiline laser source emitting a laser beam at predetermined wavelengths, such as, for example, at wavelengths 488.0 nm and 514.5 nm, and a diffractive beam-dividing element having diffractive grating to divide the incident beam into nine diffracted beams. A design wavelength &lgr;M of the diffraction grating, at which the light quantity of the incident beam is equally distributed among the plurality of diffracted beams, is determined so as to satisfy the condition 488.0 nm<&lgr;M<514.5 nm. When the design wavelength &lgr;M is 501.1 nm, the light quantities of the divided beams, which are the sums of the quantities of the peak wavelengths 488. 0 nm and 514.5 nm, become nearly equal to one another among the nine diffraction orders. As a result, the distribution of the light quantities among the diffracted beams are balanced.

Abstract: An achromatic beam shaping prism is disclosed which compensates for a fluctuation in oscillating wavelength of a semiconductor laser source of a recording type optical disc system using a single prism having a diffraction grating with a specified pitch so as to make the beam shaping prism achromatic. Two equations are given for specifying the pitch d or d′ of the diffraction grating, depending on whether the diffraction grating is applied to the output surface or the input surface of the prism, respectively.

Abstract: An optical waveguide device comprising a free space region, suitably provided by a slab waveguide, having optical signal ports for coupling to input and output waveguide sections and an optical waveguide grating including an array of grating waveguides coupling the free space region to a reflector surface to provide a folded structure. Dielectric waveguide structures are preferred. The grating includes tapered optical waveguide sections laterally spaced and optically isolated from each other which extend from the free space region, with the grating waveguides continuing as extensions of the tapered waveguide sections. Each of the grating waveguides differs in length from a neighboring grating waveguide by a constant increment, preferably an optical path length increment.

Abstract: Device, method, and system for recording diffractive high resolution text, pictorial, and/or other graphical information is provided which is particularly suited to recording information that would be difficult to reproduce by typical counterfeiting methods. The information recorded may be used to authenticate the recorded item, or indirectly, an item to which the recording is attached. Such items may include legal, financial and commercial instruments, credit cards, and packaging for such items as software, art, and other items where forgery of the item may be a concern. In one embodiment of the invention light is selectively passed by a shutter, and a spatial filter then cleans the beam to remove undesirable frequency components.

Abstract: An infra-red imaging system has two variable focal length optical components (6, 7) whose positions are fixed relative to one another. The system also comprises an image detector (8). Control means (13) is provided such that the focal length of one of the variable focal length optical components (7) can be varied in relation to the focal length of the other variable focal length optical component (6). The system can be used to produce an image of variable magnification while maintaining an in-focus image at the detector (8). The control means (13) may comprise a mechanical linkage, an electronic circuit, or a computer program. In an alternative embodiment the optical system is a beam expander. Controlling a focusing mirror can achieve a dither effect. Controlling a focusing mirror can also de-focus the image, giving a mean scene temperature evaluation.

Abstract: A device is presented that is adapted to have an optical wave travel through it and to filter that wave in terms of wavelength, in which an optical parameter of the device varies along the path of the wave in such a manner that the device has a series of sections each constituted by a pair of two successive segments, one in which the values of the optical parameter are less than an average value and the other in which the values of the optical parameter are greater than the average value. The device has at least one zone of more than two sections. The two sections have lengths alternately less than and greater than an average length of the sections in that zone.

Abstract: A material for a bismuth substituted garnet thick film comprising Gd, Yb, Bi, Fe and Al as the main ingredient grown by a liquid phase growing method on a garnet substrate in which the composition of the garnet thickness is represented by the general formula: Gd3-x-yYbxBiyFe5-zAl2O12 (0<x≦0.5, 0.85≦y≦1.55 and 0.15≦z≦0.65), and each of boron oxide (B2O3) and lead oxide (PbO) is contained by from 0 to 4.0 wt % (not including 0) in the garnet thick film.

Abstract: An improved highly doped waveguide is provided which comprises a waveguide employing an Er dopant and Pr sensitizer ions. The present invention also provides a method of efficient coupling from an optical source into a waveguide using a rotated optical element.

Abstract: An N×N crossconnect switch, for large N, is implemented using an arrangement of smaller wavelength routers combined with space switches. An N×N crossconnect switch is constructed in three stages, using a plurality of input space switches, a plurality of (N/m)×(N/m) router (whose reduced size N/m allows efficient realization in integrated form), and a plurality of output space switches. In the router, the number of wavelengths is reduced by a factor m. The input and output space switches can be implemented using crossbar or Clos type construction. In one arrangement each modulator is combined with a small space switch consisting of 2×2 elements. Each space switch can be realized with negligible crosstalk by using a dilated arrangement.

Abstract: A high reflection mirror has a layer structure comprising on a substrate, a TiOx layer, an Ag layer, an Al2O3 layer and a TiO2 layer in this order, or alternatively on a substrate, an SiOx layer, a Cr layer, an Ag layer, an Al2O3 layer and a TiO2 layer in this order (1≦x≦2). An SiOy protective layer may be formed on the top TiO2 layer (1≦y≦2). The high reflection mirror shows a high reflectance and a high durability and can be produced at a lower cost because of the reduced number of layers.