Abstract: An optical communication network node apparatus including input terminals 111 to 11n, 1:2 optical branch units 121 to 12n, a pass-through optical switching network d101, 2:1 optical connectors 151 to 15n, output terminals 171 to 17n, a drop optical switching network 102, output interfaces 13-1 to 13-mn, input interfaces 14-1 to 14-mn and an insert optical switching network. Accordingly, in the optical communication network node apparatus, various types of optical switching networks are separated from one another and each optical switching network supports only a necessary switching state, so that the number of optical switch elements can be reduced.

Abstract: Described herein is an optical multilayered-film filter which provides less interference and a good optical characteristic and is high in productivity. The optical multilayered-film filter wherein dielectric thin films are stacked on each other in a multilayer form in a single direction, comprises a refractive-index inclined laminated portion in which refractive indices of dielectric thin-film layers are successively inclined and changed in a laminating direction, and an alternately-laminated portion in which a dielectric thin-film layer having a high refractive index and a dielectric thin-film layer having a low refractive index are alternately laminated on each other.

Abstract: A reflection control member includes a multilayer stack that is adhered to a substrate using a primer layer to promote adhesion. The multilayer stack includes pairs of layers in which the first layer is a grey metal and the second layer is a substantially transparent material. In the preferred embodiment, the grey metal is nickel chromium and the transparent layer is a silicon oxide. For each pair of layers, the grey metal is nearer to the surface of the substrate for which antireflection is a concern. The primer layer has a thickness of less than 50 angstroms. Although the primer layer is deposited in an essentially oxygen-free environment, it may oxidize following deposition.

Abstract: Zinc sulfide and an optical component are provided that significantly reduces transmission for visible light and infrared rays of not more than 3 .mu.m in wavelength, having high transmittance for infrared rays in the wavelength range of 8-12 .mu.m, and that shields visible light. The optical component is constituted by a polycrystalline zinc sulfide sintered compact formed by hot compression molding fine zinc sulfide powder of high impurity at the temperature of 900-1000.degree. C. and the pressure of 150-800 kg/cm.sup.2. The light transmittance at the region where the thickness is 2 mm is 0% to 3% at the wavelength range of visible light, 0% to 20% at the wavelength range of 2.5-3 .mu.m, 30% to 75% at the wavelength range of 8-12 .mu.m, and 50% to 90% at the same wavelength range with the formation of antireflection coating film.

Abstract: A secondary focuser which facilitates minute and measured incremental changes of the focal length within a limited travel distance is disclosed. The secondary focuser is used to micro focus telescopes for astro photography. A method of constructing the micro focuser comprises the following steps: constructing a housing having an open central axis therethrough; slidably disposing a travelling inner sleeve within the housing; and, mounting and arranging a micrometer head on the housing. When the micrometer head is turned the inner sleeve travels within the housing finely adjusting an axial length therethrough. In a preferred aspect of the invention the micrometer head is configured to turn about an axis generally perpendicular to the central axis through the housing, pivoting a rocker arm so that when one end portion of the rocker arm is moved in a radial direction, the other end moves in a direction generally parallel to the central axis, thereby longitudinally shifting the travelling sleeve.

Abstract: A semiconductor TE/TM mode converter comprises a semiconductor waveguide layer including a compressive-strained first region and a tensile-strained second region, and a diffraction grating formed on the first region. The first region and second region are reversed-biased and forward-biased, respectively. TE mode light incident on the facet of the first region generates TM mode light outgoing from the facet of the second region. The diffraction grating in the first region has selective reflectance against TM mode light and reflects the TM mode light toward the second region, to lower the lasing threshold of TM mode light and raise the conversion efficiency.

Abstract: In an optical member having a coating for reducing a ray reflecting on the coating and for reducing an electromagnetic wave incident on the coating, the optical member includes: a transparent substrate; and the coating including, and formed on the transparent substrate in the order named from the transparent substrate, a first light transmitting thin layer having a high refractive index, a first light transmitting thin layer having a low refractive index, a second light transmitting thin layer having a high refractive index, a second light transmitting thin layer having a low refractive index. At least one of the first light transmitting thin layer having the high refractive index and the second light transmitting thin layer having the high refractive index is a transparent conductive layer having a sheet resistivity of 100 .OMEGA./.quadrature. or less.

Abstract: A high-frequency circuit exhibiting favourable characteristics even in frequency domains in excess of 40 GHz is obtained by configuring a matching circuit 40 with open stubs 16 joined to a microstrip line 14.

Abstract: The invention relates to a method for replicating a volume hologram having an image of a scattering object recorded therein according to a hologram replicating technique, wherein the diffraction 13 of unnecessary light due to zero-order light, etc. arising from regular reflection and a visual range capable of viewing a recorded image is limited to a desired range .alpha., so that the image can be displayed more brightly than would be possible with the original hologram plate, and a volume hologram as well. When replicating a volume hologram 4' having an image O' of a scattering body recorded therein, replicating illumination light is incident on the volume hologram 4' at an angle of incidence I.sub.1 at which a group of fringes can be replicated and recorded, said group of fringes being such that, in the vicinity of an apex defined by a supposed slant angle S.sub.g at which a replicated hologram 4' can be viewed at a supposed viewing center angle .phi. within a range .alpha.

Abstract: A gain measuring apparatus of a multi-channel optical fiber amplifier for amplifying an input multi-channel optical signal of a predetermined wavelength range includes a plurality of optical signal sources for generating an optical signal, the number of optical signal sources being less than the number of channels of the multi-channel optical signal, in a wavelength range of the multi-channel optical signal, a probe optical signal source for generating a probe signal of a wavelength of which gain is subject to measurement, an optical multiplexer for multiplexing optical signals output from the optical signal sources and the probe optical signal source, an optical amplification portion for splitting the optical signals multiplexed by the optical multiplexer in an equal ratio and passing one optical signal of the split optical signal with amplification and the other optical signal of the split optical signal without amplification, and a measuring system for respectively measuring intensities of the amplified pr

Abstract: A metal-coated multilayer mirror having high reflectivity and high specularity. The mirror comprises a multilayered polymer film and a reflective metal layer. The multilayered polymer film preferably comprises layers of a crystalline, semi-crystalline, or liquid crystalline material, such as a naphthalene dicarboxylic acid polyester, having an average thickness of not more than 0.5 microns and layers of a second polymer having an average thickness of not more than 0.5 microns. Preferably, the layers of semi-crystalline naphthalene dicarboxylic acid polyester have a positive stress optical coefficient. The reflective metal layer comprises a metal selected from the group consisting of silver, gold, aluminum, nickel, copper, and titanium, with silver and aluminum being particularly preferred. The metal-coated multilayer mirrors are useful in applications requiring broad bandwidth reflection, high specularity, low manufacturing costs, and high reflectivity.

Abstract: A diffractive device has a surface relief structure which when illuminated by a light source, generates one or more diffraction effects which are observable from a range of viewing angles around the device. At least part of the surface relief structure is arranged in a series of tracks, each track being less than 0.25 mm in width. The device, which may be embossed onto a metallised foil, is suitable for use as an anti-forgery authentication element on valuable documents.

Abstract: The present invention relates to multilayered filter films, and in particular, a multilayered filter film not having a substrate and a method for making the same. The method for making the multilayered filter film not having a substrate includes a step for forming a filter frame layer having a window on the substrate, a step for forming a multilayered film on the substrate inside the window and on the filter frame layer, and a step for removing the substrate from the filter frame layer and the multilayered film.

Abstract: The invention is directed to a double refracting planar plate arrangement and a .lambda./4 plate suitable for deep ultraviolet light. The .lambda./4 plate or the like is configured as a planar plate with stress-induced birefringence. The planar plate 1 is made of high quality quartz glass and is torsion-free and uniformly loaded in tension via suitable construction having several parallel tension devices (3, 7).

Abstract: An illuminated roof ornament attachment for attaching to the roof of a vehicle in a funeral procession. The attachment includes a base designed for attachment to an exterior surface of a vehicle and an ornament upwardly extended from the base. The ornament comprises a translucent material for permitting passage of light therethrough. A light source is provided in the ornament for illuminating the ornament.

Abstract: A method for determining a position of a microscope (1) in space is disclosed. In image detecting unit (3) is fixed to the microscope. In an operating state, the image detecting unit detects a field of view of the microscope from an angle to an optical axis (2) and is connected to a computer which is equipped with an image recognition program and with comparison data for determination of the position of the microscope with respect to the field of view.

Abstract: A surgical microscope includes an illumination optical system for illuminating a microscope visual field, an observation optical system which has an eyepiece lens and an imaging lens and allows observation of a first image of an observation target by guiding reflected light from the observation target irradiated with illumination light to the eyepiece lens from the illumination optical system, an image projection optical system for projecting a second image as image information within a portion of the microscope visual field, and visual field adjusting mechanism which has a field stop placed at an imaging position of the imaging lens and having a changeable stop shape and adjusts an area of the microscope visual field by changing the stop shape of the field stop in accordance with a projection state of the second image with respect to the microscope visual field.

Abstract: A display device includes an image bearing device for generating one or more viewable images, optical elements for generating one or more viewing zones for viewing the viewable images, and an optical element with positive optical power. The elements are arranged and constructed such that the optical element with positive optical power forms a real image of the or each viewing zone and a virtual image of the or each viewable image, whereby the or each virtual image is visible to a viewer only when a light ray can be traced from the viewer's eye through the real image of an associated viewing zone, the optical element and the viewable image. The display may be an autostereoscopic display.

Abstract: A stereomicroscope has a left and a right stereo radiation path and an adjusting device for selecting a stereo base. A main lens is arranged between an object to be observed and the adjusting device, which may be designed as an opto-mechanical switching device. The arrangement allows an integrated structure with low light losses.

Abstract: An aquarium light fixture includes a plural number of brackets for supporting an aquarium light assembly on an aquarium. Each bracket includes a base, a pair of arms in U-shaped and a slide block at the top of each arm. The slide block is slidably engageable with a longitudinal groove formed in each of two lateral side walls of the light assembly. The base further has a plural number of spaced wedge feet extending downward for clamping a top portion of the aquarium slidewall. Therefore two brackets mounting on two opposite sidewalls may support the aquarium light assembly like a bridge manner. The bracket may be adapted easily and flexibly to different size of aquariums.