Abstract: The invention relates to a dispersion shifted monomode optical fiber which, in the wavelength range 1400 nm to 1650 nm, presents both a chromatic dispersion maximum and a chromatic dispersion slope of absolute value less than 0.05 ps/nm2·km. Advantageously, the maximum in the wavelength wave 1400 nm to 1650 nm is a single maximum. The fiber also presents dispersion having a slope of absolute value less than 0.03 ps/nm2·km in the wavelength range 1530 nm to 1580 nm. The fiber of the invention is particularly suitable for wavelength division multiplexed transmission systems.

Abstract: A laminated film including two polyester films each having a thermal shrinkage. A metal layer is deposited on one surface of at least one of the polyester films which are secured together using a laminating adhesive to form a laminated reflector film. In one embodiment in which the laminated film is used to manufacture a thin film mirror using a wrap around technique, the thickness of each of the polyester films is less than or equal to approximately 0.001 inch and a total combined thickness of less than or equal to approximately 0.002 inch (50 microns) thick. Preferably, each polyester film has a thickness of approximately 0.0005 inch and a total thickness of approximately 0.001 inch. Alternatively, the laminated film may be used to manufacture a thin film mirror using a face bond technique, wherein the total combined thickness of the two polyester films is less than or equal to approximately 0.004 inch, preferably the total thickness is less than or equal to approximately 0.003 inch.

Abstract: A compact inline fiber optic polarization splitter/combiner for use in fiber optic communications. The splitter/combiner uses two birefringent wedges aligned with their optical axis at 90° from each other and their bases disposed oppositely to each other. One lens is used at the input to couple light from the input fiber. A single output lens is used to couple light into two adjacent polarization maintaining fibers. When used as a combiner a beam of a first linear polarization state from one input fiber is combined with a beam of second linear polarization state from a second input fiber into a third output fiber carrying both beams. The splitter/combiner also provides for the ready alignment of the input and output beams further saving cost and complexity.

Abstract: A thin film electrical optical filter includes a thin film electrooptical dielectric having a voltage controlled electrooptical refractive index that is disposed between opposing stacks of alternative layers having differing refractive indices for transmitting received incident light through a target passband. An applied voltage to the electrooptical dielectric can serve to alter the actual passband to the target passband for compensating for thin film manufacturing tolerances for producing controllable optical filters with precise passbands.

Abstract: An optical fiber is composed of silica glass and comprises a center core region doped with F element, a ring core region doped with GeO2, and an inner cladding region doped with F element; wherein a buffer layer composed of undoped SiO2 or SiO2 doped with one or both of P and Cl or a concentration gradient region in which GeO2 concentration radially decreases toward the boundary is provided between the center core region and the ring core region.

Abstract: A ferrule is positioned on a ceramic package by a ferrule support member and is fixed between the ferrule support member and the ceramic package by an adhesive. On the side in the vicinity of one end of the ferrule, a groove is formed around the ferrule as an adherence enhancement.

Abstract: A reflection type optical device comprises a transparent base member having an incident light receiving surface, at least a reflection surface for internally reflecting the incident light and a light emitting surface for emitting the reflected light. A dielectric layer is formed on each of the incident light receiving surface and the light emitting surface, and a metal layer is formed on all the remaining surfaces of the transparent base member other than the incident light receiving surface and the light emitting surface.

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: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.

Abstract: A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles &thgr;b spaced along the substrate surface, with the blaze angles substantially differ from the Littrow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface. The grating may be used in interference orders greater than first order and may diffract signals with low polarization-dependent losses in addition to high polarization-averaged efficiency.

Abstract: A description is provided of an optical information recording and reproducing apparatus. The apparatus comprises: a holographic memory made of a photorefractive crystalline material; a support portion for detachably supporting the memory; a reference beam supplying portion for supplying a coherent reference beam of a first wavelength incident on the memory; a signal beam generating portion for supplying a coherent signal beam of the first wavelength, which is modulated in accordance with image data, incident on the memory, intersecting therein the signal beam with the reference beam, and generating a three-dimensional interference pattern of the beams; a detecting portion for detecting a diffracted light from a refractive index grating of the interference pattern in the memory, due to irradiation of the reference beam; and a medium position adjusting portion for moving a position of the support portion in accordance with a signal corresponding to positioning images from the detection portion.

Abstract: A grating device with a substantially polarization-independent diffraction efficiency is disclosed. The grating device is preferably a surface grating that can be produced by ruling or holographically, and includes at least two different grating elements with the same grating period, but different modulation depths or blaze angles. The blaze angles and the illuminated areas of the respective grating elements can be selected to produce a substantially polarization-independent and optionally also wavelength-independent response of the grating device.

Abstract: There is provided a hologram with excellent heat resistance. The hologram comprises a hologram film (10) in which a diffraction grating has been recorder, a substrated (11) situated on one side of the hologram film (10) via a bonding material (13), and a polymer film (12) situated on the other side of the hologram film (10) via a bonding material (13), wherein the thickness of the polymer film (12) is no greater than 100 &mgr;m. Otherwise, the polymer film (12) is subjected to prior heat treatment. There is further provided a production process for holograms with minimal appearance defects.

Abstract: Disclosed is a multi-beam optical system that includes a laser source, a diffractive beam dividing element that divides the light beam emitted from the laser source into a plurality of light beams, a propagation optical system through which the divided light beams propagate, a polygon mirror and a scan lens. The propagation optical system includes a curved surface mirror that is arranged such that center axes of the reflected light beams are spatially separated from center axes of the incident light beams at a predetermined separation angle. The diffractive beam-dividing element Is arranged such that the center axis of the incident light beam is inclined with respect to the normal to a diffraction grating surface thereof so as to compensate bending of a beam spot line, along which the beam spots align, depending on the separation angle of the curved surface mirror.

Abstract: There is disclosed an optical isolator, wherein one surface of an optical element comprising at least one polarizer and at least one Faraday rotator is bonded and fixed to a substrate in which a height of an optical element bonded portion surface has a level difference from a height of a peripheral portion surface, and the optical isolator, wherein a rectangular parallelepiped optical element comprising at least one polarizer and at least one Faraday rotator, which are bonded in the face of each light-transmitting surface, is bonded and fixed with a bonding agent to the substrate while the Faraday rotator in the optical element is not bonded to the substrate. There is provided a reliable and low cost optical isolator that can bond and integrate an optical isolator element and permanent magnets on a substrate, can realize positional adjustment in assembly with high precision and high bonding strength, and can avoid bonding distortion for an optical element.

Abstract: A light emitted from the supervisory light source is supplied to the input port of any one of a plurality of switching sections provided in the optical switching device. A light emitted from the output port of the switching section is converted into electric signals and then compared with the threshold value by a supervisory receiver. The supervisory control circuit discriminates the state of connection at each switching section in the optical switching device according to the compared result obtained by the supervisory receiver, whereby each switching section in the optical switching device is supervised.

Abstract: A multi-wavelength etalon comprises at least two regions with different indices of refraction. The change in refractive index alters the wavelengths of incident light, and thus the number of wavelengths between the reflective surfaces of the etalon, and therefore the etalon's transmission characteristics. By selecting specific indices of refraction, an etalon can be provided which produces peaks and troughs at preselected wavelengths in each region. The transition between two adjacent regions with different indices of refraction can be graded to reduce optical interference which may result from an abrupt transition.

Abstract: An apparatus for switching one of a plurality of optical signals from a plurality of optical fibers. The apparatus has an input fiber bundle housing comprising an outer side and an inner side. The input fiber bundle housing has a plurality of sites oriented in a spatial manner on the outer side for coupling to a plurality of input optical fibers. Each of the input optical fibers is capable of transmitting an optical signal. The apparatus also has a first mirror array disposed facing the inner side of the input fiber bundle housing. The first mirror array includes a plurality of mirrors. Each of the mirrors corresponds to one of the sites on the outer side of the input fiber bundle housing. A second mirror array is disposed facing the first mirror array. The second mirror array is also disposed around a periphery of the input fiber bundle.

Abstract: A receptacle with high productivity is provided, wherein rear openings 4 of a connector housing 2 of the receptacle 1 continue to respective terminal led-out portions 22 so that terminals 34 and 35 of a light receiving element module 6 and a luminescence element module 7, respectively, are easily fitted to the connector housing 2 and projecting portions 38, which project into the respective terminal led-out portions 22 near to the respective terminals 34 and 35, are formed on a cap member 8.

Abstract: An optical connector 21 has sleeves 25 and 25 placed between an optical fiber 40 and reception and transmission modules 26 and 27, wherein the N.A. of each sleeve 25 is larger than the N.A. of the optical fiber 40. A holder 36 forming a part of the sleeve 25 is made of a synthetic resin and can be colored. Further, the sleeve 25 is formed by cutting an optical fiber source line 52, etc.