Abstract: A semiconductor photodetection device includes a light incident facet for receiving light from an optical waveguide. Light received at the light incident facet is refracted through a photo-absorption layer to register photonic events. A material may be introduced between the optical waveguide and the light incident facet to improve responsiveness of the device. The light incident facet may be at an angle to the direction of the light emitted from the optical waveguide to cause the incident light to be refracted through several layers of the semiconductor photodetection device.

Abstract: An optical connector plug has a front housing 1, a rear housing 2, a ferrule 3, a coil spring 4 and an optical cord fixing member 5, and in addition to the ferrule 3 and the coil spring 4, the optical cord fixing member 5 for fixing a tension resistive member and a cord outer jacket is received and held within an internal through space defined when the front housing 1 and the rear housing 2 are coupled. Also, upon assembling the optical connector plug, assembling of these members 1 to 5 can be realized by movement in an axial direction as much as possible. Accordingly, assembling of the optical connector plug is facilitated and suitable for automatic assembling.

Abstract: An optical switch device includes at least an optical switch element and driving control circuit. In the optical switch element, a fixed electrode portion is arranged, via a dielectric layer, on a semiconductor substrate on which an integrated circuit is formed. A mirror structure has a plate-shaped movable portion arranged above the fixed electrode portion while opposing the fixed electrode portion. A reflecting portion is formed at least at part of the movable portion to reflect light. A support member is fixed around the fixed electrode portion on the semiconductor substrate via a dielectric layer and supports the mirror structure. The driving control circuit is incorporated in the integrated circuit to drive the optical switch element by applying a predetermined potential to the movable portion and fixed electrode portion.

Abstract: The object of the present invention is to provide a compact dispersion slope equalizer by which it is possible to simultaneously recover distorted waveforms of WDM signals by dispersion slope of DSF or NZ-DSF at 1.55 ?m band, and to compensate for the dispersion of various fiber transmission lines having various dispersion values and variation of dispersion value caused by the temperature change or the like. WDM signals distorted by the dispersion slope of the fiber are introduced into an input waveguide, and are demultiplexed by a wavelength demultiplexer into each wavelength component, and pass through lattice-form optical circuits, transversal-form optical circuits, or the combination of these circuits. The dispersion slope of the signals is compensated for by these circuits. The recovered signals are multiplexed by a wavelength multiplexer, and the multiplexed light is outputted at an output waveguide. Arrayed-waveguide gratings can be used as the wavelength demultiplexer and multiplexer.

Abstract: A wearable communication device includes a bone conduction actuator which is applicable for being in contact with a user's wrist, hand, back of the hand, finger or nail in order to transmit voice signals. The user inserts the user's finger into the user's ear canal, or touches the user's finger to a part near the user's ear, or puts the user's fingertip or nail on the user's ear canal so as to block the user's ear canal when the user uses the wearable communication device.

Abstract: Optical wavelength control method and apparatus which are capable of controlling an optical wavelength of a light source with a central wavelength which is uncertain and unstable at nanometer order is disclosed. In the optical wavelength control apparatus, the control target light entered from the variable wavelength light source is scanned at a prescribed period and optical pulses having a phase corresponding to the optical wavelength of the control target light are obtained. Then, a phase difference between a phase of the optical pulses and a phase corresponding to a reference optical wavelength is detected, and the variable wavelength light source is controlled by feeding back the phase difference to the variable wavelength light source such that the optical wavelength of the control target light is controlled by an optical frequency pulling with respect to the reference optical wavelength according to the phase difference.

Abstract: A tomographic image reading method for extracting a comparison image corresponding to a diagnostic image, the diagnostic image being one of first tomographic images, the comparison image being one of second tomographic images, the method including the steps of: inputting the first images and the second images; generating a first projection image from the first images and a second projection image from the second images; measuring shift amount between the first projection image and the second projection image by using a template; correcting the slice position according to the shift amount; and displaying the diagnostic image and the comparison image to a monitor.

Abstract: The present invention relates to a white light source. This white light source comprises a plurality of amplified spontaneous emission light generating sections each comprising at least an active fiber. At least two of the amplified spontaneous emission light generating sections are connected together in series. The plurality of amplified spontaneous emission light generating sections generate amplified spontaneous emission lights having at least partially overlapping wavelength ranges. Furthermore, a white light source of the present invention includes amplified spontaneous emission light generating sections each comprising at least an active fiber. At least one of the amplified spontaneous emission light generating sections comprises a mirror.

Abstract: In a method for performing OTDR measurement in an optical transmission system including a first terminal station and a second terminal station, OTDR signal light is transmitted from an OTDR provided in the first terminal station to the second terminal station, in which the OTDR signal light is Raman amplified by using main signal light of the optical transmission system as pump light.

Abstract: A conductive transparent probe used in a probe control apparatus for adjusting a distance between the apex of the probe and a sample by vibrating the probe with an vibrator in a direction perpendicular to the axis of the probe is provided. The conductive transparent probe includes: an optical fiber having a taper part at one end; a conductive transparent film formed on the surface of the taper part; a first metal film formed on the surface of the optical fiber other than the taper part; wherein the conductive transparent film and the first metal film are electrically connected, and length and thickness of the first metal film are determined such that the conductive transparent probe vibrates while contacting with the vibrator.

Abstract: A single core optical fiber cord having an outer diameter of 1.2 mm or less, and having a structure in which an optical fiber core wire having a resin coating provided at the center, a tensile-strength-fiber layer around the periphery of the optical fiber core wire, and a coating layer around the outer periphery of the tensile-strength-fiber layer is provided. The coating layer can be composed of a non-halogen fire-retardant resin. The optical fiber cord has excellent fire retardant, mechanical and handling properties, although the outer diameter thereof is 1.2 mm or less.

Abstract: A method and apparatus are disclosed wherein, while holding an optical fiber 1 by an optical fiber holder section 4 so as to serve a distal end 1a of the optical fiber 1 as a free end and holding the distal end 1a of the optical fiber 1 in contact with a grinding flat portion 5b to cause the distal end 1a of the optical fiber 1 to be flexed on the grinding flat portion 5b, reciprocating movement for causing the distal end 1a of the optical fiber 1 to slide on the grinding flat portion 5b in a first sliding direction and an oppositely orientated second sliding direction is relatively implemented a plural number of times between the grinding flat portion 5b and the distal end 1a of the optical fiber 1.

Abstract: A down sampler 13 down samples a digital signal in the sampling frequency thereof from 96 kHz to 48 kHz on a frame-by-frame basis. The converted signal is compression encoded and output as a main code Im. An up sampler 16 converts a partial signal corresponding to the main code Im to a signal having the original sampling frequency 96 kHz, for example. An error signal between the up sampled signal and an input digital signal is generated. An array converting and encoding unit 18 array converts bits of sample chains of the error signal, thereby outputting an error code Pe. On a decoding side, a high fidelity reproduced signal is obtained based on the main code Im and the error code Pe, or a reproduced signal is obtained based on the main code Im only.

Abstract: Novel polythiophenes which exhibit strong main chain absorption in the ultraviolet to visible region, show optical activity depending on the polymeric chain alone, and comprise as repeating units thiophene rings containing chiral substituent groups, and are represented by the following general formula: (wherein R1 and R2 are the same or different, each representing a hydrogen atom or an organic group, of which at least one is an enantiopure alkyl group with a branch structure at the ?-position, and n represents the number of repeating units selected from 10 to 100,000).

Abstract: The present invention relates to a precision phase mask for forming diffraction grating in optical fiber and optical waveguide, to provide them with nonlinear chirped grating for dispersion compensation use and having low fluctuation or crosstalk in the group delay characteristics. The diffraction grating is formed by means of interference fringe between diffracted lights of different orders, in which the cycle of the diffraction grating 20 increases nonlinearly, wherein plurality of diffraction gratings G1, G2, G3 . . . having different cycles are assembled on a plane in increasing order of the cycle with the directions of the diffraction gratings directed to the same direction, and assembled in such a manner that, where the cycle of grating changes nonlinearly and discontinuously, the regions having larger rate of change of the cycle contain proportionally more discontinuous phases per unit length.

Abstract: A method of extracting information from a structured document includes the steps of assigning a partial tree identifier inclusive of a tag identifier to a selected partial tree wherein the tag identifier includes a name of a tag corresponding to a root of the selected partial tree, a name of at least one format attribute of the tag, and a value of the at least one format attribute, arranging names of format attributes in a predetermined order in the tag identifier if the at least one format attribute of the tag includes two or more format attributes, and identifying a partial tree having a partial tree identifier identical to the partial tree identifier of the selected partial tree from a list of partial tree identifiers of partial trees that exist in the structured document after updating thereof.

Abstract: A mixer circuit used in a radio receiver for mixing two frequencies and providing an intermediate frequency which is the difference of the two frequencies. Excellent image rejection is provided by decreasing an amplitude error and a phase error of an output IF signal in differential form.

Abstract: A wavelength tunable light source includes an optical pulse generating section for generating an optical pulse; an amplitude control section for controlling the amplitude of the optical pulse generated by the optical pulse generating section by superimposing control light on the optical pulse to output a short optical pulse; and an optical frequency converting section for converting the frequency of the short optical pulse by launching the short optical pulse output from the amplitude control section into an optical nonlinear medium whose refractive index varies in response to the electric-field intensity of the incident light. The amplitude control section can be configured such that it carries out the time division multiplexing and outputs the short optical pulse, thereby constituting an optical pulse light source.

Abstract: An optical parametric circuit for separating an input signal light and a wavelength-converted light even when the wavelength difference is small is provided. The optical parametric circuit includes: a nonlinear Mach-Zehnder interferometer which includes a first optical path and a second optical path; optical dispersive mediums and second-order optical nonlinear mediums provided in the first and second optical paths; wherein optical dispersive medium and second-order optical nonlinear medium in the first optical path are placed in the reverse order of optical dispersive medium and second-order optical nonlinear medium in the second optical path.

Abstract: A system which improves wavelength tolerance, compensates dispersion in a simple way, reduces limitation of the fiber input power is disclosed. The operation includes receiving a clock signal from a system clock source; modulating a single mode optical signal based on the clock signal and generating an optical pulse signal having two longitudinal modes, the frequency interval thereof being n×B, n being a natural number and B being a transmission speed; generating a partial response signal by converting a binary NRZ signal from a digital signal source in synchronism with the system clock source; and modulating the optical pulse signal based on the partial response signal, and outputting a binary RZ modulated signal. The binary RZ modulated signal is input into a receiver, where two partial response components in the optical spectra of the input signal are divided, and one or both of the components are received.