Abstract: An inspection apparatus inspects an inspected object based on a waveform quality of a signal that the inspected object outputs. The inspection apparatus has a power supply section which outputs a control signal that controls an output of the inspected object, a waveform measuring section which measures the signal that the inspected object outputs to generate a waveform image, an analyzing section which derives a value indicating a waveform quality from the waveform image that the waveform measuring section measures, a deciding section which decides whether or not the value derived by the analyzing section satisfies a target value, and an optimizing section which changes a set value of the control signal that the power supply section outputs, based on a decision result of the deciding section.

Abstract: An optical communication apparatus includes: an erbium-doped optical fiber amplifier for amplifying a modulated optical signal, wherein a DC (direct current) light which is not modulated is inputted to the erbium-doped optical fiber amplifier together with the optical signal.

Abstract: Disclosed is a repeater including: a recognizing unit to recognize a destination address of an optical packet from the optical packet which includes the destination address assigned in unit of bit and a bit indicating whether or not a plurality of destination addresses are assigned; an optical splitting unit to split the optical packet into a plurality of optical packets; and selecting units to select transmission channels for the split optical packets on the basis of recognition results by the recognizing units, respectively.

Abstract: An optical packet network system of a ring type, capable of preventing degradation of an optical signal, can be implemented by providing a mechanism relatively simple in structure, capable of erasing light noise if the optical packet signal does not exists. In the optical packet network system made up by interconnecting respective nodes adjacent to each other, and connecting a sending source of an optical packet signal to a ring, a light noise removal function block is provided between the respective nodes adjacent to each other.

Abstract: A photoelectric apparatus has a phototransistor which receives a light signal and in which a collector current thereof varies according to intensity of the received light signal, and a transistor in which a collector current thereof varies according to a base voltage thereof. The phototransistor and the transistor constitute a differential amplification circuit. At least one of the phototransistor and the transistor outputs an electric signal.

Abstract: An optical AND element includes a semiconductor laser having a plurality of saturable absorption regions on an optical waveguide, electrodes of the saturable absorption regions being separated from each other, and a light inputting section for inputting light into the respective saturable absorption regions.

Abstract: An optical waveform shaping device includes a first waveguide portion, formed on a substrate, for transmitting the optical signal and simultaneously absorbing a portion of the optical signal, which has a signal level equal to or smaller than a predetermined value, so as to shape the optical signal; and a second waveguide portion, formed on the substrate, for transmitting the optical signal, which was transmitted through the first waveguide portion, and simultaneously amplifying the optical signal. The first waveguide portion may be formed using a saturable absorber. A first electrode for supplying electric current to the first waveguide portion so that the first waveguide portion is provided with a function of absorbing the optical signal; and a second electrode for supplying electric current to the second waveguide portion so that the second waveguide portion is provided with a function of amplifying the optical signal may also be provided.

Abstract: A matrix optical switch that can switch the transmission path of an optical signal without requiring a driving unit for each optical switch is realized. A matrix optical switch for switching a transmission path of an optical signal by connecting plural input sides and plural output sides, respectively, comprises: a semiconductor optical waveguide substrate; a photo mask choosing system for selecting and arranging one photo mask from plural photo masks each of which has printed thereon a pattern connecting plural input sides to plural output sides; and a light source for casting output light having larger energy than a band gap of the semiconductor optical waveguide substrate onto a photon injection area between the plural input sides and the plural output sides on the semiconductor optical waveguide substrate via the selected photo mask.

Abstract: An optical router capable of efficiently allocating optimum optical paths to optical signals at optimum timings is provided in accordance with the present invention. The optical router is capable of delaying a plurality of the optical signals containing routing information attached to the header parts thereof. The optical router contains an optical switch which has a plurality of input and output ports; an optical-electrical converter for converting a plurality of the optical signals to electrical signals; memory wherein path control information and delay time information are stored; and a controller for generating an electrical routing control signal which can change the optical path of the optical signals by finding the path control information according to the routing information extracted from the output of the optical-electrical converter and which can delay the electrical routing control.

Abstract: An optical switch changes over transmission paths of an optical signal by a refractive index change. The optical switch has an optical waveguide layer having an optical waveguide whose output path of an optical signal branches into two, and reflection diffusing ditches which are provided in a portion outside the optical waveguide in the optical waveguide layer, wherein the portion is closed to a branch portion of the optical waveguides. The reflection diffusing ditches extend in a direction crossing a traveling direction of the optical signal.

Abstract: In an optical packet processing apparatus, an optical coupler joins optical packets transmitted through a plurality of input side optical transmission lines and outputs the joined optical packets to an output side optical transmission line. The optical packet processing apparatus has delay sections for delaying desired optical packets for each input side optical transmission lines. Delay times of the delay sections are different by one optical packet time period, while a minimum delay time thereof is the optical packet time period or more.

Abstract: When a voltage is applied to plural spot electrodes selected from the spot electrodes arranged in the matrix form and the light incident on the two-dimensional plane waveguide is reflected by at least two parallel lines, the refractive index of the optical waveguide is partly changed so that the wavelength of the light, the angle of the two lines to the incident light and the distance between the lines satisfy the Bragg reflection condition.

Abstract: The present invention makes improvements in a mobile communication system that performs a communication via a communication network provided in a mobile body to execute a data transfer. The present system comprises a plurality of nodes, a path control device which receives data from the nodes respectively, selects a path for the data transfer on the communication network, and outputs the data, first optical fibers which connect each of the nodes and the path control device and transfer the data, and second optical fibers provided in parallel with the first optical fibers. In the present system, the path control device communicates with the node via the second optical fiber when a failure occurs in the first optical fiber.

Abstract: In a forward error correction method and a forward error correction addition apparatus, error correction is performed on the basis of data, to which forward error correction code is added, transmitted through a network to output decoded data. The data transmitted through the network includes information bits represented by an information bit matrix with n rows and m columns (n, m are natural numbers), and redundancy bits represented by an odd number of redundancy information bit rows and an odd number of redundancy information bit columns based on the information bit matrix, which are provided in the row direction and in the column direction of the information bit matrix respectively. The redundancy bits are the forward error correction code.

Abstract: An inspection apparatus inspects an inspected object based on a waveform quality of a signal that the inspected object outputs. The inspection apparatus has a power supply section which outputs a control signal that controls an output of the inspected object, a waveform measuring section which measures the signal that the inspected object outputs to generate a waveform image, an analyzing section which derives a value indicating a waveform quality from the waveform image that the waveform measuring section measures, a deciding section which decides whether or not the value derived by the analyzing section satisfies a target value, and an optimizing section which changes a set value of the control signal that the power supply section outputs, based on a decision result of the deciding section.

Abstract: A variable light signal delay apparatus includes a first delay optical fiber, a second delay optical fiber having a length different from the first delay optical fiber, and an optical switch having two input ports, two output ports, and paths, through which a light signal propagates, provided between the first delay optical fiber and the second delay optical fiber, in which a light signal input from at least one of the input ports propagated through either the first delay optical fiber or the second delay optical fiber or through neither the first delay optical fiber nor the second delay optical fiber to be output from a desired first output port.

Abstract: A photoelectric apparatus has a phototransistor which receives a light signal and in which a collector current thereof varies according to intensity of the received light signal, and a transistor in which a collector current thereof varies according to a base voltage thereof. The phototransistor and the transistor constitute a differential amplification circuit. At least one of the phototransistor and the transistor outputs an electric signal.

Abstract: An optical path control device includes a hole formed perpendicularly to the plane of a substrate, an optical waveguide formed on the substrate to cover the hole, an upper electrode formed on the optical waveguide above the hole, a lower electrode formed on a bottom part of the hole, and a voltage application unit for applying a voltage between the upper and lower electrodes. As the applied voltage is controlled to change an electrostatic attraction force between the upper and lower electrodes and the magnitude of flexure of the waveguide is thus changed, the traveling direction of light can be changed into an arbitrary direction.

Abstract: In an optical switch, a carrier-accumulating layer in which injected carriers are accumulated is provided on a semiconductor substrate having a waveguide formed thereon so that injected effective carriers tend to be accumulated in an effective part, and the burden on a driving circuit is thus reduced to realize high-speed operation. At the same time, when a clad on the carrier injection side, of clad layers formed on both sides of the waveguide, is a second clad layer, and a clad on the substrate side is a first clad layer, a third clad layer is formed on the first clad layer to reduce propagation loss in the waveguide.

Abstract: An object of this invention is to realize a pulse pattern generating apparatus that outputs a test signal of high waveform quality even when the shape of an eye pattern is changed. This invention is an improvement of a pulse pattern generating apparatus that generates a test signal of a predetermined pattern by using plural digital-analog converters and outputs the test signal to a test subject.