Abstract: The present invention is applicable to a burst transmission system such as an ATM-PON optical subscriber system. An optical receiver for extending tolerable variation of input signal is disclosed. The optical receiver includes; an optical signal receiver for receiving an optical signal in burst transmission to regenerate and reshape waveform of the received optical signal; and a bit synchronizer for detecting the rise and fall change points of the signal being output from the optical signal receiver using an externally-input clock, for determining a discrimination phase according to the detected change points; and for discriminating to output the received optical signal at the timing of the determined discrimination phase. The optical signal receiver provides an amplitude detector for detecting received optical signal intensity.

Abstract: In an input-output optical system of spatially optical coupled type, a spacer is provided in at least one of input and output optical systems and interposed between a lens array block and a fiber block without blocking an optical path for ensuring a distance corresponding to a focal distance of collimating lenses. As a result, highly-accurate, highly-stable alignment of an optical axis can be readily realized.

Abstract: Disclosed is a photonic switch that includes a plurality of optical-path switching means having movable light reflecting portions that guide light from each of a plurality of input ports to any output port among a plurality of output ports. Each of the optical-path switching means is made to produce a specific loss so as to reduce path-to-path variations in loss along the paths from the input to the output ports. Specifically, loss along a path is the total of loss based upon optical path length and loss produced by the optical-path switching means. A specific loss is produced by each of the optical-path switching means in such a manner that total loss is equalized from path to path.

Abstract: The present invention is applicable to a burst transmission system such as an ATM-PON optical subscriber system. An optical receiver for extending tolerable variation of input signal is disclosed. The optical receiver includes; an optical signal receiver for receiving an optical signal in burst transmission to regenerate and reshape waveform of the received optical signal; and a bit synchronizer for detecting the rise and fall change points of the signal being output from the optical signal receiver using an externally-input clock, for determining a discrimination phase according to the detected change points; and for discriminating to output the received optical signal at the timing of the determined discrimination phase. The optical signal receiver provides an amplitude detector for detecting received optical signal intensity.

Abstract: The invention is aimed at providing an optical switch using tilt mirrors, in which easy mounting of the optical components is possible by simplifying the construction, and in which a short spatial propagation distance for the light beam is realized. To this end, the optical switch using tilt mirrors of the present invention comprises; a collimator array and a tilt mirror array each formed with an input section and an output section aligned and integrated, and a shift type turn-back mirror that shifts the optical path of the incident light in a predetermined direction and turns back and outputs this.

Abstract: The invention is aimed at providing an optical switch using tilt mirrors, in which easy mounting of the optical components is possible by simplifying the construction, and in which a short spatial propagation distance for the light beam is realized. To this end, the optical switch using tilt mirrors of the present invention comprises; a collimator array and a tilt mirror array each formed with an input section and an output section aligned and integrated, and a shift type turn-back mirror that shifts the optical path of the incident light in a predetermined direction and turns back and outputs this.

Abstract: Disclosed herein is a terminal device including a photodetector, amplitude detecting circuit, light source, drive circuit, and control circuit. The photodetector receives a first optical signal. The amplitude detecting circuit detects the amplitude of an output from the photodetector. The drive circuit supplies a drive current to the light source so that the light source outputs a second optical signal. The control circuit decreases and increases the drive current according to an increase and decrease in the amplitude detected by the amplitude detecting circuit, respectively. In the case that this terminal device is used with another terminal device to construct a network, the dynamic range of the other terminal device can be reduced. Accordingly, the use of this terminal device can improve the extensibility of the network.

Abstract: A retiming circuit able to constantly perform sampling by a clock at a center portion of input data and performing a correct discrimination of logic “1” and “0” even if there is duty fluctuation of a pulse, provided with delay unit for imparting a variable delay to input data or a clock; a reference clock generating unit for generating a reference clock synchronized with the clock; a first phase difference detection unit for detecting a phase difference between a rising edge of the reference clock and the rising edge of the input data; a second phase difference detection unit for detecting a phase difference between the rising edge of the reference clock and a falling edge of the input data; and an intermediate phase setting unit for calculating the intermediate phase of the input data based on the outputs of the first and second phase difference detection units, the delay being controlled based on the intermediate phase.

Abstract: A reflecting-type optical switch is constructed by stacking a parallel plate-shaped glass substrate and a parallel plate-shaped polarization controller, providing a reflecting portion in such a manner that incident light propagates in zigzag fashion owing to reflection, and depositing a polarizing separating film on the glass substrate where two prescribed incident light beams intersect owing to reflection. Further, a transmission-type optical switch is constructed by providing a polarization controller in front of a polarizing prism, and depositing a polarizing separating film on the glass substrate of the polarizing prism where two prescribed incident light beams intersect owing to reflection. Furthermore, an optical distributor is constructed by stacking a plurality of parallel plate-shaped glass substrates and depositing a partial reflecting film on the glass substrate where two prescribed incident light beams intersect owing to reflection.

Abstract: This invention relates to high-hardness, high-toughness, high-density composite materials containing diamond, and a process for making such materials comprising applying shock compression to the composite powders and inducing an exothermic chemical reaction. The process is useful in making metal, ceramic and cermet diamond composite materials.

Abstract: A high density boron nitride-containing sintered body consisting of 60-95% by volume of high density boron nitride and 40-5% by volume of metal alone or in admixture with a ceramic, which high density boron nitride consists of 60-95% by volume of cubic system boron nitride and 40-5% by volume of wurtzite-structured boron nitride, and which cubic system boron nitride has an average particle size of at least 5 times that of the wurtzite-structured boron nitride. The sintered body has a high cutting performance and is suitable as a cutting tool for chilled roll, ultra-heat resisting alloy, cast iron and the like.

Abstract: A composite sintered compact containing high density boron nitride, which consists of zincblende-type boron nitride, wurtzite-type boron nitride, ceramic material and metal in a specifically limited mixing ratio and has a high abrasion resistance, can be obtained under a relatively mild sintering condition and can be easily worked into a cutting tool.