Abstract: An optical switch includes a substrate having therein optical waveguides made of silicon and a silicon layer deposited on its top surface. A space is formed in the crossing portion of the optical waveguides which is covered with a lid, preferably made of low alkali borosilicate glass, and which is bonded to the silicon layer by anodic bonding. Preferably, a groove is formed in a surface of the optical waveguide substrate or a bonding surface of the lid. The groove, after the lid has been bonded, makes a passage which communicates between the space and an outside. The passage is a pouring slit for pouring an index-matching liquid and is connected to the space which acts as a driving slit in which the index-matching liquid moves. In one embodiment, the width of the pouring slit is smaller than that of the driving slit. The optical switch can be manufactured by providing an optical waveguide substrate and a lid substrate, one of which is formed with a groove in its surface on which the two substrates are bonded.

Abstract: An optical fiber cross connection apparatus is provided for connecting and disconnecting input optical fibers to desired output optical fibers, each of the input optical fibers being equipped with a plug on a tip thereof.

Abstract: A transmission-reception apparatus wherein signals are bidirectionally and mutually transmitted and received between a transmitter and a receiver using a single transmission line, characterized in that the input and output portions of the transmitter and the receiver are respectively equipped with bidirectional line drivers and with flip-flops that are set by signals received through the line drivers, are reset by signals transmitted through the line drivers and change over the line drivers to signal transmission and reception. Said receiver is equipped with a counter for counting the number of signal receptions, a decoder for decoding the output of the counter and means for discriminating the reception signals by means of the output of the decoder.