Optical switch and method for assembling the same

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. The optical waveguide substrate and the lid substrate are bonded together by anodic bonding to make a passage which communicates between the space formed in a crossing portion of the optical waveguides and an outside. The regulation of the volume of the index-matching liquid is time-, temperature-, or pressure-based regulation.