WAVELENGTH MULTIPLEX TRANSMITTING/RECEIVING MODULE

PURPOSE:To manufacture a small guide of optical fibers with high precision at a low cost by providing a wave guide path type substrate having a directional coupler and light merging/diverging functions, fixing the optical fibers taper- machined at one end to it, and directly connecting it to light emitting/receiving elements via the optical fibers. CONSTITUTION:A wave guide path type substrate 1 constituted of a directional coupler 3 is used. To connect the wave guide path 1 to light emitting/receiving elements 7, 6, optical fibers 8, 9 taper-machined at one end are fixed at the other end (not taper-machined) to the end face of a light marging wave guide path 5 and the end face of a light diverging wave guide path 4, respectively. An optical fiber machined with an optical connector at one end is fixed to a common wave guide path at the other end. V-grooves 10 to connect and support the taper-machined optical fibers 8, 9 and the light emitting/receiving elements 7, 6 are formed on the same Si substrate 1 as the wave guide path. A small transmitting/receiving module can be mass-produced at a low cost, and low noise and low cross talk can be realized.