OPTICAL SIGNAL TRANSMISSION AND RECEPTION MODULE

摘要

PROBLEM TO BE SOLVED: To obtain an optical signal transmission and reception module which is smaller in the number of parts, is small in size and low in cost by installing a light emitting element on the extension of an optical route of an optical medium for bidirectionally propagating signal light and disposing a light receiving element on the base line connecting the optical medium route and the light emitting element so as to approach the base line with the side face. SOLUTION: A laser 70 is arranged on the forward axial line of the end face 63 of an optical fiber 62. A photodiode 64 is installed laterally in mid-way of the line (base line) connecting the centers of the laser 70 and the optical fiber 62. The photodiode 64 is disposed in the position where its side end 66 is in proximity to the axial line (base line) between the laser fibers. The light emitted from the laser 70 spreads spatially and the light 72 advancing along the base line falls onto the optical fiber end face 63 and is made incident on the optical fiber 62. Rays 73, 74 advancing upward and downward are wasted. On the other hand, the beams 67 to 68 which are emitted from the optical fiber 62 and head slightly downward out of the base line in the signal reception light enters the photodetecting surface 65 of the photodiode 64 and forms the signals effective for signal reception.