PURPOSE: To improve the optical coupling effect of light, by providing the first lens system which converts the divergent radiant light of a light emitting element of a parallel light, the second lens system which converts this parallel light to a convergent light, and an optical fiber to which this convergent light is made incident.
CONSTITUTION: A module body lower part 11 has a recessed taper 11a to be fitted to its projecting taper, and a rod lens 9 and an optical fiber 12 are attached to its through hole 11b. The position of the rod lens 9 is so adjusted that the end face of the optical fiber coincides with the focal surface of the rod lens 9. The concentricity between a hole 11'b for lens and a hole 11"b for a core 12a incorporating the fiber 12 is enhanced easily, and the precision of the hole 11'b for lens is improved to make adjustments unnecessary except the adjustment for the focal length. In respect to the adjustment of the focal length, a ring 14 or the like is attached to a selfox lens and is fixed to the module body 11 so that the length between the lens 9 and the fiber 12 coincides with the focal length.
IIYAMA KEIICHI
SUEHIRO YOSHIKAZU
MOCHIDA YOSHIHISA
