LIGHT TRANSMITTING AND RECEIVING MODULE

摘要

PROBLEM TO BE SOLVED: To obtain a module which can be coupled with a single mode fiber and in which the number of parts is small and which is small in size and is of inexpensive by arranging a translucent type photodiode ahead and a laser diode behind the photodiode. SOLUTION: An optical fiber 62, a photodiode 64 and a laser diode 70 are arranged on the same optical path in series. The photodiode 64 has a light receiving layer 65 on the surface 66 and is such a semi-transmissive type photodiode that the half of an incident light passes through toward the rear 67. The laser diode 70 is placed behind the photodiode. The light receiving layer 65 of the photodiode 64 and the light emitting layer 71 of the semiconductor laser 70 are arrange by one another on the optical path of the optical fiber. Then, the end face 69 of the optical fiber is obliquely cut and a light is condensed by a condenser lens and moreover this chip is housed in a package. As a result, a light transmitting and receiving module indispensable for two-way communications by a light, especially for a light subscriber system is made to be mass-produced at low cost.