| 摘要 |
PROBLEM TO BE SOLVED: To improve the stroke characteristics by absorbing and diffusing reflected light, which is emitted by an optical element for transmission and reflected by a distribution body, in a light nonreturn chamber. SOLUTION: On a metallic body 7, the optical element 1 for transmission and an optical element 2 for reception are arranged having their optical axes at a right angle to each other, and at the intersection of their optical axes, a beam splitter plate 3 is provided at 45 deg. to the optical axes; and a ferrule 6 which holds an optical fiber 5 along the optical axis of the optical element 1 for transmission is arranged. At the position of the body 7 where the transmit light 20 emitted by the optical element 1 for transmission is reflected by a beam splitter plate 3 and the reflected light 23 impinges, the light nonreturn chamber 8 is formed. This light nonreturn chamber 8 consists of a recessed part 7a and a lid member 9 and has a closed space except the boring of a pinhole in the internal wall of the body 7. Consequently, the reflected light 23 enters the light nonreturn chamber through the pinhole and in this light nonreturn chamber 8, the light is repeatedly reflected and diffused, so that it is absorbed. |
