Patent ID: 7561799

Claim:
An optical path switching device comprising: optical input means including a first optical fiber collimator for emitting a parallel luminous flux; output means including a second optical fiber collimator for receiving a parallel luminous flux; optical path switching means including a fixed prism and a movable prism disposed on an optical path coupling the means and the output means to each other; moving means including an actuator for moving the movable prism; monitor means constituted of an optical tap device and a light-receiving device; and control means which determines whether or not a failure has occurred, on the basis of an electric signal from the monitor means, and which sends an electric signal to the actuator upon occurrence of a failure, wherein each of the optical fiber collimators, the fixed prism, the optical tap device, and the light-receiving device are separately formed and mounted onto a platform; and the movable prism is separately formed in front of the fixed prism toward the first and second optical fiber collimators and moved on the platform to be inserted in an optical path between the optical input means and the output means when the failure has occurred, the input means, the optical path switching means, the output means, and the monitor means are optically coupled by means of the parallel luminous flux on an identical plane on the platform.