2003 年 31 巻 9 号 p. 612-617
In the International Thermonuclear Experimental Reactor (ITER), pipe welding/cutting has to be carried out under severe gamma-ray conditions in a limited space inside the pipe. A laser and image transmitting system using a composite-type optical fiber was proposed and tested so as to weld, cut and observe inside a pipe. The composite fiber system consists of one fiber for laser transmission, a number of small fibers for image information transmission located around the laser transmission fiber, and a coupling/distributing device for laser energy and images. As a result, high-power laser transmission for welding/cutting and observation tests using the composite fiber system were successfully carried out. Based on the test results, the proposed laser and image transmission system was determined to be applicable not only in a limited space such as inside the pipe, but also in a human body for medical treatment.