COIL development in Kawasaki Heavy Industries, Ltd.

The Chemical Oxygen-Iodine Laser (COIL) has been studied for military use because it has many excellent features. These features count with not only the military but also the industry. The wavelength of COIL 1.315 mm, is a significant features of the industrial laser because it is located in a minimum loss transmission region for optical silica fibers. Therefore, we started the COIL development for industrial use in 1986. In the first stage, we developed a subsonic type. In 1992, the first 1 kW class commercial COIL was delivered. This system was successfully operated for several hours, and its output beam was delivered through the optical silica fiber of 0.3 mm core diameter. But the subsonic COIL has the disadvantage that the device size is relatively large. To solve this problem, the supersonic COIL has been introduced and developed. In 1994, 1 kW supersonic output power was attained. On the basis of this technology, we constructed a 10 kW class in 1996. This system achieved over 12 kW output power and chemical efficiency of 26 percent.