To provide an ultraviolet-ray irradiation apparatus which is low in power consumption and running cost and to provide a method for forming a coating of an optical fiber.
The ultraviolet-ray irradiation apparatus UVA includes a cylindrical encircling body 502 which has a light-emission opening 502C at one end the cylindrical encircling body 502. A gas introducing port is provided at the another end of the encircling body 502, and a gas introducing pipe 503 is connected to the gas introducing port. An inert gas G such as nitrogen is introduced into the encircling body 502 from the gas introducing pipe 503. In the encircling body 502, a semiconductor light-emitting element 35 for emitting an ultraviolet ray and a condenser lens 34, attached in the vicinity of the light-emission opening 502C of the encircling body 502 and condensing the ultraviolet ray from the semiconductor light-emitting element 35, are provided. The vicinity of the light-emission opening 502C, where the condenser lens 34 is provided, is a position of the tip part of the encircling body 502, where it is possible to condense the ultraviolet ray toward an optical fiber F.
OISHI KAZUMASA
TAKAMIZAWA HIROSHI
Shiro Terasaki
Yoshiki Kuroki
Ichira Kondo