WINDOW MEMBER FOR LIGHT TRANSMISSION TUBE

摘要

PURPOSE: To make it possible to surely protect the ends of the core of a light transmission tube against external environment and to prevent the thermal influence by direct irradiation of the core with light by mounting a window member particularly to the end on a light incident side. CONSTITUTION: This window member is mounted attachably and detachably at the end of the light transmission tube A formed by packing the solid core C having a refractive index higher than the refractive index of the tubular clad B into this clad B so as to cover the end face of the core C. An annular recessed part 3 is formed in the intermediate part in the axial direction of the inner peripheral surface of a tubular window member body 1 which is inserted onto the clad B and is mounted with a light transmissive window body 2 to close the aperture at the front end. An annular recessed part 4 and an annular notched and step part 5 are successively and continuously formed behind this recessed part 3. An annular elastic body 7 is disposed in the recessed part 3 and a cylindrical release bushing 10 is disposed axially movably at the body 1 in such a manner that its front part side exists in the recessed part 4, its rear part side exists in the notched step part 5 and its rear end projects backward of the body 1.