OPTICAL CABLE

摘要

PURPOSE:To avert the contamination of a lens by providing a shutter which is opened and closed by a shape memory alloy in correspondence to the lens to the front end of a pipe in the stage of housing an optical fiber provided with the lens or the like at the front end into the pipe and making a prescribed treatment by inserting such pipe into a living body. CONSTITUTION:The optical fiber 8 for transmission of laser light is inserted into a protective tube 9. A front end protective means 10 having the lens or window 5 is put on the front end of the tube 9. Such structural body is inserted into the pipe 11 to constitute a hand piece 3. The shutter 12 to face the means 10 is provided to the front end of the pipe 11 in this stage. The shutter 12 in such constitution is constituted of a wire 14 consisting of the shape memory alloy extended between two points 16a and 16b at the end 13 of the pipe 11 and a shape variable film 15 fixed to the inside surface of the pipe 11. Such constructions are combined to form one shutter. The shutter 12 is held closed until the front end arrives at the intended position. The contamination of the lens 5 is thus averted.