PURPOSE:To completely prevent running of water on the laminated surface of optical fiber tape cores, by filling up the space between the laminated optical fiber tape cores with an oily substance. CONSTITUTION:An optical unit 6 is formed by putting plural optical fiber tape cores 3 in the groove 4 of a grooved spacer 5 with the spiral groove 4 in a laminated state. Moreover, a keep winding 7 of a plastic tape, etc., is made as occasion demands, then a sheathe 8 is put on the winding 7 and the space inside the sheathe 8 is filled up with a jelly-like water proofing mixture or water proofing material 9 which swells and becomes a gel when it absorbs water. Then the space between each laminated surface of the optical fiber tape cores 3 is filled up with an oily substance 11 of a synthetic oil, such as silicone oil, polybutene oil, etc., or mineral oil, such as naphthenic oil, etc. The oily substance 11 is, for example, applied to the cores 3 before the cores are laminated. Therefore, running of water in the space between each optical fiber tape core 3 can be prevented completely.
展开▼
