Abstract: This invention provides a connecting method and the like for between optical fibers with little connection loss without heat treatment after fusion-splicing. This connecting method is a method of optically connecting first and second optical fibers which differ in core diameter to such an extent that the fusion-splicing loss is 0.45 dB or more. In the method, a connecting member is prepared between these first and second optical fibers, and the two end faces of the connecting member are directly fusion-spliced to one end face of the first optical fiber and one end face of the second optical fiber, respectively. The prepared connecting member, in particular, is comprised of a third optical fiber whose core diameter is large enough to exhibit a fusion-splicing loss of 0.45 dB or less at a wavelength of 1.55 &mgr;m when it is connected to the first optical fiber, and a fourth optical fiber whose core diameter is small enough to exhibit a fusion-splicing loss of 0.

Abstract: This invention relates to micro-driving members for performing alignment of optical fibers and the like. Backlash is eliminated by forming constituent elements as integral components, thereby improving driving precision. Each micro-driving member includes a base portion in which an insertion hole for an urging means is formed, a support portion integral with the base portion and opposing the insertion hole, an urged portion urged by the urging means, and a table portion for supporting a driving target. The table portion has one side connected to a first horizontal flexible portion extending from the support portion, and the other side which is open.

Abstract: An optical unit, particularly for use with a composite overhead conductor. The cylindrical, aluminum core of the optical unit has spirally shaped grooves on its surface into which optical fibers are placed. A tape is spirally wound to hold the optical fibers in the grooves. The winding pitch is such that the tape edges overlap. An aluminum pipe encases the spacer, optical fibers and tape. The tape consists of a thermally insulating middle layer and two sheets of aluminum foil sandwiching the middle layer, the aluminum foil contacting the pipe and the core so as to conduct electricity therebetween.