Toshiaki Katagiri

Optical fiber switching device having one of a robot mechanism and an optical fiber length adjustment unit

There is disclosed an optical fiber switching device having a coupling board comprising a plurality of first optical fibers connected to one surface of the coupling board in the arrangement to one surface of the coupling board, a plurality of second optical fibers connected to the another surface of the coupling board, an optical fiber length adjusting unit for handling surplus portions of the second optical fibers and switching unit for pulling out any one of the second optical fibers selected from the plural second optical fibers from the another surface of the connecting board and for connecting the any one optical fiber to different switching position of the another surface of the connecting board to coupling the any one optical fiber with any one of the first optical fibers.

Optical microscope observation method of a single-mode optical-fiber core for precise core-axis alignment

A new method is presented for observing a single-mode optical-fiber core by the use of an optical microscope to achieve precise core-axis alignment. The formation mechanism of a core image and its observation condition have been investigated using a ray tracing method. Simulation results show good accordance with practical observed results. Precise alignment of cores can be achieved when the dimension of a core image becomes equal to the core diameter multiplied by the magnification of the observation system. In the core aligning experiment for a single-mode fiber with a large core eccentricity of 3.4 μm, the average misalignment was 0.6 μm.

Design and development of optical fiber joining techniques for efficient construction of aerial distribution cable systems

Two new optical fiber joining techniques have been developed for aerial distribution cables. One employs a compact mass-fusion splicer and the other involves a small mechanical splice. This paper describes their design and performance. These techniques are excellent for use in aerial sites and enable aerial distribution cable systems to be constructed efficiently. They will be useful for the economical construction of optical access networks for fiber-to-the-home.

Basic design for highly stable mechanical optical fiber splice and its development

In mechanical splice technology, one of the basic problems is the slippage between fibers and fiber-holding substrates. We analyzed the relationship between the dimensions and material constants of a splice in a fiber butt-joint region and the force distributions along fibers, when external tensile forces or thermal stress acted on the fiber joint region. We evaluated factors relating to the slippage and these effects quantitatively. We then designed the joint region largely based on this analysis. We confirmed the joint characteristics using a temperature cycling test in accordance with the relevant Telcordia Technologies (formerly Bellcore) test specification and microscope observations of the damage to the fiber ends after the test. We achieved a highly stable mechanical splice for single fibers and four-fiber ribbons with an insertion loss change of less than /spl plusmn/0.1 dB during the test and with no damage to the fiber ends.

Rapid reinforcement for fusion mass-spliced fibers using low-power induction heating.

A rapid reinforcement method using low-power induction heating is developed. The reinforcement of a mass-spliced fiber ribbon unit comprising five graded-index multimode fibers was completed in 30 sec with good performance by supplying 30 W of electric power.