Micro-magnetic alloy tubes for switching and splicing single-mode fibers

The author describes a novel technique for switching and splicing single-mode fibers that uses micromagnetic alloy tubes. A micro-magnetic alloy tube, with an inner diameter a few microns larger than that of a standard single-mode fiber and a thickness of several tens of microns, has been successfully fabricated by a combination of the metallization and etching of a glass fiber. The tube can easily be inserted into the fiber and fixed by adhesive to construct an optical switch or to splice fibers. The developed mechanically actuated single-mode fiber switch has a latching-type switching mechanism and exhibits a low insertion loss of 0.9 dB and a low driving power of 9 mW with a relatively short switching response time of <6 ms. It exhibits high stable operation throughout endurance, vibration, and shock tests. The microtube has also been applied to single-mode fiber splicing. In the tube, facing fibers can be aligned with a lateral misalignment of less than 2 μm. Transparent adhesive is used to bond the fibers to the tube. The adhesive also serves as an index matching fluid to reduce the Fresnel reflection loss at the fiber ends. The measured splicing losses are 0.3-0.5 dB