Fizoptika fiber optic gyroscopes (FOGs) are fabricated using a specialized in-line technology. The basis of the technology is an exclusive 40-micron PM fiber with a number of distinctive optical and mechanical characteristics. The fiber maintains its optical guiding ability under high elastic or even plastic deformations. This makes possible the fabrication of various fiber optic components directly on a fiber length by shaping it at high temperatures when quartz glass becomes soft. The spliceless fabrication of the ring interferometer components (couplers, polarizer, SLD module) makes them naturally connected without optical losses.
For fiber shaping, a fusion-tapering technology and equipment were developed. During the couplers fabrication process the two fiber leads are held together by two moveable holders. A stabilized high-frequency arc discharge is applied to the fibers so that they melt together. Simultaneously, the fiber holders are moved apart so that a fused tapered region is formed. To ensure a low-loss coupler (polarizer), it is essential that the holders move apart in a straight line with no sideways motion or vibration. The speed of separation and heating length control the taper shape which in turn has a significant influence on the resulting loss. It is necessary to use an optimal arc length and arc current not to disturb the taper.