Why 80 micron?
Choosing 80 microns resulted in fiber stiff enough to be handled, but allowed greater quantities to be packaged in the same volume casing. At that time, fiber gyro designs were large; coil diameters were around 30 centimeters. Even as late as 1990, the cumbersome nature and poor performance of these early FOGs caused one researcher to project a slide of an AWACS plane, complete with its enormous radar “mushroom,” and say, “At last, the fiber gyroscope has found its way onto a real aircraft.” As is common with optoelectronic devices, packaging and interconnection of devices are key issues. At a time that coil diameters were 60 millimeters or larger, bend diameters were 10 millimeters or smaller, and 80 microns accommodated this reduction in coil diameter. Obtaining components for 80 microns was difficult until about five years ago; until this time, most people made their own components or simply spliced standard 125-millimeter components directly to the 80-micron tails. With practice, s
