Abstract: A sensor coil for a fiber optic gyroscope. The coil is formed on a spool of carbon composite material or of another material whose coefficient of thermal expansion approximates that of the overlying windings of the glass optical fiber. The windings are potted in an adhesive material. Various bias effects are addressed by the coil design. The close matching of the thermal expansion characteristics of the spool and the fiber windings as well as proper selection of the coil potting material minimize the Shupe-like bias caused by thermal stress that would be otherwise exerted by a standard metallic spool. By careful selection of potting material (particularly its modulus of elasticity) vibration-induced bias, coil cracking, degradation of h-parameter and temperature-ramp bias sensitivity are also minimized.

Abstract: A method for tuning a sensor coil for a fiber optic gyroscope. The coil is initially wound in a known pattern. One end of the fiber of the wound coil is then adjusted relative to the other end so that a known differential is obtained that effectively displaces the midpoint of the winding pattern. The coil is then attached to an interferometer test apparatus and performance measured. After successive observations a "trimmed" coil is obtained of acceptable performance characteristics.