John R. Feth

PARTIALLY POLARIZED FIBER-OPTIC GYRO

We present a new design for an all-fiber-optic gyroscope that makes use of a single-mode coil containing a Lyot depolarizer along with a partial depolarizer placed between the polarizer and the loop coupler. This design provides an optimal trade-off between the suppression of polarization errors and the reduction of drift errors arising from external magnetic f ields and changes in temperature.

Performance improvements in depolarized fiber gyros

We describe amplitude-type polarization errors in depolarized fiber gyros and show a management scheme for their suppression. Prototypes operating both at 0.8 micrometers and 1.3 micrometers wavelengths exhibiting navigation grade drift and noise performance have been realized.

Progress in low cost interferometric fiber optic gyros

Low cost interferometric fiber optic gyros (both polarization maintaining and depolarized types) having bias drift less than one degree/hr over wide temperature ranges are reported. The depolarized fiber gyros exhibit significantly lower sensitivity to temperature transients than the polarization maintaining fiber gyros.