Patent ID: 7751055

Claim:
A fiber optic gyro for measuring a rotation rate of the fiber optic gyro about an axis, the fiber optic gyro comprising: a ring resonator having first and second counter-propagating directions, said ring resonator comprising: a coil having the axis and comprising an optical fiber having a hollow core, said ring resonator configured to: produce a first resonance frequency when a first light beam circulates through said hollow core in said first counter-propagating direction; and produce a second resonance frequency when a second light beam circulates through said hollow core in said second counter-propagating direction, a difference between said first resonance frequency and said second resonance frequency indicating the rotation rate; and a recirculator configured to facilitate the circulation of the first and second light beams through the hollow core of the optical fiber, such that the majority of the first and second light beams travel in free space within the optical fiber and substantially all of the first and second light beams travel in free space while within the recirculator, wherein a preferred polarization state of the first and second light beams is substantially completely maintained while traveling within the recirculator.