Leland Stanford Junior University

Shangyuan Huang

Byoung Yong Kim

Keiichiro Toyama

Herbert J Shaw

Hebert J Shaw

A Brillouin fiber optic gyroscope has a cavity loop that includes a first length of optical fiber wound as a first number of turns in a first direction to provide a selected system response that includes the dynamic range of gyroscope rotation rate, the resolution of the gyroscope rotation rate measurement, the relative lock-in range and the relative Kerr-effect-induced beat-frequency bias. The cavity loop further includes a second length of optical fiber wound as a second number of turns in the same direction as the first number of turns and wound as a third number of turns in an opposite direction to the winding direction of the first and second number of turns. The effect of the second and third number of turns is to increase the overall length of the optical fiber in the cavity loop to reduce the pump power required to generate Brillouin laser light within the cavity loop without increasing the Sagnac effect within the cavity loop. Thus, the system response that includes the dynamic range of gyroscope rotation rate, the resolution of the gyroscope rotation rate measurement, the relative lock-in range and the relative Kerr-effect-induced beat-frequency bias of gyroscope rotation rate, is not substantially affected by the increased number of turns provided by the second length of optical fiber.

Winding technique for decreasing the pump power requirement of a

A Brillouin fiber optic gyroscope having a feedback system which monitors the difference between counterpropagating Brillouin intensities and utilizes this difference in the form of a correction signal to control one of the circulating pump intensities so as to equalize the circulating pump intensities. The Brillouin fiber optic gyroscope further includes a second feedback system which detects electrical signals proportional to the phase-modulated, counterpropagating intensities in the gyroscope, and utilizes a combination of the electrical signals as an error signal to stabilize the resonant cavity at a length substantially equal to a length midway between the resonant lengths of the counterpropagating pump signals. The Brillouin fiber optic gyroscope of the present invention also provides a dynamic range of the gyroscope rotation rate that is twice the dynamic range of existing gyroscopes.

Growing community of inventors

Willowdale, Canada

Shangyuan Huang