Polarization maintaining silica waveguide resonator optic gyro using double phase modulation technique

Abstract

Resonator micro optic gyro (RMOG) is a promising candidate for applications requiring small, light and robust gyros. In optical passive ring resonator gyros, clockwise and counter clockwise lightwaves are modulated at different frequencies to reduce the backscattering induced noise. The effectiveness of this technique, however, is determined by the carrier suppression level. Accurate modulation index and high environmental temperature stability is required for achieving high total carrier suppression for the traditional single phase modulation technique (SPMT). In this paper, we propose an RMOG based on the double phase modulation technique (DPMT). Compared with the traditional SPMT, two additional phase modulations are added to provide additional carrier suppression. It is found that the control accuracy of the modulation index and temperature stability is relaxed more than 30 times. It is easily performed for reducing the backscattering error below the shot noise limited sensitivity. The modulation parameters in the DPMT are analyzed and optimized. Based on the optimum parameters of the DPMT, a bias stability of 1.85×10⁻⁴ rad/s is successfully demonstrated in the polarization maintaining silica waveguide resonator with the length of 7.9 cm. This is the best result reported to date, to the best of our knowledge, for a waveguide type passive ring resonator gyro.

Recent advances in miniaturized optical gyroscopes

“…Depending on the RF signal driving the modulator, different modulation techniques can be implemented: Single Phase Modulation Technique (SPMT) [62], Double Phase Modulation Technique (DPMT) [65], and Hybrid Phase Modulation Technique (HPMT) [66]. In the first case a couple of phase modulators, driven by sinusoidal signals at different frequencies, is used to achieve the suppression of the carrier components of the two counter-propagating beams [62,64].…”

“…In the first case a couple of phase modulators, driven by sinusoidal signals at different frequencies, is used to achieve the suppression of the carrier components of the two counter-propagating beams [62,64]. While this technique requires an accurate optimization of the modulation index, the DPMT has more relaxed constraints because two pairs of phase modulators in series are used to obtain additional carrier suppression [65]. In the last case the phase modulators are driven by signals, which are the sum of opposite slope triangle waves and sawtooth waves [66].…”

Large Sagnac frequency splitting in a ring resonator operating at an exceptional point

“…They are widely used as key components of inertial navigation systems in many industrial and military applications, such as airplanes, ships, satellites, and so on. Considerable research effort has been devoted to realizing chip-scale compact optical gyroscopes [4][5][6][7][8][9][10][11][12][13][14][15][16][17] because such small and navigation-grade rotation sensors have the potential to be used in mobile platforms and may extend into numerous applications. However, the sensitivity of an optical gyroscope decreases as the size of the sensing element decreases.…”

Towards a fully integrated optical gyroscope using whispering gallery modes resonators

“…The most common design is the integrated SiO 2 ring resonator used by Ma [5][6] thanks to which a theoretical minimum rotation rate resolution of 17 °/h has been achieved. The resonator used by Hotate and Lei [7][8][9], a square waveguide with rounded corners, is the resonator with the highest quality factor (3.9×10 6 ) used to date as a sensitive part of an IORG, with a theoretical resolution of 1.4 °/h. However most of the aforementioned resonator designs have a diameter of few centimeters.…”