Random walk reduction in dithered ring laser gyroscope.

We experimentally demonstrated that the random walk in a dithered ring laser gyroscope caused by lock-in crossing can be eliminated by lock-in error compensation. Computer simulations demonstrated the effectiveness of this method. The experimental results show that the random walk coefficient can be reduced as predicted.

Optically pumped NMR oscillator based on Xe nuclear spins.

A Xe nuclear magnetic resonance (NMR) oscillator can be used in the measurement of rotation rates, CPT and Lorentz violation tests, etc. To improve the measurement precision of devices based on a Xe NMR oscillator, its characteristics need to be fully understood. Under the conditions where the Zeeman interaction is much larger than the quadrupolar interaction, the characteristics of the Xe NMR oscillator involving the magnetic resonance, free induction decay, and closed-loop oscillation are investigated both experimentally and theoretically.

Theoretical analysis on the rotation-induced frequency difference in ring lasers with coupled cavities.

We analyzed the effective scale factor of ring laser gyros with coupled cavities in a general way. The coupled cavities can be made of both an odd and even number of mirrors, or even fiber coil. Compared with the "zero-vector-area" design in previous publications, we use the propagation loss rather than transmittance and reflectivity of mirrors to characterize the coupled cavities, which are more universal and controllable.

Practical Considerations on the Multi-layer Mirrors for Superluminal Ring Laser Gyroscopes.

We have created a simple model to analyze the restrictions on superluminal ring laser gyroscopes arising from the absorption of coating materials. For a ring laser gyroscope with a cavity length of 15 cm, the scale factor enhancement is nearly impossible due to absorption from the high dispersion mirror. In order to obtain a practical superluminal ring laser gyroscope, the extinction coefficient of coating materials should be less than 1E-10, which is a challenge at present.

Research on the thermal relaxation effect of nonplanar four-frequency differential laser gyro.

The nonplanar four-frequency differential laser gyro (NFFDLG, also called ZLG in the United States) has many advantages, such as the absence of mechanical noise, a whole solid state, high stability of scale factor, and no time delay. Because of its excellent performance, NFFDLG is currently the subject of research. In this paper, the error induced by the thermal relaxation effect is investigated both theoretically and experimentally, and some methods and conclusions that could restrain this error effectively are proposed.