Implementation and Evaluation of Two Design Concepts of the Passive Ring Resonator Laser Gyroscope

摘要

Two configurations of the passive resonant ring laser gyroscope were evaluated. The first configuration detected cavity resonance by monitoring the beams transmitted through the cavity. The second configuration detected resonance by monitoring the beams reflected from the cavity input mirrors. The resonant cavity of both configurations had a rated finesse of 9800, making the gyro much more sensitive than earlier versions. Additionally, much of the cavity noise that plagued earlier experiments was eliminated by mounting the cavity mirrors on a solid ceramic block, and evacuating the beam paths. Alignment data indicated that the signal strength in the reflected beam had six times the power of the signal in the transmitted beam. However, the bias on the reflected signal was seven times the signal strength. This bias intensity increased the shot noise in the detector circuit. Rotation was simulated in the gyro by shifting beam frequencies. The strength of the error signal was calibrate to angular rotation. A signal to noise ratio of one was then converted to a noise equivalent rotation. Using a 100 second integration time, the noise equivalent rotation of the first configuration was twelve milli-earthrate, and four milli-earthrate for the second configuration. The detection of resonance using the reflected beam increased sensitivity three-fold.