Application of superresolution techniques to ring laser gyroscopes: exploring the quantum limit

Two methods for extracting Linewidth estimates from evenly sampled partiall y coherent signals, where white frequency fluctuations are the major source of noise, are discussed. The first method utilizes the Allan deviation, re quiring multiple frequency estimates for each linewidth estimate. The secon d method utilizes the second-order autoregressive model to provide a Linewi dth estimate with each frequency estimate. A characterization shows that th e latter technique is reliable for short data sets (less than or equal to1 s). The application of these techniques to large, quantum-noise-limited rin g laser gyroscopes is demonstrated. The results of the analysis compare fav orably with a theoretical analysis. (C) 2000 Optical Society of America OCI S codes: 060.2800, 070.4790, 070.6020, 120.5790, 140.3370, 270.2500.