Novel Approaches to Sensitivity Enhancement of Ring Laser Gyros

A main theme of these papers are the role of quantum effects and determining how the sensitivity of optical sensor, such as the ring-laser gyro, can be improved. The correlated-spontaneous-emission laser CEL is a concept which permits reduction of quantum noise associated with the relative phase angle between two correlated laser transitions. The mechanism of quantum noise quenching in the original CEL device quantum beat laser has been explained using a geometrical approach, and a more rigorous analysis where amplitude noise is also included. Extensive studies on the CEL, including the effects of nonlinear saturation and atomic motion, was performed. The CEL concept has been found applicable to various types of devices, besides the quantum beat laser, for the purpose of quantum noise reduction. Using the CEL concept, we have developed the following four devices, which have the ability of quantum noise reduction, even squeezing.