We show that correlated-emission noise quenching can be achieved in a ring laser via a spatially modulated active medium. A gyroscope based on such a correlated-emission laser has a potential sensitivity superseding the usual quantum limit.
Abstract : 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.
In addition to this fundamental research in the nature of the noise present in a measurement of phase, and the consequent development of the CEL concept, we have carried out research in a number of related topics. This includes acting as a theoretical support group for (now defunct) large, passive, resonant-ring gyroscope experimental effort which was carried out at F.J. Seiler laboratories at the Air Force Academy. In addition, a preliminary experimental RLG effort has begun at the University of New Mexico under the auspices of this contract. Finally, we studied in a somewhat general manner the quantum distribution functions. Techniques involved in this latter study are very useful in calculations of quantum noise. (Author)
In addition to this fundamental research in the nature of the noise present in a measurement of phase, and the consequent development of the CEL concept, research was carried out in a number of related topics. This includes acting as a theoretical support group for (now defunct) large, passive, resonant-ring gyroscope experimental effort at the Air Force Academy. In addition, a preliminary experimental RLG effort has begun at the University of New Mexico under the auspices of this contract. Finally, the authors studied in a somewhat general manner the quantum distribution functions. Techniques involved in this latter study are very useful in calculations of quantum noise.
The idea of using correlated emission to reduce spontaneous-emission noise in an active interferometer1 has recently been successfully implemented in a He–Ne Zeeman laser,2 an advance of particular significance for the development of high-sensitivity probes of metric gravity.1 Because the sensitivity of such probes is expected to increase with increasing laser power, we have begun assessing the degree to which instability imposes limitations on the operating levels of correlated-emission-laser (CEL) devices. In particular, we have found that the model of Bergou et al.3 of a homogeneously broadened, three-level CEL exhibits transitions to chaos that are very similar to the well-known Haken–Lorenz instability, and at quantitatively similar threshold powers. A CEL model more appropriate to Ref. 2 is also considered.