Quenching of quantum noise and detection of weak optical signals in the quantum beat laser

Abstract

Starting from a Hamiltonian model of the coupled three-level/two-mode system, a nonlinear quantum theory of the quantum beat laser is developed. The theory is valid under the special conditions that lead to correlated spontaneous emission laser (CEL) operation in the linear theory. It is shown that vanishing of the diffusion constant for the relative phase persists in the nonlinear theory and this operation is stable above threshold.. We show, on the example of the CEL gyro/gravity wave detector, how this effect can advantageously be applied to the detection of weak optical signals. A detailed analysis of the noise performance suggests that, the “in principle” sensitivity of CEL detectors might exceed the standard quantum limit. A theoretical upper limit for the sensitivity increase is established,