In a recent paper, it was shown that the uncertainty in the relative frequency of a two-mode laser can be eliminated by preparing the laser medium to produce a coherent superposition of the two upper states. Since in an active heterodyne detection scheme, phase diffusion sets the ultimate limit on sensitivity, such a diffusion-free correlated emission laser (CEL) has the potential for application in various areas of precision measurement (optical detection of rotation in particular). In a subsequent publication the quantum theory of the CEL was developed, and an explicit expression was given for the diffusion constant of the relative phase of the two modes. The excitation conditions in which the diffusion coefficient can vanish were derived from this general expression. It was then shown that CEL operation can be achieved in a ring resonator and that this arrangement is suitable for gyro application. From a detailed analysis of the CEL gyro it became clear that an appropriate coupling of the two modes can greatly reduce the losses. The previous analysis is extended here to the case in which the coupling between the two modes proceeds via a CEL active medium, namely, the ring resonator of the CEL gyro is coupled to another ring resonator filled with an active CEL medium.
