Abstract

When two phase-conjugate mirrors with gain are placed near each other, an oscillation will build up between them. This is called a double phase-conjugate oscillator (DPCO). DPCOs have many interesting physical properties that can be used to make sensors. For example, the frequencies of the counterpropagating oscillations in a linear DPCO are independent of the reciprocal optical path length of the resonator and dependent on the nonreciprocal optical path length. This is the exact opposite of linear oscillators using conventional mirrors (i.e., lasers). Since inertial effects produce nonreciprocal phase shifts, the DPCOs can be used to sense motion. In fact, the DPCO is the only oscillator that is known to be capable of measuring translation. Although conventional optics can be used to make rotation sensing oscillators (i.e., ring laser gyros), these devices cannot use solid-state gain media due to gain competition, and they suffer from the problem of frequency locking. These problems do not exist in phase-conjugate oscillators.

© 1988 Optical Society of America