Abstract

We study theoretically the dynamics of a microchip laser subject to external optical injection and generating the second harmonic (SH) inside its doubly resonant cavity. Two cases of optical injection have been considered and compared: the injection field with a frequency close to the fundamental frequency ω of the slave laser and with a frequency close to 2ω. The traditional use of injection locking is for purposes of linewidth narrowing, stabilization [1] and squeezing of a laser light [2]. We show that optical injection opens new potentials for the control of dynamics of a frequency doubling laser. One of such new possibilities is switching the steady states of the slave laser. In the absence of an injected signal, the laser considered has two steady states with the different values of the phase shift ψ in the intracavity nonlinear element and, consequently, with the different values of the optical frequency ω. One of these states is unstable. We have shown that optical injection can provide stabilisation of the unstable state and switching of the laser from the first previously stable state to the second state.

© 2000 IEEE