Abstract

We report the observation of an amplitude instability near the phase-locking threshold of two single-mode, linearly polarized, Nd:YAG (neodymium doped yttrium-aluminum garnet) lasers excited by pump beams in the same crystal, and coupled to each other through the overlap of the infrared light [1]. The system is known to display phase-locking above a certain threshold of the coupling strength [1] and synchronized chaos under circumstances of pump or loss modulation [2] with a threshold in the same order of magnitude. A comprehensive set of measurements allows us to characterize the dynamics of the intensities and relative phase of the lasers, and to investigate the amplitude instability of the lasers as a function of the coupling between them, which can by controlling the lateral separation of the lasers be accurately determined and varied through a range of many orders of magnitude.

© 1996 IEEE