Bistable Two-Mode Lasers and Most Probable Tunneling Paths.

Bistability is a problem of considerable interest in many fields of physics.1 The problem generally involves mode competition through nonlinear dynamics, quantum and classical fluctuations, and probability of "tunneling" from one metastable state to another.2-4 When the modemode coupling is an adjustable parameter as in the case of recent experiments involving a free running broad band, standing-wave cw dye laser,5 the transition from a many-mode to a two-mode operation has the characteristic of a thermodynamic phase transition at a certain critical point.4