Multi-threshold second-order phase transition in laser

Abstract

We present a theory of the multi-threshold second-order phase transition, and experimentally demonstrate the multi-threshold secondorder phase transition phenomenon. With carefully selected parameters, in an external cavity diode laser system, we observe secondorder phase transition with multiple (three or four) thresholds in the measured power-current-temperature three dimensional phase diagram. Such controlled death and revival of second-order phase transition sheds new insight into the nature of ubiquitous secondorder phase transition. Our theory and experiment show that the single threshold second-order phase transition is only a special case of the more general multi-threshold second-order phase transition, which is an even richer phenomenon. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.