Multi-threshold second-order phase transition

TL;DR

This paper introduces a theory and experimental evidence for multi-threshold second-order phase transitions, revealing a more complex behavior than traditional single-threshold transitions in laser systems.

Contribution

The work develops a theoretical framework and demonstrates experimentally the existence of multi-threshold second-order phase transitions in laser systems, expanding understanding of phase transition phenomena.

Findings

Observation of 3-4 thresholds in laser power-current-temperature phase diagram

Experimental validation of multi-threshold second-order phase transition

Single threshold transition is a special case of the more general phenomenon

Abstract

We present a theory of the multi-threshold second-order phase transition, and experimentally demonstrate the multi-threshold second-order phase transition phenomenon. With carefully selected parameters, in an external cavity diode laser system, we observe second-order 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 second-order 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.