Phase noise of four-wave mixing in semiconductor lasers

Abstract
A simple theoretical analysis shows that the linewidth of the conjugate wave produced in four‐wave mixing in semiconductor lasers is equal to the linewidth of the probe plus four times the linewidth of the pump. Experimental results in good agreement with the theory are presented. This result implies an enormous enhancement in the phase noise of the conjugate wave and sets a limitation on some practical applications of four‐wave mixing.