Pump-induced correlation between two lasers

We have studied the intensity correlation between two lasers induced by the pumping mechanism. This correlation is studied through the noise spectrum of the intensity difference between the two lasers. We have shown, in the c ontext of atomic lasers, that this spectrum may be smaller than the corresp onding shot noise if the pumping noises of the two lasers are correlated. 8 5% noise reduction with respect to shot noise is predicted under reasonable operating conditions. [S1950-2947(99)04608-9].