Module 8 : Laser- II
Lecture   : Rate equations for Lasers
 

In the absence of stimulated emission $ \sigma=0$, so that the population in the steady state is guven by

$\displaystyle N_u^0 = R_u\tau$

The population reaches the steady state in an exponential fashion

$\displaystyle N_u(t) = R_u\tau(1-e^{-t/\tau}$
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