Module 8 : Laser- II
Lecture   : Rate equations for Lasers
  \includegraphics{temporal.eps}
   
The temporal coherence length can be defined as $ l = c\Delta t$, so that
$\displaystyle l = \frac{c}{\Delta\nu} = \frac{\lambda^2}{\Delta\lambda}$
where $ \lambda$is the mean wavelength and $ \Delta\lambda$is the spread of wavelengths about this mean, which is also a measure of the degree of monochromaticity of the wave.
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