Talk:Spectral purity

what is v stand for? Voltage?
 * In this case it's a nu, and it stands for frequency. DS (talk) 20:19, 9 January 2010 (UTC)

This page is WRONG!
"Spectral purity" is not at all a well-defined concept, and certainly not as defined here. $$\frac{\triangle v}{v}$$ is not 'particularly important', in fact it is close to meaningless. Physicists use linewidth $$\triangle v$$ instead, which is much more useful.

When use in the scientific literature, "spectral purity" usually refers to the ratio of amplified spontaneous emission and/or side modes to the main laser line. — Preceding unsigned comment added by 2001:630:12:10C0:9E8E:99FF:FEE3:4FDF (talk) 16:39, 12 December 2014 (UTC)