Thanks to both of you, physics monkey I am going to assume that t2-1=20ns and t1-0=1000ns would give a large enough inversion for CW operation
May I also extend my question a bit more...If the resonator of a laser has one curved mirror and the other a flat grating will this make any...
Q) Why is it easy to see the output of a laser pointer on a screen illuminated by an overhead projector. Assume 1mW laser and 500W quartz halogen bulb. Explain quantitatively, and state all other assumptions.
Im not sure whether it involves the coherence length/time of the two waves...