- #1
doctortim
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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, visibility or some variation of the two. I am really desperate for help on this one.
Im going to ask a double question (still lasers though) since this is my first post
Q) second things is simply what controls whether a energy level scheme is suitable or unsuitable for CW operation
I believe it depends on the difference between the two decy rates, or is that slightly wrong? or totally?
Im not sure whether it involves the coherence length/time of the two waves, visibility or some variation of the two. I am really desperate for help on this one.
Im going to ask a double question (still lasers though) since this is my first post
Q) second things is simply what controls whether a energy level scheme is suitable or unsuitable for CW operation
I believe it depends on the difference between the two decy rates, or is that slightly wrong? or totally?