What waveform does the light coming off different types of artificial light sources have and (of course) what are the underlying physical reason for them?
I was inspired to ask this question because of several things I have been hearing lately.
Firstly, there was a recent TED talk about how LED bulbs can be used to transmit data. Researchers have been working on the problem for a little while now and they've made a fairly impressive product, but it was only recently made possible by the LED technology, which has such a fast response that it can easily compare to the transfer rates of electric information condiuits that we normally use.
My understanding is that incandescent bulbs flicker because they have 60 Hz AC power being pulsed through them. In fact, I think 60 Hz was chosen in the first place because it was a threshold that was unnoticeable to humans. Looking at a high speed youtube video of such a bulb demonstrates that it has a very significant lag time responding to both the normal electrical phasor and being turned off. In other words, it flickers but it doesn't go dark at any point in the AC waveform.
Looking for more information, however, I was a little disappointed, since nothing seemed to give a graph of lumens emitted over time for all different kinds of bulbs. Of course, there isn't just one relevant time scale. A light could flicker with 60 Hz and also flicker with 2000 Hz (I just made that up). I'm interested in the complete picture of what lights exhibit what patterns.