- #1
RedX
- 970
- 3
Why is a laser monochromatic? I read somewhere that the reason is because of a Fabry-Perot cavity, and not necessarily because of stimulated emission, so that if you have an ordinary light bulb in such a cavity, it would produce monochromatic waves.
Can you just send the stimulated light through a light filter instead of such a cavity? Also, how high is the bandwidth for atomic transitions? It can't be that high, since you can still see fine lines in spectroscopy? So do you need a filter at all?
So if I'm understanding it right, the length of the Fabry-Perot cavity has to be half a multiple of the wavelength of the atomic transition? How accurate do you have to make this length, since it seems that the light should be close to monochromatic anyways just from the fine spectral lines?
Can you just send the stimulated light through a light filter instead of such a cavity? Also, how high is the bandwidth for atomic transitions? It can't be that high, since you can still see fine lines in spectroscopy? So do you need a filter at all?
So if I'm understanding it right, the length of the Fabry-Perot cavity has to be half a multiple of the wavelength of the atomic transition? How accurate do you have to make this length, since it seems that the light should be close to monochromatic anyways just from the fine spectral lines?