as the single photon recoil is p=hbar k
What is it you want to know? The velocity change of an atom that absorbs or emits a photon?
Single-photon recoil can be expressed as a momentum or as a velocity. It doesn't make sense to express it as a distance (as your implying by asking about meters). Can you explain some more about what you wish to know?
yes yu are right,
I just wanna calculate the width of a velocity distribution in recoils.
if e.g 1 pixel=2 micro meter, which is the width in pixel or microns,
how ca we express this width in recoils.
Here is a "3-step program":
1. Divide the recoil momentum by the atom's (or molecule's) mass. This gives you the recoil velocity:
vrec = hbar k / M
2. Express the width of the velocity distribution in velocity units, such as m/s. (Not in pixels or micro meters, that is not making sense to me.)
3. With the recoil velocity and velocity width expressed in the same velocity units, take their ratio:
[width in recoils] = vwidth / vrec
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