The following content is provided under a Creative
Commons license.
Your support will help MIT OpenCourseWare
continue to offer high-quality educational resources for free.
To make a donation or view additional materials
from hundreds of MIT courses, visit MIT OpenCourseWare
at ocw.mit.edu.
PROFESSOR: In this experiment, we're
going to illustrate how sodium atoms exhibit
very strong absorption when excited
by light at the resonance frequency of sodium.
We're going to use a dye laser over here
and a vapor cell of atomic sodium.
We're going to tune the laser to 5890 angstroms or so,
which is the resonance frequency for four sodium.
And we're going to observe the sodium resonance fluorescence.
So when we come back, we'll have it set up for you
so that you can observe for yourself
this tremendous absorption exhibited by sodium when
excited by dye laser radiation at the sodium resonance.
The sodium is in a cell--
in a heated cell--
on the right.
And what you can see right now, inside, you
see the resonance scattering by sodium at 5890 angstrom.
Now, all I have to do is I tune the dye laser waveform
resonance, and there's fluorescence.
[? Onto ?] the resonance, here we
are, plenty of scattered light.
And I go the other side of resonance,
and there's no absorption.
So here we are again, on resonance and off resonance.
On resonance and off resonance.
CREW: How was that?
PROFESSOR: Great.