Photo Tour -- Raizen Laboratory
This is a copy of the original photo tour written by Daniel Steck
and accessible here.
Dan and I were both students of Mark Raizen
at the University of Texas at Austin,
and although this is a photo tour of Dan's Cesium trapping experimental apparatus
my Sodium apparatus (see the last photo in this tour),
and the ones we are buildling in this lab,
are basically the same as pictured here.
This is just a brief tour of my Ph.D. experiment in Mark Raizen's
lab at The University of Texas at Austin. This will give you a rough
idea of what the experiments I have planned look like, although there
will be a lot of updates and improvements.
This was an experiment that used ultracold cesium atoms to
study fundamental effects in the areas of quantum chaos and the
In the same lab, just beyond
the curtain, there is another similar experiment, but I don't have
any good pictures of it (save for the last one).
This lab looks a lot different now; since I left, it has been converted
to a rubidium BEC experiment.
You can click on any of the photos to get larger versions.
|| The heart of the experiment is a bunch of optics on an optical table.
And I do mean a bunch. Don't worry too much, though; I started in the
fall of 1995 with a blank table, and this photo was taken in the
late summer of 2001. Even though it looks like a mess, it was quite
managable for 2 or 3 people to build it up over 6 years.
The experiments I'm planning may get to look like this over that time,
but the initial experiments in 1-2 years will look simpler.
Just to give you a sense of scale, the optical table here measures
4'x12' (I'm planning on a 5'x12' table to reduce some of the
“skyscraper effect” that you see here).
Like I said, these aren't easy experiments, but once you get one of
these working, you'll be a damn good experimentalist.
|| This is approximately the same photo taken some three years earlier,
just to show you the progression of the experiment. The experiments
were pretty simple back then.
|| This is a view of the other end of the table. More optics, and you
can see the two big lasers of the experiment, a Ti:sapphire laser
and the argon-ion laser that pumps it. These probably won't be
necessary, since diode lasers can give similar performance now
at much lower cost and effort. However, a large 1 micron solid-state laser
will be necessary for some of the experiments.
|| This is a closeup of the Ti:sapphire laser, where you can see the crystal
being pumped by the argon-ion laser light. Again, not so relevant for
experiments I'm planning, but hey, it's a cool picture, no? Incidentally,
this is a home-built laser. It was actually a home-built dye laser
based on a design by Jim Bergquist at NIST when I started. Then Bruce
Klappauf (another grad student) and I tore it apart and used the pieces
to build this laser.
|| This is a homebuilt, grating-stabilized diode laser. We used this for the
repump light of the magneto-optical trap, if that means anything to you.
They're still using a modification of this laser with much success,
and the Heinzen group
at UT also adopted this design, so I'm planning to stick with this laser
rather than commercially available designs.
|| This is a distributed Bragg reflector diode laser, which stabilizes
itself to the proper wavelength without any external optics. Pretty
cool and simple, but not as good performance as the other laser.
This was our primary laser for our atom trap. These aren't really
available anymore, so I don't plan to use these, but I plan to
slave some high-power diodes from the grating-stabilized lasers,
and the slaves will look something like this. That's a collimation
lens in front of the laser diode there, and it's supported by two
glass rods and glued into place. Sounds strange, but this was based
on an idea in use at the ENS in Paris, and once we switched to this
design, the beam line would stay aligned for months at a time. Very nice.
|| An up-close view of the vacuum chamber, where the atoms actually get trapped.
It's kind of big compared to what I'm thinking for the future, which
will be based on smaller, all-glass cells, with independent sections
for trapping and science. You couldn't actually see the atoms with
your eye even if the lasers were on in this photo, since the 852 nm
resonance is too far in the infrared to be visible. (Well, you actually
can see 852 nm light at sufficiently high intensities, but then
it's not exactly good for your eye.)
|| And of course no experiment would be complete without...5 racks full of
electronic equipment. There's a good mix of homebuilt and commercial
stuff here, all for controlling and debugging the experiment.
Again, this isn't nearly as unreasonable as it looks. I'd also like
to build up a system of control equipment that is homebuilt and
internet-compatible, with the goal of replacing commercial equipment
that you see here that is based on surprisingly old technology given
|| Finally, a photo of the other experiment to show you what trapped atoms
actually look like. In the center of that glass vacuum cell is a cloud of
100,000 trapped sodium atoms. Sodium is kind of a painful atom to
work with though, so don't expect to see any yellow atoms in my lab
like this (much more likely are red clouds of rubidium atoms).