Friday, May 21, 2010

Background Information

Here are some information and images from John Lorenz about what they've been doing:
As I described before, I currently have a dual species MOT and am about ready to take atom number measurements - the density of out atoms in our trap are an important parameter in photoassociation.  I have attached a diagram of my experimental setup and a picture (experimental_setup.jpg and experimental_pic.jpg respectively).  The don't reflect the most current state of things, but they give a rough idea.  Right now I have 3 diode lasers (DL) and a tapered amplifier (TA) (which amplifies light from one of the diode lasers) to create the trap.  They are all locked to a given frequency with homemade locking circuits and AOM's or EOM's - which are devices which can shift the frequency of light in a crystal by up to a few hundred megahertz.  One of the DL's is homemade.  I will soon put a new DL on the table (also homemade) for the purposes doing the Photoassociation.  The kind of data I will be taking this summer are images of the MOT (as seen in mot.jpg) and molecular spectra.  I've included a fluorescence spectra of a lithium dimer taken from a heat pipe (fluorescence.jpg) - fluorescence spectra collect light from the fluorescing molecules in a resonant laser beam and record energy level as peaks.  My spectra will look for decreases in MOT fluorescence when molecules are formed, so energy levels will be dips instead of peaks - this is called trap loss spectroscopy. 
experimental_pic.jpg

experimental_setup.jpg

fluorescence.jpg

MOT.jpg

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