Laser Optics and Quantum Mechanics

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Laser Optics and Quantum Mechanics

• Jason Goff, UCORE Summer 07
• Steck Lab, University of Oregon
• Oregon Center for Optics

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Overall Goals

• Currently, the table is being tuned to allow for
  dipole operation. However, the Magneto-Optical
  Trap (MOT) is operating as designed.
• Short term goals would include a one-way barrier
• Long term goals include Quantum feedback control,
  measurement, Chaos, and Quantum to classical
  transitions

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Table Lay-out

• The table is arranged with a MOT and a dipole
  trap. Of the two, the MOT is the one that has a
  magnetic coil assembly.

Visible MOT in Hellma Cell with AH coils
visible above and below the cell assembly
(courtesy of Steck Lab).
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Quantum Mechanisms

• MOT
• Considered by the communitee to be the general
  workhorse for quantum experimentation.
• Uses 6 lasers with optics to create a focus in
  the center of Hellma Cell. These beams can be
  emitted by multiple lasers or by one laser and
  split via a beam splitter.
• In tandem to the lasers are two coils called
  AntiHelmholtz Coils. These work in concert to
  ensure that the 87Rb is collected in the center
  of the Hellma cell for sampling and testing.
• Not as effective as a dipole trap for
  experimental testing

Courtesy of Steck Lab
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MOT arrangement

• These pictures demonstrate the arrangement of the
  MOT assembly the circles being the AH coil, the
  6 red arrows signifying the laser beam trajectory
  to the center, and then the blue dot which
  signifies the trapped element (in this case,
  87Rb).

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AH Driver Board

• An Anti-Helmholtz driver board completely
  stuffed and ready to use.
• Has two different voltage circuits, a 15V circuit
  for running the board and a 40V circuit for
  running the coils.
• Boards are designed to run a single coil and
  operate in tandem as a Master-Slave system.
• The master board controls the current control to
  the coils while the slave control adjusts the
  gain of the slave coil, i.e. the difference
  current through each coil.
• The optimal gain is 11

Pictures courtesy of Jeremy thorn
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UCORE Contribution

• Upon arrival in to the Steck lab, I was assigned
  the task of diagnosing a laser voltage supply
  board. However, due to the enormous task and my
  lack of experience, it was decided that I should
  build and test Anti-Helmholtz driver boards.
• This task would give me the necessary skills to
  understand future projects which might need
  electronics or a circuit background.
• UCORE made possible the construction of 3
  separate boards as well as other minor equipment
  additions.

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Sources and Acknowledgements

• Pictures courtesy of Steck lab, University of
  Oregon
• Thanks to Dan Steck, University of Oregon
• Phillips, William D. (1998) Laser cooling and
  trapping of neutral atoms, in Reviews of Modern
  Physics 3 / 70, S. 721-741.
• Steck, Daniel A (2006) Classical and Modern
  Optics, Class Notes, pg 207-227.

Research made possible by grants from the NSF and
UCORE