Optical pumping
In this experiment we learn all about atomic physics. Atoms with a single valance electron, which determines its optical properties.
Learn
- the physics of the energy levels of these atoms
- (with simple apparatus) how to manipulate the state of that external electron.
- how to add angular momentum components, this controls the energy level available to the electron.
To manipulate the electrons we shine light. Turns out if light circularly polarized is shined, can induce transitions among a cluster of states. We do this in a cleaver way (called "pumping") so all the electrons are in one of these energy levels.
Thermal distribution –> To particular state.
Important for
- laser physics / quantum optics / q-bits
- q-bits optically pumped Rb is one of the textbook models for how you can create q-bits
Equipment :
- oven that gives off light from a Rb gas
- central cell that contains the Rb vapor
- Rb light through optical elements, which will circularly polarize the light.
- Light goes through the cell
- at the end simple photo-diode detector, measure how much of the input light makes it through
When we pump the atoms in the cell, can make the cell either transparent or opaque to the light that is coming through.
Coils ("Helmholtz coil") create a very uniform magnetic field . Also have a control box and a oscilloscope(No computers! )
Can measure earths magnetic field, Zeeman effect, time scales of pumping, other cool effects Rabi oscillations