Laser Spectroscopy

Absorption spectroscopy usually implies having a tunable frequency source and producing a plot of absorption as a function of frequency. This was not feasible with lasers until the advent of the dye lasers which can be tuned over a nearly continuous range of frequencies.

Laser spectroscopy has led to advances in the precision with which spectral line frequencies can be measured, and this has fundamental significance for our understanding of basic atomic processes. This precision has been obtained by passing two laser beams through the absorption sample in opposite directions, selectively triggering absorption only in those atoms that have a zero velocity component in the direction of the beams. This effectively eliminates the Doppler broading of spectral lines from the distribution of atomic velocities present in the sample.

Picosecond Laser Spectroscopy Lab

This work is in progress and will be posted when it's a little more develped. For a start, see laser oscillator.