Optical Spectroscopy

Confinement of particles in Penning traps yields two major advantages for spectroscopy, namely localisationLocalisation for extended periods (i.e. the particle position is constant and well-known) and cooling (which leads to small Doppler shifts and broadening of transitions). Also, the particle ensemble can often be treated as a point-like source, which facilitates detection. We give a short account of the important aspects to optical spectroscopy when performed in a Penning trap.