Natural line shape
P. V. Elyutin
Department of Physics, Moscow State University, 119991 Moscow, Russia
PACS: 32.70.Jz, 42.50.-p
Abstract
The observable line shape of the spontaneous emission
depends on the procedure of atom's excitation. The spectrum of
radiation emitted by a two-level atom excited from the ground
state by a pi pulse of the resonant pump field is calculated for
the case when the Rabi frequency is much larger than the
relaxation rate. It is shown that the central part of the spectral
distribution has a standard Lorentzian form, whereas for detunings
from the resonance that are larger than the Rabi frequency the
spectral density falls off faster. The shape of the wings of the
spectral line is sensitive to the form of the pi pulse. The
implications for the quantum Zeno effect theory and for the
estimates of the duration of quantum jumps are discussed.