Coherent population trapping in a non-monochromatic laser field

I. E. Mazets, Boris G. Matisov, D. Parsons

D. Miletic, Thejesh Bandi, C. Affolderbach +1 more

We present a comparative study of the light-shifts (ac Stark shift) in a Rb vapour cell using two possible schemes for Rb atomic clocks: double resonance (DR) and coherent population trapping (CPT). For both schemes, the same wall-coated cell in a compact atomic resonator was used. The light-shift resulting from a monochromatic (DR) or a non-monochromatic (CPT) optical excitation was measured as a function of the laser intensity and the laser frequency and compared with existing theoretical results.

I. E. Mazets, Boris G. Matisov

D. Miletic, Thejesh Bandi, C. Affolderbach +1 more

We report on a comparative study on the light shift in two possible clock schemes for vapor-cell standards, Double Resonance (DR) and Coherent Population Trapping (CPT), by using the same wall coated cell and compact atomic resonator. Our experimental setup allowed us to measure and study the AC Stark shift, resulting from a mono-chromatic or a non monochromatic optical excitation. The light-shift was investigated as function of the laser intensity and the laser frequency.

Bryan J. Dalton, P. L. Knight

Xiao-Yong 肖勇 Lu 卢, Ya-Peng 亚鹏 Sun 孙

The four-color three-step selective photoionization process of atom is very important in laser isotope separation technology. The population trapping phenomena and their influences are studied theoretically in monochromatic and non-monochromatic laser fields based on the density matrix theory in this work. Time evolutions of the photoionization properties of the four-color, three-step process are given. The population trapping effects occur intensely in monochromatic excitation, while it gradually turns weak as the laser bandwidth increases. The effects of bandwidth, Rabi frequency, time delay, and frequency detuning on the population trapping effect are investigated in monochromatic and non-monochromatic laser fields. The effects of laser process parameters and atomic parameters on the effective selective photoionization are also discussed. The ionization probability and selectivity factors, as evaluation indexes, are difficult to improve synchronously by adjusting systematic parameters. Besides, the existence of metastable state may play a negative role when its population is low enough.