Pulsed coherent population trapping spectroscopy in microfabricated Cs-Ne vapor cells

Pulsed coherent population trapping (CPT) spectroscopy is applied in buffer-gas filled Cs-Ne vapor microfabricated cells. The properties of the Ramsey-CPT clock transition central fringe (linewidth, signal amplitude, and contrast) are studied versus several experimental parameters, including the Ramsey sequence and the input laser intensity, and are compared to those obtained in the conventional continuous (CW) interrogation mode. In the pulsed case and for short Ramsey-free evolution times T-R, the central fringe linewidth is found to exhibit a small but visible power broadening and is measured to be narrower than the value of 1/(2T(R)) that is reached for long T-R. The microwave hyperfine coherence lifetime T-2 in the Cs-Ne microcells is measured to be in the 50-500 mu s range. Its dependence to the buffer gas pressure or cell temperature is briefly studied. (C) 2018 Optical Society of America.