title: Doppler-free spectroscopy on the Cs D1line with a dual-frequency laser.
abstract: We report on Doppler-free laser spectroscopy in a Cs vapor cell using a dual-frequency laser system tuned on the Cs D1line. Using counter-propagating beams with crossed linear polarizations, an original sign reversal of the usual saturated absorption dip and large increase in Doppler-free atomic absorption is observed. This phenomenon is explained by coherent population trapping (CPT) effects. The impact of laser intensity and light polarization on absorption profiles is reported in both single-frequency and dual-frequency regimes. In the latter, frequency stabilization of two diode lasers was performed, yielding a beat note fractional frequency stability at the level of 3×10-12at 1 s averaging time. These performances are about an order of magnitude better than those obtained using a conventional single-frequency saturated absorption scheme.
authors.forename: Moustafa Abdel
authors.initials: MA
authors.lastname: Hafiz
authors.forename: Grégoire
authors.initials: G
authors.lastname: Coget
authors.forename: Emeric
authors.initials: E
authors.lastname: De Clercq
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Boudot