We investigate systematic errors associated with a common modulation technique used for phase-sensitive detection of a coherent-population-trapping (CPT) resonance. In particular, we show that modification of the CPT resonance line shape due to the presence of off-resonant fields leads to frequency shifts that may limit the stability of CPT-based atomic clocks. We also demonstrate that an alternative demodulation technique greatly reduces these effects.
© 2005 Optical Society of America
(020.1670) Atomic and molecular physics : Coherent optical effects
(020.3690) Atomic and molecular physics : Line shapes and shifts
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(300.6380) Spectroscopy : Spectroscopy, modulation
David F. Phillips, Irina Novikova, Christine Y.-T. Wang, Ronald L. Walsworth, and Michael Crescimanno, "Modulation-induced frequency shifts in a coherent-population-trapping-based atomic clock," J. Opt. Soc. Am. B 22, 305-310 (2005)