We present an experimental technique that permits mechanical-noise-free, cavity-enhanced frequency measurements of an atomic transition and its hyperfine structure. We employ the 532-nm frequency-doubled output from a Nd:YAG laser and an iodine vapor cell. The cell is placed in a folded ring cavity (FRC) with counterpropagating pump and probe beams. The FRC is locked with the Pound-Drever-Hall technique. Mechanical noise is rejected by differencing the pump and probe signals. In addition, this differenced error signal provides a sensitive measure of differential nonlinearity within the FRC.
© 2005 Optical Society of America
Glenn de Vine, David E. McClelland, Malcolm B. Gray, and John D. Close, "Pump-probe differencing technique for cavity-enhanced, noise-canceling saturation laser spectroscopy," Opt. Lett. 30, 1219-1221 (2005)