Modulation-free laser frequency stabilization and detuning

We have developed a modulation-free technique for stabilizing a laser to a Doppler-free saturated absorption spectrometer without the need for phase sensitive detection. By using two acousto-optic modulators, we can lock, with variable offset, to atomic resonances. The new technique works equally well with both vapor and discharge reference cells. We demonstrate the technique using rubidium and metastable argon as references. (C) 2002 Elsevier Science B.V. All rights reserved.