High resolution sub-Doppler laser FM-spectroscopy of molecular iodine vapor

We apply the self-calibrated sub-Doppler laser FM-spectroscopy to the study of hyperfine structure of molecular iodine. The ability of proposed technique to the high accurate measurements of iodine hyperfine structure in wide region of mode-hope free tuning of diode laser is demonstrated. The nonlinear absorption spectra of molecular iodine embedded into the pores of synthetic opal are studied with sub-megahertz resolution.