High resolution molecular spectroscopic system assisted by an optical frequency comb

Abstract

We developed a high resolution laser spectroscopic system to study detailed structures and dynamics in excited states of molecules. The cooperation of an optical frequency comb and a single-mode dye laser realized high resolution, high accuracy, and wide tuning range simultaneously with short measurement time and easy operation. To demonstrate the ability of our system, we observed hyperfine spectra of B–X rovibronic transitions of molecular iodine distributed in the range of 570–612 nm. The absolute frequencies of hyperfine components were determined with the uncertainty of about 100 kHz, and vibrational dependences of the hyperfine constants were examined.