Frequency Measurements and Hyperfine Structure of the R(85)33–0 Transition of Molecular Iodine with a Femtosecond Optical Comb

Absolute frequency measurements of the R(85)33-0 transition of molecular iodine at the blue end of the tuning range of a frequency-doubled Nd:YAG laser are implemented with a femtosecond optical comb based on a mode-locked Ti:sapphire laser. The hyperfine structure of the R(85)33-0 transition is observed by use of high-resolution laser spectroscopy and is measured by the femtosecond optical comb. The observed hyperfine transitions are good frequency references for both frequency-doubled Nd:YAG and Nd:YVO4 lasers in the 532-nm region. High-accuracy hyperfine constants are obtained by our fitting the measured hyperfine splittings to a four-term Hamiltonian, which includes the electric quadrupole, spin-rotation, tensor spin-spin, and scalar spin-spin interactions. (C) 2004 Optical Society of America.