High-Performance Molecular Iodine-Stabilized Laser

This study focuses on the development and optimization of the frequency-stabilized laser system based on molecular iodine, aiming to meet the demands of high-precision measurements. We have developed two high-performance molecular iodine optical frequency references based on modulation transfer spectroscopy, both referencing the R(56)32-0:a1 transition of molecular iodine. The 30 cm long saturated absorption cell is used by the first system and operated at a pressure of 3.3 Pa to achieve high short-term stability, with a fractional frequency instability of 3.3 x 10^-15 at 2 s. The unsaturated absorption cell with a length of 25 cm is employed by the second system and maintained at a pressure of 0.88 Pa to achieve high long-term stability, with a fractional frequency instability of 1.7x 10^-15 at 10000 s.