Absolute frequency and hyperfine structure of I-127(2) transitions at 531.5 nm by precision spectroscopy using a narrow-linewidth diode laser

摘要

The absolute frequency and hyperfine structure of the P(98)34-0, R(38)32-0, P(35)32-0, P(112)35-0, R(75)33-0, R(37)32-0, and P(34)32-0 transitions of molecular iodine at 531.5 nm are measured using high-resolution spectroscopy based on a narrow-linewidth planar-waveguide external cavity diode laser. The absolute frequencies of the transitions are determined with an uncertainty of 5.7 kHz, while the hyperfine structures are measured with an uncertainty of < 1 kHz. High-precision hyperfine constants are obtained by fitting the measured hyperfine splittings, with an uncertainty of approximately 1 kHz, to a four-term Hamiltonian that includes the electric quadrupole, spin-rotation, tensor spin-spin, and scalar spin-spin interactions. The measured absolute frequencies and hyperfine structures are useful for optical frequency metrology and studies of molecular iodine. (C) 2020 Optical Society of America