We report an experimental investigation on the Doppler-free saturated absorption spectroscopy of buffer-gas-cooled Barium monofluoride(BaF)molecules in a 4 K cryogenic cell.The obtained spectra with a resolution of 19...We report an experimental investigation on the Doppler-free saturated absorption spectroscopy of buffer-gas-cooled Barium monofluoride(BaF)molecules in a 4 K cryogenic cell.The obtained spectra with a resolution of 19 MHz,much smaller than previously observed in absorption spectroscopy,clearly resolve the hyperfine transitions.Moreover,we use these high-resolution spectra to fit the hyperfine splittings of excited A(v=0)state and find the hyperfine splitting of the laser-cooling-relevant A^(2)Π_(1/2)(v=0,J=1/2,+)state is about 18 MHz,much higher than the previous theoretically predicted value.This provides important missing information for laser cooling of BaF molecules.展开更多
A novel cryogenic MgF molecular beam,characterized by high flux and exceptional stability,has been successfully generated within a helium buffer gas environment.This achievement is facilitated by the innovative use of...A novel cryogenic MgF molecular beam,characterized by high flux and exceptional stability,has been successfully generated within a helium buffer gas environment.This achievement is facilitated by the innovative use of an in-cell stepper motor,which continuously rotates the sample rod during laser ablation.Through meticulous optimization of the ablation laser energy,the position of the ablation spot,and the gas flow rate,among other critical parameters,the resulting MgF beam exhibits a remarkable forward velocity of 209 m/s and an impressive brightness of approximately 1.36×10^(12)molecules per pulse per steradian per internal state.Subsequent attempts at one-dimensional Doppler cooling of the MgF beam have been made,with theoretical calculations closely aligning with experimental outcomes.These findings demonstrate a significant compression in the transverse spatial distribution of the molecular beam,from 7.8 to 6.5 mm,and a substantial cooling of the transverse temperature,from 8.1 to 5.6 mK.This work lays a crucial foundation for the advancement of molecular slowing and magneto-optical trapping techniques for MgF molecules.展开更多
基金support from the National Key Research and Development Program of China under Grant No.2018YFA0307200the National Natural Science Foundation of China under Grant Nos.U21A20437 and 12074337+2 种基金the Natural Science Foundation of Zhejiang Province under Grant No.LR21A040002Zhejiang Province Plan for Science and technology No.2020C01019the Fundamental Research Funds for the Central Universities under No.2021FZZX001-02.
文摘We report an experimental investigation on the Doppler-free saturated absorption spectroscopy of buffer-gas-cooled Barium monofluoride(BaF)molecules in a 4 K cryogenic cell.The obtained spectra with a resolution of 19 MHz,much smaller than previously observed in absorption spectroscopy,clearly resolve the hyperfine transitions.Moreover,we use these high-resolution spectra to fit the hyperfine splittings of excited A(v=0)state and find the hyperfine splitting of the laser-cooling-relevant A^(2)Π_(1/2)(v=0,J=1/2,+)state is about 18 MHz,much higher than the previous theoretically predicted value.This provides important missing information for laser cooling of BaF molecules.
基金the National Natural Science Foundation of China under Nos.12174115,91836103,and 11834003.
文摘A novel cryogenic MgF molecular beam,characterized by high flux and exceptional stability,has been successfully generated within a helium buffer gas environment.This achievement is facilitated by the innovative use of an in-cell stepper motor,which continuously rotates the sample rod during laser ablation.Through meticulous optimization of the ablation laser energy,the position of the ablation spot,and the gas flow rate,among other critical parameters,the resulting MgF beam exhibits a remarkable forward velocity of 209 m/s and an impressive brightness of approximately 1.36×10^(12)molecules per pulse per steradian per internal state.Subsequent attempts at one-dimensional Doppler cooling of the MgF beam have been made,with theoretical calculations closely aligning with experimental outcomes.These findings demonstrate a significant compression in the transverse spatial distribution of the molecular beam,from 7.8 to 6.5 mm,and a substantial cooling of the transverse temperature,from 8.1 to 5.6 mK.This work lays a crucial foundation for the advancement of molecular slowing and magneto-optical trapping techniques for MgF molecules.
