High resolution spectroscopic measurement of 130Te2: Reference lines near 444.4 nm for eEDM experiment using PbF molecules

摘要

Molecular tellurium (Te-2) offers a wide range of potential applications, including frequency reference. Spectroscopic results about the Te-130(2) spectrum were previously reported, but few lines lie around the PbF transition of A ((2)Sigma(+)) (upsilon' = 0) <- X-1(2)Pi(1/2) (upsilon = 0) (similar to 444.4 nm) which is regarded as an eEDM (electron's Electric Dipole Moment) sensitive transition. Here electronic transition lines for Te-130(2) were determined using the Saturated Absorption Spectroscopy method, where the origin of the transition band was inves- tigated for the B-1 ((3)Sigma(-)(u))0(u)(+) (upsilon' = 10) <- X-1 ((3)Sigma(-)(g))0(g)(+) (upsilon = 5) transition. The Dunham model with high orders was utilized to assign these transition lines, while Dunham parameters of the excited state B-1 (upsilon' = 10) were updated to a new level. The Toptica TA-SHG Pro laser was then locked to a single absorption line using a P-I servo. Our results here not only provide the assigned atlas of Te-2 spectrum near 444.4 nm, but also contribute to a stable and sensitive spectroscopic detection of PbF molecules toward the eEDM measurement, which is significant in understanding the fundamental physics beyond the Standard Model.

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