High resolution spectroscopy of B0_u⁺←X0_g⁺ transitions in ¹³⁰Te₂: Reference lines spanning the 443.2–451.4 nm region

Molecular tellurium (¹³⁰Te₂) has long been regarded as a promising candidate for a variety of spectroscopic applications, especially as a frequency reference. Absorption lines of ¹³⁰Te₂ were published extensively in the past few decades, however, the spectral resolution was not sufficiently high to be considered a precision spectroscopic reference. Here, a high resolution spectral atlas of ¹³⁰Te₂ Doppler-free saturated absorption transitions is reported, and used to assign multiple ro-vibrational bands in the B(Σu-3)0_u⁺←X(Σu-3)0_g⁺ electronic transition via the Dunham model, giving updated Dunham parameters and diatomic constants for the B(Σu-3)0_u⁺ state at an unprecedented level of precision. Our findings reveal spectroscopic properties of ¹³⁰Te₂ that might eventually contribute to frequency reference in precision measurement such as the quest for non-zero electron's Electric Dipole Moment (eEDM).