Photoassociative Spectroscopy of ⁸⁷Sr

We demonstrate photoassociation (PA) of ultracold fermionic ⁸⁷Sr atoms via the dipole-allowed atomic transition in Strontium (Sr) near 461nm. The binding energies of a series of molecular states on the 5s² (¹S₀) + 5s5p (¹P₁ )molecular potential are fit with the semiclassical LeRoy-Bernstein model, and PA resonance strengths are compared to predictions based on the known ¹S₀ + ¹S₀ ground state potential. Similar measurements and analysis were performed for the bosonic isotopes ⁸⁴Sr and ⁸⁶Sr, allowing a combined analysis of the long-range portion of the excited-state potential and determination of the 5s5p ¹P₁ atomic state lifetime. The results enable prediction of PA rates across a wide range of experimental conditions.