Laser-cooling Cadmium Bosons and Fermions with Near Ultraviolet Triplet Excitations

Abstract

Cadmium is laser-cooled and trapped with excitations to triplet states with UVA light, first using only the $67$kHz wide $326$nm intercombination line and subsequently, for large loading rates, the $25$MHz wide $361$nm ${}^3{P}_2$$\to$${}^3{D}_3$ transition. Eschewing the hard UV $229$nm ${}^1{S}_0$$\to$${}^1{P}_1$ transition, only small magnetic fields gradients, less than $6$Gcm${}^{-1}$, are required enabling a 100\% transfer of atoms from the $361$nm trap to the $326$nm narrow-line trap. All 8 stable cadmium isotopes are straightforwardly trapped, including two nuclear-spin-$\frac{1}{2}$ fermions that require no additional repumping. We observe evidence of ${}^3{P}_2$ collisions limiting the number of trapped metastable atoms, report isotope shifts for ${}^{111}$Cd and ${}^{113}$Cd of the $326$nm ${}^1{S}_0$$\to$${}^3{P}_1$, $480$nm ${}^3{P}_1$$\to$${}^3{S}_1$, and $361$nm ${}^3{P}_2$$\to$${}^3{D}_3$ transitions, and measure the ${}^{114}$Cd 5s5p${}^3{P}_2$$\to$5s5d${}^3{D}_3$ transition frequency to be $830096573(15)$MHz.