Observation of the ${}^{87}$Rb $5S_{1/2}$ to $4D_{3/2}$ electric quadrupole transition at 516.6 nm mediated via an optical nanofibre

Tridib Ray, Ratnesh K. Gupta, Vandna Gokhroo +4

Light guided by an optical nanofibre can have a very steep evanescent field gradient extending from the fibre surface. This can be exploited to drive electric quadrupole transition…