Two-photon optical frequency reference with active AC Stark shift cancellation
Vladislav P. Gerginov, Kyle P. Beloy
An optical reference based on two-photon optical transition with AC stark shift cancellation is proposed. The reference uses two interrogating laser fields at different frequencies. Compared to conventional optical two-photon references, the new approach offers the possibility for increased short-term stability resulting from a higher signal-to-noise, and improved long-term stability due to active AC Stark shift cancellation. We demonstrate the AC Stark shift cancellation method on the 5s 2S1/2 -> 5d 2D5/2 two-photon transition in 87Rb.