Two-photon rubidium clock detecting 776 nm fluorescence

Opt Express. 2024 Feb 26;32(5):7417-7425. doi: 10.1364/OE.513974.

Abstract

The optical atomic clock based on the 5S1/2 → 5D5/2 two-photon transition in rubidium is a candidate for a next generation, manufacturable, portable clock that fits in a small size, weight, and power (SWaP) envelope. Here, we report the first two-photon rubidium clock stabilized by detecting 776 nm fluorescence. We also demonstrate the use of a multi-pixel photon counter as a low voltage substitute to a photomultiplier tube in the feedback loop to the clock laser.