Digitally encoded RF to optical data transfer using excited Rb without the use of a local oscillator

Abstract

We present a passive RF to optical data transfer without a local oscillator using an atomic “Rydberg” receiver. We demonstrate the ability to detect a 5G frequency carrier wave (3.5 GHz) and decode digital data from the carrier wave without the use of a local oscillator to detect the modulation of the RF signal. The encoding and decoding of the data are achieved using an intermediate frequency (IF). The rubidium vapor detects the changes in the carrier wave's amplitude, which comes from the mixing of the IF onto the carrier. The rubidium vapor then upconverts the IF into the optical domain for detection. Using this technique for data encoding and extraction, we achieve data rates up to 238 kbps with a variety of encoding schemes.