Sensitive laser-powered antenna utilizing all-optical quantum radio receiver based on Rydberg atomic properties provides internal calibration
https://www.eurekalert.org/news-releases/1102028 "replaces antenna/ electronic mixer with new medium: atoms released from rubidium placed in glass cell vacuum harnessed for 3-laser controlled choreography... rubidium vapor, sealed enclosure, lasers convert radio waves into infrared radiation... non-invasive measurements enable recording weak fields without metal antenna disturbance... concealable wiretap... future: detector could take form of mere thickening on optical fiber containing lasers, as well as received IR, sent in opposite direction in optical fiber"