Tunable Quantum Counter For Far-Infrared Radiation

Zusammenfassung

We report on a quantum counter which converts far‐infrared radiation to visible light. The 891‐Ghz radiation of an HCN laser, absorbed in optically pumped ruby by the transition Ē (2E) →2Ā (2E), was detected by an increased R2 fluorescence. By Zeeman splitting of the 2E levels the narrow‐band detector was tuned to the laser line.