Rydberg-atom detector conquers a new spectral frontier

Using Rydberg atoms as a quantum antenna, we measured a single tooth of a terahertz frequency comb and calibrated its intensity, at room temperature (Optica 12, 1854). Read the Faculty of Physics press release.

The detector spans an octave with MHz-level selectivity and reaches a power sensitivity of 1.84 fW Hz⁻¹ᐟ² within a single mode of the comb.