Fig. 4: Atomic bright resonances enabling the conversion process.
From: Continuous wideband microwave-to-optical converter based on room-temperature Rydberg atoms

a, Measured conversion in the domain of bare-state detunings from energy levels 552D5/2 and 542F7/2 (other detunings being near zero), revealing the underlying bright resonances \(\left\vert B+\right\rangle\) and \(\left\vert B-\right\rangle\). From this measurement we obtained the optimal level detunings Δ55D = 16 × 2π MHz, Δ54F = 0. b, The same conversion interdependence predicted by the numerical simulation.