Fig. 3. Comb-like ultrahigh-resolution spectroscopy of Floquet maser.

(A) Comparison between conventional Floquet spectrum based on 129Xe free-decay signal (blue lines) and a spectrum based on Floquet maser (red lines). The driving frequency is νac = 0.050 Hz, and its amplitude is Bac = 56.15 nT. a.u., arbitrary units. (B) Spectrum based on Floquet maser, where νac = 0.010 Hz and Bac = 56.15 nT.