Nonlinear magneto-optical rotation measured with the DC and AC magnetometers. (a) In-phase component of the signal recorded versus the AC-field frequency near resonance (ωAC ≈ ωL ≈ 5.25 kHz) for two static-field values. The change of the DC field by 15 μG leads to the 10-Hz resonance shift. (b) Change in the in-phase component of the signal for the fixed frequency (initially ωAC = ωL ≈ 5.25 kHz) when the static field is modified by 15 μG at t = t0. (c) Amplitude of the NMOR signal measured for two different AC-field amplitudes and a fixed static field of ωL ≈ 5.25 kHz. (d) Rotation signal measured for ωAC = ωL ≈ 5.25 kHz when amplitude of the AC field is changed by 15 μG at t = t0 and other experimental parameters remain unchanged. The vertical arrows in (a and c) mark the NMOR signals at ωAC = 5.25 kHz when DC and AC fields are changed by 15 μG [signals presented in (b and d)].