Aircraft-level vibration effects on hyperfine laser locks for Rydberg electric-field sensing.

We present a subsystem-isolated study of aircraft-level vibration coupling to a hyperfine laser lock and its propagation to a two-photon Rydberg superheterodyne RF sensor. Here, the probe laser is stabilized to an atomic hyperfine transition, and RF electric fields are detected via a Rydberg-atom superheterodyne process that down-converts the signal to an optical readout. A compact Doppler-free saturated-absorption spectroscopy (SAS) module probing the 87Rb5S1/2→5P3/2 hyperfine manifold was driven to NASA DC-8 in-flight vibration levels (<2kHz) to investigate the effects of vibration on the stabilization of a 780 nm laser. The stabilized 780 nm probe was combined with a 480 nm coupling laser to excite a room-temperature Rydberg sensor to the 63D5/2 state and driven for the RF superheterodyne detection via a ∼8.35GHz local oscillator coupling to the 64P3/2 state (RF 100 kHz detuned). Under nominal PID settings, vibration introduced low-frequency noise but did not cause the laser to unlock nor did it degrade the atomic RF readout. Probe wavemeter Allan deviations remain ⟨60kHzatτ⟩20s at with and without vibration, indicating no loss of lock or MHz-scale drift. Independent frequency-noise-density measurements show no measurable difference between vibration and no-vibration conditions under nominal PID settings. The Rydberg spectrum showed <10% RF-amplitude deviation and a sensitivity of ∼1.5×10-5Vm-1Hz-1/2. Increasing integral gain by >103 transferred vibration noise to the servo, elevating low-frequency noise in the atomic RF spectrum, but with no measurable degradation of the RF sensing at 100 kHz detuning.