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

Area of Science:

• Atomic Physics and Spectroscopy
• Quantum Sensing
• Aerospace Instrumentation

Background:

• Atomic hyperfine transitions are sensitive to environmental noise, including vibration.
• Rydberg atom sensors offer high sensitivity for radiofrequency (RF) electric field detection.
• Stabilizing lasers to atomic transitions is crucial for precision measurements.

Purpose of the Study:

• To investigate the impact of aircraft-level vibration on a hyperfine laser lock.
• To assess the propagation of vibration effects to a two-photon Rydberg superheterodyne RF sensor.
• To evaluate the robustness of atomic RF sensing under dynamic operational conditions.

Main Methods:

• A compact Doppler-free saturated-absorption spectroscopy (SAS) module probing ⁸⁷Rb was subjected to in-flight vibration levels (<2kHz).
• A 780 nm probe laser stabilized to the ⁸⁷Rb hyperfine transition was used.
• A two-photon Rydberg sensor utilizing a 480 nm coupling laser and a 8.35 GHz local oscillator detected RF fields.

Main Results:

• Under nominal Proportional-Integral-Derivative (PID) control, vibration introduced low-frequency noise but did not cause laser unlocking or degrade RF readout.
• Probe laser Allan deviations remained below 60 kHz at 20s, indicating no loss of lock or significant drift.
• The Rydberg sensor exhibited <10% RF-amplitude deviation and a sensitivity of ~1.5×10^-5 Vm^-1Hz^-1/2; increased integral gain transferred vibration noise but did not degrade RF sensing at 100 kHz detuning.

Conclusions:

• Aircraft vibration, within the tested range and under nominal control, does not compromise the stability of a hyperfine laser lock or the performance of a Rydberg RF sensor.
• The subsystem-isolated study demonstrates the potential for robust atomic RF sensing in dynamic environments like aircraft.
• The findings support the use of Rydberg sensors for precise RF measurements in challenging field conditions.