Stabilization of Rydberg Dissipative Time Crystals Using a Scanning Fabry–Pérot Interferometer Transfer Lock

Stabilization of laser frequencies is critical for sensitive Rydberg measurements, including in applications such as dissipative time-crystal (DTC) dynamics, yet conventional approaches often require complex or costly hardware. We demonstrate a compact, low-cost stabilization method using a scanning Fabry–Pérot interferometer (SFPI) to transfer lock a 960nm coupler laser to an 852nm probe. The lock suppresses coupler multi-MHz free-running drift and improves the Allan deviation by up to an order of magnitude, reaching <75kHz at 𝜏∼66s. Applied to DTC oscillations using a Rb 2-photon D2 transition, the second harmonic generated 480nm (from 960nm lock) reduces DTC frequency drift from >20kHz to a few kHz and lowers instability by more than an order of magnitude with a minimum Allan deviation of 0.2kHz at 𝜏<10s. These results establish SFPI-based transfer locking as a practical and accurate approach for scalable multi-laser Rydberg experiments requiring long-term stability in a compact and low-cost system.