2025/10/04 by D. S. Chuchelov, M. I. Vaskovskaya, Chuchelov, D. S. +9
Engineering · Physics and Astronomy · #Advanced Frequency and Time Standards #Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Magneto-Optical Properties and Applications #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2510.03908
openalex publication_date 2025/10/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report the observation and characterization of a high-contrast dual-frequency Doppler-free ground-state crossover resonance in the D1 line of 87Rb.The crossover appears at a two-photon detuning exceeding the natural linewidth of the excited state and is formed by the optical pumping effect. Unlike the previously proposed resonance at zero two-photon detuning, which we show becomes sensitive to magnetic-field fluctuations due to residual ellipticity of the optical fields-resulting in frequency shifts and profile asymmetry-the crossover resonance is largely immune to this effect. Our theoretical analysis attributes the observed sensitivity to the dispersive contribution of ground-state coherences to absorption. Stability measurements under magnetic-field fluctuations demonstrate that using the crossover resonance provides more than an order-of-magnitude improvement, making it a promising reference for frequency stabilization in compact, field-deployable optical standards.