Dual-frequency Doppler-free crossover resonance with suppressed magnetic-field sensitivity for compact optical frequency standards
Abstract
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.
Keywords
Cite
@article{arxiv.2510.03908,
title = {Dual-frequency Doppler-free crossover resonance with suppressed magnetic-field sensitivity for compact optical frequency standards},
author = {D. S. Chuchelov and M. I. Vaskovskaya and E. A. Tsygankov and V. V. Vassiliev and S. A. Zibrov and V. L. Velichansky},
journal= {arXiv preprint arXiv:2510.03908},
year = {2025}
}