Laser frequency locking based on Rydberg electromagnetically induced transparency
Jiao Yuechun, Li Jingkui, Wang Limei, Zhang Hao, Zhang Linjie, Zhao Jianming†, , Jia Suotang
       

(a) An EIT signal without frequency modulation. A typical modulated EIT spectrum (b) and corresponding error signal (c) for the probe beam locking to transition 6S1/2 (F = 4) → 6P3/2 (F′ = 5) with SAS spectrum and the coupling laser scanning through resonance 6P3/2 (F′ = 5) → 49D5/2.