Method for establishing a quantum frequency standard in the visible range using atomic absorption lines and a cw dye laser

A theoretical analysis is made of the self-stabilization of the frequency of a cw dye laser with a nonlinear absorption cell. It is shown that the self-stabilization effect may be anomalously large when use is made of the forbidden (intercombination) transitions in alkaline earth atoms and this may increase the short-term frequency stability of dye lasers by between two and four orders of magnitude. The absence of a hyperfme structure and other characteristics of the transitions discussed suggest that the frequency reproducibility may be 10^–13 or better.