High-contrast dark resonances on the D1 line of alkali metals in the field of counterpropagating waves

A new method providing a significant increase in the amplitude and contrast of dark resonances is proposed. The method is based on the use of the σ₊−σ₋ configuration of polarized counterpropagating waves, D₁-line excitation in alkali metal atoms, and small-sized cells. Qualitative considerations of the scheme are confirmed by the results of numerical calculations. A variant of a standing wave with homogeneous circular polarization is also discussed.