Features of Selective Reflection of High-Intensity Laser Radiation Using Rubidium Nanocell

The effect of selective reflection (SR) of laser radiation from the boundary of ⁸⁷Rb D₂-line atomic vapors and a dielectric window was studied using a nanocell (NC) with a vapor column thickness of ~300 nm. The formation of an SR with a spectral width of 25 MHz, located on atomic transitions, is demonstrated. This is a record narrowing of the 670 MHz Doppler width by a factor of 27 using single-pass geometry. The SR signal reaches several percent of the intensity of its forming radiation, and the SR amplitude’s linear dependence is maintained up to 100 mW/cm², which is almost two orders of magnitude greater than the saturation intensity of optical processes when using centimeter-long cells with atomic vapors. Such a high saturation intensity value is achieved by using the nanocell.