Spectral hole-burning in pump-probe studies of nonlinear selective reflection spectroscopy

Special hole-burning effects on the spectrum of gas atoms near a glass-vapour interface were obtained by observing the reflection of a weak probe beam. Sub-Doppler reflection spectroscopy has been achieved and the unabsorption dip was measured for different pump laser power and detuning. The nonlinear optical properties of the atomic system were investigated by taking into account the collisions between the atoms and the walls of the cell. We also demonstrated the absorption reduction in a V-type energy level configuration with a linewidth of about 6.5 MHz. The experimental results agree with reasonable accuracy with the predictions derived from a theoretical explanation of the nonlinear optical susceptibility