Novel non-intrusive laser-spectroscopic methods for the diagnostics of gas-surface interactions in the near-field of dielectric surfaces are described basing on either two-photon evanescent wave or combined evanescent-volume wave excitation. Such resonant optics at gas-solid interface exhibits huge sensitivity to gas-surface interactions since the gas volume that determines the optical response is restricted to very small distances to the surface limited by the depth of the wave penetration into the gas. Due to this fact the corresponding optical spectra are very sensitive to the polarization behavior of the gas near the surface. Since this behavior is different for atoms or molecules moving to the surface compared to those that depart from it, one can distinguish in a spectroscopic manner between the two contributions. This allows to close the gap between the low-and high-pressure regimes in an unique way and to extract two-dimensional velocity distributions. From a detailed analysis of the spectral line shapes the contribution of inelastically scattered atoms is identified and the mean energy transfer and the mean probability of direct scattering mediated by surface phonons are deduced. Further prospects of these promising techniques are highlighted.