A semimicroscopic approach based on linear response theory is applied to analysis of the near-field-reading process, both for an isolated recording bit and for bits periodically arranged by means of photon scanning tunneling microscopy (PSTM). The polarization effects and typical characteristics of super-resolution are shown by simulation. The results are valid not only for the read-out process in optical storage, but also for sensing of local indices of refraction or absorption in samples observed with PSTM, in general. Some theoretical results are compared with experimental data in terms of the resolving power.