<title>Recharging of local centers and diagnostics of laser and nonlinear crystals</title>

The oscillator regularity E equals h(omega) _i (n + 1/2) at the traps energy spectra was observed in a number of complex crystals: in Ba₂NaNb₅O₁₅ and YAlO₃ one series was observed; in CsCdCl₃ -- two; in ZnWO₄, ZnWO₄:Ni -- three; in Y₃Al₅O₁₅ -- five series. Most of the h(omega) _i are coincident with the high- frequency lines of the first-order Raman spectra, others -- with the second order Raman lines or the Raman lines caused by impurities. Accuracy of coincidence is 0.1 - 3.3%. The explanation of the oscillator regularity was done within the framework of the polaron trap model. Two variations of the model are offered: the trap is either an autolocalized polaron or a polaron stabilized by the field of intrinsic or impurity defects. In both cases the polaron energy states are described by the parabolic potential curves with equidistant vibration levels. The thermal activation energy is then determined by the number of a level from which the tunneling either in the polaron band or in the excited exciton state adjacent to the luminescence center is possible.