Direct multi-channel optical spectrum analysis of radio-wave signals using collinear wave heterodyning in the single acousto-optical cell

摘要

An attempt is made to improve the accuracy of a multi-channel parallel acousto-opticalspectrum analysis through involving an additional nonlinear conversion into data processing.For this purpose we investigate the potential of exploiting a co-directional collinear waveheterodyning within an analysis of ultra-high-frequency radio-wave signals. The waveheterodyning under the proposal is performed via mixing the longitudinal elastic waves of finiteamplitudes. It leads to a two-cascade processing in the single-crystalline cell and makes itpossible to improve the relative frequency resolution of the acousto-optical spectrum analysisby an order of magnitude at the same frequency range. Both the theoretical findings and thecorresponding estimations were used in proof-of-principle experiments directed at creating anew type of acousto-optical cell. The general concept of the proposed method and the basicconclusions are confirmed by experiments with the developed acousto-optic cell made of a leadmolybdate crystal.