Аннотация:The investigation of quasicollinear acousto-optic (AO) interaction implemented by reflecting an acoustic wave from the input optical face of an AO cell is fulfilled. AO cells on the base of three mercury halide crystals: chloride, bromide, and mercury iodide were examined theoretically. The parameters of acoustic beam reflection realization were calculated – the angle between the transducer and the optical input facet was determined and the acoustic beam widening in the reflection process was studied. The optical characteristics – spectral resolution, AO interaction phase matching frequency, possible optical pulse compression rate of the quasicollinear AO devices were also examined and compared with those obtained for tellurium dioxide crystal.