Nonreciprocity of acousto-optic interaction in collinear tunable acousto-optic filters

Abstract

The investigation of a nonreciprocal effect for the example of collinear acousto-optic interaction is presented. It is shown that this effect influences the parameters of diffraction and the operation of modern acousto-optic devices, particularly acousto-optic tunable filters (AOTFs), at the frequencies of ultrasound of about 1 GHz and higher. The analytical expressions are obtained, and the calculations of the nonreciprocal effect for different acousto-optic materials are carried out. The effect is registered experimentally at the optic wavelengths of 633 and 532 with the help of a collinear AOTF on the base of a lithium niobate crystal.

Non-reciprocal optical mirrors based on spatio-temporal acousto-optic modulation

“…This is nothing but the Bragg angle. The nonreciprocal effect described here therefore relies on the violation of the Bragg matching condition for light beams propagating in the opposite direction with respect to the traveling acoustic wave [80,81]. While it is not necessarily surprising that we can break time-reversal symmetry imparting a synthetic linear momentum to the resonator, a question of crucial importance is whether we can practically induce large non-reciprocity in reflection with this setup, considering a moderate modulation frequency (hundreds of MHz), orders of magnitude below the optical signal frequency (hundreds of THz), and with a small modulation depth typically achievable via acousto-optical interactions (D = -/ n n 10 6 to 10 −5 ) [82,83].…”