Study of acousto-optic interaction in 1D Thue-Morse phoxonic quasicrystal

A C T 1D simple and generalized Thue-Morse phoxonic quasicrystals with the minimum and the maximum number of layers of 10 and 25, respectively have been investigated to improve the acousto-optic interaction in C-band.SiO 2 and Si materials have been utilized and the analysis is carried out by the finite element method.Diverse sequences of the proposed structures were investigated, starting with SiO 2 or Si materials.Among various configurations of the Thue-Morse sequence, only the TM(5) structure with "a" (being the sum of A and B layers' thickness; a = d A + d B ) of 420 nm, 540 nm, and 465 nm exhibited optical resonant modes regarding the sequence starting with SiO 2 or Si materials.The proposed structure with a = 420 nm and a = 465 nm presented double phononic transmission peaks, with SiO 2 material being the starting layer.While, for the structure starting with Si, only a single phononic mode appeared for a = 465 nm.Regarding the moving boundary and photoelastic effects, the enhanced acousto-optic interaction with ~0.8 nm shift for the optical mode at ~1550 nm has been obtained in the TM(5) structure.To the author's knowledge, this is the strongest optical wave modulation caused by mechanical waves in multilayers composed of SiO 2 and Si.The above-mentioned optical frequency shift has been obtained for a = 420 nm, with layer thicknesses of d SiO2 = 132 nm and d Si = 288 nm and applying a displacement of 0.17 nm at a phononic frequency of 13.562 GHz.TM(5) structure also showed the highest photonic quality factor of 1150, among all regarded structures.