Investigation of optomechanical interaction in 1D phoxonic quasicrystals

Abstract The optomechanical interaction in 1D phoxonic quasicrystals with simple and generalized Fibonacci, Symmetry, and Rudin-Shapiro sequences, comprised of Si and SiO 2, has been investigated using the finite element method, for the first time. Among different structures, only the S(4) sequence with ‘ a ’ (‘ a’ is the sum of the thicknesses of A and B layers; a = d A +d B ) of 460 nm, starting with SiO 2 material, and RS(5) sequence with a = 595 nm and a = 606 nm, both beginning with Si, exhibited photonic modes with high quality factor (over 500). Also, only the RS(5) structure with a = 606 nm showed a phononic mode confined at an identical layer along with electric field confinement. Considering the moving boundary and photoelastic effects, the optomechanical interaction with ~0.5 nm shift for the optical mode at ~1550 nm has been obtained for the RS(5) structure. The mentioned optical frequency shift occurred for the displacement of 0.15 nm at a phononic frequency of 4.5946 GHz. The quasiperiodic structures present strong acousto-optic interaction compared to periodic structures, with the same material types and using fewer layers.