A GaAs phononic crystal with shallow noncylindrical holes.
A square lattice of shallow, noncylindrical holes in GaAs is shown to act as a phononic crystal (PnC) reflector. The holes are produced by wet-etching a GaAs substrate using a citric acid:H2O2 etching procedure and a photolithographed array pattern. Although nonuniform and asymmetric etch rates limit the depth and shape of the phononic crystal holes, the matrix acts as a PnC, as demonstrated by insertion loss measurements together with interferometric imaging of surface acoustic waves propagating on the GaAs surface. The measured vertical displacement induced by surface phonons compares favorably with finite-difference time-domain simulations of a PnC with rounded-square holes.
Joseph A
JA
Petrus
Reuble
R
Mathew
James A H
JA
Stotz
D001152:Arsenicals / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D005708:Gallium / Q000737:chemistry*; D008422:Materials Testing; D055617:Micro-Electrical-Mechanical Systems / Q000379:methods*; D008956:Models, Chemical; D016062:Porosity; D012542:Scattering, Radiation; D013016:Sound
D001152:Arsenicals; C043055:gallium arsenide; D005708:Gallium