Open AccessAn optical Bragg scattering readout for nano-mechanical resonances of GaN nanowire arrays
Author(s) -
J. P. Houlton,
Matthew D. Brubaker,
Denzal Martin,
Kristine A. Bertness,
Charles T. Rogers
Publication year - 2018
Publication title -
applied physics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 442
eISSN - 1077-3118
pISSN - 0003-6951
DOI - 10.1063/1.5043211
Subject(s) - materials science , nanowire , cantilever , resonance (particle physics) , resonator , optics , gallium nitride , interferometry , scattering , optoelectronics , laser , light scattering , bragg's law , nanotechnology , physics , layer (electronics) , particle physics , diffraction , composite material
We report the use of optical Bragg scattering and homodyne interferometry to simultaneously measure all the first order cantilever-mode mechanical resonance frequencies and quality factors (Q) of gallium nitride nanowires (GaN NWs) in 100 NW periodic selected-area growth arrays. Hexagonal 2D arrays of 100 GaN NWs with pitch spacings of 350-1100 nm were designed and prepared to allow optical Bragg scattering. The NWs studied have diameters ranging from 100-300 nm, lengths from 3-10 μm, resonance frequencies between 1-10 MHz, and Q-values near 10,000 at 300 K. The system can passively detect the thermally induced Brownian mechanical motion of the NWs and can study driven NW motion, enabling the simultaneous monitoring of hundreds of mechanical resonators in a 10-100 μm 2 area with a single optical beam. The read-out system allows large arrays of NWs to be characterized and applied as e.g. spatially resolved temperature and mass sensors.