Experimental observation of acoustic sub-harmonic diffraction by a grating

Journal Article · Sat Jun 28 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4884836· OSTI ID:22304052

Liu, Jingfei

A diffraction grating is a spatial filter causing sound waves or optical waves to reflect in directions determined by the frequency of the waves and the period of the grating. The classical grating equation is the governing principle that has successfully described the diffraction phenomena caused by gratings. However, in this work, we show experimental observation of the so-called sub-harmonic diffraction in acoustics that cannot be explained by the classical grating equation. Experiments indicate two physical phenomena causing the effect: internal scattering effects within the corrugation causing a phase shift and nonlinear acoustic effects generating new frequencies. This discovery expands our current understanding of the diffraction phenomenon, and it also makes it possible to better design spatial diffraction spectra, such as a rainbow effect in optics with a more complicated color spectrum than a traditional rainbow. The discovery reveals also a possibly new technique to study nonlinear acoustics by exploitation of the natural spatial filtering effect inherent to an acoustic diffraction grating.

• OSTI ID: 22304052
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 24 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACOUSTICS
COLOR
DIFFRACTION
DIFFRACTION GRATINGS
EQUATIONS
FILTERS
NONLINEAR PROBLEMS
PHASE SHIFT
RESOURCE EXPLOITATION
SOUND WAVES
SPECTRA