Recording of Long Low-Amplitude Bulk Elastic Waves in Transparent Solid Waveguides by Digital and Classical Holography

Abstract

In this paper we compare two implementations of the holographic technique for recording long, nonlinear, elastic waves of low amplitude in solid polymer waveguides: classical holographic interferometry and digital holography. Both implementations are realized in transmission configuration, with recording in the off-axis schematic. The advantages and disadvantages of these implementations are discussed as applied to the investigation of the evolution of shock waves and strain solitons in transparent solid waveguides.

Shock Wave Evolution into Strain Solitary Wave in Nonlinearly Elastic Solid Bar

“…The system of equations ( 6) -( 8), ( 10), (11) defines the dynamics of nonlinear viscoelastic body. For the generalized Maxwell model ( 12), the integro-differential equation ( 11) can be written as a system of N differential equations using the retarded strain rates q (s)…”

“…Optical techniques, in particular holographic interferometry and digital holography, proved to be quite suitable and informative in analysis of long bulk elastic waves in transparent waveguides (e.g. [6,10,11]). While classical holographic interferometry with recording on high-resolution photographic materials required utilization of pulsed lasers and optical reconstruction of holograms, recent progress in fast-response global-shutterassisted digital cameras allowed for simplification of the experimental procedure and usage of continuous-wave (CW) lasers for recording of wave patterns and computer-based hologram reconstruction.…”