All-optical probing of GHz acoustic waves in multiferroic MEMS

2018 ◽  
Author(s):  
Derek Bas ◽  
Nian X. Sun ◽  
Timothy J. Bunning ◽  
Michael E. McConney ◽  
Hwaider Lin ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
All Optical ◽  
Optical Probing

Laser-Based Ultrasound Interrogation of Surface and Sub-Surface Features in Advanced Manufacturing Materials

2021 ◽  
Author(s):  
Kathryn Jinae Harke ◽  
Nicholas Calta ◽  
Joseph Tringe ◽  
David Stobbe
Keyword(s):  
Acoustic Waves ◽  
Surface Defects ◽  
Surface Acoustic Waves ◽  
Acoustic Energy ◽  
Advanced Manufacturing ◽  
Powder Bed ◽  
Surface Features ◽  
Performance Targets ◽  
All Optical ◽  
X Ray Computed

Abstract Structures formed by advanced manufacturing methods increasingly require nondestructive characterization to enable efficient fabrication and to ensure performance targets are met. This is especially important for aerospace, military, and high precision applications. Surface acoustic waves (SAW) generated by laser-based ultrasound can detect surface and sub-surface defects relevant for a broad range of AM processes, including laser powder bed fusion (LPBF). In particular, an all-optical SAW generation and detection configuration can effectively interrogate laser melt lines. Here we report on scattered acoustic energy from melt lines, voids, and surface features. Sub-surface voids are also characterized using X-ray Computed Tomography (CT). High resolution CT results are presented and compared with SAW measurements. Finite difference simulations inform experimental measurements and analysis.

All-optical probing of laser-induced modulation of crack parameters by surface Rayleigh and surface skimming longitudinal bulk acoustic pulses

2012 ◽  
Vol 131 (4) ◽  
pp. 3477-3477 ◽  
Author(s):  
Chen-Yin NI ◽  
Nikolay Chigarev ◽  
Vincent Tournat ◽  
Nicolas Delorme ◽  
Zhong-Hua Shen ◽  
...  
Keyword(s):  
All Optical ◽  
Optical Probing

scholarly journals Viscoelasticity of amyloid plaques in transgenic mouse brain studied by Brillouin microspectroscopy and correlative Raman analysis

2017 ◽  
Vol 10 (06) ◽  
pp. 1742001 ◽  
Author(s):  
Sara Mattana ◽  
Silvia Caponi ◽  
Francesco Tamagnini ◽  
Daniele Fioretto ◽  
Francesca Palombo
Keyword(s):  
Transgenic Mouse ◽  
Acoustic Waves ◽  
Brillouin Scattering ◽  
Complex Structure ◽  
Amyloid Plaques ◽  
Brain Parenchyma ◽  
Correlative Analysis ◽  
All Optical ◽  
Contrast Mechanism ◽  
The Brain

Amyloidopathy is one of the most prominent hallmarks of Alzheimer’s disease (AD), the leading cause of dementia worldwide, and is characterized by the accumulation of amyloid plaques in the brain parenchyma. The plaques consist of abnormal deposits mainly composed of an aggregation-prone protein fragment, [Formula: see text]-amyloid 1-40/1-42, into the extracellular matrix. Brillouin microspectroscopy is an all-optical contactless technique that is based on the interaction between visible light and longitudinal acoustic waves or phonons, giving access to the viscoelasticity of a sample on a subcellular scale. Here, we describe the first application of micromechanical mapping based on Brillouin scattering spectroscopy to probe the stiffness of individual amyloid plaques in the hippocampal part of the brain of a [Formula: see text]-amyloid overexpressing transgenic mouse. Correlative analysis based on Brillouin and Raman microspectroscopy showed that amyloid plaques have a complex structure with a rigid core of [Formula: see text]-pleated sheet conformation ([Formula: see text]-amyloid) protein surrounded by a softer ring-shaped region richer in lipids and other protein conformations. These preliminary results give a new insight into the plaque biophysics and biomechanics, and a valuable contrast mechanism for the study and diagnosis of amyloidopathy.

All-optical probing of the nonlinear acoustics of a crack

2011 ◽  
Vol 36 (17) ◽  
pp. 3449 ◽  
Author(s):  
Sylvain Mezil ◽  
Nikolay Chigarev ◽  
Vincent Tournat ◽  
Vitalyi Gusev
Keyword(s):  
Nonlinear Acoustics ◽  
All Optical ◽  
Optical Probing

All-optical generation of surface acoustic waves in a silica optical microwire

2014 ◽  
Author(s):  
Jean-Charles Beugnot ◽  
Sylvie Lebrun ◽  
Gilles Pauliat ◽  
Herv Maillotte ◽  
Vincent Laude ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Optical Generation ◽  
All Optical
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