Local characterization of collagen architecture and mechanical failure properties of fibrous plaque tissue of atherosclerotic human carotid arteries

Atherosclerotic plaque rupture in carotid arteries is a major cause of cerebrovascular events. Plaque rupture is the mechanical failure of the heterogeneous fibrous plaque tissue. Local characterization of the tissue's failure properties and the collagen architecture are of great importance to have insights in plaque rupture for clinical...

Full Temporal Characterization of Ultrabroadband Few-Cycle Laser Pulses Using Atomically Thin WS₂

Nowadays, the accurate and full temporal characterization of ultrabroadband few-cycle laser pulses with pulse durations below 7 fs is of great importance in fields of science that investigate ultrafast dynamic processes. There are several indirect methods that use nonlinear optical signals to retrieve the complex electric field of femtosecond...

Global and local analysis of the mechanical and structural characteristics of carotid atherosclerotic plaques for rupture risk assessment

The rupture of atherosclerotic plaques present in vital arteries is the main trigger of fatal cardiovascular events, such as heart attacks and strokes. Plaque rupture is a mechanical failure of the fibrous plaque tissue that ensues upon large deformations of the tissue, induced by the blood pressure. Current knowledge on the rupture...

Nonlinear Optical Response of a WS₂Monolayer at Room Temperature upon Multicolor Laser Excitation

Currently, the nonlinear optical properties of 2D materials are attracting the attention of an ever-increasing number of research groups due to their large potential for applications in a broad range of scientific disciplines. Here, we investigate the interplay between nonlinear photoluminescence (PL) and several degenerate and nondegenerate...

Acoustic effects on nonlinear optical processes

We studied the effects of two types of ultrasonic waves, shear waves and longitudinal waves, using two nonlinear optical techniques, second-harmonic generation and hyper-Rayleigh scattering. Since shear waves hardly propagate in liquids, their influence on molecules at the interface between a surface and a liquid was studied using second...

Ultrasonic Detection of Acoustically Transparent Cracks Using Harmonics

Detection and sizing of closed cracks is challenging as these cracks exhibt a transparent behavior when interacting with ultrasonic waves. To face this challenge, high amplitude ultrasonic waves are used by which harmonics are generated at the crack interface. Exploting this non-linear response, the probability of detection and sizing of such...

Computation of nonlinear ultrasound fields using a linearized contrast source method

Nonlinear ultrasound is important in medical diagnostics because imaging of the higher harmonics improves resolution and reduces scattering artifacts. Second harmonic imaging is currently standard, and higher harmonic imaging is under investigation. The efficient development of novel imaging modalities and equipment requires accurate simulations...

Correlated photon-pair generation in a periodically poled MgO doped stoichiometric lithium tantalate reverse proton exchanged waveguide

We demonstrate photon-pair generation in a reverse proton exchanged waveguide fabricated on a periodically poled magnesium doped stoichiometric lithium tantalate substrate. Detected pairs are generated via a cascaded second order nonlinear process where a pump laser at wavelength of 1.55 ?m is first doubled in frequency by second harmonic...

Nonlinear surface waves over topography

As ocean surface waves radiate into shallow coastal areas and onto beaches, their lengths shorten, wave heights increase, and the wave shape transforms from nearsinusoidal to the characteristic saw-tooth shapes at the onset of breaking; in the ensuing breaking process the wave energy is cascaded to small-scale turbulent motions in the surf zone....