From laser ultrasonics to optical manipulation

Abstract

During the interaction of a laser pulse with the surface of a solid object, the object always gains momentum. The delivered force impulse is manifested as propulsion. Initially, the motion of the object is composed of elastic waves that carry and redistribute the acquired momentum as they propagate and reflect within the solid. Even though only ablation- and light-pressure-induced mechanical waves are involved in propulsion, they are always accompanied by the ubiquitous thermoelastic waves. This paper describes 1D elastodynamics of pulsed optical manipulation and presents two diametrical experimental observations of elastic waves generated in the confined ablation and in the radiation pressure regime.

Nonlinear laser ultrasound formation in silicon

“…Therefore the main mechanism of signal formation was based on the thermal expansion. 23 Further increasing of the laser intensities leads to modification and ablation of the surface.…”

Laser-induced ultrasonic waveform derivation and transition from a point to a homogeneous illumination of a plate

“…In ultrasonic research and associated applications, it is essential for interpreting measurements and understanding the underlying physical mechanisms. Due to recent strides in fundamental research, particularly regarding the measuring of light-pressure-induced ultrasound [1,2] and the so-called Abraham-Minkowski controversy [3,4,5,6,7,8,9,10,11], laser ultrasound modeling is gaining a new momentum and a novel aspect in its applicability.…”

“…A laser-stimulated source, in general, combines light pressure, thermal expansion due to light absorption, electrostriction, and material ablation as means of producing ultrasonic waves. Each of these mechanisms may be experimentally fairly well isolated with appropriate selection of elastic materials and their surface treatments, laser energies and wavelengths [1,2].…”

“…Particular attention is given to individual wave arrivals and their effects on the waveforms. Selected simulated waveforms are compared to the independent models from the literature [2,20,40].…”

Generation and detection of thermoelastic waves in metals by a photothermal mirror method

“…10 Detection of light-induced elastic waves is feasible with many different experimental approaches. [3][4][5][6][7][8][9][10][11][12][13][14][15] Bulk and surface waves can be detected utilizing capacitive, piezoelectric, electromagnetic, and optical transduction mechanisms. 16 The possibility of remote generation and stand-off detection of elastic waves using optical probes makes photothermal methods attractive for material characterization 15 and non-destructive testing.…”