Additive laser excitation of giant nonlinear surface acoustic wave pulses

Editors' Suggestion

Additive laser excitation of giant nonlinear surface acoustic wave pulses

Jude Deschamps, Yun Kai, Jet Lem, Ievgeniia Chaban, Alexey Lomonosov, Abdelmadjid Anane, Steven E. Kooi, Keith A. Nelson, and Thomas Pezeril

Phys. Rev. Applied 20, 044044 – Published 17 October 2023

Abstract

The technique of laser ultrasonics perfectly meets the need for noncontact, noninvasive, nondestructive mechanical probing of nanometer- to millimeter-size samples. However, this technique is limited to the excitation of low-amplitude strains, below the threshold for optical damage of the sample. In the context of strain engineering of materials, alternative optical techniques enabling the excitation of high-amplitude strains in a nondestructive optical regime are needed. We introduce here a nondestructive method for laser-shock wave generation based on additive superposition of multiple laser-excited strain waves. This technique enables strain generation up to mechanical failure of a sample at pump laser fluences below optical ablation or melting thresholds. We demonstrate the ability to generate nonlinear surface acoustic waves (SAWs) in Nb- ${Sr Ti O}_{3}$ substrates, with associated strains in the percent range and pressures up to 3 GPa at 1 kHz repetition rate and close to 10 GPa for several hundred shocks. This study paves the way for the investigation of a host of high-strain SAW-induced phenomena, including phase transitions in conventional and quantum materials, plasticity and a myriad of material failure modes, chemistry and other effects in bulk samples, thin layers, and two-dimensional materials.

Received 29 September 2022
Revised 17 August 2023
Accepted 28 August 2023

DOI:https://doi.org/10.1103/PhysRevApplied.20.044044

Physics Subject Headings (PhySH)

Acoustic wave phenomena

Additive manufacturing Laser ablation Optical techniques Strain engineering Surface acoustic wave

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Jude Deschamps ¹, Yun Kai ¹, Jet Lem ^1,2, Ievgeniia Chaban ¹, Alexey Lomonosov ³, Abdelmadjid Anane ⁴, Steven E. Kooi ², Keith A. Nelson ^1,2, and Thomas Pezeril ^1,5,*

¹Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
²Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
³B+W Department, Offenburg University of Applied Sciences, 77652 Offenburg, Germany
⁴Unité Mixte de Physique CNRS/Thales, UMR CNRS 137, 91767 Palaiseau, France
⁵Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes, France

^*Corresponding author. pezeril@mit.edu

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 20, Iss. 4 — October 2023

Subject Areas

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
Schematic representation of the platform. (a) A pulsed laser beam, focused by a cylindrical lens into a tilted optical cavity, generates a pulse train with a temporal separation $τ = 2 d / c$ , in the nanosecond range. (b) The pulse train is focused on the sample surface; each laser pulse is laterally displaced by an amount $Δ x$ to match the propagation of the acoustic wave generated. The lateral displacement is fine-tuned by adjusting the mirror misalignment angle $α$ . (c) Representative time-integrated image of the sample surface, showing the laser excitation profile of the pulse train and the locations of the two interferometric probes.
Reuse & Permissions
Figure 2
Time traces of the interferometric displacements $u_{z}$ and corresponding calculated in-plane strains $u_{x, x}$ . (a) Amplification of the SAW for a $Nb$ -STO sample, at $1.0 {J cm}^{- 2}$ laser fluence. (b) Same as (a) but for a SSLW. (c) Comparison of the current multiline approach (blue circles) to a single-line generation scheme (black diamonds). On $Nb$ -STO, the multiline approach generates SAWs that can bring the material into the plastic regime (empty circles), with mechanical failure occurring from cumulative fatigue. The range of surface displacements and corresponding strains achievable can be extended by lowering the repetition rate of SAW generation, from the 1 kHz rate (full circles) to the finite-shot regime (empty circles). A comparison to the ring shock geometry [22] with a 160 µm diameter circular pattern of pump laser light is also shown (crosses). The colored regions denote the regimes where mechanical and/or optical damage is observed on the sample.
Reuse & Permissions
Figure 3
Shock-induced mechanical damage without optical damage. (a) Confocal image of the surface of a $Nb$ -STO(100) sample showing SAW-induced mechanical damage hundreds of micrometers away from the laser-excitation region. The SAW propagated along the [010] direction. Inset: depth profile along the dotted line. (b) Snapshots of SAW-induced damage on $Nb$ -STO(100) after various numbers of laser shots/ SAW shocks. It takes about 3000 laser shots for the mechanical damage to spread to the laser-excitation region.
Reuse & Permissions
Figure 4
Nonlinear reshaping of the SAW. (a) Time-resolved femtosecond reflectivity images for SAWs traveling along the $[\bar{11} 2]$ direction of a $Nb$ -STO(111) sample. An arrow points to the SAW location in each frame. The excitation region is outlined with a dashed box. Profiles extracted from a cut of the reflectivity maps along the horizontal dimension are shown on the right. (b) Numerical modeling of the longitudinal strain $u_{x, x}$ that matches the experimental observations in (a). The arrow shows the increase in peak strain as the wave propagates. (c) Corresponding simulated optical reflectivity profiles.
Reuse & Permissions
Figure 5
Schematic illustration of the platform. $λ / 2$ , half-wave plate; CL1, cylindrical lens 1 ( $f = 500 mm$ ); PBS, polarizing beam splitter; $λ / 4$ , quarter-wave plate; FACED, free-space angular-chirp-enhanced delay device; CL2, cylindrical lens 2 ( $f = 500 mm$ ); DM, dichroic mirror; OL, objective lens (Mitutoyo M Plan Apo $10 \times$ ); PM, binary phase mask; SL1, spherical lens 1 ( $f = 100 mm$ ); SL2, spherical lens 2 ( $f = 175 mm$ ); SL3, spherical lens 3 ( $f = 100 mm$ ); APD, avalanche photo-diode (Hamamatsu C5658); SL4, spherical lens 4 ( $f = 400 mm$ ); CMOS, complementary metal oxide semiconductor sensor (Hamamatsu ORCA).
Reuse & Permissions
Figure 6
Acoustic resonances obtained on $Nb$ -STO from scanning the line spacing $Δ x$ of the excitation pattern. Dotted lines are guides to the eye.
Reuse & Permissions

Physical Review Applied