Photoacoustic nondestructive evaluation combines optical absorption contrast with acoustic information for material characterization. This Perspective examines PA A-line sensing, photoacoustic microscopy and photoacoustic remote sensing across energy storage, semiconductor manufacturing, civil infrastructure, transportation and aerospace. Representative applications highlight defect inspection, morphology monitoring and quantitative material property evaluation.
Photoacoustic (PA) nondestructive evaluation (NDE) is a hybrid approach to material characterization that converts optical absorption into acoustic information. In a Perspective published in Optics and Photonics Research , Siqi Liang, Myeongsu Seong and Sung-Liang Chen examine its applications in industrial material characterization, including defect inspection, morphology monitoring and quantitative material property evaluation.
When a material absorbs pulsed or intensity-modulated light, the deposited optical energy induces transient heating and thermoelastic expansion, which generate ultrasonic waves. Through this mechanism, PA NDE combines optical absorption contrast and acoustic features, including time-of-flight and frequency-domain characteristics. These acoustic features are associated with material composition, structures, morphology and depth distribution.
Key highlights include:
Complementary measurement formats: PA A-line sensing emphasizes signal analysis, PA microscopy (PAM) enables spatially resolved PA imaging, and PA remote sensing (PARS) provides non-contact optical detection.
Representative applications : The Perspective focuses on energy storage, semiconductor manufacturing, civil infrastructure, transportation, aerospace and other industrial fields. Examples include lithium (Li) deposition monitoring, metallic microstructure inspection, steel corrosion and crack evaluation, and damage imaging in carbon-fiber-reinforced polymers.
Quantitative characterization : PAM images of Li deposits in Li metal battery have been used to quantitatively analyze Li growth patterns, while PARS microscopy images have enabled quantitative evaluation of surface roughness. Frequency-dependent PA signals have also been used to estimate thermal parameters of Li metal battery, including thermal diffusivity, thermal conductivity, heat capacity and thermal expansion.
A MEMS-based operando PAM study reviewed in the article enabled real-time monitoring of Li plating. Its depth-resolved capability enables the conversion of time-of-flight information into Li height, allowing three-dimensional Li structures and morphologies to be reconstructed. In semiconductor inspection, PARS microscopy visualized metal patterns and subsurface defects beneath a silicon layer up to 525 μm thick, with a lateral resolution of approximately 2.3 μm. The Perspective highlights future directions in damage-free optical excitation, non-contact inspection, wavelength-selective characterization, quantitative signal interpretation, image-based analysis and measurement consistency. These directions extend PA NDE from feature visualization toward quantitative material characterization.
Liang S, Seong M, Chen S. Photoacoustic nondestructive evaluation for material characterization: recent advances and future perspectives. Opt. Photonics Res. 2026(2):0005, https://doi.org/10.55092/opr20260005.
Optics and Photonics Research
Literature review
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Photoacoustic nondestructive evaluation for material characterization: recent advances and future perspectives
16-Oct-2026