8–12 Sept 2026
Europe/Vienna timezone

The Use of a Spatial Light Modulator for Increased Flexibility and Efficiency in Laser Ultrasound Array Imaging

FA2026/659
10 Sept 2026, 15:20
20m
Saal 11A (Messe Congress Graz)

Saal 11A

Messe Congress Graz

A13 Physical Acoustics and Ultrasound A13.01 Guided waves for NDT & SHM applications

Speaker

Hilde Metzger (University of Strathclyde)

Description

This paper explores how a spatial light modulator (SLM) can improve 3D imaging using laser induced phased arrays (LIPA), by reducing data acquisition time, increasing efficiency and adding flexibility to the existing LIPA platforms.2D LIPAs have enabled remote, couplant-free volumetric imaging for non-destructive evaluation (NDE) [1]. Current LIPA platforms, that scan a single point-focused laser beam, easily exceed the damage threshold of the irradiated component. NDE imaging necessitates laser beam attenuation, which makes inefficient use of laser energy resources. Extensive signal averaging is used to improve low signal-to-noise ratio (SNR), at a significant cost to data acquisition time. Full Matrix Capture, where all generation–detection combinations are captured, enables a wide range of imaging angles and the detection and characterisation of diverse defect types but is time-consuming. Reducing single measurement time significantly impacts overall acquisition time. The SLM facilitates arbitrary laser generation patterns, distributing the incident laser energy to an array of focused points, each below the damage threshold, thereby making more efficient use of a high-power laser. This multi-point excitation enables spatial encoding techniques such as Hadamard multiplexing for parallel averaging of multiple signals with a single detector, reducing data acquisition time. The results presented will be compared with those from scanning-based LIPA platform.Additionally, this SLM-based setup with multi-channel laser ultrasonic generation introduces flexibility into generating arbitrary array designs using all optical means. 2D spiral and random LIPA configurations will be presented to compare array performance and flexibility of array optimisation between platforms. [1] P. Lukacs, et al. IEEE Trans. Ultra. Ferro. Freq. Cont., pp.1, 2025.

Authors

Hilde Metzger (University of Strathclyde) Jakub Trybek (University of Strathclyde) Peter Lukacs (University of Strathclyde) Geo Davis (University of Strathclyde) Stephan Weiss (University of Strathclyde) Theodosia Stratoudaki (University of Strathclyde)

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