Compensated laser vibrometry using wavefront-reversal via a MEMS SLM integrated with a metasurface retro-array: a proposal

Abstract

Laser-based ultrasound and laser vibrometry are quite mature technologies that have been in use in both manufacturing applications and applied research for several decades. One area of continuing research is in the field of compensated vibrometry, where shot-noise limited performance is sought under real-world manufacturing conditions, including in situ inspection diagnostics and process control of such in-factory applications as additive manufacturing and thermal processing. We propose a compensated vibrometry system, involving a novel spatial light modulator, comprised of a metasurface retroreflector array, combined with a MEMS spatial phase modulator, with the potential to achieve adaptive optical correction of dynamic workpiece distortions, leading to shot-noise limited detection of ultrasound surface displacements and vibrations.