Nice Shot
Holograms capture ghosts of things in the spaces they leave behind – patterns of light they once reflected, recorded and illuminated from different angles. Comparing 'live' holograms produced by a changing object, like a vibrating plane’s wing or a speeding bullet, creates holographic interference – seen here as shock waves around a bullet in flight. These patterns reveal subtle changes, like how stress affects a surface. Holographic interferometry has a bright future in forensic science, architecture and engineering – perhaps spotting damaging vibrations in load-bearing beams. But it may also detect subtle changes in living tissues, comparing how they change from moment to moment, possibly revealing diagnostic patterns for circulatory disorders, or monitoring the stresses inside medical implants.
Written by John Ankers
Image by Karl A. Stetson
Karl Stetson Associates LLC, Coventry, CT, USA
Image copyright held by Karl A. Stetson
Published in Light: Advanced Manufacturing, June 2022
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