First demonstration of the structured Montgomery effect in free space

In the latest publication from our group, Murat Yessenov and colleagues have experimentally demonstrated the Montgomery effect, a long-predicted optical phenomenon in which structured light repeatedly defocuses and refocuses in free space without lenses or mirrors. Published in Optica, the work shows that self-imaging is possible for a wide range of custom light patterns, extending far beyond the strictly periodic structures required by the Talbot effect.

By using a spatial light modulator to precisely sculpt the phase of a laser beam, the team created programmable beams that reform sharply at chosen distances, with low background intensity, across multiple propagation planes. This fully tunable, lensless control of light could enable new capabilities in applications such as three-dimensional optical tweezers for neutral-atom quantum computing and simultaneous multiplane microscopy.

See the publication in Optica and the press release from Harvard SEAS.

Image credit: Joshua Mornhinweg