Deformable curvature and beam scanning with an elastomeric concave grating actuated by a shape memory alloy.

A concave diffraction grating with a tunable radius of curvature R is fabricated by embedding a nitinol wire within an elastomeric grating replica. Curvature of the grating is controlled via the shape memory effect, where strain in the wire is recovered due to martensite-austenite phase transformations induced by resistive heating. The generated force bends the grating into a variable curvature determined by applied current.