Stretchable phase-mode Fresnel zone plates for focus tuning

This paper presents a phase-correcting Fresnel Zone Plates array produced by maskless grayscale lithography, electroforming and transfer film. The Fresnel Zone Plates is fabricated on a polydimethylsiloxane (PDMS) layer, which allows for the adjustment of optical focus. The Fresnel Zone Plates array material has the transparency and stretch ability of the PDMS. By stretching the elastomeric composite in radial direction, the lens focal length is tuned. Good focusing response is demonstrated and a large focus change (≥50%) was achieved by stretching lenses up to 25%. The stretchable Phase-mode Fresnel Zone Plate could be integrated with electronics and have a wide range of potential applications, from medical imaging to surveillance.