Diffractive metasurface light-shaping from fiber endoscope probes for increased depth of field

Abstract

In applications such as optical coherence tomography, there is a need both to achieve large depth of field by light shaping and to maintain ultracompact form factors. Flat metasurfaces on optical fibers can achieve such requirements, with designs such as encapsulated diffractive axicon masks. They have the advantages of simple fabrication and transfer, scalability to multi-layer structures and ability to wavelength and/or polarization control. We show a method to shape light from optical fibers via diffractive metallic metalenses bonded onto fiber facets. We discuss a novel process for fabrication and, as proof-of-principle, demonstrate Fresnel zone plates and diffractive axicons on optical fiber facets. © 2023 SPIE.