Computer generated volume holograms fabricated on a coreless fiber tip by two photon polymerization

Computer-generated volume holograms (CGVHs) contain 3D refractive index modulations designed to create complex-shaped wave fields for various optical applications. Two-photon polymerization (2PP) lithography is a single-step fabrication method for such CGVHs that allows the tailoring of refractive index distributions by applying locally varying printed powers. In this work, we fabricate 3D Ronchi gratings on top of modified optical fiber using two different printing powers. To expand the beam to illuminate the whole grating structure we use coreless termination fiber (CTF). This approach paves the way for fabricating complex CGVHs on the fiber tip by tailoring refractive index distributions through controlled power variations.