On-Fiber 3D-Printed Metalenses for Higher-Order Mode Supercontinuum Generation

This work presents a compact and alignment-free method for efficiently exciting higher-order modes (HOMs) in nonlinear optical fibers using 3D-printed metalens directly integrated on the fiber endface. The proposed metafiber platform uses dielectric nanostructures fabricated through 3D nanoprinting, offering robust performance, high reproducibility, and strong device integration within a small footprint. This approach allows stable coupling of broadband ultrashort pulses without bulky external optics. The integrated design supports efficient HOM excitation and soliton-based SCG, demonstrating a promising and scalable route toward compact, fiber-integrated light sources for nonlinear frequency conversion and broadband light generation.