Lensed fiber is an optical fiber with the tip shaped like a lens. Lensed fibers are used in integrated optics, optical trapping, and fiber sensors. Lens fiber creates a tight focal spot at some distance away from the fiber edge. This tight focal spot can be used to couple light into an optical chip, or collect light from a laser diode or even trap a microparticle.

Conventional lensed fibers are made using polishing, laser cutting or plasma arc. All these techniques restrict the shape and material of the lens, which limits the performance and potential applications. Using our fiber nanoimprint technology we were able to remove these constraints. Our lensed fibers have free-form lenses that are made out of high refractive index materials.