Efficient mirco- and nanoparticle trapping by improved optical fiber tweezers using 3D printed diffractive optical elements

An original approach of highly efficient fiber-based optical tweezers using 3D printed diffractive optical elements at an optical fiber facets is presented. As an example Fresnel lens structures, with focal lengths in the range of 50 to 200 µm, are fabricated by femtosecond two photo lithography. Compared to conventional fiber tip tweezers based on chemically wet etched fiber tips, significant trapping efficiency enhancement by a factor of up to 50 is observed in both axial and transverse direction. An outlook on further concepts of enhanced optical fiber tweezers based on 3D diffractive structures will complete the presentation.