3D direct laser writing of microstructured optical fiber tapers on single-mode fibers for mode-field conversion

Abstract

We present a design and fabrication approach for 3D printed polymer microstructured optical fiber tapers on standard single-mode glass fibers for efficient and compact mode-field conversion. This paves the way towards complex functionalized fiber tips for various applications, like sensors and beam shaping components, currently limited by the mode-field size and distribution of standard optical fibers. In this paper, we demonstrate the potential of mode-field converting tapers for relaxing the misalignment tolerance in fiber-to-fiber connections and maximizing the coupling efficiency in fiber-to-chip connections. We demonstrate a mode-field diameter expansion ratio of 1.7 and reduction ratio of 3 and show that our microstructured tapers achieve a comparable performance in coupling efficiency as their step-index counterparts, while providing greater robustness.

Optical meta-waveguides for integrated photonics and beyond

“…Nevertheless, the maturity of diverse fiber fabrication techniques has made optical fiber metatips and metamaterial fibers one step closer from lab demonstrations to potential market products. Figure 7a summarizes currently available approaches to fabricate meta-structured optical fibers 76,97,104,228,229,[283][284][285][286][287][288][289][290][291][292] . For optical meta-tips, ordinary photo-and electron beam lithography generally confront challenges in sample mounting and uniform resist coating for the small fiber facet 229,287 .…”

“…Leveraging femtosecond laser pulses and two-photon polymerization 302,303 , direct laser writing can be applied to define micro-structures at fiber facets. Despite submicrometer resolution has been achieved by this multiphoton lithography technology 302,304 , currently demonstrated structures on fiber facets generally have feature sizes bigger than light wavelength 290,292,293,[305][306][307] . Wet-transferred gold nanoslit grating membrane on a fiber facet 288 .…”

Optical Fiber-Integrated Metasurfaces: An Emerging Platform for Multiple Optical Applications

“…(5) Direct laser writing: by either employing the femtosecond laser pulse or the two-photon polymerization, direct laser writing could also be used for the patterning of nanostructures on top of the fiber facets. Nevertheless, subwavelength structures obtained via femtosecond laser ablation usually encounters relatively low resolution, featuring larger dimensions than the operating wavelength [ 96 , 97 , 98 ]. Alternatively, the two-photon direct laser writing technique prevails in the aspect of constructing complex three-dimensional (3D) structures which are hardly completed by top-down lithography.…”

Optical Biomedical Diagnostics Using Lab-on-Fiber Technology: A Review

“…The device production cost is low for mass production applications with the trade off in precise control of shape of nanostructure. Many bottom-up approaches like self-assembled monolayers and bio-assisted synthesis [20][21][22], chemical vapor deposition (CVD) [23], physical vapor deposition (PVD) [24,25], self-guided photo-polymerization [26] and direct 3D laser printing [27,28] have been reported for the fabrication of nanomaterials on optical fibers. In contrast, the top-down approach involves the scaling down of a bulk material into its component nanomaterials or nanostructures with a defined morphology.…”