Efficient taper optical hydrogel fiber coupler drawn from suspended photocuring 3D printing

Integrating bio-friendly optical hydrogel fibers (HFs) with solid-state fibers (SFs) could expand the horizons of fiber-optic technology for bio-photonics. However, methods for coupling HF and SF-based systems are inefficient due to the mode field mismatch. Here, a hydrogel fiber coupler with a taper core-cladding structure is demonstrated for efficiently coupling HF to SF and fabricated through sus-pended photocuring 3D printing. Coupling efficiencies of 8.3 and 9.4 dB are obtained at 632 and 473 nm, respectively, which are 22% better than those of conventional couplers. The working bandwidth covers visible wavelengths, satis-fying bioengineering requirements. This research removes obstacles to optical fiber applications in bioscience.(c) 2022 Optica Publishing Group