UV polymerized microtips on multimode optical fibers

Technology of Polymer Microtips’ Manufacturing on the Ends of Multi-Mode Optical Fibers

“…Microtips' manufacturing procedure consists of two steps. The first step is the application of a liquid monomer mixture as a drop at the end of a cleaved optical fiber [6,13,14] or immersion of the optical fiber into a cuvette with this mixture. In the second step, light propagated in the optical fiber core cures the photopolymer so it becomes a hardened 3D polymer microstructure.…”

“…The ranges of possible percentage compositions of mixtures are presented in Table 1. In this mixture, the PIS 2,2-Dimethoxy-2-phenylacetophenone (DMPAP) was used, which belonged to the α-Dialkoxy-acetophenones' photo-initiator class [14]. The VIS-curable mixture needs three compounds, i.e., monomer, sensitizer dye, and co-initiator.…”

“…In previous papers, the results obtained by using separately coherent light sources [3,13] or UV LED [14] have been presented. In this paper, the influence on the microtip geometry of such source parameters as a full width at half maximum (FWHM) and a central wavelength are investigated.…”

“…Both microtips have quasi-trapezoidal cross-sections, wider in the bottoms (base) and narrower at their tops. Although the broadband source is key for obtaining a smooth microtip surface [14], the other source parameter has an influence on the general microtip shape. In Figure 3 are shown SEM images of the microtips manufactured by using UV ( Figure 3a) and VIS ( Figure 3b) LEDs based on a PETA monomer obtained on the same type of MMF as in the previous test.…”

“…In this paper were used: gradient-index MMF with a 62.5 µm core diameter and three step-index MMFs with 50 µm, 105 µm, and 200 µm cores diameters. Based on the previous studies, these MMFs were selected in terms of their reflective properties [13,14]. In Table 3, the main parameters of the used MMFs are presented.…”