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A novel direct-laser writing fabrication process for micro-axicons is demonstrated. A fiber-axicon-generated Bessel beam was utilized to write on UV-curable optical epoxy to form new axicons and axicon arrays, and geometrical parameters of the replicated epoxy axicons were analyzed in terms of both apex angle and proximity of the writing axicons. The shape of the fabricated axicons was demonstrated to be controllable through laser exposure, proximity, and apex angle of the source axicon, and the fabricated axicons are capable of generating a quality Bessel beam with an excellent focusing performance. Published version

A printable microlens on fiber end for coupling between a laser diode to a single-mode fiber (SMF) is demonstrated. The fiber microlens fabricated by the novel technique based on laser direct writing using a quasi-Bessel beam has gained high coupling efficiency, long working distance, and sufficient alignment tolerance. A coupling efficiency of 53.5% was measured for SMF coupling at a working distance of 16 μm. The tolerances for a 1-dB loss increment for translational displacements and angular deviations between the fiber microlens and the laser diode were 2.5 and 1.2 μm, and 2.0 and 5.0 degrees, respectively. The printable fabrication of a microlens on a fiber endface by laser direct writing allows for a batch process to reproduce a multiple microlens with a high consistency in a simple and fast fabrication cycle, with no need of individual fiber loading and unloading.