Automated System for Femtosecond Laser Writing of Photonic Structures

Abstract

An automated system is reported in this work with the goal of fabricating photonic structures by the direct-write technique with femtosecond laser pulses. This technique uses a fine focused laser beam into transparent substrates and the translation of the substrate parallel or perpendicular to the propagation direction of the incident laser beam. Control procedures related to laser pulses and the sample translation were implemented and integrated, giving rise to a fully automated femtosecond writing system. Functional straight-line and curved waveguides have been successfully achieved with the automated writing system, where single-mode propagation is observed from their near-field profiles when 635-nm light is injected and guided. In addition, the possibility of writing 2D and 3D photonic structures is confirmed by tracing a logarithmic spiral structure (2D) and a fan-out structure (3D). These results show that the developed system is fully operational in practice for the purpose of fabricating a variety of photonic structures with potential applications in the modern communication networks and integrated photonic circuits.