Tunable kHz distributed feedback fiber laser fabricated in 3D-printed glass

For short sections of fiber tailored to a specific application, fast laser-based manufacturing techniques can be considered as an attractive alternative to the often-cumbersome traditional manufacturing routes. With the use of high-power lasers, localized hot zones that are necessary for glass making can be obtained rapidly. For instance, laser-powder-deposition enables rapid fabrication of short, high gain fibers used in, e.g., distributed feedback fiber lasers (DFFLs). DFFLs offer sought after performance suitable for a broad range of applications in modern photonics, i.e., superior stability and narrower, single-frequency linewidth compared to conventional fiber lasers. Tunable, narrow laser sources with output in an eye-safe spectrum are desired for sensing, signal multiplexing, LIDAR systems, quantum applications, etc. In this work, we present DFFL obtained using laser-powder-deposition made Er-doped silica fiber. Milliwatt level, narrow line lasing (<704 kHz, equipment limited) was obtained using a phase-shifted grating written in 16 mm long fiber. The backward slope efficiency was as high as 24% when pumping at 976 nm. The results presented in this work showcase new possibilities in fiber fabrication that were unlocked through laser-assisted additive manufacturing. This fiber laser sets the stage for the future of rapid fabrication of advanced fiber devices through unconventional manufacturing routes. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license