Wavelength-switchable L-band fiber laser assisted by ultrafast laser fabricated random reflectors

¹ Department of Electrical, Electronic and Communication Engineering, Public University of Navarra, 31006 Pamplona, Spain
² Institute of Smart Cities (ISC), Public University of Navarra, 31006 Pamplona, Spain
³ Photonics Engineering Group, University of Cantabria, 39005 Santander, Spain
⁴ CIBER-bbn, Instituto de Salud Carlos III, 28029 Madrid, Spain
⁵ Instituto de Investigacion Sanitaria Valdecilla (IDIVAL), 39005 Cantabria, Spain

^* Corresponding author: rosa.perez@unavarra.es

Published online: 13 October 2022

Abstract

A wavelength-switchable L-band erbium-doped fiber laser (EDFL) assisted by an artificially controlled backscattering (ACB) fiber reflector is here presented. This random reflector was inscribed by femtosecond (fs) laser direct writing on the axial axis of a multimode fiber with 50 μm core and 125 μm cladding with a length of 17 mm. This microstructure was placed inside a surgical syringe to be positioned in the center of a high-precision rotation mount to accurately control its angle of rotation. Only by rotating this mount, three different output spectra were obtained: a single wavelength lasing centered at 1574.75 nm, a dual wavelength lasing centered at 1574.75 nm and 1575.75 nm, and a single wavelength lasing centered at 1575.5 nm. All of them showed an optical signal-to-noise ratio (OSNR) of around 60 dB when pumped at 300 mW.