Broadband fiber-optic thulium-doped source of amplified spontaneous emission

Abstract

We report on experimental setup and characterization of a broadband fiber-optic thulium-doped source of amplified spontaneous emission, which generates radiation in a spectral region around 2 micrometer wavelengths. We present a broadband source based on core-pumped thulium-doped fiber fabricated in house using the modified chemical vapor deposition method and solution doping method, pumped by erbium-doped fiber laser at 1566 nm. The source in a backward configuration with respect to the pump operates in a single-ended configuration achieved using a simple all-fiber geometry and produces radiation with an output power of up to 350 mW. The output spectrum is combined from two local emission peaks of the Tm-doped fiber, at around 1850 nm and at around 1950 nm, with total 3-dB width of more than 140 nm and output power of 130 mW.