Widely wavelength-tunable 2 μm Brillouin fiber laser incorporating a highly germania-doped fiber.

Abstract

We present, for the first time to our knowledge, a wavelength-tunable 2μm Brillouin fiber laser based on a homemade thulium-doped fiber laser pump and a segment of highly germania-doped fiber (HGDF). The laser wavelength can be continuously tuned over 110nm from 1920 to 2030nm with single frequency operation, and the linewidth is estimated to be less than 0.9kHz at 1950nm. Benefiting from the high nonlinearity and low loss of the HGDF, a low lasing threshold of 47mW is also achieved.