Thulium-doped fiber lasers working in the 2-μm wavelength range are particularly important because they belong to the group of so-called eye-safe lasers. Although their efficiencies are getting closer to the efficiencies of the matured ytterbium fiber lasers, the record output power of thulium fiber lasers is still orders of magnitude below its potential, looking for technology breakthroughs that would overcome the current limitations. Novel fiber designs, e.g., using structured core of the active fiber, and new ways of mitigating thermal and temperature effects may enable further increase of the output power. In the paper, we will review our proof-of-concept experiment of the pedestal-free thulium doped silica fiber with a large nanostructured core, where the initial preforms of the active medium were made by the nanoparticle-doping and MCVD methods. Next, measurement of temperature-dependent thulium cross sections will be reviewed as well as application of these cross-section spectra for prediction of thulium fiber laser operation using recently derived closed form expressions for the laser threshold and slope efficiency under pumping at 790 nm by the two-for-one process.
Thulium fiber amplifiers (TDFA) operating in the spectral region extending the standard telecom C- and L- bands should increase the robustness of telecom infrastructure. We present the development and achieved experimental results for a TDFA applicable over a broad spectral range from 1650 nm to 2020 nm.
While the amplifier optimized for small-signal amplification in the spectral range 1820-2020 nm is based on a thulium-doped silica-based optical fiber with a standard refractive index profile, the amplifier optimized for amplification in the range 1650-1820 nm is based on a thulium-doped optical fiber with a specially tailored internal waveguide structure effectively suppressing guided modes at the longer wavelengths of the thulium emission band and simultaneously promoting mode propagation at the shorter wavelengths. We present the values of the output properties for both types of amplifiers, such as small-signal gain or noise figure.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.