Novel Fiber Concepts for High Power Single Mode Fiber Lasers
Technical Report,10 Aug 2012,09 Aug 2019
Clemson University Research Foundation Clemson United States
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Major Goals The program described in this proposal consists of two thrusts. The first thrust is to investigate the feasibility of high-power single-mode hydrogen-based Raman lasers in hollow-core double-clad photonic bandgap fibers PBF. Nonlinear thresholds are expected to be significantly improved over what are possible in solid fiber lasers due to the much lower density of gas. This concept also provides for much improved mode quality due to the unique robust single-mode regime in PBF. This novel approach is expected to enable single-mode fiber lasers with power levels well beyond current state-of-art solid fiber lasers. We will study the limits for average power scaling to 100kW with this approach. This concept works with any optically pumped gas lasers, including the very promising diode-pumped alkali vapor lasers. The second thrust is to investigate power scaling in single-mode ytterbium-doped 100micrometer core size resonantly enhanced leakage channel fibers reLCF for much improved nonlinear thresholds and mode quality. The resonantly enhanced leakage channel fibers make use of naturally existing resonant couplings between higher order modes and the leakage channel cladding in a leakage channel fiber for significant additional higher-order mode suppression over standard leakage channel fibers LCF. The 100micrometer core fiber provides a simple, elegant and practical all-solid solution with much enhanced mode quality suitable further power scaling to 20kW. We will investigate limits to power scaling to 20kW with this approach. This new concept can provide a critical solution for resolving the recently observed mode instability issues at high powers.
- Lasers and Masers