Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power

TLDR

The authors aim to derive new general relationships based on practical considerations. The study analyzes scalability of diffraction‑limited fiber lasers by considering thermal, nonlinear, damage, pump‑coupling limits and fiber mode‑field‑diameter restrictions, and derives new general relationships based on practical considerations. The analysis indicates that, even with arbitrarily large mode‑field diameters, diffraction‑limited fiber lasers could reach 36 kW, but thermal and nonlinear limits ultimately cap power, and practical mode‑size restrictions may further limit output.

Abstract

We analyze the scalability of diffraction-limited fiber lasers considering thermal, non-linear, damage and pump coupling limits as well as fiber mode field diameter (MFD) restrictions. We derive new general relationships based upon practical considerations. Our analysis shows that if the fiber's MFD could be increased arbitrarily, 36 kW of power could be obtained with diffraction-limited quality from a fiber laser or amplifier. This power limit is determined by thermal and non-linear limits that combine to prevent further power scaling, irrespective of increases in mode size. However, limits to the scaling of the MFD may restrict fiber lasers to lower output powers.