Measuring Thermal Load in Fiber Amplifiers in the Presence of Transversal Mode Instabilities

Abstract

We report on detailed in-situ distributed temperature measurements inside a high power fiber amplifier. The deducted thermal load and the TMI-threshold of a commercial LMA fiber with 25 micron core and 400 micron cladding was measured at various seed wavelengths. By matching these results with detailed simulations we show that photodarkening has a negligible impact on the thermal load and, therefore, on the TMI threshold in this fiber.

References in corpus (2)

• 1.3kW monolithic linearly-polarized single-mode MOPA and strategies for mitigating mode instabilities
• Steady-periodic method for modeling mode instability in fiber amplifiers

Cited by in corpus (2)

• Experimental Investigations on the TMI Thresholds of Low-NA Yb-doped single mode fibers
• Temperature distribution inside a double-cladding optical fiber laser or amplifier