Power scaling limits in high power fiber amplifiers due to transverse mode instability, thermal lensing, and fiber mechanical reliability

Zervas, Michalis N. (2018) Power scaling limits in high power fiber amplifiers due to transverse mode instability, thermal lensing, and fiber mechanical reliability. In Fiber Lasers XV: Technology and Systems. vol. 10512, SPIE.. (doi:10.1117/12.2289792).

Record type: Conference or Workshop Item (Paper)

Abstract

We introduced a simple formula providing the mode-field diameter shrinkage, due to heat load in fiber amplifiers, and used it to compare the traditional thermal-lensing power limit (P^TL) to a newly developed transverse-mode instability (TMI) power limit (P_TMI), giving a fixed ratio of P_TMI/P_TL≈0.6, in very good agreement with experiment. Using a failure-in-time analysis we also introduced a new power limiting factor due to mechanical reliability of bent fibers. For diode (tandem) pumping power limits of 28kW (52kW) are predicted. Setting a practical limit of maximum core diameter to ∼35μm, the limits reduce to 15kW (25kW).

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Power scaling limits in high power fiber amplifiers due to transverse mode instability, thermal lensing, and fiber mechanical reliability - Accepted Manuscript

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Accepted/In Press date: 20 November 2017

e-pub ahead of print date: 26 February 2018

Additional Information: Acceptance date date and AM added.

Venue - Dates: Fiber Lasers XV: Technology and Systems 2018, , San Francisco, United States, 2018-01-29 - 2018-02-01

Keywords: high power fiber amplifiers, high power fiber lasers, mechanical reliability, power scalability, thermal lensing, transverse mode instability

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