Nonlinear ultrafast fiber amplifiers beyond the gain-narrowing limit

Abstract

Ultrafast lasers are becoming increasingly widespread in science and industry alike. Fiber-based ultrafast laser sources are especially attractive because of their compactness, alignment-free setups, and potentially low costs. However, confining short pulses within a fiber core leads to high intensities, which drive a host of nonlinear effects. While these phenomena and their interactions greatly complicate the design of such systems, they can also provide opportunities for engineering new capabilities. Here, we report a new fiber amplification regime distinguished by the use of a dynamically-evolving gain spectrum as a degree of freedom: as a pulse experiences nonlinear spectral broadening, absorption and amplification actively reshape both the pulse and the gain spectrum itself. The dynamic co-evolution of the field and excited-state populations supports pulses that can broaden spectrally by almost two orders of magnitude and well beyond the gain bandwidth, while remaining cleanly-compressible to their sub-50-fs transform limit. Theory and experiments provide evidence that a nonlinear attractor underlies the management of the nonlinearity by the gain. Further research into the mutual, pulse-inversion propagation dynamics may address open scientific questions and pave the way toward simple, compact fiber sources that produce high-energy, sub-30-fs pulses.

References in corpus (3)

• Spatial beam self-cleaning in multimode fiber
• Multi-megawatt, self-seeded Mamyshev oscillator
• Experimental Investigations on the TMI Thresholds of Low-NA Yb-doped single mode fibers

Cited by in corpus (9)

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• The LCLS-II Photoinjector Laser Infrastructure
• 1720nm-1800nm tunable chirped pulse amplification based on thulium-doped fiber
• Nonlinear optical pulses in media with asymmetric gain
• Tunable megawatt-scale sub-20 fs visible pulses from a fiber laser source
• Investigation on the self-starting Mamyshev oscillator with low threshold
• Few-cycle THz Pulse Generation in DSTMS Crystal Pumped by a 8.3-MHz Amplified Mamyshev Oscillator