The nonlinear propagation of picosecond or femtosecond optical pulses in multimode fiber amplifiers underlies a variety of intriguing physical phenomena as well as the potential for scaling sources of ultrashort pulses to higher powers. However, existing theoretical models of ultrashort-pulse amplification do not include some critical processes, and, as a result, they fail to capture basic features of experiments. We introduce a numerical model that combines steady-state rate equations with the unidirectional pulse propagation equation, incorporating dispersion, Kerr and Raman nonlinearities, and gain/loss-spectral effects in a mode-resolved treatment that is computationally efficient. This model allows investigation of spatiotemporal processes that are strongly affected by gain dynamics. Its capabilities are illustrated through examinations of amplification in few-mode gain fiber, multimode nonlinear amplification, and beam cleaning in a multimode fiber amplifier.
This content will become publicly available on November 22, 2024
Kerr resonators generate stable frequency combs and ultrashort pulses with applications in telecommunications, biomedicine, and metrology. Chirped pulse solitons recently observed in normal dispersion Kerr resonators with an intracavity spectral filter can enable new material design freedom, reduced fabrication requirements, and the potential for improved ultrashort pulse peak powers. This study examines the design and formation properties of chirped pulse Kerr solitons essential to enable these advances. First, prior theoretical predictions that chirped pulse solitons are relatively insensitive to cavity loss and the strength of the dispersion map are experimentally validated. The loss insensitivity property is applied to demonstrate high-energy pulses in a cavity with a large output coupling and the map insensitivity property is applied to demonstrate femtosecond pulses, for the first time to the best of our knowledge, from chirped pulse solitons in a dispersion-mapped cavity with small net-normal dispersion. The relationship between chirped pulses and bright pulses enabled by higher order dispersion is examined with respect to pulse formation, cavity design parameters, and performance properties. Finally, guidelines for additional improvements are detailed for chirped pulse soliton-based high-performance pulse generation.
more » « less- NSF-PAR ID:
- 10475306
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Journal of the Optical Society of America B
- Volume:
- 40
- Issue:
- 12
- ISSN:
- 0740-3224; JOBPDE
- Format(s):
- Medium: X Size: Article No. 3255
- Size(s):
- Article No. 3255
- Sponsoring Org:
- National Science Foundation
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