Spatiotemporal self-similar fiber laser

Uğur Teğin,Babak Rahmani,Demetri Psaltis,Eirini Kakkava,Christophe Moser

doi:10.1364/optica.6.001412

Uğur Teğin, Babak Rahmani + Show 3 more

Open Access

https://doi.org/10.1364/optica.6.001412

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Journal: Optica	Publication Date: Nov 4, 2019
Citations: 107	License type: cc-by

Affiliation: École Polytechnique Fédérale de Lausanne

Abstract

In this Letter, we demonstrate, to the best of our knowledge, the first spatiotemporally mode-locked fiber laser with self-similar pulse evolution. The multimode fiber oscillator generates parabolic amplifier similaritons at 1030 nm with 90 mW average power, 2.3 ps duration, and 37.9 MHz repetition rate. Remarkably, we observe experimentally a near-Gaussian beam quality (M^2<1.4) at the output of the highly multimode fiber. The output pulses are compressed to 192 fs via an external grating compressor. Numerical simulations are performed to investigate the cavity dynamics which confirm experimental observations of self-similar pulse propagation. The reported results open a new direction to investigate new types of pulse besides beam shaping and nonlinear dynamics in spatiotemporal mode-locked fiber lasers.

Highlights

For single-mode fiber lasers, ytterbium-based laser systems are generally preferred to achieve high power pulses with relatively broadband spectra
Renninger et al reported that, in an allnormal-dispersion cavity design, with strong spectral filtering (≤4 nm), an amplifier similariton pulse can be generated in the gain segment of the laser cavity
In addition to the aforementioned studies, spatiotemporal mode-locking was demonstrated with graded-index multimode fibers in multimode fiber laser cavities by Wright et al [21]

Summary

Introduction

For single-mode fiber lasers, ytterbium-based laser systems are generally preferred to achieve high power pulses with relatively broadband spectra. Dispersion engineering techniques have been demonstrated to obtain various ultrashort pulse types in ytterbium-based fiber cavities such as soliton [1], dispersion-managed [2] and passive self-similar pulses [3]. Renninger et al reported that, in an allnormal-dispersion cavity design, with strong spectral filtering (≤4 nm), an amplifier similariton pulse can be generated in the gain segment of the laser cavity.

Results

Conclusion