# Spatiotemporal self-similar fiber laser

## TL;DR

This paper reports the first demonstration of a spatiotemporal mode-locked fiber laser producing self-similar pulses with high beam quality, enabling new research directions in pulse dynamics and beam shaping.

## Contribution

It introduces the first spatiotemporal self-similar mode-locked fiber laser, combining self-similar pulse evolution with multimode fiber technology.

## Key findings

- Generation of parabolic amplifier similaritons at 1030 nm
- Output pulses compressed to 192 fs
- Near-Gaussian beam quality (M^2<1.4)

## 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.

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Source: https://tomesphere.com/paper/1904.08456