# Low noise all-fiber amplification of a coherent supercontinuum at 2 \mu m and its limits imposed by polarization noise

## TL;DR

This paper demonstrates low-noise amplification of a coherent supercontinuum in an all-fiber system at 2 μm, achieving high peak power and ultrashort pulses, with limits set by polarization noise.

## Contribution

It introduces a novel all-fiber amplification system for supercontinuum pulses at 2 μm with high coherence and low noise, advancing ultrashort pulse generation technology.

## Key findings

- Over 300 nm bandwidth in 1800-2100 nm range
- 66 fs pulse duration with >70 kW peak power
- Excellent noise performance limited by polarization noise

## Abstract

We report the amplification of an all-normal dispersion supercontinuum pulse in a Thulium / Holmium co-doped all-fiber chirped pulse amplification system. With a -20 dB bandwidth of more than 300 nm in the range 1800-2100 nm the system delivers high quality 66 fs pulses with more than 70 kW peak power directly from the output fiber. The coherent seeding of the entire emission bandwidth of the doped fiber and the stability of the supercontinuum generation dynamics in the silicate glass all-normal dispersion photonic crystal fiber result in excellent noise characteristics of the amplified ultrashort pulses.