Spectral shaping of an ultrafast modelocked Ytterbium fiber laser output through a passive intracavity optical filter; a simple and reliable route to sub-45 fs pulses

TL;DR

This paper demonstrates that passive intracavity optical filters can effectively shape the spectrum of ultrafast Ytterbium fiber lasers, enabling routine generation of sub-45 fs pulses with improved performance.

Contribution

It introduces a simple, reliable method using intracavity filters to control spectral bandwidth and achieve shorter pulses in Yb:fiber lasers, advancing laser pulse engineering.

Findings

Spectral shaping with intracavity filters extends laser bandwidth.

Achieved sub-45 fs pulse durations routinely.

Improved pulse compression and noise performance.

Abstract

Here we investigate the use of passive intracavity optical filters for controlling the laser output spectrum of a polarization-mode-locked, ultrafast Ytterbium fiber laser. With strategic placement of the filter cutoff frequency, the overall lasing bandwidth can be increased or extended. Overall laser performance, including pulse compression and intensity noise, is investigated for both shortpass and longpass filters with a range of cutoff frequencies, tuned by rotating the filters. We demonstrate the use of an intracavity filter not only shapes the output spectra, it provides a route for overall broader bandwidths and shorter pulses in Yb:fiber lasers. These results demonstrate that spectral shaping is a useful tool to routinely achieve sub-45 fs pulse durations in Yb:fiber lasers.