Intracavity-birefringence-enabled soliton states and wavelength control in the (C + L)-band fiber lasers

TL;DR

This paper presents a compact all-fiber laser that uses intracavity birefringence to achieve wavelength-tunable soliton states in the C + L band, enabling diverse pulsed light sources for imaging and sensing.

Contribution

First experimental demonstration of wavelength-manipulated multiple soliton states covering the C + L band in a single-fiber laser oscillator using intracavity birefringence.

Findings

Achieved wavelength tuning ranges of 72.85 nm and 45.54 nm for CSs and SMs.

Demonstrated wavelength-switchable harmonic mode-locking over 1 GHz.

Implemented dual-wavelength mode-locking in the C + L band.

Abstract

We demonstrate a compact all-fiber nonlinear-polarization-evolution (NPE) fiber laser capable of outputting wavelength-manipulated multiple laser states in the C + L band. Leveraging the intracavity birefringence-induced filtering effect, without external spectral filters, the laser achieves wavelength-tunable conventional solitons (CSs) and soliton molecules (SMs) with a tuning range of 72.85 nm and 45.54 nm, respectively, by adjusting the polarization states and pump power. Furthermore, wavelength-switchable harmonic mode-locking (over 1 GHz) and dual-wavelength mode-locking can also be achieved in the C + L band. To the best of our knowledge, this is the first experimental realization of wavelength-manipulated multiple soliton states covering the C + L band in a single-fiber-laser oscillator. Two examples of digital multi-letter encoding and transmission are further demonstrated on this platform by means of pump-driven wavelength/soliton states switching. By enabling controllable multi-state solitons and broad spectral tunability within a compact architecture, our work provides a promising source for spectrally diverse and temporally stable pulsed light sources that hold significant promise for applications in microscopy, bioimaging, and LiDAR.