Modeling the 3-micron Class Er-Doped Fluoride Fiber Laser with a Cubic Energy Transfer Rate Dependence

TL;DR

This paper introduces a cubic energy transfer model for accurately simulating high-power erbium-doped fluoride fiber lasers near 2.8 microns, outperforming previous models and applicable across various doping levels.

Contribution

The paper presents a novel cubic energy transfer rate model that improves accuracy in simulating high-power erbium-doped fluoride fiber lasers, surpassing existing weakly and strongly interacting models.

Findings

Accurately reproduces laser efficiencies and powers for multiple fiber laser systems.

Valid across erbium doping concentrations from 1% to 7%.

Accounts for wavelength redshifting by considering full cross section spectra.

Abstract

We propose an energy transfer model with a cubic atomic population dependence to accurately model the behavior of various reported high-power erbium-doped fluoride fiber lasers operating near 2.8 microns. We first show that the previously introduced weakly interacting (WI) and strongly interacting (SI) models are not adequate for precisely modeling such high-power erbium-doped fluoride fiber lasers. We compare results obtained with the WI and SI models to the proposed model by simulating 4 different highly doped (7 mol.%) fiber lasers previously reported in the literature. Laser efficiencies and powers are reproduced with great accuracy. In addition, four other independent fiber laser systems based on erbium doping concentrations varying from 1-6 mol.% are also simulated with good accuracy using the proposed model with the exact same set of spectroscopic parameters, which confirms its validity for various erbium doping concentrations. Redshifting of laser wavelength is also taken into account by considering the full cross section spectra and computing signal powers over several wavelength channels.