Design of a Multi-Wavelength Fiber Laser Based on Tm:Er:Yb:Ho Co-Doped Germanate Glass

Mario Christian Falconi,Stefano Taccheo,Dario Laneve,Vincenza Portosi,Francesco Prudenzano

doi:10.1109/jlt.2020.2966999

Abstract

In this article, for the first time, an efficient multi-wavelength fiber laser based on a Tm:Er:Yb:Ho co-doped germanate glass, optically pumped at 980 nm wavelength and simultaneously emitting at 1550 nm, 1800 nm and 2050 nm wavelengths, is designed and optimized. An exhaustive model, taking into account the energy transfer phenomena between different rare earths, is developed. The device behavior is investigated by means of several parametric sweeps with respect to the input pump power, the fiber length, the dopant concentrations and the output mirrors reflectivities. Four optimal concentrations have been found by means of a home-made computer code based on particle swarm optimization (PSO) approach, allowing a global solution search. These concentrations allow levels of output powers very close to each other, equal to 20 mW $\pm$ 0.1 $\%$ at 1550 nm, 1800 nm and 2050 nm, respectively. These results predict the possibility of tailoring the dopant concentrations in order to construct broadband optical sources with similar emission powers at multiple wavelengths and broadband amplifiers.

Highlights

I N RECENT years, novel optical fiber amplifiers and lasers providing multi-wavelength laser emission and broadband signal amplification in the wavelength range λ = 1.5 μm to 2.2 μm have attracted a lot of interest
There are several glasses which can be exploited for making lasers and amplified spontaneous emission (ASE) sources operating at these wavelengths, such as silicate, chalcogenide, Manuscript received October 22, 2019; revised November 24, 2019; accepted January 6, 2020
The optical cavity is composed of three couples of high reflective (HR) fiber Bragg gratings, i.e. three input mirrors and three output mirrors, which allow simultaneous laser emission at λs1 = 1550 nm, λs2 = 1800 nm and λs3 = 2050 nm

Summary

INTRODUCTION

The optical cavity is composed of three couples of high reflective (HR) fiber Bragg gratings, i.e. three input mirrors and three output mirrors, which allow simultaneous laser emission at λs1 = 1550 nm, λs2 = 1800 nm and λs3 = 2050 nm This configuration exhibits both low cost (only one laser diode is needed for pumping) and high compactness (only one active medium is needed). It shows that, in principle, wideband amplification and multi-wavelengh laser emission can be finely tailored in a single fiber via a proper choice of the different dopant concentrations. This suggest, as a consequence, the feasibility of ultrashort pulse emission which is of interest in many fields of application

TM:ER:YB:HO LASER MODEL

NUMERICAL RESULTS

REFINEMENT OF TM:ER:YB:HO LASER VIA PARTICLE SWARM OPTIMIZATION