Nanostructuring an erbium local environment inside sol–gel silica glasses: toward efficient erbium optical fiber lasers

Abstract

To extend the use of erbium- (Er-)/aluminum- (Al-) codoped optical fibers in hostile environments, the reduction of the Al amount has been identified as a serious way to harden them against harsh radiation. In this work, sol–gel monolithic Er3+-doped and Er3+/Al3+-codoped silica glasses were prepared from nanoporous silica xerogels soaked in a solution containing an Er salt together or not with an Al salt. After sintering, these glasses were used as the core material of microstructured optical fibers made by the stack-and-draw method. The influence of Al incorporation on the optical properties of Er3+-doped silica glasses and fibers is investigated. This approach enabled the preparation of silica glasses containing dispersed Er3+ ions with low Al content. The obtained fibers have been tested in an all-fibered cavity laser architecture. The Er3+/Al3+-codoped fiber laser presents a maximum efficiency of 27% at 1530 nm. We show that without Al doping, the laser exhibits lower performances that depend on Er content inside the doped fiber core. The effect of Er pair-induced quenching also has been investigated through nonsaturable absorption experiments, which clearly indicate that the fraction of Er ion pairs is significantly reduced in the Al-codoped fiber.

Introducing theLaser PhysicsandLaser Physics Lettershighlights of 2016

“…• Nanostructuring an erbium local environment inside sol-gel silica glasses: toward efficient erbium optical fiber lasers-a new approach for fiber laser fabrication based on the nanoporous texture of a SiO 2 xerogel and its simultaneous doping with Er/Al salts is presented [59].…”

Study of Radiation Effects on Er3+-Doped Nanoparticles Germano-Silica Fibers

“…The attenuation spectra of Er 3+ -doped germano-silica fibers are recorded in the near infrared spectral range of 650-1750 nm, before γ-ray irradiation. They exhibit two significant absorption bands located at around 980 nm and 1530 nm, which are commonly referred to the electronic transitions from a ground state ( 4 I 15/2 ) to the respective excited states 4 I J (J = 11/2, 13/2) of Er 3+ ions [21]. Before γ-irradiation, the background attenuation of all fibers is found to be smaller than ∼0.005 dB/m.…”