RESUMEN
A nanoparticle (NP) doping technique was developed for fabricating erbium (Er)- and holmium (Ho)-doped silica-based optical fibers for high energy lasers. Slope efficiencies in excess of 74% were realized for Er NP doping in a single mode fiber based master oscillator power amplifier (MOPA) and 53% with multi-Watt-level output in a resonantly cladding-pumped power oscillator laser configuration based on a double-clad fiber. Cores comprising Ho doped LaF3 and Lu2O3 nanoparticles exhibited slope efficiencies as high as 85% at 2.09 µm in a laser configuration. To the best of the authors' knowledge, this is the first report of a holmium nanoparticle doped fiber laser as well as the highest efficiency and power output reported from an erbium nanoparticle doped fiber laser.
RESUMEN
The present article focuses on the influence of gamma irradiation on nanoscale polymer grafted films and explores avenues for improvements in their stability toward the ionizing radiation. In terms of applications, we concentrate on enrichment polymer layers (EPLs), which are polymer thin films employed in sensor devices for the detection of chemical and biological substances. Specifically, we have studied the influence of gamma irradiation on nanoscale poly(glycidyl methacrylate) (PGMA) grafted EPL films. First, it was determined that a significant level of cross-linking was caused by irradiation in pure PGMA films. The cross-linking is accompanied by the formation of conjugated ester, carbon double bonds, hydroxyl groups, ketone carbonyls, and the elimination of epoxy groups as determined by FTIR. Polystyrene, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, dimethylphenylsilanol, BaF2, and gold nanoparticles were incorporated into the films and were found to mitigate different aspects of the radiation damage.
RESUMEN
This Letter provides a qualitative proof of concept for purposefully tailoring the emission spectrum of glass by spatially localizing dissimilar dopants to control the degree of energy transfer. More specifically, modified-chemical-vapor-deposition-derived silica preforms were solution doped with either a solution of individually Eu(3+)- or Tb(3+)-doped nanoparticles or a solution of Eu(3+)/Tb(3+)-codoped nanoparticles. The preform prepared using the codoped nanoparticles exhibited energy transfer from the Tb(3+) to the Eu(3+) ions, whereas the preform containing individually doped nanoparticles yielded only discretely Tb(3+) or Eu(3+) emissions. The extension of this work to broadband amplifiers and lasers is discussed.
RESUMEN
Eu3+ doped LaF3 nanoparticles functionalized with a 3-4 formylphenyl benzoic acid ligand were synthesized. Excitation energy-dependent energy transfer from the ligand to Eu3+ yields color tunability from the red to greenish-blue as a function of excitation wavelengths. This synthetic approach provides large shifts in the resultant chromaticity with an excitation wavelength including the generation of white light.
