Super Broadband at Telecom Wavelengths From RE(3+)-Doped SiO(2)-Ta(2)O(5) Glass Ceramics Planar Waveguides

This paper reports on the preparation of Er(3+)/Yb(3+)/Tm(3+), Er(3+)/Yb(3+)/Nd(3+), and Er(3+)/Tm(3+)/Nd(3+) triply doped and Er(3+)-doped SiO(2)-Ta(2)O(5) glass ceramic nanocomposites and active planar waveguides by the sol–gel process using the dip-coating technique as deposition method. The investigation of their structural, morphological, and luminescent properties using XRD, AFM, and photoluminescence analysis, are reported here. The XRD results showed the presence of L-Ta(2)O(5) nanocrystals dispersed in the SiO(2)-based amorphous host for all the nanocomposites and films. The rare earth ion (RE(3+)) doping concentration affected both the crystallinity, and the crystallite sizes of the Ta(2)O(5) dispersed into SiO(2)-Ta(2)O(5) nanocomposites and waveguides. AFM characterization revealed crack free and smooth surface roughness and differences in viscoelasticity on the Er(3+)-doped SiO(2)-Ta(2)O(5) films surface, which allows the identification of Ta(2)O(5) nanocrystals on the SiO(2) amorphous host. The Er(3+) doped and triply doped SiO(2)-Ta(2)O(5) nanocomposites displayed broad- and super broadband NIR emissions with a FWHM up to 173 nm achieved in the telecom wavelengths. The lifetime of the (4)I(13/2) emitting level of the Er(3+)-doped SiO(2)-Ta(2)O(5) waveguides is strongly dependent on Er(3+) concentration and an emission quenching was negligible up to 0.81 mol%. The structural and luminescent investigations indicated that RE(3+)-doped SiO(2)-Ta(2)O(5) glass ceramics are promising candidates for photonic applications in optical devices operating in wide wavelengths at the telecom bands.