Gurvan Brasse

Nanostructured optical fiber by the sol-gel process in the SiO2–ZrO2 system

A SiO2–ZrO2 nanostructured optical fiber developed using the chemical sol-gel method is fabricated and its waveguiding properties are studied. The refractive index difference between the core and the cladding is 0.021 for a (30%ZrO2–70%SiO2) molar core composition. Illumination of the fiber with a supercontinuum source (350–1750nm) shows that the light is guided over this entire range. The measured attenuation losses are 0.7dB∕m at a 1064nm wavelength and the calculated cutoff wavelength is 714nm.

Cascade emissions of an erbium-ytterbium doped silica-zirconia nanostructured optical fiber under supercontinuum irradiation

An erbium-ytterbium doped silica-zirconia nanostructured optical fiber is elaborated by using the chemical sol-gel method and its waveguiding properties are studied. A supercontinuum irradiation of the so-fabricated fiber leads to an exotic cascade emission of photons at 515 and 640 nm, as well as a wide emission band between 530 and 590 nm. Upconversion mechanisms and downconversion mechanisms are finally highlighted to explain these phenomena.

Fluoride waveguide lasers grown by liquid phase epitaxy

High optical quality rare-earth-doped LiYF4 (YLF) epitaxial layers were grown on pure YLF substrates by liquid phase epitaxy (LPE). Thulium, praseodymium and ytterbium YLF crystalline waveguides co-doped with gadolinium and/or lutetium were obtained. Spectroscopic and optical characterization of these rare-earth doped waveguides are reported. Internal propagation losses as low as 0.11 dB/cm were measured on the Tm:YLF waveguide and the overall spectroscopic characteristics of the epitaxial layers were found to be comparable to bulk crystals. Laser operation was achieved at 1.87 μm in the Tm3+ doped YLF planar waveguide with a very good efficiency of 76% with respect to the pump power. Lasing was also demonstrated in a Pr3+ doped YLF waveguide in the red and orange regions and in a Yb3+:YLF planar waveguide at 1020 nm and 994 nm.

Nanostructured optical fiber obtained by the sol-gel process in the SiO 2 -ZrO 2 system doped with erbium ions

We present experimental results concerning the first silica-zirconia nanostructured optical fiber doped with erbium ions obtained by the sol-gel process. The microstructure and the optical properties of the fiber are characterized.