Preparation and luminescent properties of Rh6G-doped lamellar, hexagonal, and cubic mesostructured SiO₂ waveguides

Abstract

We successfully fabricated laser dye (Rh6G)-doped lamellar, hexagonal, and cubic mesostructured SiO 2 waveguides with a combined method of inorganic/organic co-assembly and soft-lithography. These mesostructured SiO 2 waveguide arrays were made on low-refractive index mesoporous SiO 2 clad films (the upper cladding is air), and waveguiding was confirmed for all samples. When pumping the waveguides with an excitation light at normal incidence, they exhibited a broad emission peak (yellow in color) below certain pumping intensity (pumping threshold), and above the threshold a sharp emission peak (orange in color) was observed from the end of the waveguides. The gain-narrowing is attributed to amplified spontaneous emission that results from the homogenous distribution of highly doped dye molecules (up to 0.8 mol%) within the organized mesochannels of the arrays. The pumping threshold values for the respective mesostructured waveguides are different from each other, increasing in the order of lamellar , hexagonal , cubic mesostructure. q