A method includes a providing a molten glass fiber core and disposing a plurality of nanoparticles that include a transition metal oxide on the molten glass fiber core at or above the softening temperature of the glass fiber core, thereby forming a nanoparticle-laden glass fiber. The plurality of nanoparticles are embedded at the surface of said glass fiber core. A method includes providing a mixture of molten glass and a plurality of nanoparticles. The plurality of nanoparticles include a transition metal. The method further includes forming nanoparticle-laden glass fibers, in which the plurality of nanoparticles are embedded throughout the glass fibers.