Femtosecond laser induced thermophoretic writing of waveguides in silicate glass.

ABSTRACT: Here in, the fs-laser induced thermophoretic writing of microstructures in ad-hoc compositionally designed silicate glasses and their application as infrared optical waveguides is reported. The glass modification mechanism mimics the elemental thermal diffusion occurring in basaltic liquids at the Earth's mantle, but in a much shorter time scale (10⁸ times faster) and over a well-defined micrometric volume. The precise addition of BaO, Na₂O and K₂O to the silicate glass enables the creation of positive refractive index contrast upon fs-laser irradiation. The influence of the focal volume and the induced temperature gradient is thoroughly analyzed, leading to a variety of structures with refractive index contrasts as high as 2.5 × 10^-2. Two independent methods, namely near field measurements and electronic polarizability analysis, confirm the magnitude of the refractive index on the modified regions. Additionally, the functionality of the microstructures as waveguides is further optimized by lowering their propagation losses, enabling their implementation in a wide range of photonic devices.

SUBMITTER: Macias-Montero M 

PROVIDER: S-EPMC8052338 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature