Waveguides in crystalline materials

Abstract

Crystalline media offer a variety of unique properties, such as even order nonlinearities, birefringence, and broad transparency ranges, which make them of great interest for applications in integrated optics. However, the extension of femtosecond laser direct inscription techniques [Nolte et al., Appl. Phys. A 77, 109 (2003), J. Mod. Opt. 51, 2533 (2004); Itoh et al. MRS Bull. 31, 620 (2006); Gattass, Mazur, Nature 2, 219-225 (2008); Della Valle et al., J. Opt. A: Pure Appl. Opt. 11 (2009)] with their vast potential for the fabrication of buried three-dimensional structures of arbitrary shapes to crystals has proven to be a challenging task. Results achieved so far in direct writing of optical devices in crystals will be reviewed.