Optical waveguide fabrication inside transparent materials by use of plasma channeling induced by tailored femtosecond laser

Abstract

With a loosely focused femtosecond laser, refractive index change is induced in silica glass without any scanning process. By decrease numerical aperture of the incident laser, the induction of irregular structure can be avoided such as clacks and spatial splitting of the induced refractive index change region. We demonstrate controlling of the refractive index change by optimizing the numerical aperture and input energy and input pulsewidth and laser shot number. A new method of fabrication of photonic devices in silica glass is proposed.