Ultrafast defect manipulation with optical anisotropy in fused silica

Abstract

We report the evidence that the oxygen defects induced by focusing an intense infrared femtosecond laser pulse in fused silica can be self-organized by the interference pattern between photon and electron plasma wave. Self-organized nanostructure with a sub-wavelength modulation in refractive index exhibits form birefringence which is rewritable and directionally-controllable. Intriguingly, such optical anisotropy, which indicates a remarkable non-reciprocity, has initially evolved from residual birefringence originated from internal stress distribution due to local heating followed by structural change, regardless of interpulse time. This anisotropic light-matter interaction could be interpreted in terms of an asymmetric relation between light polarization and pulse front tilt. Apart from fundamental understanding of self-organization mechanism, the direction of encoded birefringence can introduce an entirely new concept for rewritable optical storage beyond the diffraction limit of light.