Physical origin of nanograting formation on fused silica with femtosecond pulses

Abstract

We present a comprehensive analysis of physical evolution of nanograting formation based on an experiment performed with femtosecond pulses focused under moderate focusing conditions and where pulse energy is slowly increased as the focused beam is moved along the sample surface. The results demonstrate that nanograting inscription is initiated at the location of the maximum plasma density and evolves through local intensity side lobes, whose locations are self-regulated in a closed feedback loop, in agreement with the plasmonic model.

Polarisation-independent ultrafast laser selective etching processing in fused silica

“…, SiODC (II). 7,20–23 The few pulses limit the defect incubation process 28 (null formation of nanogratings, see Fig. 3a), being distributed within a narrow region with certain orientation, but still low anisotropic degree as will be shown below.…”

“…The point defects include E′ centres, non-bridging oxygen hole centres (NBOHC), and divalent silicon with oxygen deficiency centres, i.e., SiODC (II). 7,[20][21][22][23] The few pulses limit the defect incubation process 28 (null formation of nanogratings, see Fig. 3a), being distributed within a narrow region with certain orientation, but still low anisotropic degree as will be shown below.…”