Manufacturing of diffractive elements in fused silica using high repetition rate femtosecond Yb:KGW laser pulses

Anotacija

In this work we discuss volume phase gratings made in fused silica using high-repetition-rate femtosecond Yb:KGW laser pulses. By exposing fused silica to focused femtosecond laser radiation, regions of modified refractive index were induced. Exploiting this phenomenon gratings were fabricated in the bulk of fused silica by the direct laser writing technique. Gratings with index change of 0.008 and diffraction efficiency of 57% were successfully manufactured using 300-fs laser pulses focused in the fused silica with a 0.42 numerical aperture objective. Keywords: volume phase grating, refractive index change, femtosecond microfabrication, fused silica