Laser-induced microexplosion confined in a bulk of silica: Formation of nanovoids
We report on the nanovoid formation inside synthetic silica, viosil, by single femtosecond pulses of 30–100 nJ energy, 800 nm wavelength, and 180 fs duration. It is demonstrated that the void is formed as a result of shock and rarefaction waves at pulse power much lower than the threshold of self-focusing. The shock-compressed region around the nanovoid is demonstrated to have higher chemical reactivity. This was used to reveal the extent of the shock-compressed region by wet etching. Application potential of nanostructuring of dielectrics is discussed.