Laser-induced microexplosion confined in a bulk of silica: Formation of nanovoids

Abstract

Articles you may be interested inInternal structure of the nanogratings generated inside bulk fused silica by ultrafast laser direct writing

Three-Dimensional Micro- and Nano-Structuring of Materials by Tightly Focused Laser Radiation

“…32,67,68 Channels inside high purity silica and sapphire are required for electrophoresis applications where impurity ions are hampering high-resolution measurements of DNA fragmentation via electrical screening of an applied field and due to background emission intervening with photo-detection of photoluminescence. 69 It was demonstrated that faster etching occurs in densified silica by formation of Lewis base structure in which Si-O-Si angle is decreased. The decrease of the intensity ratio of a D 1 Raman line at 495 cm À1 to the D 2 at 606 cm À1 signifies decrease of 4-ring with respect to 3-ring structures.…”

Holographic Fabrication of Periodic Microstructures by Interfered Femtosecond Laser Pulses

“…However, the intensity at the focal point of the femtosecond laser beam where three beams interfere together could reach to 100 TW/cm 2 nearly. Such a high-energy influence within the focal volume ionized the silica glass quickly through the combined action of the avalanche and multiphoton processes [17,35]. A layer of plasma formed on the surface of the silica glass at the time of the laser pulse duration.…”

“…Femtosecond laser pulse is also becoming into a powerful tool for microfabrication and micro-machining of various multi-functional structures in dielectric materials through multi-photon absorption because of its high-quality and damage-free processing. Up to now, many highquality material processing techniques have been achieved by using femtosecond laser pulses with the methods of directly writing [1][2][3][4][5][6][7][8][9][10] and holographic fabrication [11][12][13][14][15][16][17][18][19][20][21][22], such as waveguide [1], special diffractive optical elements (DOE) [4][5][6][7][8][9][10], micro-gratings [11][12][13][14][15], and photonic crystals [16][17][18][19][20]. Because multiphoton nonlinear effects play a major role in this process, the resulting change in refractive index or cavity formation can be highly localized only in the focal volume where the fluence is above a certain material dependent threshold, which makes it possible to micro-fabricate devices inside the bulk of transparent materials.…”

Several Diffractive Optical Elements Fabricated by Femtosecond Laser Pulses Writing Directly

“…However, the intensity at focus point would be approximate to 100 TW/cm 2 . So, high energy fluence within the focal volume would quickly ionize the silicate glass by the combined action of avalanche and multi-photon processes [13,33]. To reconstruct the optical vortex beam from the fabricated CGH, a collimated He-Ne laser beam was incident on the CGH inclined at 30° against the sample, and both the transmission and reflection pattern grating can be realized.…”