Effect of double-pulse-laser polarization and time delay on laser-assisted etching of fused silica

Abstract

High-aspect-ratio microchannels were fabricated by femtosecond-double-pulse-laser-assisted polarization-selective etching. The etching rate and uniformity of the microchannels were mainly determined by the double-pulse polarization and time delay. We found that when the two sub-pulses had a different polarization (one linear, the other circular), the microchannel etching rate increased by a factor of 10 compared to when both sub-pulses were linearly polarized. The maximum etching rate was obtained when the polarization combination was circular for the first sub-pulse and vertical for the second one. In this case, the etching rate was independent from the time delay. Laser confocal microscopy images showed that when the polarization was circular, the area modified by the laser was larger than when the polarization was linear, explaining the higher etching rate value obtained after irradiation with circularly polarized laser light.

Enhancement of the Conductivity and Uniformity of Silver Nanowire Flexible Transparent Conductive Films by Femtosecond Laser-Induced Nanowelding

“…Femtosecond (fs) laser with ultrashort pulse durations and high peak power without causing thermal damage to the part is usually employed in nanostructures manufacture and nanomaterials modification [24,25,26,27]. It is an ideal tool for the excitation of surface plasmon resonances (SPRs), because the fs laser excitation can minimize thermal damage in the adjacent nanomaterials and substrate materials [28,29].…”

Nanoscale confinement of energy deposition in glass by double ultrafast Bessel pulses

“…This has mainly been attributed to a reduction of nonlinear ionization due to the intensity decrease when splitting the pulse in two, as well as to a screening effect from the plasma [17][18][19][20][21]. In contrast, the case of in-volume material excitation, at fluences lower than the ablation threshold, shows stronger modifications of fused silica (index of refraction, nanogratings formation) with double pulses in comparison with single pulses of identical total energy, for inter-pulse delay typically on the order of 10-100 ps [22][23][24][25][26][27]. The stronger modifications were attributed to an increase of the total deposited energy because of a higher absorption of the second pulse by the material softened after the first pulse.…”

Manipulation of self-organized nanograting for erasing and rewriting by ultrashort double-pulse sequences irradiation in fused silica

“…Most of the theoretical and experimental research has focused on laser-induced periodic surface structures upon an fs doublepulse sequence irradiation in the time domain from sub-ps to dozens of ps. Related applications include the enhancement of etching, ablation, micro welding [29][30][31], and control of electron dynamics [32]. For example, Shimotsuma et al observed ultrafast writing dynamics of formed nanograting in fused silica within 10 ps, and successfully demonstrated rewritable 5D optical memory and polarization imaging filter mediated by birefringence intensity [28,33].…”