1. Limitations to laser machining of silicon using femtosecond micro-Bessel beams in the infrared.
- Author
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Grojo, David, Mouskeftaras, Alexandros, Delaporte, Philippe, and Shuting Lei
- Subjects
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BESSEL beams , *FEMTOSECOND lasers , *SILICON , *GLASS , *LIGHT absorption , *GAUSSIAN function , *SEMICONDUCTORS - Abstract
We produce and characterize high-angle femtosecond Bessel beams at 1300-nm wavelength leading to nonlinearly ionized plasma micro-channels in both glass and silicon. With microjoule pulse energy, we demonstrate controlled through-modifications in 150-μm glass substrates. In silicon, strong two-photon absorption leads to larger damages at the front surface but also a clamping of the intensity inside the bulk at a level of ≈4 × 1011 W cm-2 which is below the threshold for volume and rear surface modification. We show that the intensity clamping is associated with a strong degradation of the Bessel-like profile. The observations highlight that the inherent limitation to ultrafast energy deposition inside semiconductors with Gaussian focusing [Mouskeftaras et al., Appl. Phys. Lett. 105, 191103 (2014)] applies also for high-angle Bessel beams. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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