In this thesis different methods have been investigated for characterizing permanent modifications induced by 2.1 μm ultrashort laser pulses inside the bulk of silicon. While similar phenomena have already been studied at shorter wavelengths, no involume modifications in silicon generated by ultrashort pulses in the wavelength range above 2 microns have been reported in the literature yet. Ultrashort pulses interact differently with silicon at longer wavelengths, impacting the morphology of the triggered modifications. The influence of the experimental setup and laser parameters on the buried modifications in silicon were studied through this thesis.
Simultaneously, this thesis was supporting a project aiming at producing silicon wafers and dies with a small amount of material loss, called kerf. This project is based on the creation of permanent buried modifications in silicon, induced by infrared ultrafast pulsed lasers. A preliminary economic outlook for this technology was conducted at the end of the thesis, limiting the study to the solar cell industry.