Microstructuring of silicon is performed to alter its optical and electrical properties for use in photonic devices. Femtosecond lasers are a favourable structuring tool because they are extremely precise due to the confinement of their interaction to the focal volume. Experiments were carried out on N-type, P-type, and intrinsic silicon with a femtosecond laser operating at 800 nm, with pulse duration of 40 fs, and 1 kHz repetition rate. A single pulse produced a micro-ring structure surrounding a crater. It is caused by the motion of material according to the pressure gradient induced by the Gaussian profile of the laser. Multiple-pulse structures were similar to the single pulse except for the central protrusion of material. Two factors are responsible for multiple-pulse structures: (1) geometrical difference of the plasma compared to the single pulse (2) reflections of shockwaves produce protruding structures. Polarization dependence of all structures was observed.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/31909 |
| Date | January 2015 |
| Creators | Al-Khazraji, Hajar |
| Contributors | Bhardwaj, Ravi |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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