Date of Award

Fall 2012

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Engineering Physics

Supervisor

Harold Haugen

Co-Supervisor

Gianluigi Botton

Language

English

Committee Member

Qiyin Fang

Abstract

This thesis explores the ablation and texturing of synthetic single crystal diamond under ultrashort laser pulse irradiation in rough vacuum ambient conditions. Experiments were performed with a 1 kHz repetition rate titanium sapphire laser system producing pulses at 800 nm central wavelength and 150 fs pulse duration. First, the production of ordered periodic nanostructures (ripples) on the diamond surface was characterized and the periodicity of these structures was analyzed against irradiation parameters. Ripples were usually found to fall into one of two categories: one with a spatial period near the irradiation wavelength and one with a spatial period near λ/2n, where λ is the central laser wavelength in air and n is the refractive index of diamond at λ. The spatial periods were plotted against irradiation conditions including the peak fluence, number of incident pulses, and the angle of incidence. Unique outcomes arising out of complex irradiation conditions were also explored. Second, the ablation thresholds for single pulse up to 1000 pulse irradiation were determined using the D2 method at both the fundamental central wavelength (800 nm) and the second harmonic (400 nm). The single 800 nm pulse ablation threshold for synthetic single crystal diamond was determined to be 2.3 J/cm2 with an incubation coefficient of 0.54. The single 400 nm pulse ablation threshold was determined to be 1.5 J/cm2 with an incubation coefficient of 0.73.

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