ORC Seminar Series

Pre-viva talk

Date: Wednesday 26 September 2007
Time: 2pm
Venue: Building 46 - Lecture Theatre B

I investigate aspects of dispersion controlled high nonlinearity all silica holey fibres, including design, fabrication, sample applications, and modelling.

Microstructured fibre fabrication allows for great flexibility in core and cladding structure designs, with the large available refractive index contrast between glass and air. This allows the control of waveguide dispersion across a wide wavelength range, which can be used to offset the material dispersion of the core glass. Therefore, this technology provides improved overall dispersion control via fibre design. This often requires a complex arrangement of air holes in the structure.

The full fabrication procedures for small-core holey fibres are presented. In particular, the fabrication of fibres with a graded-hole-size structure is reported. A structural accuracy of ±6% is achieved and improvements are proposed for future work.

A systematic study of the Supercontinuum Generation phenomenon is presented in this thesis. By using fibres with different dispersion profiles, pumping at 1.06 miron, the nonlinear effects such as Self-Phase-Modulation, Four-Wave-Mixing and Self-Soliton-Frequency-Shift, which dominate the spectral broadening in fibres with one or two zero-dispersion wavelengths are identified accordingly.

The latest work has been focussed on controlled structural variation of holey fibres along their length to obtain fibre with a longitudinal variation of dispersion and nonlinearity. I fabricated a dispersion-decreasing holey fibre and performed the first demonstration of soliton compression in a holey fibre. A compression factor of 2 has been achieved with pJ pulses at 1.06 micron. Further numerical modelling has been carried out from a holey fibre design contour map, to optimize holey fibre tapers for soliton compression at 1.55 micron. A compression factor of 6 is possible in a 15-m holey fibre taper with a loss of 0.1 dB/m.

Vincent is a PhD student at the ORC more...