Linear and Nonlinear Optics in Coupled Waveguide Arrays

  • Charles De Nobriga

Student thesis: Doctoral ThesisPhD


The following thesis is comprised of four main areas of work. These are centredaround the experimental observation of phenomena associated with both linearand non-linear optics in silicon photonic-wires. As a comparison, I also discuss asimilar coupled-waveguide system; dual-core hollow-core photonic crystal fibre.To introduce the reader to this work, the first chapter will recap some undergraduate level theory; a general introduction to optical waveguides. It is notintended to be a complete theoretical picture, as many beautiful texts on opticsalready exist [1–3]. This chapter concerns itself only with the aspects of opticswith which the author was intimately aware of throughout the completion of thisthesis.Thereafter, the chapters become specific to the particular experiments undertaken.Each one follows a simple framework: examination of the relevant theory,extending upon that already discussed in the first chapter, a literature reviewand finally a discussion of the work I completed within this thesis.Chapter 2 is the only chapter not related to silicon based photonics. Here Idiscuss dual-core hollow-core photonic crystal fibres; including guidance mechanisms, fabrication methods and the numerical modelling techniques employed in my work. I will compare these numerical results to experimental results taken by colleagues at the university of Bath.Chapter 3 analyses linear propagation in arrays of silicon photonic wires.I extend the simple picture of light propagating in waveguides to discuss thedi↵erent types of dispersion inherent in this system and how dispersion tailoringcan be achieved; with reference to the other literature on this topic. Experimentalresults are examined and discussed.Chapters 4 and 5 discuss non-linear propagation in silicon photonic wire arrays;modulation instability and spatio-temporal solitons respectively. In eachcase I extend the ideas on non-linearity presented in Chapter 1 to explain bothmodulation instability and optical solitons. Detailed descriptions of the experiments undertaken, and associated numerical modelling completed are then discussed.Whilst the work I present is incomplete, I will discuss subsequent workperformed by my colleagues at the University of Bath based on my initial work.Finally, Chapter 6 draws together my conclusions.
Date of Award24 Apr 2013
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorJonathan Knight (Supervisor)


  • optics
  • photonics
  • silicon
  • coupled waveguides

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