MESA+ Institute for Nanotechnology

In Chapter 1 the author attempted to present the basic concepts of photonic crystal physics in an intuitive way, while sacrificing the mathematical rigor as little as possible.

Chapter 2 contains an overview of most common computational methods and modeling tools applicable to photonic crystal (PhC) analysis and design. The emphasis was put on strengths and weaknesses of each method. In the design process of photonic crystals considered in this thesis, two kinds of problems have been addressed: (1) band diagrams of unbounded photonic crystals with 2D periodicity; (2) wave propagation in finite-sized photonic crystals, including their coupling to the outside world.

Chapter 3 contains calculation results for silicon on insulator 2D PhCs and 3D photonic crystal slabs, and design and optimization criteria derived from them. The configuration considered is a triangular lattice of hexagonal holes.

Chapter 4 refers to the design of line defect waveguides for the purpose of optical signal transport. We proposed a novel hybrid design (hexagonal holes plus triangular inclusions) in which the PhC waveguide resembles closely a ridge waveguide. This has the desired characteristics: broad bandwidth, single-mode, low-losses. Propagation losses on the order of 15 dB/mm for H-like excitation were obtained.

In Chapter 5 we presented fabrication techniques for photonic crystals. We discussed two patterning techniques with nanometer resolution, namely laser interference lithography (LIL) and focused ion beam (FIB) processing.

Chapter 6 contains preliminary characterization measurements using end-fire coupling and imaging of out-of-plane scattered light using an infrared camera with high resolution.