Dispersion Diagrams of Bloch Modes Applied to the Design of Directive Sources

We present an original study which makes use of a convenient representation of the dispersion diagrams of Bloch modes for the design of angular selective sources.These diagrams provide us all the pertinent information about the radiative properties of the photonic crystal, and a guideline to optimize the structure in order to obtain the suitable properties.We apply these tools in two cases: when the radiated field propagates normally to the device, and also for an off-axis radiating device.Several numerical examples obtained from a rigorous numerical method show the relevance of this approach.1 Introduction 2 Dispersion Diagrams 2.1 Energy and Phase Velocities 2.2 Crystals with Finite Thickness 3 Application to the Design of Directive Sources 4 Off-Axis Radiation Device 5 Conclusion References