In these lectures, we will start with a brief reminder of basics of semiconductor optoelectronics by addressing the role of heterostructures (not only as diodes but also as guides or Bragg mirrors) in edge-emitting laser, light-emitting diode (LED) and VCSELs. We will classify the different modes in heterostructures through the effective index. We will also introduce the more complex "photonic integrated circuits" which are able to carry out sophisticated treatments of light beams, ideally on a monolithic system.
We will then turn to the impact of lower photon dimensionality on spontaneous emission in optoelectronics. The planar microcavity case is interesting to start with, as it is a case of modulation of the DOS in different directions, without much difference of the overall DOS and it is well documented for application to LEDs. Then, the feasibility of single mode emission in a cavity defined in a waveguide and/or in a micropillar defined in a microcavity will be examined in the limit case of negligible " Purcell effect ."
We will next discuss specifically the modelling tools and the properties of 2D PC etched through waveguides. One issue of paramount importance for applications in optolectronic devices is how far these structures can be regarded as ideal 2D ones, i.e. as infinite air rods in a homogeneous matrix. The light line is a basic concept to examine the role of the guide index contrast (3.3:1 in the case of InP-based self-supported membranes and 3.5:3, or less, in the case of conventional substrates). However, the light line is not adapted to discuss the defect modes, which are the only to be used in devices. A complementary perturbative approach based on a separable solution of the etched waveguide will be introduced. It will be shown to provide quite realistic estimates of light losses in various kind of experiments with a single parameter added to the 2D problem. Cavities, which are an essential building-block of various devices, will be used as examples to illustrate possible treatments of these losses.
The last part of these lectures will be devoted to issues in integrated optics : What are the approaches to design a basic PC-based straight guide? What are the technological issues towards large scale? How could coupling be engineered in all-PC structures, e.g. between a PC microcavity and a guide ? How far do the existing tool box and concepts extend? and also what remains to be set up towards optoelectronics applications?