ABSTRACT
Mastering the flux of light at the wavelength scale is the main challenge addressed by integrated communication systems. Miniaturization in integrated optics was thought as an ideal playground for Photonic crystals (PhC). The emergence of PhCs arose from the need to implement an ultimate control of light down to spontaneous emission itself, and in all degrees of freedom, which notably means in all directions of space. The first convincing demonstration of two-dimensional near-infrared PhCs was made in 1996–1997. The chapter focuses on complex structures, as they lead to consider PhCs as promising candidates either for future miniature photonic integrated circuits (PIC) or for ultimate sources based on the extreme confinement of light. Having substantiated some simple PhC building blocks, it is possible to envision the advent of ultracompact PhC-based circuits. Most elements are those of a general PIC except for in/out functions needed to couple to external fibers.
