5. Conclusion

More than ten years after their introduction to the world of optics, photonic crystals remain fascinating not only because of their analogy with solid crystals, but also and above all because of the unique opportunity they offer to bring together on a single theme a range of knowledge from solid-state physics to electromagnetism and optics. In particular, we were able to show that the electromagnetic properties of photonic crystals could be approached using both the photonic band diagram and the field propagation models more commonly used in electromagnetism. The plane-wave method has played, and continues to play, a key role in the calculation of photonic bandgaps; inspired by the modeling of electron properties in a solid crystal, it allows the electron-photon analogy to be taken to its furthest limits. That said, electromagnetic problems are generally more daunting than equivalent electronic...