Optical extinction due to intrinsic structural variations of photonic crystals

Abstract

Unavoidable variations in size and position of the building blocks of photonic crystals cause light scattering and extinction of coherent beams. We present a new model for both 2 and 3-dimensional photonic crystals that relates the extinction length to the magnitude of the variations.The predicted lengths agree well with our new experiments on high-quality opals and inverse opals, and with literature data analyzed by us. As a result, control over photons is limited to distances up to 50 lattice parameters (∼ 15 µm) in state-of-the-art structures, thereby impeding large-scale applications such as integrated circuits. Conversely, scattering in photonic crystals may lead to novel physics such as Anderson localization and non-classical diffusion.

Perfect absorption and no reflection in disordered photonic crystals

“…Increasing degrees of structural disorder, even orders of magnitude larger than those for the geometric case, do not destroy the crystal which remains periodic on average, hence exhibiting still efficient reflectivity resonances (Bragg peaks). In the case of geometric disorder, already a few percent level [61][62][63][64][65][66][67]. As a matter of fact, geometric disorder is especially detrimental to our setup as it implies a concomitant variation in the phase mismatch between atomic distribution N j (z) and dynamic shift δ ds (z); this point is clearly confirmed in Fig.…”

Optical surface resonance may render photonic crystals ineffective

“…5(d)] are appreciably lower than those predicted by simulations. This is likely due to diffuse scattering from defects and disorder within the original artificial opal, 28,29 indicating that the quality of the artificial opals may need to be improved for demanding applications. As shown before, the inverse Ge woodpile is also affected by the presence of a surface resonance.…”

Controlling waves in space and time for imaging and focusing in complex media

“…In a non-absorbing medium, the energy in the beam is not lost, but is instead converted into a diffuse glow of scattered light. This light hides the internal structure of any material thicker than a few multiples of l, and thus represents a major obstacle to the imaging and focusing of light in fields such as biomedical imaging 4 , laser therapy 5 , art preservation 6 and photonic crystal fabrication 7 .…”