Abstract:
We describe the surprising phenomenon of near-perfect coupling from free space into uniform twodimensional
rod-type photonic crystals over a wide range of incident angles. This behavior is shown to be a
generic feature of many rod-type photonic crystal structures that is related to strong forward scattering resonances
of the individual cylinders. We explain these results using both semianalytic analysis and twodimensional
numerical calculations and identify the conditions under which efficient, wide-angle coupling can
occur. The results may lead to more efficient designs for in-band photonic crystal devices such as superprisms
and self-collimation based photonic circuits.
