PHOTONIC BAND STRUCTURES OF 2-DIMENSIONAL AND 3-DIMENSIONAL PERIODIC METAL OR SEMICONDUCTOR ARRAYS

The photonic band structures of a square lattice array of metal or semiconductor cylinders, and of an fcc array of metal or semiconductor spheres, are computed numerically. The frequency-dependent dielectric function of the metal or semiconductor is assumed to have the free-electron form epsilon(omega) = 1 - (omega(p)2/omega2), where omega(p) is the plasma frequency of the charge carriers. A plane-wave expansion is used to transform the vector electromagnetic wave equation into a matrix equation. The frequencies of the electromagnetic modes are found as the zeros of the determinant of the matrix. In general, the plane-wave method is found to be most effective for structures with filling fractions f less-than-or-equal-to 0.1% but provides a semiquantitative description of the band structures of these systems for f > 0.1% .