We study a class of photonic crystals in which both the dielectric constant ε and the magnetic permeability μ vary within the crystal. We find that in the case where both ε and μ have their maximum values in the same material, the photonic band gaps tend to disappear. However, in the opposite case where ε and μ have their maximum values in different materials, the gaps become wider with maximum gap over midgap frequency as high as 0.8. We also discuss the possibility of designing such photonic crystals with ferrites.

• Received 25 February 1997

DOI:https://doi.org/10.1103/PhysRevB.56.959