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Abstract
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This paper investigates the optical properties of the two plasma photonic crystal structures. The first structure
contains periodic thin layers of plasma with heterogeneous densities, and in the second one, the heterogeneous
plasma layer has been applied as the defect layer of a one-dimensional photonic crystal.Herein, the plasma density
distribution function is considered a continuous function of plasma critical density as follows: n D ncr f .Er/, where
ncr D me"0!2=e2 represents the critical density of the plasma and f .Er/ indicates the plasma density distribution
function. The heterogeneous plasma layer is assumed to be composed of several homogeneous sublayers with
constant density. The transfer-matrix method is applied in calculations, and the total transfer matrix is obtained
by multiplying the transfer matrices of each sublayer. Properties and behavior of the photonic bandgap and the
defect mode for five different plasma density distribution functions and applied external constant magnetic field
are comparatively investigated.Results showthat, in the first structure, increasing the incident angle from0 to 30
causes a bandgap shift to higher frequencies. So, the incident angle is a parameter that can control the bandgap. In
the defective structure, the intensity of the defect modes is almost the same in all five distributions, but their locations
in the spectrum are different. The effect of the lateral position of the maximum density and external constant
magnetic field on the defect mode position is also investigated. The capability of controlling the photonic bandgaps
and defect modes of the plasma photonic crystals creates wide applications in promising tunable optical devices,
such as optical filters.
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