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Abstract
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In this paper, we introduce plane wave modulators that are designed using one-dimensional
photonic crystals (1DPC) containing radial gradient refractive index (r-GRIN) defect layers. Three
kinds of r-GRIN materials with di®erent refractive index distribution functions are applied in numerical
analysis. The properties of the phase and intensity of the transmitted plane wave beam through
proposed structures are studied using the transfer matrix method. Radially-dependent defect modes,
modulated phase and intensity are obtained according to the refractive index distribution functions.
The results are predictable by regarding the Bragg condition and destructive interference, which are the
origins of the photonic band gap (PBG). Due to the radial-dependency of the defect layer's refractive
index, the rays passing through di®erent transverse positions experience di®erent optical pathways.
Therefore, the defect modes and transmitted spectrum (phase and amplitude) vary transversely. This
study demonstrates another ability of the arti¯cial PC structures to design plane wave modulators and
manipulate its phase and intensity.
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