Tuesday, April 11, 2017

Abstract-The Special Polarization Characteristic Features of a Three-Dimensional Terahertz Photonic Crystal with a Silicon Inverse Diamond Structure

The band structure of a Si inverse diamond structure whose lattice point shape was vacant regular octahedrons was calculated using plane wave expansion method and a complete photonic band gap was theoretically confirmed at around 0.4 THz. It is said that three-dimensional photonic crystals have no polarization anisotropy in photonic band gap (stop gap, stop band) of high symmetry points in normal incidence. However, it was experimentally confirmed that the polarization orientation of a reflected light was different from that of a incident light, {I(X,Y)}, where (X,Y) is the coordinate system fixed in the photonic crystal. It was studied on a plane (001) at around X point's photonic band gap (0.36 - 0.44 THz) for incident light direction [001] ({\Gamma}-X direction) by rotating a sample in the plane (001), relatively. The polarization orientation of the reflected light was parallel to that of the incident light for the incident polarization orientation I(1,1), I(1,-1). In contrast, the former was perpendicular to the latter for the incident polarization orientation I(1,0), I(0,-1) in the vicinity of 0.38 THz. As far as the photonic crystal in this work is concerned, method of resolution and synthesis of the incident polarization vector isn't apparently able to apply to the analysis of experimental results.

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