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