Investigation of Bragg reflectors and 2-D photonic crystals in THz domain

This paper presents new studies on Bragg reflectors and 2-D photonic crystals designed by R-Soft software, fabricated via deep reactive ion etching (DRIE), and characterized using a newly developed THz source. Results demonstrate the existence of the 2-D photonic bandgaps within the ranges of 284-325 μm and 277-316 μm for two different incident angles. At each of the two angles the transmissions below 200 μm are low, which is probably due to the absorption of the THz beam by the Si bridges. On the other hand, the modulations at the wavelengths longer than 450 μm could be due to the imperfections present in the structure. The FTIR is also used to measure the transmission spectrum of the 2-D photonic crystal for the normal incidence.