Figure 1

(a) Schematic diagram describing a THz beam passing through two identical GMR filters. The inserted photos show top-view and cross-sectional images of the GMR filter (quartz). Each GMR filter has a width of 30 mm and length of 30 mm. The two GMR filters are 15 cm apart from each other. The linearly polarized THz beam enters the GMR filter to a diameter of 25-mm. The separation between each of the grooves is 313 μm (D1 = 60 μm, D2 = 168 μm, ∧ = 460 μm, and filling factor = 32%). Each GMR filter has a total of 65 grooves. (b) Schematic diagram of a THz beam diffracted inside of the GMR filter.