Figure 4
From: High-efficiency terahertz devices based on cross-polarization converter
(a) Photograph of the object to be imaged. The size of each letter is 4 × 5 mm2 and the slit width is 1 mm. The letters were drilled on a stainless steel slice with a thickness of 0.3 mm. (b–d) Images of the three letters. The images are reduced based on the object-image relationship.
