Terahertz Single-Pixel Imaging Improved by Using Silicon Wafer with SiO2 Passivation

Abstract

We demonstrate terahertz single-pixel imaging is improved by using a photomodulator based on silicon passivated with SiO ${}_2$ . By exploring various SiO ${}_2$ thicknesses, we show that the modulation factor of the as-fabricated terahertz photomodulator can reach 0.9, three times that based on bare silicon. This improvement originates from chemical passivation, as well as anti-reflection. Single-pixel imaging experiments based on the compressed sensing method show that reconstructed images adopting the new photomodulator have better quality than the conventional terahertz modulator based on bare silicon. Since the passivation process is routine and low cost, we expect this work will reduce the cost of terahertz photomodulator and single-pixel THz imaging, and advance their applications.