It was demonstrated that optical modulation together with simultaneous terahertz (THz) imaging application enables an increase in contrast by an order of magnitude, thereby illustrating the technique as a convenient contactless tool for characterization of graphene deposited on high-resistivity silicon substrates. It was shown that the single- and double-layer graphene can be discriminated and characterized via variation of THz image contrast using a discrete frequency in a continuous wave mode. Modulation depth of 45% has been reached, and the contrast variation from 0.16 up to 0.23 is exposed under laser illumination for the single- and double-layer graphene, respectively. The technique was applied in the development and investigation of graphene-based optical diffractive elements for THz imaging systems.
Advantages of optical modulation in terahertz imaging for study of graphene layers
Note: This paper is part of the Special Topic on Microwave Absorption by Carbon-Based Materials and Structures.
R. Ivaškevičiūtė-Povilauskienė, A. Paddubskaya, D. Seliuta, D. Jokubauskis, L. Minkevičius, A. Urbanowicz, I. Matulaitienė, L. Mikoliūnaitė, P. Kuzhir, G. Valušis; Advantages of optical modulation in terahertz imaging for study of graphene layers. J. Appl. Phys. 21 January 2022; 131 (3): 033101. https://doi.org/10.1063/5.0074772
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