Feasibility of terahertz generation and detection in 3C-SiC single crystal

• Published in: Japanese Journal of Applied Physics 2015-08, Vol.54 (8), p.82601
• Main Authors: Zhao, Zhen-Yu, Song, Zhi-Qiang, Shi, Wang-Zhou, Zhang, Jing-Tao
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.54.082601

We theoretically investigate the feasibility of terahertz generation and detection in a 〈110〉-oriented 3C-SiC single crystal excited by a frequency-doubled Yb-doped femtosecond pulse laser. The phase-matching condition of optical rectification (OR) and electro-optic (EO) sampling are analyzed on the basis of the dispersion relation of 3C-SiC. The THz generation bandwidth as well as the peak frequency position via OR are calculated at different crystal thicknesses. The THz detection bandwidth on EO sampling is discussed on the basis of 2 different schemes. In the collinear incidence scheme, the cut-off frequency as a function of crystal thickness is revealed. In the noncollinear incidence scheme, the phase-matching condition can be achieved locally by using a silicon prism to couple the THz radiation into a 3C-SiC single crystal. The relationship between THz coherence length and the apex angle of the Si prism is discussed. The detection sensitivity of 3C-SiC at the wavelength of an Yb-doped femtosecond pulse laser is compared with those of other zinc blende EO crystals, which is found to be higher than that of GaP but lower than those of GaAs and ZnTe. Considering the optimal phase-matching condition at a wavelength of 515 nm, 3C-SiC is found to be a potential EO crystal for THz generation and detection using a frequency-doubled Yb-doped femtosecond laser.