Optically tunable terahertz-band interference fringe shift based on indium oxide

Abstract

An optically tunable terahertz (THz)-band shift in interference fringes based on an indium oxide structure was investigated. An interference phenomenon formed by the combination of partial-through measurements with a shift in the periodic peaks in a THz time-domain spectroscopy system was reported. When the THz beam passes through the edge of the material sample, equally spaced interference fringes are obtained in the frequency domain and these interference fringes can be varied using a 450 nm external continuous-wave laser. The peak of the THz interference fringe shifts by almost half a period. This work offers the ability to observe THz-band interference fringes in the frequency domain and shows that these interference fringes change with variations in the intensity of the applied excitation light.