Stability of the formation of an image using a terajet with respect to the beam shift

The shift of an image of a dielectric sphere asymmetrically irradiated by a terahertz Gaussian beam in terahertz imaging systems has been demonstrated experimentally. Numerical calculations using the operator scattering theory have shown the bending of the localization region of the electromagnetic field near the shadow surface of the dielectric sphere when it is shifted with respect to the waist center of the Gaussian beam, leading to the formation of the so-called “photonic hook” with the properties depending on the polarization and frequency of the incident radiation. The possibility of reaching a spatial resolution of $0.38\lambda$ in the studied range has been shown experimentally. The obtained results can be used to increase the resolution of commercial scanning terahertz systems.