Speckle patterns formed by broadband terahertz radiation and their applications for ghost imaging

Abstract

Speckle patterns can be very promising for many applications due to their unique properties. This paper presents the possibility of numerically and experimentally formation of speckle patterns using broadband THz radiation. Strong dependence of the statistical parameters of speckles, such as size and sharpness on the parameters of the diffuser are demonstrated: the correlation length and the mean square deviation of the phase surface inhomogeneity. As the surface correlation length is increasing, the speckle size also increases and its sharpness goes down. Alternatively, the magnification of the standard deviation of the surface height leads to the speckle size diminishing and growth of the speckle sharpness. The dimensions of the experimentally formed speckles correspond to the results of numerical simulation. The possibility of utilizing formed speckle patterns for the implementation of the ghost imaging technique has been demonstrated by methods of numerical modeling.

Segmentation of THz holograms for homogenous illumination

“…It should be noted that the range of applications of the discussed methods covers all kinds of THz imaging or tomography systems, where speckle patterns are an issue. On the other hand, there are also applications of the speckle patterns themselves, such as, for example, ghost imaging 32 , 33 . Therefore, the methods of manipulating such patterns (whether to mitigate or enhance their presence) can serve as an important role in THz imaging systems.…”

Expanding THz Vortex Generation Functionality with Advanced Spiral Zone Plates Based on Single‐Walled Carbon Nanotube Films

“…In particular, THz vortex generators play an essential role in numerous applications: in the detection of magnetic properties, [28] quantum condensate control, wireless communications, [29][30][31] generation of plasmon polaritons, [32][33][34] THz imaging, and ghost imaging. [35][36][37] The importance of vortex comes from the fact that these beams carry orbital angular momentum (OAM), which characterizes the composition of vortex modes in the beam. The properties of their orthogonality are actively used to expand the information capacity of optical channels.…”

Vegetation Loss Measurements for Single Alley Trees in Millimeter-Wave Bands

“…As new frequency bands are envisioned for future communication systems, including mmWaves, sub-terahertz, and terahertz, a new investigation is needed. In the terahertz domain, there are some interesting works related to speckle patterns [12], spatiotemporal wave synthesis [13], and sampling of the terahertz field [14]. In sub-terahertz, conducted measurements in the urban micro scenario showed the foliage loss to be no greater than 11 dB [15].…”