“…However, on the condition of not modulating the pump lasers, they all lack flexible control over the properties of the generated THz waves, such as their amplitude, phase, wavefront and pump polarization dependence. As for THz manipulators, they have undergone a rapid development in recent years benefitting from the metasurface method, and they includes chiral devices, [ 13–15 ] deflectors, [ 16–18 ] special beam generators, [ 19,20 ] holograms, [ 21,22 ] and active spatial THz modulators, [ 23,24 ] etc. However, such linear devices can only manipulate existing THz waves and their use will also introduce additional insertion loss and bandwidth limitations.…”