Synthesis of higher-order Poincaré sphere THz beams

Abstract: A novel method to generate vector vortex THz beams with angular momentum by a pair of pumps was reported. The helicity of the vector THz beam, that from polarization to orbital angular momentum can be finely tuned by manipulating the pulse delay between two pump pulses and a S-waveplate. All the states of THz vector vortices on the higher-order Poincar\'e sphere are able to be generated. The synthesis was theoretically explored and experimentally verified. This approach paves the way to the sources of versatile structured THz beams and may benefit the potential applications.