Large-area photoconductive switches as emitters of terahertz pulses with fully electrically controlled linear polarization

Precise and accurate control of the ellipticity of THz radiation using a photoconductive pixel array

“…The THz radiation emitted by the four pixels overlaps in the farfield to produce a coherent beam of THz radiation, with a linear polarisation state and a polarisation angle controlled by the relative bias voltages applied to horizontally-emitting and vertically-emitting pixels. 20,21 The emitter was photoexcited by 80 fs pulses from a Ti:sapphire oscillator, with an average optical power of 350 mW, and a beam larger than the entire 300 µm × 300 µm active area of the device.…”