Multi-pixel Addressable Photoconductive Arrays for THz Beam Shaping and Polarization Control

Photoconductive sources of pulses of THz radiation enable the reliable, compact, broadband and high dynamic range THz spectrometers most often used in academia and industry. In this Keynote Talk I will describe our recent work on photoconductive arrays that allows exquisite control of the spatial profile or polarization state of a THz beam. High purity linear, circular, radial or azimuthal THz beams were created using photoconductive pixel arrays with orthogonally-oriented elements. Multi-pixel devices with parallel elements were used to dynamically steer the position of a THz beam, or to adjust its profile from Gaussian to flat top. Photoconductive arrays are thus attractive for high-speed beam modulation in THz spectroscopy and imaging applications.