Schematic diagram of the multi-pixel interdigitated photoconductive emitter, showing (a) the interdigitated electrodes and (b) the completed device with the masking layer. V_H (G_H) and V_V (G_V) signify the biased (grounded) contacts for horizontally and vertically polarized emission, respectively. The direction of the bias field, and therefore polarization state of the emitted THz pulse, is demonstrated by the arrows in (b) for emission at at a target polarization angle of 135°.