Polarisation-sensitive terahertz detectors

We have developed a detector of coherent terahertz (THz) radiation that can recover the full polarisation state of a THz transient. The device is a three-contact photoconductive receiver, which is capable of recording two time-varying electric field components of a THz pulse simultaneously. Our receiver was fabricated on Fe/sup +/ implanted InP and showed a cross-polarised extinction ratio greater than 100:1. The detector will be useful for spectroscopy of birefringent and optically active materials.