Detecting the full polarisation state of terahertz transients
  We have developed a detector which records the full polarisation state of a terahertz (THz) pulse propagating in free space. The three-electrode photoconductive receiver simultaneously records the electric field of an electromagnetic pulse in two orthogonal directions as a function of time. A prototype device fabricated on Fe+ ion implanted InP exhibited a cross polarised extinction ratio better than 390:1. The design and optimisation of this device are discussed along with its significance for the development of new forms of polarisation sensitive time domain spectroscopy, including THz circular dichroism spectroscopy. 
E. Castro-Camus, J. Lloyd-Hughes, M.D. Fraser, H.H. Tan, C. Jagadish   and M.B. Johnston