Optical Detection of Terahertz using Nonlinear ParametricUpconversion

摘要

We have shown that its possible to detect THz by upconverting it to an optical signal and using commercially available detectors. Currently our conversion efficiencies are limited and can be improved by better modal overlap between the THz and the optical beams, use of a quasi-phase-mismatced crystal, and use of optimally focussed beams. We are in the process of pursuing each of these avenues. In addition, we have recently performed experiements using a photon-counting optical Geiger-mode Avalanche Photodiode detector and expect significantly better THz detector performance. We intend to report on this work shortly.