A Novel Analytical Model as a Design Tool for Uni-Traveling-Carrier Traveling Wave Photo Detectors Approaching 1 THz

The generation of sub-millimeter waves and terahertz signals is a difficult challenge, and a few approaches are being studied by several groups. We are investigating the approach of heterodyning two optical signals in a uni-traveling-carrier photo detector, which has been identified as the device of choice for very high frequencies. In this paper we present a novel analytical model, which was developed as a design tool for the above device. The model was validated by designing, fabricating and testing a new 100 GHz photo detector. In addition, performance limits for the UTC traveling wave photo detector are calculated by the new model, and it is shown that this device has the potential of delivering more than 1 mW of power at frequencies approaching 1 THz.