Dynamic properties of optical-microwave mixing processes utilizing FET devices

The dynamic behavior of the optical-microwave mixing process is investigated in detail. First, the dynamic properties of mixing and detection are compared. With increasing optical modulation frequency a more remarkable decay is obtained in the mixing product than in the detected signal. Based on the investigations there is a further reason for the decay in the mixing product beside the time constant exhibited by the barrier depletion region: the optically induced substrate current which does not contribute to the mixing effect. To describe the operation of combined optical-microwave mixing effects a new approach, the parametric method is introduced which provides a better description for these processes