Enhanced THz Generation From Interdigitated Quantum Dot Based Photoconductive Antenna Operating in a Quasi-ballistic Regime

In this paper, we present a new approach for the enhancement of pulsed terahertz (THz) generation in quantum dot (QD) based photoconductive antennas (PCA). We demonstrate the benefits of the combination of a QD substrate based PCA and an interdigitated electrodes topology which allows the photocarriers to reach the antenna terminals in a quasi-ballistic regime and immediately contribute to the THz emission. A 50-fold increase in the generated THz power is observed. Such enhancement is made possible by unique combination of QD substrate properties, such as very high electric and thermal breakdown ruggedness, high carrier mobility, and yet short carrier lifetimes, compared to typical low temperature grown materials. We expect this solution to become favourable for development of powerful compact THz emitters.