International System of Units (SI) Traceable Noise-Equivalent Power and Responsivity Characterization of Continuous Wave ErAs:InGaAs Photoconductive Terahertz Detectors
Anuar de Jesus Fernandez Olvera,
Axel Roggenbuck,
Katja Dutzi,
Nico Vieweg,
Hong Lu,
Arthur C. Gossard,
Sascha Preu
Affiliations
Anuar de Jesus Fernandez Olvera
Terahertz Devices and Systems, Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt, Germany
College of Engineering and Applied Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, China
Arthur C. Gossard
Materials Department, University of California Santa Barbara, Santa Barbara, CA 93106, USA
Sascha Preu
Terahertz Devices and Systems, Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt, Germany
A theoretical model for the responsivity and noise-equivalent power (NEP) of photoconductive antennas (PCAs) as coherent, homodyne THz detectors is presented. The model is validated by comparison to experimental values obtained for two ErAs:InGaAs PCAs. The responsivity and NEP were obtained from the measured rectified current, the current noise floor in the PCAs, and the incoming THz power for the same conditions. Since the THz power measurements are performed with a pyroelectric detector calibrated by the National Metrology Institute of Germany (PTB), the experimentally obtained values are directly traceable to the International System of Units (SI) for the described conditions. The agreement between the presented model and the experimental results is excellent using only one fitting parameter. A very low NEP of 1.8 fW/Hz at 188.8 GHz is obtained at room temperature.
