Lateral photoconductivity of InAs/GaAs quantum dots for 1.5 μm-wavelength excitation photoconductive terahertz antenna devices

We report lateral photoconductive properties of multilayer-stacked undoped InAs/GaAs quantum dots (QDs) for the application to photoconductive terahertz (THz) antenna devices which operate in 1.5 μm-telecom-wavelength band. The excitation power-dependent photocurrent showed a high value without saturation under high excitation power for the excitation wavelength of 1460 nm. From the reflection pump-probe signal, a fast photocarrier lifetime was derived. These results together with the low dark current characteristic support the applicability of the multilayer-stacked undoped InAs/GaAs QDs to photoconductive THz antennas operating in 1.5 μm-wavelength band.