Detection of terahertz waves using low-temperature-grown InGaAs with 1.56μm pulse excitation

Abstract

The authors have investigated the dc and terahertz-detection characteristics of the photoconductive antennas made on low-temperature-grown (LTG) InxGa1−xAs (0.4<x<0.53). It was found that the resistivity of the LTG In0.4Ga0.6As can be as high as 700Ωcm, with which the resistance of the antenna becomes higher than 3MΩ. Terahertz waves were detected by the antennas with the pulse excitation at 1.56μm, with a spectral range exceeding 3THz, and a dynamic range of about 55dB. The results also indicate that the photocarrier dynamics depend on the In content.