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

The authors have investigated the dc and terahertz-detection characteristics of the photoconductive antennas made on low-temperature-grown (LTG) Inx Ga1-x As (0.4 < x < 0.53). It was found that the resistivity of the LTG In0.4 Ga0.6 As can be as high as 700 cm, with which the resistance of the antenna becomes higher than 3 M. Terahertz waves were detected by the antennas with the pulse excitation at 1.56 μm, with a spectral range exceeding 3 THz, and a dynamic range of about 55 dB. The results also indicate that the photocarrier dynamics depend on the In content