TIA-2000, a high-speed photodetector module manufactured by Terahertz Technologies Inc., is designed for direct optical-to-electrical conversion of radio-frequency modulated optical signals. It offers a typical bandwidth of DC to 20 GHz, with 18 GHz minimum. The optical input is supplied through a single-mode 9/125 fiber connector with an ultrapolish FC-PC connector or, optionally, with an angle-polished low-reflection FC/APC connector. The radio-frequency output is provided through an SMA connector. Typical optical responsivity is 22 V/W at 1550 nm when the unit is terminated with a 50-Ω load. Electrical return loss is 10 dB, operating temperature ranges from 0 to 40 °C, and the input numerical aperture is 0.11.