1.5 GHz operation of an AlxGa1¿xAs/GaAs modulation-doped photoconductive detector

We demonstrate a planar AlxGa1¿xAs/GaAs modulation-doped photoconductive detector operating at frequencies up to 1.5 GHz. This detector exhibits a peak responsivity of 2 A/W at these operating conditions, which corresponds to a gain of 3. We found that the peak responsivity increased with reduced pulse repetition rates, reaching 5 A/W at 1 MHz. We also measured the noise power at 800 MHz. This investigation suggests that the detector can be useful for shortwavelength (¿ ¿ 0.82 ¿m) giga-bit-rate integrated photoreceiver applications.