At the receiving end, the optical signal is directly detected with a high-speed wideband InGaAs pin photodiode and reconverted to a microwave signal. For long-distance links, one can also employ a wideband InGaAs avalanche photodiode with a 50- to 80-GHz gain-bandwidth product or use an optical preamplifier. For amplifying the received microwave signal, one can use a commercially available wideband low-noise amplifier or a pin-FET receiver