Photonics illuminates the future of radar

The first implementation of a fully photonics-based coherent radar system shows how photonic methods for radio-frequency signal generation and measurement may facilitate the development of software-defined radar systems. See Letter p.341 Photonics is on the radar The next generation of radar systems will need to be highly automated and use software-defined signal generation and detection for flexible operation in surveillance and wireless communication applications. However, the necessary analogue-to-digital conversion poses serious technical limits for conventional microwave electronic components. That makes photonic radar an attractive option, well suited to digital operation. Until now photonics-based generation and detection of radio signals have generally been studied separately. Here Paolo Ghelfi et al . combine the individual components to produce a functioning, complete photonic radar system. The system's effectiveness and precision are demonstrated in a field trial involving the detection of passing aircraft.