Photonics-based array radar imaging using an optically injected semiconductor laser

We propose and demonstrate a high-resolution array radar imaging system with broadband photonic signal generation and processing. The proposed array radar transmits linear frequency modulated (LFM) signals generated by an optically injected semiconductor laser. Since the signal bandwidth is greatly enlarged over traditional electric radars, a significantly improved range resolution can be achieved. To obtain high-quality images, a sub-aperture weighting method is applied, which can suppress the high-energy artifacts and background interferences. In the experiment, an LFM signal with a bandwidth of 8 GHz (18 GHz - 26 GHz) is generated, and the theoretical range resolution is 1.875 cm. Using this signal generator, a photonics-based 1×16 array radar is established, based on which high-resolution imaging is successfully demonstrated.