Vertical-Cavity Surface-Emitting Laser for Tunable Microwave Photonic Filter

This study demonstrates a tunable microwave photonic filter using a vertical-cavity surface-emitting laser (VCSEL). A simple and economic microwave photonic notch filter is achieved with over 26 dB rejection level by properly aligning the VCSEL side mode with the target of interest. Additionally, its tuning range is significantly extended to 40 GHz by adjusting the VCSEL driving current. In contrast to the published photonic filter schemes, the proposed scheme presents outstanding characteristics in its cost and tuning range. Additionally, it is much more convenient to be coupled into an optical fiber link.