Photonic generation of tunable wideband dual-chirp microwave waveforms using a monolithic integrated three-section laser

A method for flexibly generating dual-chirp microwave waveform (DCMW) is proposed and experimentally demonstrated. The scheme uses a monolithic integrated three-section laser, which consists of a front section laser, a phase section and a rear section laser. Under the appropriate control current, the integrated laser works in the period-one (P1) state, and the two beams of different frequencies generated by the integrated laser can produce stable beat frequency. After photoelectric conversion, the generated DCMW has the flexible tunability of the central frequency. Through theoretical analysis and experimental demonstration, the DCMW with time-bandwidth-product (TBWP) of 6 x 105 and chirp rate of +/- 0.03 GHz/mu s is obtained at different centre frequencies. In addition, the auto-ambiguity function of the generated DCMW is also studied and it is proved that the proposed scheme can improve the range-velocity resolution, so it has application prospects in microwave photonic radar systems.