Broadband frequency-doubled linearly chirped microwave waveform generation based on Fourier domain mode-locked optoelectronic oscillator

We propose and experimentally demonstrate a novel method to generate frequency-doubled linearly chirped microwave waveform (LCMW) with wide instantaneous bandwidth, large time bandwidth product (TBWP). The key is to re-modulate the LCMW generated by a Fourier domain mode-locked optoelectronic oscillator to the frequency scanning optical carrier by using an external Mach-Zander modulator for bandwidth superposition. LCMWs with a frequency sweep instantaneous bandwidth of up to 10 GHz, and a TBWP of up to 221,800 have been successfully generated in the experiment.