Generation and anti-dispersion transmission of quadrupling-bandwidth dual-chirp microwave waveform based on a polarization-division multiplexing Mach-Zehnder modulator

We propose and demonstrate a photonic approach to generate and transmit a quadrupling-bandwidth dual-chirp microwave waveform with anti-dispersion transmission. Commonly, dual-chirp microwave waveforms are generated by double-sideband modulation, which brings severe chromatic-dispersion-induced power fading (CDIP) over fiber transmission. In this scheme, we perform optical carrier suppression via a polarization controller based on an integrated polarization-division multiplexing Mach-Zehnder modulator (PDM-MZM) to eliminate the CDIP. Moreover, by properly adjusting two bias voltages of PDM-MZM, we find that the bandwidth of the generated dual-chirp microwave signal is quadrupled. It is worth mentioning that we just need to operate in the central office to realize the above-mentioned functions and no optical filters are needed, which significantly improves the limitation of the devices. The method is analyzed theoretically and proved experimentally, which is of great significance for improving range-Doppler resolution and the detection capability of radars for one-to-multi base stations over fiber transmission. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)