Single-passband chirped microwave photonic filter based on optical phase modulation and nonlinear dispersion

We demonstrate a single-passband chirped microwave photonic filter (MPF) based on phase modulation of a broadband optical source and nonlinear dispersion. Compared to optical intensity modulator, phase modulator has the advantages of low loss, simple structure and absence of bias drift. At the receiver, the optical signal is directly detected due to the phase to intensity modulation (PM-IM) conversion. The baseband response is also eliminated without any additional setup thanks to the conversion property. The PM-IM conversion under nonlinear dispersion and the MPF´s transfer function are investigated theoretically and verified experimentally.