Improvement of linearity in phase-modulated analog photonic link.

A method to improve the linearity of the analog photonic link is proposed and experimentally demonstrated, which consists of a phase modulator and an optical tunable bandpass filter. By carefully optimizing the bandwidth and center wavelength of the filter, we can significantly suppress the third-order intermodulation distortion by ~32 dB. Subsequently the spurious-free dynamic range of the link is improved by ~14 dB.