Improvement of Linearity and Mitigation of Dispersion-Induced Power Fading in Multi-Channel Phase-Modulated Analog Photonic Link Based on a Polarization Modulator

Abstract

We propose a multi-channel phase-modulated analog photonic link (APL) with linearization and mitigation of dispersion-induced power fading based on a polarization modulator (PolM). When the modulated signal from the PolM goes through a polarization controller and a polarization beam splitter (PBS), the odd- and even-sidebands of the phase-modulated signal can be separated into orthogonal polarization states and travel out from the two outputs of the PBS. By introducing a proper phase shift between two orthogonal polarization states, the third-order intermodulation distortion can be suppressed while the dispersion-induced power fading can be mitigated with different working frequency of the APL and different transmission length of the subchannel. Both theoretical analysis and experimental verification are given. Experimental results show the spurious free dynamic range of above 96 dB·Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2/3</sup> at the noise floor of -143 dBm/Hz, which is improved by 10.2 dB as compared with conventional phase-modulated APL.