Title :
A Phase-Modulated Microwave Photonic Link With an Extended Transmission Distance
Author :
Ruoming Li ; Xiuyou Han ; Xiang Chen ; Xiangfei Chen ; Jianping Yao
Author_Institution :
Sch. of Electr. Eng. & Comput. Sci., Univ. of Ottawa, Ottawa, ON, Canada
Abstract :
A novel technique to transport a microwave signal over an optical fiber based on phase-modulation and coherent in-phase (I) and quadrature-phase (Q) demodulation with an extended transmission distance is proposed and experimentally demonstrated. In the transmitter, a Sagnac loop incorporating a phase modulator (PM) is used to generate two orthogonally polarized optical signals with one being phase modulated and the other with no modulation that acts as a remote optical reference signal. The orthogonally polarized optical signals are transmitted over a single-mode fiber (SMF) to a polarization and phase diversity coherent receiver, and are coherently detected with a free-running optical local oscillator at the receiver. Since the phase-modulated and the reference signals are transmitted over the same SMF, the optical phases are correlated, and the original signal can be recovered based on a digital signal processing algorithm. The proposed technique is experimentally evaluated. Compared with a phase-modulated coherent I/Q demodulated link without using an optical phase correlated reference signal, the transmission distance is extended from 50 m to 10 km, while providing a link gain and a spurious-free dynamic range (SFDR) of -9.5 dB and 115.8 dB · Hz2/3, respectively.
Keywords :
demodulation; microwave photonics; optical fibre communication; optical fibre polarisation; optical information processing; optical modulation; optical receivers; optical transmitters; phase modulation; PM; SFDR; SMF; Sagnac loop; coherent in-phase demodulation; digital signal processing algorithm; distance 50 m to 10 km; extended transmission distance; free-running optical local oscillator; link gain; microwave signal; optical fiber; optical phase correlated reference signal; orthogonally polarized optical signals; phase diversity coherent receiver; phase-modulated coherent I/Q demodulated link; phase-modulated microwave photonic link; quadrature-phase demodulation; remote optical reference signal; single-mode fiber; spurious-free dynamic range; transmitter; Optical fiber communication; Optical fibers; Optical polarization; Optical receivers; Optical transmitters; Microwave photonics; analog photonic link; coherent detection; phase modulation;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2478135