Optical Sideband Processing Approach for Highly Linear Phase-Modulation/Direct-Detection Microwave Photonics Link

We propose an optical sideband processing approach for phase-modulation direct-detection microwave photonics link in this paper. With optical sideband processing, phase modulation signal is converted to intensity modulation signal for direct detection and nonlinearity compensation is realized to suppress third-order intermodulation distortion simultaneously. Theoretical analysis shows that, by imposing proper phase shifts on zero and second-order optical sidebands, corresponding third-order intermodulation distortion components can cancel each other. A proof-of-concept experiment is carried out for verification. Experimental results demonstrate a 30.06 dB suppression of third-order intermodulation distortion and the linearized link's dynamic range can also be improved by 17.42 dB compared with the nonlinearized link, which verify well a highly linearized phase-modulation direct-detection microwave photonics link using this proposal.