A novel photonics-assisted method for frequency up/down conversion with tunable optoelectronic oscillator (OEO) and phase shift is presented based on an integrated dual-polarization dual-parallel MachZehnder modulator (DP-DPMZM). The local oscillator (LO) signal with high spectral purity and low phase noise is generated by an OEO loop in one of the sub-DPMZMs. The frequency can be adjusted by an electrical band-pass filter (EBPF). The radio frequency (RF) signal is injected into another sub-DPMZM. The carrier-suppressed single-sideband (CS-SSB) modulation of both LO and RF signals is achieved. The phase of converted signal can be tuned by an integrated dual-channel phase modulator (DPM). The frequency up/down conversion can be switched by tuning a single bias voltage of the DP-DPMZM. Multiple functions including tunable LO, up/down conversion and phase shift can be realized. Meanwhile the dispersion-induced power fading is well compensated due to the CS-SSB modulation. In experiments, the tunable LO signal from 5 to 18 GHz, with the sidemode suppression ratio as high as 46.1 dB and the phase noise of 104.5 dBc/Hz@10 kHz at 10 GHz is generated successfully. The spur suppression ratios of the up/down converted signals are 32.6 dB and 35.6 dB respectively. The up/down conversion performance for RF carrying 16 quadrature amplitude modulation (16-QAM) signal is also investigated. The phase shifting of dual-channel converted signals can be varied continuously and independently in the range of 360 and the phase deviation is 1.8. The proposed compact link is characterized by function multiplexing and inherent dispersion compensation.

A photonics-assisted frequency conversion and self-interference cancellation approach is proposed and experimentally demonstrated for in-band full-duplex (IBFD) communication. Carrier suppressed single sidebands (CS-SSB) of the intermediate frequency (IF) signal and the local oscillator (LO) signal are simultaneously obtained through the X-DPMZM in a dual-polarization dual-parallel Mach-Zehnder (DP-DPMZM) modulator. A transmit signal with high purity is produced, and a shared LO optical sideband is also provided for the subsequent downconversion. The carrier suppressed double sideband (CS-DSB) modulation for the signal of interest (SOI) is achieved via the Y-DPMZM. The self-interference signal is suppressed by adjusting the bias voltage of its main MZM. An optical bandpass filter (OBPF) is combined to realize frequency downconversion. The experimental results show that the spurious-free dynamic range (SFDR ₃ ) is 102.6 dB/Hz ^2/3 for frequency upconversion, a cancellation depth of more than 50 dB for single-frequency self-interference cancellation (SIC), and more than 22 dB for wideband SIC. The proposed link has superiority in multifunctionality, including in-band transmission, reception, and self-interference cancellation, with a shared LO.