A photonic frequency downconverter based on a single dual-drive Mach-Zehnder modulator

A novel photonic frequency downconverter is proposed and demonstrated using a single dual-drive Mach-Zehnder modulator (DMZM). In the proposed scheme, the local oscillator (LO) and radio frequency (RF) signals are sent to the two RF ports of the DMZM, respectively. By biasing the modulator at the minimum transmission point, a downconverted intermediate frequency (IF) signal with the RF and LO components suppressed is obtained. An experiment is carried out to demonstrate the feasibility of the downconverter. Results show that a 30-GHz RF signal with 50-Mbaud 16 quadrature amplitude modulation (QAM) is successfully downconverted to the 2.4-GHz IF band. The error vector magnitude (EVM) of the downconverted signal is less than 2.0%.