An efficient photonic mixer with frequency doubling based on a dual-parallel MZM

We propose and demonstrate a novel photonic microwave mixer based on an integrated dual-parallel Mach–Zehnder modulator (DPMZM). The local oscillator (LO) signal is frequency doubled and modulated onto the optical carrier through one sub-modulator which is biased at the maximum transmission point, while the radio-frequency (RF) signal is modulated onto the optical carrier through the other sub-modulator. The mixer is simple in structure, stable in performance, and the frequency requirement of the LO is only one-half of that of conventional schemes. Experimental results demonstrate a significant improvement of 17.1 dB in conversion efficiency, 10.5 dB in noise figure (NF) and 7.7 dB in spurious free dynamic range (SFDR) as compared with the scheme based on two cascaded intensity modulators (IMs).