Linearization of two cascaded intensity-modulator-based analog photonic link

A linearization scheme based on two cascaded intensity modulators is proposed and experimentally demonstrated. By optimizing the biases, the power ratio and the phase difference between the drive signals applied to the two Mach-Zehnder modulators (MZMs), the third-order intermodulation distortion (IMD3) can be effectively eliminated over a wide operating bandwidth of 1 to 12 GHz without the same RF phase at two modulators, which is required in previous works. The ratio of the fundamental output to the IMD3 reaches 50.21 to 63.28 dB, which has an improvement of 18.35 to 31.42 dB compared to that of a single MZM link. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)