Dense Wavelength-Division Multiplexing Transmitter Chip Based on Lithium-Niobate-on-Insulator Platform

We demonstrate a compact photonic chip <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$({0.78\times 0.58}\ {{mm}^{2}})$</tex> for DWDM transmitters on lithium-niobate-on-insulator with a channel spacing of 1.6 nm, exhibiting an excess loss of 1.3 dB and enabling 4×100-Gbps PAM4 signals generation.