An 8 × 200 Gbps wavelength-division multiplexing transmitter using lithium tantalate

Large-capacity data transmission is increasingly required to meet the growing demands of big data and artificial intelligence applications. Wavelength-division multiplexing (WDM) technology is a reliable method of increasing link capacity by enabling multiple wavelength signals to be transmitted in a single channel. Here, for the first time, a large-capacity transmitter on thin-film lithium tantalate-on-insulator (LTOI) is demonstrated by monolithically integrating an 8-channel WDM and Mach–Zehnder interferometer (MZI) electro-optic modulators (EOMs). The integrated 8-channel WDM, comprised of 8 cascaded waveguide Bragg grating optical filters, realizes channel spacing of 16.8 nm, 1-dB bandwidth of 15.4 nm, and thermal sensitivity of 10 pm/ºC. The MZI EOMs show low direct current drift and 3-dB bandwidth beyond 67 GHz. Finally, the WDM transmitter achieves a data rate of 100 Gbps OOK and 200 Gbps PAM4 for a single channel, indicating the demonstrated total capacity of 1.6 Tbps. Therefore, the demonstrated large-capacity WDM transmitter will find many applications, such as artificial intelligence and data centers.