fJscaler Inc. is a fabless semiconductor company in Beaverton, Oregon that designs high-speed analog and mixed-signal integrated circuits for optical communications. Its products are linear Mach-Zehnder modulator drivers and transimpedance amplifiers used inside coherent and direct-detect optical transceivers, spanning 100G, 200G, 400G and up to 800G links. The company was formed in 2022 as a majority-owned US subsidiary of NTT Electronics, whose coherent DSP line its components complement, and its team says it has shipped over a billion ICs in production from 1G through 400G linear coherent optics. It has recently prototyped a 260 GBd BiCMOS linear driver aimed at 1.6T and 3.2T AI-infrastructure interconnects.