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fJscaler

Driver and amplifier chips for optical transceivers

Raised to date

$7.5M

across 1 Form D filing

Investors
2
Last filed
Mar 20, 2026

About

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.

Pairs two decades of production optical-IC design experience with digitally assisted analog signal processing, targeting femto-Joule-per-bit energy efficiency while preserving the low latency of fiber-optic interconnects — and as an NTT Electronics subsidiary its drivers and TIAs are designed alongside the coherent DSPs they sit next to.

Funding

  • EquityFiled Mar 20, 2026Form D
    $7.5M/ no target

Product

FJS1000

Optical transceiver driver IC

Quad-channel 64 GBd linear Mach-Zehnder modulator driver delivering 4 VP-P output, built for coherent optical transceivers in QSFP-DD and OSFP form factors serving 100G/200G/400G ZR and ZR+ applications.

  • Quad-channel, 64 GBd per channel
  • 4 VP-P linear output swing for Mach-Zehnder modulators
  • Targets QSFP-DD and OSFP pluggable coherent form factors

Built for

Optical transceiver and module manufacturers building coherent and direct-detect pluggables (QSFP-DD, OSFP) for telecom and hyperscale data-center operators, including AI-infrastructure interconnect vendors.

People on file