SIPHO-G will integrate advanced high-speed Germanium-Silicon Quantum-Confined Stark-Effect modulators and Avalanche photodetectors with breakthrough performance into a monolithic 300mm Silicon Photonics platform. These new building blocks will propel the bandwidth density, power efficiency, and sensitivity of silicon photonic integrated circuits across the O-band and C-band, enabling next-generation co-packaged optics, long-haul optical communications and emerging optical neuromorphic computing with applicationlevel performances of 4x-20x beyond current state of the art.
Scaling transceiver bandwidth (beyond 800Gbps) can happen along 3 main axes: (1) the symbol rate per lane; (2) the number of parallel lanes, in space, wavelength or polarization; (3) the number of bits per symbol. Scaling the symbol rate requires doubling the net symbol rate from 50Gbaud to 100Gbaud, which requires >50GHz optical and electrical component bandwidth. Scaling parallelization requires multiplying the number of optical and electrical components. With 16 or more optical lanes, the achievable transceiver yield is a concern, as overall yield drops off exponentially with increasing number of lanes. Very high single-lane yield is required to have acceptable yields for 16+ lane transceivers.
Silicon Photonics is a very attractive technology platform to implement scaling along all three axes, but a key roadblock for power-efficient scaling of the symbol rate is the lack of a low-voltage veryhigh speed electro-optic modulator [Zhou_OFC2019]. As illustrated in Table 1, the mainstream and emerging modulators available in SiPho, namely Si Mach-Zehnder modulators (MZM), Si ring modulators (RM) and GeSi Franz-Keldysh electro-absorption modulators (FK-EAM), lack one or more performance metrics to support efficient scaling. Therefore, SIPHO-G will add a superior modulator building block to the SiPho toolbox in the form of the GeSi Quantum-Confined Stark-Effect (QCSE) waveguide modulators both for direct-detect transceivers in the low-dispersion fiber-optic O-band and coherent transceivers in the low-loss fiber-optic C-band.