Photonic-Electronic convergence on Silicon (Si Photonics) is about to become the new information technology platform for our modern society, in which the appetite for computer power and communications seems unlimited. For many years, the high refractive index contrast optics (HiDex) between Si core and SiO2 cladding is the platform on which Si Photonics is developed. However, the current HiDex Si Photonics will not fulfill ITU-T Telecom standards for the next generation of dense wavelength division multiplexing (WDM). The strong refractive index contrast between Si and SiO2 of the HiDex platform leads to strong light confinement which has serious detrimental effects for dense WDM in terms of power durability (two-photon absorption and four wave mixing), temperature stability, and technological robustness. The fellow proposes to develop a new Si Photonics platform based on mid-refractive index contrast optics (MiDex) to overcome the incompatibilities of current HiDex Si Photonics for the future dense WDM system. This research project will (1) study electro-optical properties of the MiDex platform using CMOS compatible material of Si nitride (SiN) or Si oxynitride (SiOxNy), SiO2, coupled with germanium (Ge) optoelectronic components on ordinary Si wafer, and (2) demonstrate and evaluate its potentials to meet the strict requirements of future dense WDM Telecom system. The fellow anticipates that MiDex can outperform the incumbent HiDex in meeting the aforementioned challenges. The fellow aims to validate the project’s hypothesis that (i) MiDex is free from two-photon absorption and four wave mixing, (ii) MiDex has sufficiently low refractive index dependence on temperature, (iii) MiDex has lower effective index dependence on geometrical errors (low polarization dependence), and (iv) MiDex allows monolithic integration of photonic circuits on a bulk Si substrate. The ultimate goal of the project is to develop 100 Gb/s optical modules for future high-volume short-reach