The advances in Si technology and the rapid growth of broadband communication via optical fiber allow silicon integrated photonics to begin revolutionizing the electronic devices, circuits, and systems. The successful development of Si integrated photonics will enable on-chip optical interconnects for future microprocessor and giga-scale circuits, chip-to-chip fiber interconnection and will greatly decrease the cost for fiber-to-home connection. This will be one of the major moves for the next technology revolution. In this study, low optical loss silicon-based dielectrics were prepared using the microfabrication techniques. The materials were used to realize low-loss optical waveguide devices for integrated optic applications. The waveguide devices realized using these techniques have feature of low propagation loss and small size. This work further demonstrated that the silicon oxide-based nanocrystal structures can be good candidates for light-emitting devices at room temperature. The bonding structure and the optical properties of silicon-rich silicon oxide films, which were prepared using plasma-enhanced chemical vapor deposition (PECVD) with thermal oxidation, have been studied in detail. The composition and bonding structures have been explored using both Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The luminescent properties were studied using Raman spectroscopy and photoluminescence (PL) measurements. Results show that hightemperature (~1000 oC) annealing of as-deposited Si-rich silicon oxide gives rise to phase separation and formation of crystalline Si phases in the oxide films. This work has demonstrated the viable technology for making waveguide structures and optical components from Si-based materials. Visible light was obtained from Sibased the insulator-embedded Si nanoclusters. These achievements provide useful fundamentals for the development of future silicon integrated photonics.