The advancement of enabling photonic components developed for fiber-optic communication systems began nearly forty years ago while advantages of using light-wave communication in computing systems have been discussed for several decades. Following the history of microelectronics, the size of required photonic components for future communication systems will certainly need to be scaled down dramatically along a route of exploring higher system performance. The concept of photonic bandgap crystals has been around more than two decades. A line-defect within a two-dimensional photonic bandgap crystal provides efficient spatial confinement of light, which is a building block of a variety of routing and processing schemes of light. In contrast, silicon in the form of complementary metal semiconductor oxide (CMOS) platform has been a core in microelectronics. Silicon nanophotonics that allow CMOS platforms to handle light, thus, would offer a wide range of photonic functions that are required for CMOS platforms to further progress. While the photonic bandgap crystal and silicon nanophotonics are still subject to the diffraction limit of light, photonic devices that use surface plasmon polaritons and / or energy transfer mechanisms relying upon optical near-field interactions would pave the road toward ultimate photonic integration beyond the diffraction limit of light.