Over the last few decades, we have witnessed revolutionary developments in photonics technology, such as optical fiber communication, optical disc storage, lasers, LEDs, solar cells, etc. This photonics revolution has brought enormous beneficial impacts to society. More recently, dramatic developments in nanofabrication and numerical modeling techniques have enabled patterning of deep subwavelength photonic nanostructures. Many new opportunities are opening in this field, called nano-optics. These opportunities can lead to dramatic developments in all areas of optical science and technologies. Nano-optics will be a key research field for resolving many critical problems in the 21st century, such as large scale information processing, efficient energy harvesting/conversion, ultra-sensitive environmental sensing, etc.