The field of optics is entering a new era, with the recently acquired capability of large-scale photonic integration on chip. Thanks to the development in silicon nanophotonics and plasmonics in the last few years, the size of integrated optical devices has shrunk several orders of magnitude to the sub-micron and nanometer regime, and monolithic integration with electronic circuits has been demonstrated. These technologies will bring a complete revolution to the field of optics, like what IC technologies have brought to electronics. In the next decade or two, we can expect to see monolithically integrated optoelectronic systems with much expanded functionality and improved performance unmatched by the current purely electronic IC's


The most promising platform for optoelectronic integration is the one based on silicon nanophotonics, as it takes advantages of both the mature fabrication technology for microelectronics and the capability of high optical confinement in silicon. In the last few years, various photonic devices have been developed on silicon or silicon-compatible materials, including lasers, optical amplifiers, modulators, and detectors, which enable monolithic integration of a complete electro-optical system on-chip. However, many of these demonstrated devices have rather large dimensions (in millimeters), while large-scale photonic integrations require devices with small size and low power consumption.


This research group led by Prof. Qianfan Xu focuses on ultra-compact optical devices on chip, including devices based on microring resonator, photonic crystal cavities, and plasmonic nanostructures. Their small size, low power consumption and strong enhancement of photon-material interaction are critical for most applications of photonics. Large-scale integration of such devices will enable high-impact applications like optical interconnection system, optical biosensing, optical imaging and optoelectronic signal processing.