Introduction to the Special Issue on Emerging Areas in Integrated Photonics

This special issue combines 13 invited and 35 contributed papers, offering a unique perspective on the most recent developments in integrated photonics over the last few years. The invited papers, authored by world-renowned research groups and promising scientists from all over the world, present extended reviews on recent progresses and significant perspectives on future research directions. Heterogeneous integration of dissimilar materials for integrated photonics remains one of the most active and promising areas of research, with both traditional semiconductor materials such as amorphous Si, germanium, and III-V quantum dots on silicon, as well as emerging materials such as thin film lithium niobate, nitride, silicon carbide, diamond, etc. Device structures are being explored for new functional applications, from traditional Datacom/telecom to optical, RF and nonlinear signal processing, nonreciprocal optics, midwave infrared sensing, etc. Integration schemes and system architecutures are being pursued for quantum computing, signal processing, machine learning, energy efficient neuromorphic computing, etc.