Editorial Editorial Introduction to JSTQE Special Issue on Photonic Electronic Co-Integration and Advanced Transfer Printing

Welcome to the IEEE Journal of Selected Topics in Quantum Electronics (JSTQE) Special Issue on Photonic Electronic Co-Integration and Advanced Transfer Printing. Over the past two decades, we have witnessed the establishment and adoption of integrated photonic platforms which allow the design and fabrication of chips that can contain a few dozen up to even hundreds of photonic components. These so-called photonic integrated circuits (PICs) are manufactured at wafer-scale, potentially allowing similar high-volume and low-cost fabrication that has been driving the electronics industry for over half a century. A first main platform is the Indium Phosphide process which allows manufacturing of PICs that contain passive devices (waveguides, optical filters etc.), active opto-electronic devices (detectors and modulators) and optical gain elements (optical amplifiers and lasers). The second process that has emerged is Silicon Photonics, which here refers to both the SOI (Silicon-on-insulator) and the SiN (Silicon Nitride) processes. The SOI-based platform allows for integration of both passives and active devices, however monolithic integration of optical gain elements remains a difficult challenge due to Silicon's indirect bandgap. SiN platforms originally only included passive functionality, although recently monolithic platforms that include both SOI and SiN waveguides have started to emerge. A few Silicon Photonic platforms that monolithically integrate both photonics and electronics have also been established by both academia and industry.