Advances in integrated quantum photonics for quantum sensing and communication

Integrated photonics has significantly transformed the field of quantum technologies throughout the past few years. A timely evaluation of the state-of-the-art and investigation of the different approaches pursued for integrated quantum photonics is highly appropriate in the context of the current second quantum revolution. With this perspective, we discuss the present issues and future developments related to various technological systems, relying on recent developments. Recent advances from a variety of subfields will be discussed, with emphasis on applications in quantum sensing and quantum communication. Significant advances in quantum communication and the quantum internet have been made in recent years in part due to the emergence of quantum photonic chips, whose low-cost, robustness scalability, and stability allow for new device possibilities with smaller footprints. Also discussed here are the achievements in quantum photonic chips with the most widely used photonic integrated fabrication platforms and the essential parts of integrated quantum communication systems. It highlights innovative concepts, advancements in the field, and cutting-edge developments, while addressing possible drawbacks and unresolved challenges.