  Linear optics has seen a resurgence for applications in quantum information
processing owing to its miniaturisation on-chip, and increase in production
efficiency and quality of single photons. Time-bin encodings have also become
feasible owing to architectural breakthroughs, and new processing capabilities.
Theoretical efforts have found new ways to implement universal quantum
computations with linear optics requiring less resources, and to demonstrate
the capabilities of linear optics without requiring a universal optical quantum
computer.
