Nonlinear Interferometry: A New Approach for Imaging and Sensing

Nonlinear interferometers are a ubiquitous tool in quantum photonics. As such, they allow spooky-like imaging with undetected light. On the one side their working principle is based on the principle of induced coherence, which is deeply rooted in the heart of quantum mechanics. On the other side, they bear the strong potential to serve as new tool for biomedical imaging. In this review, an extensive overview about nonlinear interferometers and their working principle is given. A particular focus is set on their exploitation for quantum imaging and sensing. In addition, related side topics and further application fields as well as perspectives are provided.