Heshmat, B., Tancik, M., Satat, G. & Raskar, R. Photography optics in the time dimension. Nature Photonics 12, 560–566 (2018). 10.1038/s41566-018-0234-0

Abstract

Ultrafast sensors and depth cameras are key enablers for imaging through complex geometries, through scattering, and beyond the line of sight. However, despite accelerating advances in imaging electronics and imaging applications, the optics of such cameras have been inherited from conventional low-speed photography cameras. This has limited ultrafast cameras and their applications to the design constraints of conventional optics. Here, we exploit time as an extra dimension in the optical design and demonstrate that by folding large spaces in time using time-resolved cavities, one can enable new camera capabilities without losing the targeted information. We demonstrate lens tube compression by an order of magnitude, together with ultrafast multi-zoom imaging and ultrafast multispectral imaging by time-folding the optical path at different regions of the imaging optics. Considering the vast variety of designs that could emerge by time-folding conventional imaging optics, we expect this technique to have a broad impact on time-resolved imaging and depth-sensing optics.