Optical Time Stretch for High-Speed and High-Throughput Imaging-From Single-Cell to Tissue-Wide Scales

Initially developed for high-speed optical communication, optical time stretch has recently been adopted for ultrafast and sensitive optical imaging at an unprecedented speed. In this paper, we highlight the essential concepts as well as the enabling elements of this ultrafast technology. More importantly, we review the recent developments of optical time-stretch imaging, especially in the context of 1) quantitative optofluidic microscopy for high-content single-cell phenotyping at an imaging throughput similar to 100 000 cells/s; 2) all-optical multi-MHz (> 10 MHz) swept-source optical coherence tomography (OCT) for high-speed in vivo anatomical and functional 3-D tissue imaging. We also discuss the current technological challenges in time-stretch imaging. In particular, generating the enormous data in real time, this technology could uniquely create new insights of data-driven science in clinical diagnostics and basic biological research.