Time Stretch and its Applications in Nonlinear Dynamics, Biomedicine, and Computational Imaging

Abstract

Measurements of non-repetitive and rare signals that occur on short timescales requires fast real-time measurements that exceed the speed, precision, and record length of digitizers. Time-stretch is an optical hardware accelerator that overcomes the speed limitations of photodetectors and electronic digitizers and enables ultrafast single-shot spectroscopy, imaging and other measurements at refresh rates reaching billions of frames per second with continuous recording spanning trillions of consecutive frames. The technology has opened a new frontier in measurement science and has led to discovery of several new scientific phenomena in nonlinear optics, laser dynamics and diagnostics of relativistic electron beams. It has also created a new class of instruments that have been integrated with artificial intelligence for sensing and biomedical diagnostics. We review the fundamental principles and applications of time stretch including a spin-off technology known as the phase stretch transform, a new computational imaging algorithm that is emerging as the best edge and texture feature extractor for digital images.