e shape fs optical pulses and deliver them in a single spatial mode to the input of a multimode fiber. The pulse is shaped in time such that at the output of the multimode fiber an ultrashort pulse appears at a predefined focus. Our result shows how to raster scan an ultrashort pulse at the output of a stiff piece of square-core step-index multimode fiber and in this way show the potential for making a nonlinear fluorescent image of the scene behind the fiber, while the connection to the multimode fiber can be established via a thin and flexible single-mode fiber. The experimental results match our numerical simulation well.

Opt. Express
Nanoscale Imaging and Metrology

Velsink, M., Amitonova, L., & Pinkse, P. (2021). Spatiotemporal focusing through a multimode fiber via time-domain wavefront shaping. Opt. Express, 29(1), 272–290. doi:10.1364/oe.412714