Pixel super-resolution of time-stretch imaging by an equivalent-time sampling concept

Optical time-stretch imaging entails a stringent requirement of state-of-the-art high-speed data acquisition unit in order to preserve high image resolution at an ultrahigh frame rate-hampering the widespread application of such technology. We here propose a pixel super-resolution (pixel SR) technique tailored for time-stretch imaging that can relax the sampling rate requirement. It harnesses a concept of equivalent-time sampling, which effectively introduces sub-pixel shifts between frames. It involves no active opto-mechanical subpixel-shift control and any additional hardware. We present the system design rules and a proof-of-principle experiment which restores high-resolution images at a relaxed sampling rate of 5 GSa=s. © 2016 SPIE.published_or_final_versio