Single-frame two-color illumination computational imaging based on Kramers–Kronig relations

Annular-illumination quantitative phase imaging based on Kramers–Kronig relations (AIKK) achieves a large space-bandwidth-time product. The reconstruction algorithm is non-iteration, parameter-free, and object-independent constitutionally. Based on the observation and analyticity of intensity spectrum characteristics and symmetry in spatial and frequency domains, we propose a single-frame two-color illumination imaging based AIKK (SFTC-AIKK). In addition, we apply the two-color mode to synthetic aperture imaging, and only one measurement is sufficient with a monochrome camera. We employ SFTC-AIKK to achieve resolution corresponding to nearly two times the objective NA at camera-limited frame rate to applications with observing dynamic target at various spatial and temporal scales.