Phi Optics QPI and Pixel Intensity

Phi Optics QPI and its relation to Phase Contrast and DIC microscopy.

Phase Contrast and DIC Microscopy are a mix of amplitude and phase that varies with illumination intensity and camera gain and exposure. SLIM and GLIM have a linear relation with phase/density, which means SLIM and GLIM are quantitative. Signal to noise ratio:
Holography + common-path interferometry  nanometer spatial phase sensitivity: SLIM and GLIM have higher contrast-to-noise ratio (CNR)

T. Kim, R. Zhou et al, Nature Photonics (2014)
T. H. Nguyen, M. E. Kandel et al, Nature Communications (2017)