On-chip differential interference contrast (DIC) phase imager and beam profiler based on Young's interference

In this article, we will present a novel differential interference contrast (DIC) phase imaging device based on Young's interference. It is mainly based on either two or four nano apertures defined in an optically opaque aluminum film on a CMOS imaging sensor chip. It provides linear and disentangled differential phase and intensity images simultaneously. Furthermore, it's simple, free of bulky optical elements and compatible to the planar micro fabrication process. All of these features make it a promising device for the on-chip high resolution DIC phase imaging and beam profiling. The fabrication and operation of the device is explained in details. The performance is evaluated theoretically and is verified experimentally by examining the phase and intensity profile of a Gaussian beam and an optical vortex. The 2D quantitive differential phase distribution of an optical vortex has been recorded directly by our device with 1μm resolution.