In this episode Shahriar works on a Carl-Zeiss Axioskop with Differential Interference Contrast Microscopy. The instrument has bene meticulously restored to a working condition. The scope is retrofitted with an LED illumination source. Although not idea, it does offer good brightness and uniform illumination. An ideal source would have to be a point source.
The microscope is used to examine an integrated circuit revealing the intricate BEOL of the chip. Furthermore, DIC imaging shows the non-uniformity of the internal integrated circuit metal surfaces.