Interference Contrast Microscopy
This technique is used to enhance observation of thin or nearly transparent specimens with low contrast, especially biological samples and multilaminate polymer films. There are several forms of the technique: phase contrast, Hoffman Modulation Contrast and Nomarski Differential Interference Contrast.
Each technique manipulates light to improve contrast and provide visibility of detailed structure not seen with ordinary transmitted light or polarized light, e.g., layers in polymer films and unstained biological specimens.