Quantum entanglement microscopes are a form of confocal-type differential interference contrast microscope. Entangled photon pairs and more generally, NOON states are the illumination source. Two beams of photons are beamed at adjacent spots on a flat sample. The interference pattern of the beams are measured after they are reflected. When the two beams hit the flat surface, they both travel the same length and produce a corresponding interference pattern. This interference pattern changes when the beams hit regions of different heights. The patterns can be resolved by analysing the interference pattern and phase difference. A standard optical microscope would be unlikely to detect something so small. The image is precise when measured with entangled photons, as each entangled photon gives information about the other. Therefore, they provide more information than independent photons, creating sharper images.