By now, it is well understood that thinning a material down to a single atom thickness can dramatically change that material’s physical properties. Graphene, the best known 2-D material, has unparalleled strength and electrical conductivity, unlike its bulk form as graphite. Researchers have begun to study hundreds of other 2-D materials for the purposes of electronics, sensing, early cancer diagnosis, water desalination and a host of other applications. Now, a team of Penn State researchers in the Department of Physics and the Center for Two-Dimensional and Layered Materials (2DLM) has developed a fast, nondestructive optical method for analyzing defects in two-dimensional materials.