Differential phase contrast 2.0-Opening new “fields” for an established technique

► We describe a technique which allows the determination of inner electric fields in matter. ► Inner fields are believed to be one major reason for the so-called efficiency “droop” in green solid state lasers. ► The technique used is differential phase contrast, used for the first time for inner electric field determination. ► The technique is complementary to electron holography, offers a wider field of view and reveals new structures.