The idea stemmed from an experiment proposed by Demkov and colleagues in the early 1980s. The researchers suggested that electron waves could be imaged when interacting with a static electric field as long as the de Broglie Wavelength of these electrons was large enough. It was not until 1996 that anything resembling these ideas bore fruit. In 1996 a team of French researchers developed the first photodetachment microscope. It allowed for direct observation of the oscillatory structure of a wave function. Photodetachment is the removal of electrons from an atom using interactions with photons or other particles. Photodetachment microscopy made it possible to image the spatial distribution of the ejected electron. The microscope developed in 1996 was the first to image photodetachment rings of a negative Bromine ion. These images revealed interference between two electron waves on their way to the detector.