As an engineer specializing in lasers, Yves Gentet first worked on holographic targeting systems of the French fighter plane Dassault Rafale. In 1995, he developed a method called Ultimate, which allows the creation of muticolored holograms. It consists of three lasers (red, blue and green) instead of the usual technique of using only a red laser. This novel technique relies on an emulsion of silver particles in a gelatin, which is able to store many more interference fringes