Assigned to a project for designing a laser-based dental hand tool, Bernold Richerzhagen visualized combining a water jet and a laser for tooth ablation. His dental tool envisioned a laser within a low-pressure hair-thin water jet that guided the beam by means of total internal reflection in a manner like an optical fiber. Eventually, this fusion of light and water resulted in a new technology capable of machining hard materials with high precision. Starting with a dental tool developed in a Swiss laboratory in 1993, this invention has fostered high-precision laser machining in the aviation, diamond and semiconductor industries amongst others.
Back in 1986, Bernold Richerzhagen decided to focus on bio-medical sciences at RWTH University Aachen. He obtained his master's degree in mechanical engineering with a thesis on artificial heart design. A year later, he joined a research project at the Applied Optics Laboratory of the Federal Institute of Technology, Lausanne, EPFL, to develop a laser-based dental tool. The goal was to develop a laser energy transmission system for dental applications such as the removal of caries.