Laser-Optical Second Harmonic Generation

The performance of thin‐film‐based devices is critically dependent on material composition, design parameters, and growth conditions. Understanding and optimizing these factors is complex and tedious. Until now, the characterization of functional thin-film properties such as an electric polarization or a magnetization is typically performed after completing the deposition and outside of the growth environment.

3Wave provides fast, contactless, non-invasive, and non-destructive access to functional material properties in real time, while thin-film structures are growing or processed in the deposition chamber. The functional properties are accessed through the effect they have on the symmetry of the material. This symmetry is probed with high sensitivity by laser-optical frequency doubling, also called second harmonic generation (SHG). The observation of a certain SHG contribution indicates presence of a specific functionality – offering instant feedback for precise growth optimization.

Just as reflection high-energy electron diffraction (RHEED) has revolutionized in-situ access to the topography, in-situ SHG (ISHG) is envisaged to revolutionize access to and control of functional and application-relevant properties during the growth of epitaxial thin films or multilayer heterostructures.

3Wave relies on the strong expertise gained during more than a decade of ISHG research in the Laboratory for Multifunctional Ferroic Materials at ETH Zurich. After these investigations have led to many breakthrough publications in the field of oxide electronics, ISHG now becomes available as an affordable and compact tool, ready to drive the development of functional materials in application-orientated research laboratories around the world.