Metasurfaces are about to revolutionize the way we make optics. By use of numerical calculations it is now possible to design nanostructured surfaces with special optical properties, for example a 1 micrometer (one thousandth of a mm) thin chip which acts as a lens, where you previously would need a precisely polished glass lens with a thickness of several millimeters. This type of structures can additionally be fabricated with the same technology and processes that have been developed to make electronics, and this way they are enabling optical lenses and components that are cheaper, lighter and more compact than conventional optics, in addition to components and systems with new functionality.
The last couple of years there has been a lot of research into how to make metasurfaces with adjustable properties, for example lenses that can change focal length or components that can steer a laser beam. In this project we are making dynamic metasurfaces by combining metasurfaces with micro- electromechanical systems, which are very small mechanical systems that can be controlled by varying electrical voltages. By adjusting the separation between a mirror and an array of gold nanostructures we have for example demonstrated that we can turn on and off the optical properties of a metasurface. We have also made a component that can be used to control the polarization state of light, which now is going to be used in a research project looking at automatic analysis of tissue samples for cancer screening.