Dyed liquid crystals enable light-only control of optical components

Physicists at the ARC Centre of Excellence for Transformative Meta-Optical Systems at ANU have developed a novel technique to control optical components using light alone. By embedding a metasurface, which is typically static, within liquid crystals infused with a dye responsive to light, the researchers can dynamically manipulate the optical properties of the metasurface without the need for electrodes, magnetic components, or heating elements.

This groundbreaking approach could pave the way for faster, more energy-efficient signal processing technology with applications in holographic video, metalenses, imaging systems, and holography. The key to this achievement lies in the use of dye-doped liquid crystals, specifically methyl red, which undergoes a change in shape when exposed to green light at a specific wavelength, thereby altering the orientation of the liquid crystals and their polarization response.

This optical control method allows for the reversible tuning of the metasurface's properties, enabling functions such as optical switching and dynamic beam shaping. The researchers are now focused on optimizing response time and creating nanoscale versions of these controlled metasurfaces for use in various devices, potentially replacing bulky components in smartphones and cameras.