New optical materials provide unprecedented levels of light and heat control

A team led by Yu Nanfang, an assistant professor of applied physics at Columbia University's Department of Engineering, discovered a new phase-change optical material and showed the new device's dynamic control of light over a wider range of wavelengths, It has become possible to achieve greater modulation than current equipment.

The research team, which includes researchers from Purdue University, Harvard University, Drexel University and Bukharat National Laboratory, found that SmNiO3 in an unprecedented broad spectrum ranges from blue The visible spectrum (400 nm wavelength) to the mid-infrared thermal radiation spectrum (tens of micrometers) enables continuous control of electrically tuned transparency and opacity. The study, which is the first survey of the optical properties of SmNiO3 and the first demonstration of its use as a photonic device, has been published online in Advanced Materials.

"SmNiO3 performance includes record-breaking amplitude and wavelength tuning range," said Yu. "There is almost no other material that offers such a combination of properties and is therefore very desirable for the fabrication of optoelectronic devices. The reversible adjustment between transparent and opaque states is based on electron doping at room temperature, which The potential for transitions is very fast and opens up a wide range of exciting applications such as 'smart windows' for fully and dynamically controlled sunlight, infrared camouflage and radiant temperature control of variable emissivity coatings, light Modulator, and optical storage. "

There are also potential new features that include the use of SmNiO3 materials to control thermal radiation to create "smart" infrared camouflage and thermoregulation devices. These coatings make it possible for people and vehicles to look cooler than they actually are in the nighttime thermal imaging camera lens. By adjusting the relative thermal radiation effects of its bright and dark sides relative to the sun, the coating can help reduce the large temperature gradient on the satellites, thereby extending the life of the satellite. Since this phase change material can be switched between high-speed transparent and opaque states, it can be used in modulators and optical storage devices for free-space optical communications and optical radars.