Krasnoyarsk scientists have proposed a new structure for controlling light. Its design, which includes mirrors, liquid crystals and gold nanoparticles, can absorb up to 100% of light and create new innovative optical materials and devices. An example is an ideal 100% light absorber. The research results were published in the journal Photonics.

To develop modern solar energy devices, sensors and emitters, photodetectors and lasers, it is necessary to design and create new functional elements of optical devices.

Scientists from the Federal Research Center "KSC SB RAS" and Siberian Federal University have proposed a new structure for controlling light at the microlevel. Its design allows it to absorb 100% light. This discovery can be an important step in the development of solar energy sector and other areas where efficient conversion of light energy is required.

Scientists have created an optical structure that consists of an anisotropic mirror surrounded by a chiral material—cholesteric liquid crystal—and a metasurface—rectangular gold nanoparticles.

“The use of anisotropic mirrors, holistic liquid crystals and a metasurface consisting of gold nanobricks separated from an opaque gold substrate by a layer of silicon dioxide provides a unique combination of optical properties such as control of light polarization, optical activity and plasmon resonance. This makes it possible to create structures with a high degree of control over light waves, which can lead to the creation of new, more efficient and compact devices in the field of solar energy,” explained Candidate of Physical and Mathematical Sciences, researcher at the Laboratory of Photonics of Molecular Systems at the L.V. Kirensky Institute of Physics SB RAS, Rashid Bikbaev.

The researchers have found that at the point of critical interaction between modes, light absorption reaches 100%. The developed optical structure can be used in solar energy, where it is important to convert sunlight into electricity as efficiently as possible.

“We found that at certain values of the period of the metasurface, it begins to absorb light very efficiently. This occurs when a condition called a critical link condition is met. With this condition satisfied, the metasurface absorbs light almost completely. Thus, the proposed micro-level light control structure can absorb 100% light waves, making it an ideal light absorber. This characteristic is a key aspect for increasing the efficiency of photodetectors, sensors, lasers and other devices,” said Natalya Rudakova, Candidate of Physical and Mathematical Sciences, researcher at the Laboratory of Photonics of Molecular Systems at the L.V. Kirensky Institute of Physics SB RAS.