Due to the birefringence, if the mineral is placed on top of an image, two images can be seen through the mineral Icelandic stone. This birefringence is caused by the quality of the crystalline material called optical anisotropy (direction dependence).
When the speed of light is slowed down, the curvature of the beam will vary depending on the optical anisotropy of the different materials. Materials with optical anisotropy are critical for a variety of devices including microscopes, laser pointer, lens filters, and liquid crystal displays. Generally, devices that change the polarization of light employ materials having optical anisotropy.
A group of scientists and engineers from the University of Wisconsin-Madison and the University of Southern California have created a compound crystal that combines bismuth, titanium, and sulfur (BaTiS3), which has higher optical anisotropy than all other solid materials. . The above optical anisotropy is extremely high for infrared light. The team described the new material in a paper published in the journal Nature Photonics.
This new material may be used for imaging with mid-infrared transparent windows and other types of remote sensing. The researchers speculate that this new material may also be used in photovoltaic cells or LEDs. The researchers say that the optical birefringence (anisotropy metric) of mid-infrared light in this new crystal is about 50 to 100 times higher than previously measured.
The unique molecular structure consisting of long-chain atoms arranged in parallel gives the new laser pointer material a photodegradability. Using advanced calculations, the researchers carefully selected a row of atoms and made them accurately in the laboratory, followed by research. In the future, the team plans to investigate further the other properties of the new material as they are still trying to develop a large number of synthetic processes.