In a breakthrough discovery, scientists at the California Institute of Technology (Caltech) have found a polarizing material that combines small size with dynamic adjustment capabilities. The material, black phosphorus, allows for the creation of a polarizing filter that is only three atomic layers thick and can be manipulated by electrical signals. This filter has the potential to increase the bandwidth of optical data lines, among other applications.
The polarization of light is a crucial property for a range of optical applications, including optical sensors, hologram videos, LC displays, and data transmission over optical lines. Until now, the polarization of the necessary photons has been generated using nanostructures or special filters. However, materials that allow for dynamic adjustment of polarization have not been available. The Caltech team has discovered that black phosphorus, a phosphorus variant with a unique atom configuration, can create polarizing effects due to the atoms’ arrangement in the crystal lattice.
The physicists were able to create an effective polarizing filter from a layer of black phosphorus that was only three atomic layers thick. Because black phosphorus is a semiconductor, the behavior of the filter can be manipulated by electrical signals. This allows for the targeted manipulation of light polarization over a broad spectral range, including infrared light. The filter has the potential to increase the bandwidth of optical data lines and can be used in miniaturized optical devices. The researchers believe that this discovery represents a path to active control of optical polarization on a nanoscale and could have applications in telecommunications, displays, and photosensors.
