For the first time, researchers have used ultra-thin layers of 2D structures known as metasurfaces to create holograms that can measure the polarization of light.
For the first time, researchers have used ultra-thin layers of 2D structures known as metasurfaces to create holograms that can measure the polarization of light. The new metasurface holograms could be used to create very fast and compact devices for polarization measurements, which are used in spectroscopy, sensing and communications applications.
Metasurfaces are optical elements with nanoscale features and an overall thickness that is less than 1/50th that of a human hair. They can be made with standard microelectronics fabrication techniques, enabling mass production, and can be easily integrated into wafer-scale optical systems. Despite these promising features, they are not yet used in many practical applications.
In Optica, The Optical Society's journal for high impact research, a multi-institutional group of researchers report using metasurface holograms to effectively and quickly determine polarization at near-infrared to visible wavelengths. The new work represents a step toward functional metasurface-based devices to support a range of applications from telecommunications to chemical analysis.
Read more at: The Optical Society
Researchers used a metasurface to generate two overlapping holographic images, one that is left-handed circularly polarized (LCP) and one that is right-handed circularly polarized (RCP). By analyzing the interference of the two images (far right), they obtained the amplitude contrast and phase difference between the LCP and RCL components of the incident beam, which can directly identify the polarization state of the light. (Photo Credit: Xueqian Zhang and Jiaguang Han, Tianjin University, and Weili Zhang, Oklahoma State University)