Ultra-flat optics for broadband thermal imaging
March 15, 2024
Ultra-thin meta-optics have the potential to revolutionize imaging systems, making them lighter and thinner than ever. A multi-institutional research team, led by the University of Washington Department of Electrical & Computer Engineering (UW ECE), has demonstrated broadband thermal imaging with meta-optics, using a new inverse design framework. This breakthrough has far-reaching applications, from consumer electronics to thermal sensing and night vision.
Long-wavelength infrared (LWIR) imaging is critical in various fields, including consumer electronics, defense, and national security. However, the conventional refractive lenses used in these systems are bulky, heavy, and often made from expensive and limited-supply materials like germanium. This has prompted the need for lighter, thinner lenses that maintain high image quality.
The solution lies in the development of ultra-thin sub-wavelength diffractive optics, known as meta-optics. These optics, consisting of arrays of sub-wavelength scale nanopillars on a flat surface, can control light to produce steering and lensing. Compared to conventional lenses, meta-optics are significantly thinner, about 500 microns thick, offering a substantial reduction in overall thickness.
Despite their advantages, meta-optics have faced challenges, particularly in the form of strong chromatic aberrations, where light of different wavelengths interacts with the structure in different ways. As a result, meta-optics have not fully replaced their refractive counterparts, especially in the area of LWIR imaging, which remains relatively unexplored.
The research team’s demonstration of broadband thermal imaging with meta-optics marks a significant step forward in addressing these challenges. Their work opens up new possibilities for the use of meta-optics in LWIR imaging, offering the potential for lighter, thinner, and more cost-effective solutions across a wide range of applications.
This breakthrough paves the way for the continued advancement of ultra-flat optics, with implications for the future of imaging technology and its impact on various industries.
