Megapixel superlattice detectors with optical metasurfaces

One of the main challenges today concerns the earth’s climate and the development of a sustainable society (Agenda 2030). For monitoring and quantification of climate changes, infrared (IR) imaging detectors have been identified as one of the best tools to extract information about gases and pollution in our atmosphere.

Infrared detectors also have a major societal impact as thermal (heat) imaging enables nighttime surveillance for increased safety and security. Furthermore, during pandemics like SARS and Covid-19 IR cameras are used in high-traffic areas to identify people with fever to prevent them from spreading the disease. There is also an increasing medical interest in high-performance IR detectors for early diagnosis of skin and breast cancer. For these applications, type-II superlattices (T2SLs) sensitive in the long-wavelength infrared region (LWIR, 8 - 14 µm) have been identified as the best quantum detector material.

This project deals with fundamental understanding and development of state-of-the-art megapixel T2SL focal plane arrays (FPAs), enhanced by converting each pixel into an optical resonator tuned to different wavelength bands in the LWIR range. This is accomplished by fabricating a planar, or 3D optical metasurface on top of each pixel for trapping of the LWIR radiation.