All-dielectric metasurface lenses for focal plane arrays operating in mid-wave infrared spectrum

Focal plane arrays (FPAs) as a two-dimensional detector pixel matrix positioned in the focal plane of an optical system have been developed continuously for obtaining higher resolution. On the other hand, for developing high-resolution, compact-size FPAs, used methods such as the miniaturization of pixel size leads to serious problems such as increased optical crosstalk. In this study, we proposed highly efficient all-dielectric metasurface lens array-based FPA at mid-wave infrared spectrum. All-dielectric metasurface lens arrays were numerically demonstrated to achieve high optical efficiency above 85%. Moreover, our design compared with conventional and earlier metasurface-based studies has exhibited much superior optical crosstalk performance. While standing the high efficiency, optical crosstalk is decreased to low level of <= 2.8%. A figure-of-merit (FoM) is also defined for the device performance, which is designated as the focusing efficiency per optical crosstalk times the f-number. The results show that a FOM of approximately 90 is achieved. These proposed all-dielectric metasurface lens arrays demonstrate great potential for increasing the signal to noise ratio and sensitivity thus paving the way for compactsize and high-resolution FPAs to be deployed in various applications including thermal cameras, imaging devices and bolometers.