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 highresolution, 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 arraybased 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.
Intensive researches in the area of metasurfaces have provided a new insight to obtain flat and compact optical systems.
In this letter, we numerically show that, highly efficient tunable beam steering effect in transmission mode is achieved at
wavelength λ = 550 nm using nematic liquid crystals (LCs) infiltrated into double sided metasurfaces. Using the electrooptical
feature of LCs, the phase profile of the metasurfaces is controlled and thus, the transmitted beam is deflected
within the range from -15° to 15° steering angles. Transparent dielectric materials are used in the designed structure that
provides highly efficient beam-steering; the corresponding transmission efficiency is above 83% in the visible spectrum,
which is another superiority of the proposed hybrid tunable structure over present plasmonic/metamaterial approaches.
The designed metasurface still preserves its beam deflection property covering the visible spectrum and hence, such
hybrid structure can be implemented for broadband electro-optically controllable beam steering applications.