Submicrometer Nanostructure-Based RGB Filters for CMOS Image Sensors

Abstract

Digital color imaging relies on spectral filters on top of a pixelated sensor, such as a CMOS image sensor. An important parameter of imaging devices is their resolution, which depends on the size of the pixels. For many applications, a high resolution is desirable, consequently requiring small spectral filters. Dielectric nanostructures, due to their resonant behavior and its tunability, offer the possibility to be assembled into flexible and miniature spectral filters, which could potentially replace conventional pigmented and dye-based color filters. In this paper, we demonstrate the generation of transmissive structural colors based on uniform-height amorphous silicon nanostructures. We optimize the structures for the primary RGB colors and report the construction of sub-micrometer RGB filter arrays for a pixel size down to 0.5 μm.In the past decades we have observed a rapid growth of the spatial resolution of color imaging devices 1-8 . This technological outburst was mainly driven by daily-use hand-held devices, such as mobile phones and compact optical cameras, but a high resolution also serves a role in industrial and environmental imaging 9 . The use of complementary metal-oxide-semiconductor (CMOS) image sensor with pigmented and dye-based color filters allowed to obtain pixels as small

Spectral imaging and spectral LIDAR systems: moving toward compact nanophotonics-based sensing

“…In the previous subsections, the nanostructured spectral filters integrated with PD array or CISs are covered. In the meanwhile, there are also novel standalone spectral filters demonstrated recently, which are suitable for spectral imaging [28,75,[119][120][121][122][123]. For example, in the study by Najiminaini et al [75], nanohole arrays in a gold film has been used as spectral filter for a snapshot multispectral imager.…”

Polarization‐Sensitive Dielectric Membrane Metasurfaces

“…Metasurfaces created by periodic lattices of subwavelength resonators are able to manipulate electromagnetic waves with precise control over their different characteristics such as phase, amplitude, polarization, momentum, etc. [1][2][3][4][5][6][7][8][9][10][11][12] Unlike plasmonic metasurfaces whose transmission efficiencies are limited by Ohmic losses, dielectric metasurfaces supporting Mie resonances offer significant advantages due to their low intrinsic losses and high transmission suitable for flat optics devices [3,[13][14][15][16] In dielectric metasurfaces, magnetic and electric Mieresonant multipoles play a crucial role in controlling the the electric field upon reflection but it reverses the magnetic field, [38,39] in contrast to the conventional mirror, which gives rise to a π reflection phase for the electric field (see the Supporting Information). Such metasurface mirrors can enhance lightmatter interaction, including sensing, absorption, and photodetection.…”

“…Metasurfaces created by periodic lattices of subwavelength resonators are able to manipulate electromagnetic waves with precise control over their different characteristics such as phase, amplitude, polarization, momentum, etc. [ 1–12 ] Unlike plasmonic metasurfaces whose transmission efficiencies are limited by Ohmic losses, dielectric metasurfaces supporting Mie resonances offer significant advantages due to their low intrinsic losses and high transmission suitable for flat optics devices [ 3,13–16 ] In dielectric metasurfaces, magnetic and electric Mie‐resonant multipoles play a crucial role in controlling the interference and scattering of light. [ 2,17 ] More specifically, when magnetic and electric dipole resonances are spectrally overlapped, they may support the unidirectional scattering realizing Huygens' metasurfaces that allow light transmission with nearly 100% efficiency and a complete 2π phase coverage.…”

Flexible Image Sensors with Semiconducting Nanowires for Biomimic Visual Applications

“…Image sensors are widely used in diverse applications ranging from consumer products to healthcare and industrial applications. [1][2][3][4][5][6][7][8][9][10] Image sensing plays an important role in industrial application fields, as well as emerging applications such as machine vision, short-wave infrared surveillance, and near-infrared medical imaging. [11][12][13][14][15] Contrary to the traditional rigid substrate image sensor, flexible image sensor has better shape and can adapt to different objects.…”