Full-color-sorting metalenses for high-sensitivity image sensors

Abstract

Image sensors play a critical role in current technologies ranging from smartphones to autonomous vehicles. In these technologies, high-sensitivity image sensors are highly desired because they enable dark-scene/ultra-fast imaging. Unfortunately, a conventional sensor architecture that employs color filters on every pixel fundamentally limits the detected light power per pixel because of the filtering, which has been a long-standing barrier to sensitivity improvement. Here, we demonstrate polarization-insensitive metasurface lenses (metalenses) that sort primary colors on high-density pixels without the use of color filters. The metalenses simultaneously act as pixel-scale color splitters and lenses and are compatible with complementary metal–oxide-semiconductor sensor technology. An image sensor with such metalenses significantly enhances the detected light power, while affording high image quality, incident angle tolerance, and sub-micrometer spatial resolution. The demonstrated architecture opens the way to the development of high-sensitivity color image sensors that exceed current limits while maintaining consistency with state-of-the-art sensor technology.

Designing two-dimensional temperature profiles using tunable thermoplasmonics

“…Inspired by these two findings, we, for the first time to our knowledge, demonstrate a technology for encoding and storage of optical information using a 2D array of TiN : Si voxels at the sub-wavelength scale. In addition, the results of our study might be of practical interest in the development of thermoplasmonic sensors for nanoscale probing phase transitions, 27–29 thermal metalenses for sub-wavelength imaging, 30,31 fast optical thermocycling for polymerase chain reactions, 32 TiN nanofurnaces for catalytic reactions, 33,34 bio-interfaces for thermally patterned neuromodulation, 35 large-area broadband absorbers for solar thermophotovoltaics, 36 and, eventually, thermal metasurfaces used in analog computing. 37–39…”

Dielectric metalens for miniaturized imaging systems: progress and challenges

“…Nevertheless, owing to the index difference between the encapsulation glass and air, the efficiency of the device would be reduced by the reflection at the interface of the two media; the focal length is altered compared with the unpacked metalens, and additional monochromatic aberrations could arise. One also needs to consider the matching of metalens performances and photosensor performances 223 . Hence, the metalens should be designed and optimized according to the overall packaging module from the beginning.…”

3D-Patterned Inverse-Designed Mid-Infrared Metaoptics

“…For example, dielectric metasurfaces are arrays of subwavelength scatterers that apply a spatially varying phase, polarization or amplitude response to an incoming wavefront [1]. The local control is related to the specific shape of each scatterer which can be chosen to compactly replicate and combine functionalities of common optical components like lenses, beamsplitters, polarizers, and waveplates or realize more novel devices such as those used for visible color routing at the pixel level [2]. For metasurfaces, the absence of substantial inter-element electromagnetic coupling is often leveraged for ease of design, but this simplification also limits the available degrees of freedom.…”