A metasurface color router facilitating RGB-NIR sensing for an image sensor application

Area of Science:

• Optoelectronics
• Nanophotonics

Background:

• CMOS image sensors (CIS) are vital for capturing images across visible and near-infrared spectra.
• Increasing pixel density enhances resolution but faces trade-offs with optical sensitivity due to the diffraction limit.
• Conventional color filters limit performance in advanced CIS applications.

Purpose of the Study:

• To overcome the sensitivity-pixel size trade-off in CIS.
• To introduce a novel nanophotonic-based spectral sensing concept.
• To develop a metasurface capable of spectral splitting and routing for enhanced image sensing.

Main Methods:

• Designed and optimized a metasurface-based spectral router.
• The metasurface controls transmitted light phases for specific spectra (red, green, blue, near-infrared).
• Utilized nanofabrication techniques for precise metasurface structuring.

Main Results:

• Successfully split visible to near-infrared spectra into four distinct optical channels.
• Achieved simultaneous phase control for R, G, B, and NIR light using a single-layer metasurface.
• Demonstrated superior optical efficiency compared to conventional color filter systems.

Conclusions:

• The metasurface spectral router effectively addresses the sensitivity limitations in miniaturized CIS.
• This technology enables enhanced spectral sensing capabilities for diverse optical applications.
• The developed metasurface represents a significant advancement over traditional color filtering methods in image sensors.