The tl:dr version: new research into SPMM may have implications in the development of highly efficient and cost-effective inspection systems for display quality control and defect detection during manufacturing.
Spectrometry is a well-established technique that involves splitting light into its component wavelengths using a diffraction grating or prism, and then measuring the intensity of each wavelength using a photodetector. This results in a spectrum that shows the relative intensities of the different wavelengths present in the light. Spectrometry is widely used in various fields such as chemistry, physics, and biology to identify the composition and properties of materials based on their spectral signature.
Spectrometry has been used in the development of organic light-emitting diode (OLED) displays to measure and control the spectral properties of the light emitted by the display. This is important because the color accuracy and gamut of OLED displays can be influenced by variations in the spectral properties of the emitted light. Spectrometry can be used to ensure that the spectral properties of each display pixel are consistent and accurate.
On the other hand, a spectral and polarization multi-foci metalens (SPMM) is a newer technology that combines a metalens with a geometric phase element to capture both spectral and polarization information of light simultaneously. The metalens is designed to create multiple foci at different positions, each of which corresponds to a different wavelength and polarization state of light. The geometric phase element, which is located behind the metalens, records the phase shift caused by the polarization of light passing through each focus. By analyzing the interference pattern created by the combination of the multiple foci and polarization phase information, the SPMM can reconstruct the spectral and polarization information of the incident light.
While spectrometry captures spectral information by measuring the intensity of different wavelengths of light, SPMM captures both spectral and polarization information of light by analyzing the interference pattern created by multiple foci and polarization phase information.
Moreover, the SPMM’s unique full-aperture design with a large numerical aperture could provide superior focusing and imaging performance in display manufacturing, enabling the creation of ultra-compact multispectral and polarized imaging devices without the need for complicated spectral filters or mechanically moving parts. This could lead to the development of highly efficient and cost-effective inspection systems for display quality control and defect detection during manufacturing.
Reference
Gao H, Fan XH, Wang YX, Liu YC, Wang XG et al. Multi-foci metalens for spectra and polarization ellipticity recognition and reconstruction. Opto-Electron Sci 2, 220026 (2023). doi: 10.29026/oes.2023.220026
