Volumetric metaoptic color sorters at visible wavelengths: A performance analysis for practical applications

Three-dimensional volumetric devices with refractive index structured at sub-wavelength scale enable custom sorting of light based on its spatial, spectral, and polarization characteristics. One application is in efficient color sorting for red–green–blue color image sensors. Here, we use inverse design to investigate how the performance of these color sorters depends on the complexity of the device. We take into account hyperparameters, such as the number of device layers, the minimum feature size, and the number of materials that can be utilized. We also analyze methods to optimize performance when light is incident from an oblique angle and to attenuate crosstalk between sorters using trench isolation.