HYPERSPECTRAL SENSOR WITH PIXEL HAVING LIGHT FOCUSING TRANSPARENT DIFFRACTIVE GRATING

Wavelength determining image sensors and systems are provided. A sensor as disclosed includes a number of pixels disposed within an array, each of which includes a plurality of sub-pixels. Each wavelength sensing pixel within the image sensor is associated with a set of diffraction features disposed in a plurality of diffraction element layers. The diffraction features can be formed from materials having an index of refraction that is higher than an index of refraction of the surrounding material. At least one of the diffraction element layers is formed in a grating substrate on a light incident side of a sensor substrate. Wavelength information regarding light incident on a pixel is determined by applying ratios of signals obtained from pairs of included sub-pixels and calibrated ratios for different wavelengths to a set of equations. A solution to the set of equations provides the relative contributions of the calibrated wavelengths to the incident light.