Researchers at Rice University have found what they say is a "more intelligent way to design imaging sensors by integrating amplifiers and color filters directly into pixels." Pictured: researcher's color-selective, band-engineered photodetector. (Source: Bob Zheng/Rice University)
The Grating is serving dual purpose, it is acting as a colour filter at the same time it is acting a lens as well. It would be interesting to further investigate to exactly differentiate this feature to exploit only one feature perfectly, without affecting the other.