Panasonic has just announced its work on Color Splitters, a technology that should double the is set to replace the traditional Bayer RGBG filter. Unlike the Bayer filter where there is a red, green or blue filter for each of the pixels, the Color Splitters do not use any filters at all. This means that no light is lost. Instead of filtering it, Panasonic uses a red and blue deflectors, to project it on neighbouring pixels and then uses interpolation to calculate the right color.
Figuring out the right design for the deflectors, though, was a challenging task that required a lot of computational power that was only available now.