An image sensor comprising: a first light sensing layer absorbing light of a first wavelength band and transmitting light of other wavelength bands; a second light sensing layer positioned to face the first light sensing layer, wherein the second light sensing layer comprises a plurality of second pixels detecting light of a second wavelength band from the transmitted other wavelength bands and a plurality of third pixels detecting light of a third wavelength band from the transmitted other wavelength bands, the second wavelength band being different from the third wavelength band; and a plurality of color separation elements (130,131,132,133) positioned between the first light sensing layer and the second light sensing layer, such as to receive the transmitted light of the other wavelength bands; characterised in that the image sensor further comprises a transparent dielectric layer positioned between the first light sensing layer and the second light sensing layer, wherein the color separation elements are buried in and fixed into the transparent dielectric layer; in that the color separation elements are formed of a material having a refractive index greater than a refractive index of the transparent dielectric layer; in that the first light sensing layer comprises a plurality of first pixels having the same size as the second and third pixels (PX2,PX3) of the second light sensing layer; and in that the color separation elements (130,131,132,133) are configured to direct light of the second wavelength band toward the second pixels and direct light of the third wavelength band toward the third pixels. a first light sensing layer absorbing light of a first wavelength band and transmitting light of other wavelength bands; a second light sensing layer positioned to face the first light sensing layer, wherein the second light sensing layer comprises a plurality of second pixels detecting light of a second wavelength band from the transmitted other wavelength bands and a plurality of third pixels detecting light of a third wavelength band from the transmitted other wavelength bands, the second wavelength band being different from the third wavelength band; and a plurality of color separation elements (130,131,132,133) positioned between the first light sensing layer and the second light sensing layer, such as to receive the transmitted light of the other wavelength bands; characterised in that the image sensor further comprises a transparent dielectric layer positioned between the first light sensing layer and the second light sensing layer, wherein the color separation elements are buried in and fixed into the transparent dielectric layer; in that the color separation elements are formed of a material having a refractive index greater than a refractive index of the transparent dielectric layer; in that the first light sensing layer comprises a plurality of first pixels having the same size as the second and third pixels (PX2,PX3) of the second light sensing layer; and in that the color separation elements (130,131,132,133) are configured to direct light of the second wavelength band toward the second pixels and direct light of the third wavelength band toward the third pixels.