Patent ID: 8120851

Claim:
A stacked type diffraction optical element comprising: a first diffraction optical element having a diffraction shape formed on one surface thereof comprising (a) an organic resin and (b) fine particles of a conductive polymer material dispersed into the organic resin, wherein the Abbe's number (νd) and a secondary dispersion (θg,F) meet a relation: θ g,F≦− 2 νd× 10 −3 +0.59, and wherein an average diameter of the fine particles is 2-300 nm; and a second diffraction optical element, the Abbe's number of which is larger than the Abbe's number of the first diffraction optical element, having a diffraction shape formed on one surface thereof, wherein a diffraction plane of the diffraction shape of the first diffraction optical element and a diffraction plane of the diffraction shape of the second diffraction optical element are disposed in opposition to each other to form a gap therebetween, wherein a difference between a refractive index of the organic resin and a refractive index of the conductive polymer material is ±0.05, and wherein the conductive polymer material is poly 3,4-ethylenedioxythiophene/polystyrenesulfonic acid (PEDOT/PSS).