Superimposed surface-relief diffraction grating holographic lenses on azo-polymer films

Various superimposed chirped relief gratings, acting as diffracting holographic lenses, were photo-inscribed on azo-polymer films upon exposure to the interference pattern of a plane and a curved laser light wavefronts. Depending on the configuration used, this resulted in incident light being focused independently of polarization along the 0th or 1st diffracted order of the grating. The focal point and focalization angle of the resulting holographic lenses were easily tuned during the fabrication process. Furthermore, a dual-focus chirped holographic lens grating was fabricated and shown to exhibit a far-field interference pattern.