Devices And Methods For A Micro-Fresnel Zone Plate Optical Device

An optical device suitable for use with an optical medium for the storage and retrieval of data, the optical device comprising:

• an illumination means for providing a beam of optical radiation of wavelength λ;
• an optical path that the beam of optical radiation follows;
• and
• a diffractive optical element configured to comprise a plurality of annular sections comprising a first material alternately disposed with a plurality of annular sections comprising a second material or a different thickness of a first material, wherein the diffractive optical element is configured to generate a plurality of diffractive focal points and a plurality of densely accumulated ray points;
• and
• an optical medium is positioned at one of a selected diffractive focal point and a selected densely accumulated ray point which is surrounded by one or multiple of destructive interference ring patterns of the diffractive optical element.