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

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Holographic lenses offer unique optical properties.
• Azo-polymer films are sensitive to light, enabling photo-inscription.
• Controlling light polarization and focal properties is crucial for optical devices.

Purpose of the Study:

• To fabricate and characterize superimposed chirped relief gratings as holographic lenses on azo-polymer films.
• To investigate the polarization-independent focusing capabilities of these holographic lenses.
• To demonstrate the tunability of focal properties and the creation of dual-focus lenses.

Main Methods:

• Photo-inscription of chirped relief gratings on azo-polymer films using interference patterns of plane and curved laser wavefronts.
• Exposure to specific laser interference configurations to create diffractive holographic lenses.
• Characterization of the focusing properties and polarization dependence of the fabricated lenses.

Main Results:

• Successfully fabricated holographic lenses exhibiting polarization-independent focusing in the 0th or 1st diffracted order.
• Demonstrated tunability of the focal point and focalization angle during the fabrication process.
• Fabricated a dual-focus chirped holographic lens grating that displayed a far-field interference pattern.

Conclusions:

• Superimposed chirped gratings on azo-polymers function as effective, tunable holographic lenses.
• The fabricated lenses offer polarization-independent focusing, broadening their applicability.
• The ability to tune focal properties and create dual-focus lenses opens new avenues for optical system design.