Demonstration of a multi-color diffractive lens with adjustable focal length

Area of Science:

• Optics
• Optical Engineering
• Photonics

Background:

• Moiré lenses, formed by pairs of diffractive optical elements (DOEs), offer tunable optical power via rotation.
• Previous moiré lens designs were limited by significant chromatic aberrations.

Purpose of the Study:

• To experimentally investigate a multi-color moiré lens using multi-order DOEs.
• To assess the reduction of chromatic aberrations in these new lens designs.
• To evaluate their performance in narrow-band and white-light imaging.

Main Methods:

• Fabrication of multi-order DOEs with deeper surface structures.
• Assembly of moiré lenses by rotating pairs of these multi-order DOEs.
• Experimental testing of lens performance with narrow-band and white light.

Main Results:

• The multi-order moiré lenses demonstrated a fixed focal length for specific harmonic wavelengths.
• Significantly reduced chromatic aberrations were observed compared to earlier designs.
• Successful performance was shown for both narrow-band and white light imaging.

Conclusions:

• Multi-order DOEs enable the creation of moiré lenses with substantially reduced chromatic aberrations.
• These improved moiré lenses are suitable for advanced multi-color imaging applications.
• The tunable nature and aberration reduction offer a promising optical solution.