Complex aspherical singlet and doublet microoptics by grayscale 3D printing.

Area of Science:

• Optics and Photonics
• Additive Manufacturing
• Microfabrication

Background:

• Traditional two-photon polymerization (2PP) 3D printing creates undesirable steps on optical surfaces.
• Achieving high-precision, step-free microoptical components is crucial for advanced optical systems.
• Existing methods often struggle with surface roughness and accuracy in micro-optics fabrication.

Purpose of the Study:

• To demonstrate the fabrication of 3D printed aspherical singlet and doublet microoptical components using grayscale lithography.
• To evaluate the shape accuracy and optical performance of these micro-lenses.
• To overcome the limitations of step-based 3D printing for optical applications.

Main Methods:

• Utilized two-photon grayscale lithography (2GL) to create continuous, step-free micro-lens surfaces.
• Designed and printed aspherical singlet lenses, comparing their focusing ability to spherical counterparts.
• Designed, printed, and optimized a 300 µm diameter air-spaced doublet micro-lens.

Main Results:

• Achieved excellent shape accuracy with minimal surface deviations (<100 nm for the top lens, <20 nm for the bottom lens of the doublet).
• Demonstrated step-free surfaces for micro-lenses, verified by confocal microscopy.
• Attained a high resolution of 645 line pairs/mm using an USAF 1951 resolution test chart.

Conclusions:

• Two-photon grayscale lithography (2GL) is a viable technique for fabricating high-precision, step-free microoptical components.
• The developed micro-lenses exhibit excellent optical performance and shape accuracy.
• This method enables the creation of advanced micro-optics for high-resolution imaging applications.