Ultrathin Microlens Arrays for Dynamic Beam Shaping Based on 3D Lithography

Area of Science:

• Optics and Photonics
• Laser Technology
• Materials Science

Background:

• Conventional microlens arrays (MLAs) possess static focal properties, limiting adaptability in dynamic optical systems.
• Post-fabrication adjustments for static MLAs are challenging, hindering real-time optical modulation.

Purpose of the Study:

• To demonstrate a tunable beam shaper with real-time spot-size modulation capabilities.
• To overcome the limitations of static focal properties in conventional MLAs for dynamic applications.

Main Methods:

• Fabrication of ultra-thin MLAs with a low aspect ratio (1:187.5) and continuous surface profiles.
• Optimization of 3D lithography and ion beam etching (IBE) workflows.
• Implementation of adjustable axial displacement between a primary lens and the MLA for beam shaping.

Main Results:

• Achieved an optical-grade surface finish with a roughness (Sa) of 3 nm on ultra-thin MLAs.
• Demonstrated efficient beam homogenization with reconfigurable working distances and spot dimensions.
• Enabled real-time spot-size modulation through tunable axial displacement.

Conclusions:

• The proposed tunable beam shaper offers a versatile solution for advanced laser material processing.
• This high-fidelity, low-profile component bridges the gap between static beam shaping and dynamic laser delivery.
• The adaptable optical system enhances laser material processing by providing dynamic control over beam characteristics.