Variable focus convex microlens array on K9 glass substrate based on femtosecond laser processing and hot embossing...

Area of Science:

• Micro-optics fabrication
• Laser-based manufacturing
• Materials science

Background:

• Microlens arrays are crucial for various optical systems.
• Existing fabrication methods face challenges in precision and scalability.
• Need for variable focus microlenses for dynamic optical applications.

Purpose of the Study:

• To propose a high-precision method for fabricating variable focus convex microlens arrays.
• To investigate the influence of process parameters on microlens profile.
• To demonstrate the feasibility of batch production for micro-optical elements.

Main Methods:

• Femtosecond laser direct writing to create a sapphire master mold.
• Hot embossing lithography to replicate microlens arrays on K9 glass.
• Investigating the effect of temperature and hole diameter on microlens curvature.

Main Results:

• Successful fabrication of uniform convex microlens arrays with good imaging performance.
• Demonstrated control over microlens curvature by adjusting mold parameters (temperature, hole diameter).
• Achieved variable focus capability by modifying the sapphire mold's blind hole diameter.

Conclusions:

• The combined femtosecond laser and hot embossing method offers high precision for microlens fabrication.
• The process allows for tunable focal properties, enabling variable focus microlens arrays.
• This technique is suitable for cost-effective, large-scale production of micro-optical components.