Precision glass molding of diffractive optical elements with high surface quality.

Area of Science:

• Optics and Photonics
• Materials Science and Engineering
• Manufacturing Technology

Background:

• Diffractive optical surfaces offer advantages like weight reduction and chromatic aberration correction in optical systems.
• Fabrication of high-quality glass diffractive optics is difficult, limiting commercial use.
• Existing methods face challenges in achieving desired surface quality and durability.

Purpose of the Study:

• To develop and demonstrate a fabrication method for high-surface-quality diffractive glass optics.
• To address challenges in molding diffractive optics at elevated temperatures (up to 550°C).
• To optimize mold material selection, fabrication, and precision glass molding processes.

Main Methods:

• Selection of mold material: Nickel phosphorous (NiP) plating for cutting performance and anti-adhesion, and copper-nickel C71500 (CuNi) substrate for thermal expansion compatibility.
• Mold fabrication and precision glass molding techniques optimized for high-temperature applications.
• Evaluation of mold durability and stability during the molding process.

Main Results:

• Successful fabrication of diffractive glass optics using the developed method.
• Achieved a surface roughness of 2 nm Sa for the diffractive glass optics.
• Demonstrated the effectiveness of NiP plating and CuNi substrate in overcoming molding challenges.

Conclusions:

• The proposed fabrication method enables the production of high-surface-quality diffractive glass optics.
• The optimized mold material selection and process parameters are crucial for successful high-temperature molding.
• This advancement facilitates wider adoption of diffractive optics in commercial applications.