Innovations in Glass Freeform Optics and Low-Cost Prototyping
In the field of optics, glass freeform elements have become a cornerstone for advancing high-end optical systems due to their unique optical properties. However, traditional manufacturing techniques and high prototyping costs have long hindered the widespread adoption of these components. At Yighen Ultra Precision, we focus on magnesium fluoride (MgF₂) and calcium fluoride (CaF₂) as breakthrough materials, innovating with single-point diamond turning processes to achieve significant advancements in glass freeform manufacturing and low-cost prototyping—injecting new vitality into the optical industry.
Exploring Special Materials to Unlock Optical Potential
Calcium Fluoride (CaF₂): Characteristics and Challenges
Calcium fluoride is renowned for its exceptional optical performance, featuring a high melting point of 1360°C and excellent transmission in the 1-8μm wavelength range, making it ideal for high-temperature optical systems and laser processing equipment. However, its relatively low hardness and brittleness pose significant challenges during machining, including the tendency to crack and chip. Additionally, the abrasive dust generated during processing can corrode machinery, complicating the manufacturing process.
Magnesium Fluoride (MgF₂): Advantages and Difficulties
Magnesium fluoride is celebrated for its low refractive index (n=1.38 at 5μm) and broad spectral transmission (0.11-8μm), commonly used for optical coatings and windows. Nevertheless, its softness and low hardness make it prone to surface scratches and deformation during machining, which makes achieving high-precision freeform surfaces challenging.
Single-Point Diamond Turning: Overcoming Manufacturing Bottlenecks
Yighen employs ultra-precision single-point diamond turning technology using advanced CNC-controlled diamond tools. This method allows for precise cutting according to design specifications. When machining CaF₂ and MgF₂ freeform surfaces, this technique demonstrates significant advantages.
For CaF₂ freeform surfaces, Yighen optimizes cutting parameters by employing low-speed cutting (80-120m/min) and fine feed rates (0.3-0.5μm/rev) to minimize impact forces that could cause cracking or chipping. An inert gas protective chamber combined with specially developed diamond tools shields equipment from corrosive dust. As a result, CaF₂ freeform components achieve form accuracy (PV) up to 0.3μm and surface roughness (Ra) within 5nm.
With MgF₂, the single-point diamond turning process precisely controls tool sharpness and cutting paths to avoid surface damage and deformation. Utilizing diamond tools with extremely small edge radii and high-precision machine motion control enables minimal material removal, resulting in MgF₂ freeform surfaces with Ra<8nm, meeting stringent requirements for UV-infrared composite optical systems.
Low-Cost Prototyping Accelerates Innovation
Traditional glass freeform prototyping involves multiple complex steps such as rough grinding, fine grinding, and polishing, which are time-consuming and costly. Yighen's single-point diamond turning consolidates these steps into one setup, significantly reducing processing times from weeks to days. By optimizing tool paths and enhancing material utilization, the cost per batch drops substantially, requiring only a few thousand dollars for product validation. This greatly alleviates the financial burden on research and development.
Equipped with advanced machines like the NanoTech 650 FG ultra-precision freeform machining center and Toshiba single-point diamond lathes, Yighen ensures robust hardware support for our processes. These machines offer nanometer-level resolution and five-axis simultaneous control, enabling precise machining of complex freeform surfaces. Furthermore, our comprehensive inspection system, utilizing Zygo laser interferometers and atomic force microscopes, provides real-time monitoring and feedback during production, ensuring high precision and minimizing rework due to quality issues.
Professional Team and Innovative Strength
Our team comprises top optical talents from prestigious institutions such as Nanyang Technological University, University of Strasbourg, CIOMP under the Chinese Academy of Sciences, and Zhejiang University. With deep theoretical knowledge and extensive practical experience, they continuously optimize single-point diamond turning parameters and develop innovative machining techniques tailored to materials like CaF₂ and MgF₂.
Yighen's excellence in glass freeform manufacturing and low-cost prototyping has garnered numerous accolades. In 2024, our project won third place in the New Generation Information Technology category at the Eighth Guangming District Innovation and Entrepreneurship Competition. The same year, our optical design project received a bronze medal at the Second Guangdong-Hong Kong-Macao Greater Bay Area Postdoctoral Innovation and Entrepreneurship Competition. These honors underscore Yighen's technical innovation capabilities and industry leadership.
