EN
cn 
ja 
ko 
de 
es 
it 
vi 
th 
ms 
id 
Address:
155 Suhong East Road, Suzhou Industrial Park, Jiangsu Province, China 
WHAT ARE YOU LOOKING FOR?
Unlike conventional optical glass, lithium phosphate crystals are soft and brittle materials with a Mohs hardness of only 3-4, exhibiting significant anisotropic characteristics. This presents multiple challenges during the polishing process: achieving a nanometer-level surface roughness while maintaining the integrity of the lattice structure to avoid subsurface damage. Traditional mechanical polishing methods can lead to issues such as lattice distortion, edge chipping, and component hydrolysis, severely affecting the electro-optical performance and laser damage thresholds of the final devices.
The anisotropy of the material introduces further complexity to the polishing process, as the removal rates can vary by over 30% depending on the crystal orientation. This requires precise optimization of the polishing process to align with the crystal’s orientation, as even minor deviations can result in shape errors and edge collapse.
To address these challenges, modern ultra-precision polishing employs Chemical Mechanical Polishing (CMP) technology, achieving a balance between material removal and surface shaping. The core of this technology lies in the precise control of the chemical composition and pH of the polishing slurry, allowing for controllable chemical reactions at the microscopic level with the crystal surface. This forms a softening layer that can be easily removed by the mechanical action of nanometer-sized abrasives, thereby preventing damage to the crystal’s fundamental structure.
Designing the polishing slurry is a meticulous science, requiring careful consideration of factors such as the selectivity of chelating agents, the concentration of oxidizers, the stability of pH buffering systems, and the wetting properties of surfactants. Even minor variations in any component can significantly impact the final surface quality. An ideal polishing slurry must strike a balance between chemical activity and mechanical compatibility, ensuring sufficient material removal rates while avoiding excessive chemical erosion that could worsen surface roughness.
Controlling shape accuracy is another major technical hurdle. Through the use of finite element analysis to optimize adaptive polishing head designs, combined with real-time thickness monitoring systems, modern polishing processes can achieve shape precision standards better than λ/10 (@632.8nm). This level of precision is not only reflected in the overall shape but also requires consistency at the microscopic level.
Edge effect control represents one of the key challenges in maintaining shape accuracy. Due to uneven distribution of polishing pressure, the edges of the wafer are often prone to abnormal material removal rates. Advanced polishing techniques, utilizing specialized edge control technologies and pressure distribution optimization algorithms, can confine the edge exclusion zone to within 0.5mm, significantly increasing the effective usable area of the wafer.
As the demand for high-performance optical components continues to rise, the development and refinement of ultra-precision polishing technologies like those used for lithium phosphate crystals will play a crucial role in advancing the field of infrared optics and laser applications
Ultra-precision polishing relies not only on core techniques but also on an extreme pursuit of detail. A constant temperature and humidity ultra-clean environment (temperature fluctuation ±0.5°C, humidity fluctuation ±5% RH), a vibration isolation platform (isolation efficiency >99%), and tooling fixtures made from high-purity materials—each aspect can potentially be a key factor influencing the final result.
This is particularly important for materials like lithium phosphate, which are sensitive to temperature and moisture; the stability of the production environment directly determines product consistency. Even the purity of the polishing water needs to reach an ultra-pure level of 18.2 MΩ·cm to avoid surface defects caused by trace ion contamination. This extreme attention to detail reflects the core principle in ultra-precision manufacturing that "details determine success or failure."
The quality assessment of modern ultra-precision polishing has surpassed traditional surface roughness measurements, evolving into a multi-parameter, multi-scale comprehensive characterization system. In addition to using atomic force microscopy (AFM) for nanoscale surface morphology analysis, it is also necessary to assess subsurface damage layers using X-ray diffraction (XRD), observe edge quality using laser confocal microscopy, and measure optical performance with a spectrophotometer.
Especially for functional crystals like lithium phosphate, it is essential to specifically evaluate their electro-optic performance and laser damage threshold to ensure that the polishing process does not compromise the intrinsic properties of the crystal. This comprehensive quality assurance system ensures that the final product can operate reliably in demanding application environments.
Advancements in precision polishing technology have directly propelled the deeper application of lithium phosphate crystals in various high-end fields. In the industrial laser equipment sector, high-quality polished optical components significantly enhance the output efficiency and lifespan of lasers, providing reliable core components for precision machining and medical devices.
In the research field, ultra-polished crystals provide a reliable optical foundation for precision measurement experiments, especially in quantum optics and ultrafast laser fields, where surface quality directly affects the success of experiments. In civilian optoelectronic products, this technology has also improved the performance of infrared imaging systems and spectrometers, providing more powerful tools for environmental monitoring and industrial testing.
As optoelectronic technology continues to develop, the demands for the performance of optical components are also constantly rising. Ultra-precision polishing, as a key link between crystal materials and optical systems, will continue to drive the entire industry chain towards greater precision and more reliable performance. In this process, the deep integration of materials science, process technology, and engineering applications will continually bring us new breakthroughs and possibilities, opening new horizons for the application of optoelectronic technology.
Changsha Kehua Fine Chemicals has consistently focused on CMP precision polishing abrasives for years. We provide polishing solutions based on silica abrasives for customers with niobate polishing needs, achieving high praise from clients. We welcome both new and old customers to contact us and look forward to long-term cooperation!
