Optical Windows

Optical windows are precision-crafted, optically flat, and transparent components designed to allow light to pass into an instrument while protecting its internal elements. At MOK Optics, we provide a wide range of optical windows tailored to meet the needs of various applications, from common usage to highly demanding interferometer measurements.

Features and Applications Of Optical Windows

  1. Material Selection: Our optical windows are made from a diverse selection of high-quality materials, including BK7, fused silica, sapphire, and other specialized glasses. Each material is chosen based on its unique properties, such as high transmission, low scattering, and resistance to environmental factors.
  2. Precision Engineering: We ensure each optical window meets stringent optical and mechanical specifications. Our windows are designed to offer superior flatness, parallelism, and surface quality, ensuring minimal distortion and high performance in critical applications.
  3. Coatings: To enhance performance, our optical windows can be customized with various anti-reflective (AR) coatings, dielectric coatings, and metallic coatings. These coatings improve transmission, reduce reflection losses, and provide additional durability against harsh environments.
  4. Customization Options: Beyond standard offerings, we provide bespoke solutions tailored to specific customer requirements. Whether you need special shapes, sizes, or unique material combinations, our experienced engineers are ready to collaborate and deliver customized optical windows that fit your exact needs.
  5. Applications:
    • Scientific Research: Used in laboratories for precise measurements and experiments.
    • Industrial Use: Applied in machinery and equipment where clear visibility and protection from contaminants are crucial.
    • Aerospace and Defense: Essential for optical systems in harsh environments, ensuring reliability and performance under extreme conditions.
    • Medical Instruments: Utilized in devices requiring high optical clarity and minimal distortion for accurate diagnostics and treatment.

Guide and Support

We invite you to explore our detailed Optical Window Guide, which provides comprehensive information on the selection, application, and benefits of different optical window materials and coatings. Our guide is designed to help you make informed decisions based on your specific needs and applications.

Why Choose MOK Optics?

  1. Expertise: With years of experience in the optical components industry, our team is skilled in delivering high-precision optical solutions.
  2. Quality Assurance: We adhere to rigorous quality control processes to ensure each product meets the highest standards of performance and reliability.
  3. Customer-Centric Approach: We prioritize understanding and meeting the unique needs of our customers, offering tailored solutions and exceptional support throughout the product lifecycle.

For more information or to discuss your specific requirements, please contact us. At MOK Optics, we are committed to providing high-quality optical windows that enhance the performance of your optical instruments and systems.

Optical Windows


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Windows are applied to isolate different physical environments while allowing light to passing through. When selecting windows, it’s necessary to consider materials, transmission, scattering, wave front distortion, parallelism and resistance to certain environment.


MOK optics produce Various of precision windows, which are made from different materials

MOK optics produce extensive optical windows, which are made from different materials.

H-K9L / N-BK7 window
UV / IR fused silica window
Laser optics
Sapphire window
Germanium window (AR coating+ DLC coating)
CaF2 window
MgF2 window
Silicon window

Special sizes, shapes and materials are available upon requirement.

MOK Optics produces UV & IR fused silica with different dimension and shapes. The materials include Corning 7980, JGS1, JGS3 etc.

Sapphire window is a kind of excellent multifunctional material. It has high surface hardness, high temperature resistance, good thermal conductivity, UV-IR transmittance and good chemical stability. MOK Optics provide sapphire windows with various of dimensions and shapes, AR coating is available

CaF2 is transparent from the UV to the IR (180 nm – 8.0 µm). and is mechanically and environmentally stable.MOK Optics provides excimer grade CaF2, vacuum VUV grade CaF2, UV grade CaF2, IR polycrystal CaF2.

MgF2 is a synthetic crystalline substrate, transparent over a wide range of wavelengths (120 nm – 6.0 µm), magnesium fluoride is well suited for applications ranging from the UV to the IR. MOK Optics provides UV grade MgF2 windows, Max Diameter 170mm, Oriention:<001>,<100>,<110>.

Special sizes, shapes and materials are available upon requirement.


MOK Optics Capability:

Dimension Range


Dimension tolerance

  ± 0.02mm

Clear aperture


Surface quality

  80-50  to 10-5


   to λ/8@632.8nm


   to 30 seconds

AR coating available upon customer requirements