Optical Domes

Optical domes are hemispheric windows which provide a protective boundary while allowing a clear field of view between two environments. They are typically made of two parallel surfaces. Shanghai Optics manufactures optical domes in a wide variety of substrates, suitable for visible, IR, or UV light. Our domes are available in sizes from 5 mm to over 200 mm diameter, with custom sizes possible on request.

Popular Substrates and Their Applications

• BK7 or Fused Silica: Ideal for visible light applications, this substrate offers optimal transmission in the 300 nm to 2 µm wavelength range. It is resistant to high pressure and chemical etching. For UV-range light transmission, UV-grade fused silica is available. This optical glass provides over 85 percent transmission for wavelengths up to 185 nm.
• Sapphire: Well-suited for infrared optical dome applications, sapphire transmits up to eighty percent of light in the 2-5 µm wavelength range. It is extremely resistant to scratching and abrasion, making it an excellent choice for defense applications and high-pressure environments, such as underwater camera systems for deep sea exploration.
• Germanium: Transmitting light between 2-14 μm, germanium domes can be manufactured with diamond anti-reflection coatings to enhance durability in harsh environments.
• Zinc Selenide (ZnSe): Suitable for IR domes, ZnSe has excellent optical properties and a broader wavelength range (3 µm to 16 µm) than sapphire. However, it is less hard and best used in more controlled environments. Anti-reflection coatings are recommended due to its high index of refraction.
• MgF2 Ceramic: Offering high transmission between 2 µm to 7.5 µm, MgF2 ceramic domes have a high flexural strength rating and 1350 kg mm² Knoop hardness rating. The hot press manufacturing method allows greater flexibility in dome shape and size, making it a preferred substrate for launch tubes and missiles.

We can also manufacture acrylic domes on request.  These domes offer less light scattering than BK7 or fused silica, and are still highly durable.

Germanium Dome Lenses – Diameter: 187.3mm / Height: 60mm

Optical Domes Manufacturing Capability

To learn how S.O. could assist with your current optics project, request a quote online or contact one of our friendly representatives for more information.

Different Types of Optical Domes

Infrared optical domes are important for defense applications, and here sapphire is often the material of choice. Aside from diamond, sapphire is the hardest natural substance, and it is resistant to scratching and abrasion. It is also capable of withstanding high pressure, and transmits eighty percent of light between the 2-5µm wavelength range.Other options for infrared domes are zinc selenide, germanium, calcium fluorite, zinc sulfide, and silicon.

Silicon has primary transmission in the3-5μm range, and has low density and high thermal conductivity.  It is the most budget friendly in our lineup of IR materials.

Zinc Selenide domes have a broad wavelength length, from 3 µm to 16 µm, but ZnSe is softer than most other commonly used IR substrates and thus should not be used in harsh environments. It also a high index of refraction, but with an AR coating can achieve high transmission.  It is a good choice for thermally demanding environments.

Our Germanium IR domes have a transmission range of 2-14 μm. They are durable, and although they are not as hard as sapphire, we can provide diamond AR coatings (hard carbon or DLC) to provide optimal resistance to harsh environments.

Our Polycrystalline Zinc Sulfide domes are hotpressed under vacuum, and provide multispectral transmission—an average of 70 % from 3-5µm and 8-12µm. This hotpressed zinc has good thermal properties, and a AR/AR coating can improve transmission.  The manufacturing process allows us to customize dome shape and size, and enables us to manufacture larger domes or domes with various curvature radius.

MgF₂ translucent ceramic domes are also hot pressed, and these domes exhibit high transmission between 2-7.5mm. They are often used for missiles and launch tubes because of their high knoophardness and a flexural strength rating of 20,000 psi.

On all our domes we are able to provide anti-reflection coatings. These coatings can provide better transmission of light and hence can greatly improveimagery. For harsh environments where optical transmission is secondary to robustness we can provide specialized coatings to improve durability.

Custom Optical Domes Applications

• Underwater Cameras and Imaging: In deep sea environments, they enable the smooth functioning of precision optical assemblies within high-pressure conditions. They keep water out of the optic system while providing a clear field of view for submersible ROVs and AUVs.
• Defense: Infrared optical domes are crucial for heat-seeking missiles, providing a wide range of viewing directions without beam deflection. Durable substrates like sapphire or MgF2 perform well even under extreme conditions.
• Weather Monitoring: Used in weather monitoring systems to protect optical components while allowing accurate measurements.
• Navigation Systems: Ensure precision and protection in navigation systems.
• Head Protection Optics: Used to protect the head while allowing optical functionality.
• Security Technology: Utilized in security systems for surveillance and monitoring purposes.

With special high resistant and high anti-reflective coatings, Optical domes are used for security and defense applications to guard active optical systems.

Please contact us for assistance with:
1. Geometric design with high precision.
2. Coating design (High resistant and high anti-reflective).
3. Special adapter interface surface design with the mechanical mount.
4. Manufacturing with tight tolerance.

All components are thoroughly tested for compliance with DIN, ISO and MIL standard requirements.