Precision Optical Performance
Tight tolerances, controlled surface quality and dependable transmission for demanding optical systems.
Custom Precision Optical Windows
Broad Material Selection
UV, visible and infrared materials matched to wavelength, environment and system requirements.
Custom Manufacturing
Round, square, rectangular, wedged and custom-shaped windows from prototype through production.
Advanced Optical Coatings
AR, BBAR, laser-line, beamsplitter, filter, reflective and protective coating options.
Available Materials
Optical Window Materials for UV, Visible and Infrared Systems
Select the material according to wavelength range, thermal environment, mechanical durability, laser power, weight and coating requirements.
SapphireDurable UV–IR windows
Fused SilicaUV and laser optics
BK7 Optical GlassVisible and NIR systems
Optical GlassCustom glass selection
Calcium FluorideUV to infrared
Magnesium FluorideDeep-UV applications
Barium FluorideBroad UV–IR range
GermaniumMWIR and LWIR
SiliconLightweight infrared
Zinc SelenideCO₂ laser and IR
Zinc SulfideMultispectral windows
Available Shapes
Standard and Custom Optical Window Geometries
Windows can be supplied with precision edge treatment, mounting features, holes, slots, steps and application-specific profiles.
Round Windows
Standard diameters and custom circular apertures.
Square Windows
Precision square geometry with controlled edges and corners.
Rectangular Windows
Custom aspect ratios for sensors, enclosures and instruments.
Wedged Windows
Controlled wedge to suppress etalon effects and ghost reflections.
Brewster Windows
Angle-optimized windows for polarized laser systems.
Custom Shapes
Complex profiles, holes, slots and mounting features.
Engineering Recommendation
Choose the Right Specification — Not the Highest Specification
At COE Sapphire, we recommend optical specifications based on your application, performance requirements and budget—not simply the highest tolerance available. Appropriate specifications help reduce manufacturing cost and lead time while ensuring reliable optical performance.
01
Recommended For
Commercial Optical Systems
- Machine Vision
- General Imaging
- Medical Devices
Surface Quality60-40 / 40-20
Surface Flatnessλ/2 – λ/4
ParallelismStandard
CoatingStandard AR
Lower cost, faster delivery and reliable optical performance.
02
Recommended For
Precision Optical Systems
- Scientific Instruments
- Spectroscopy
- Semiconductor Equipment
Surface Quality20-10
Surface Flatnessλ/4 – λ/10
ParallelismPrecision
CoatingPrecision AR
Balanced performance, manufacturability and cost.
03
Recommended For
High-Power Laser Systems
- Laser Processing
- Defense Systems
- Research Applications
Surface Quality10-5
Surface Flatnessλ/10 – λ/20*
ParallelismApplication Specific
CoatingLaser Grade
Specified only when optical performance requires it.
* Engineering note: Ultra-precision specifications should only be selected when required by the optical design, as tighter tolerances increase manufacturing complexity, lead time and cost.
Need Help Selecting the Right Specification?
Contact an Optical Engineer
Our optical engineers can recommend the most cost-effective solution.
Share your wavelength, environment, performance requirements and manufacturing budget.
Technical Specifications
Quick Specifications and Detailed Capabilities
Representative capabilities are shown below. Final tolerances depend on material, size, thickness, geometry and inspection requirements.
| Diameter / Size | Prototype micro-optics through large custom apertures |
|---|---|
| Thickness | Application-specific, including thin and high-aspect-ratio windows |
| Surface Quality | Commercial through precision laser-quality finishes |
| Surface Flatness | Application-specific interferometric control |
| Parallelism / Wedge | Precision parallel or controlled wedge |
| Clear Aperture | Typically specified as a percentage of overall aperture |
| Edge Finish | Fine ground, polished, beveled, chamfered or custom |
| Optical Coatings | AR, BBAR, laser-line, filter, reflective and protective coatings |
Manufacturing Process
From Optical Material Blank to Finished Window
Every optical window moves through a controlled process designed to protect edge integrity, surface quality, optical performance and coating reliability.
Material Preparation
Material verification, blank cutting and incoming inspection.
Precision Machining
Diameter, profile, holes, slots, bevels and custom geometry.
Fine Grinding
Thickness, flatness, parallelism and wedge control.
Optical Polishing
Surface quality, transmitted wavefront and clear-aperture control.
Optical Coating
AR, BBAR, laser-line, reflective, conductive and protective coatings.
Final Inspection
Dimensional, interferometric, cosmetic and coating verification.
Typical Applications
Optical Windows for Demanding Industrial Systems
Precision windows protect sensors, isolate environments and maintain optical performance across UV, visible and infrared wavelengths.
Laser Systems
Beam protection, enclosure isolation and high-power laser applications.
Medical Devices
Diagnostic, surgical and analytical optical instruments.
Gas Detection
Infrared windows for gas analyzers and environmental sensing.
Thermal Imaging
Protective windows for MWIR and LWIR cameras.
Semiconductor Equipment
Process, inspection and lithography system protection.
Aerospace & Defense
Rugged windows for avionics, sensors and targeting systems.
Frequently Asked Questions
Optical Window FAQs
What is an optical window?
An optical window is a flat, transparent component that protects an optical system while transmitting the required wavelength range with minimal distortion and loss.
How do I choose the right optical window material?
Material selection depends on wavelength, transmission, refractive index, thermal environment, mechanical durability, chemical exposure, weight and coating requirements.
What optical coatings are available?
Options include single-band and broadband AR, laser-line AR, beamsplitter, bandpass, reflective, conductive and protective coatings.
Can COE Sapphire manufacture custom sizes and shapes?
Yes. We manufacture round, square, rectangular, wedged, Brewster-angle and custom-profile windows from prototype through repeat production.
What tolerances can be achieved?
Tolerances depend on material, aperture, thickness and geometry. Send your drawing or target specification for an application-specific review.
Engineering Resources
Technical Guides for Better Optical Decisions
Use these resources to compare materials, define practical specifications, select coatings and prepare your drawing for manufacturability review.
Design Guide
Optical Window Design Guide
Learn how to specify dimensions, tolerances, clear aperture, coatings and optical performance for your application.
Read Guide → Material ComparisonMaterial Selection Guide
Compare sapphire, fused silica, BK7, germanium, silicon, CaF₂, ZnSe and other optical materials.
Compare Materials → Coating GuideOptical Coating Guide
Understand AR, BBAR, laser-line, reflective, protective and specialty coating options.
Explore Coatings → Engineering SupportRequest Engineering Review
Submit your drawing for review of material selection, manufacturability, tolerances and cost optimization before quotation.
Submit Drawing →
Engineering-first support.
Our goal is to help you select the right optical solution—not simply the highest specification.
Before You Specify
Five Engineering Considerations Before Requesting a Quote
Review these common design considerations to avoid unnecessary cost while maintaining optical performance.
✓ Is λ/20 really necessary?
Many imaging systems perform well with λ/4 flatness.
✓ Does every surface require coating?
Coat only functional optical surfaces whenever practical.
✓ Is the material appropriate?
Material choice often matters more than tighter tolerances.
✓ Have you defined the clear aperture?
Specify the optical clear aperture separately from overall size.
✓ Can standard edge finishing work?
Standard chamfers reduce cost for many applications.
Engineering Advice: Avoid over-specification whenever possible. Balanced specifications reduce cost and lead time without sacrificing performance.
Explore Related Engineering Topics
Continue Your Engineering Journey
Explore related materials, optical components, technical resources and industries to make better optical design and sourcing decisions.
Related Optical Materials
Select the right substrate based on wavelength, durability, thermal environment and cost.
Related Optical Components
Explore additional component families for imaging, laser, sensing and analytical systems.
Technical Resources
Learn how to choose practical specifications, materials and coatings for custom optical windows.
Explore Applications by Industry
See how optical windows are used across demanding commercial, scientific and defense applications.
Still Evaluating Your Design?
Talk with an Optical Engineer
Talk with an optical engineer before finalizing your specifications.
We can review your application and recommend the most practical optical solution for performance, manufacturability and cost.
Custom Optical Windows
Need Precision Optical Windows?
Send us your material, wavelength, dimensions, tolerances, coating and quantity requirements.