Silicon Optical Windows

Name: Silicon Optical Windows
Brand: PhotonEdge
SKU: PE-WINDOW-SI-019
Availability: LimitedAvailability

Key Specifications

Material	Single Crystal Silicon (Si)
Transmission	1.2 - 8 µm
Diameter	5-100 mm
Thickness	2-30 mm
Surface Quality	40-20 / 20-10
Refractive Index	~3.4 @ 5µm
Hardness	7 Mohs
dn/dT	0.0001 /K

What Is a Silicon Optical Windows?

Silicon Optical Windows are fabricated from Silicon optical material, providing specialized transmission and mechanical properties for demanding optical applications.

PhotonEdge sources Silicon windows from certified material suppliers and coordinates precision manufacturing through our optical manufacturing network.

When Should You Use This Product?

✔ Good Choice When

✓ NIR/SWIR optical systems
✓ Thermal imaging (3-5µm MWIR)
✓ Laser systems in NIR band
✓ Semiconductor process monitoring

⚠ Consider an Alternative When

✗ Visible optics → BK7 Window

✗ Longer IR (> 5µm) → Germanium Window

✗ CO₂ laser (10.6µm) → ZnSe Window

✗ Broadband UV-IR → CaF₂ Window

Available Optical Materials

Select the optimal substrate material based on your wavelength, environment, and budget requirements.

Material	Transmission	Key Advantage	Considerations
ZnSe	0.5 - 20 µm	Excellent for CO₂ laser (10.6µm)	Toxic when machined, limited visible transmission
Germanium	2 - 14 µm	High refractive index, excellent for thermal IR	Opaque below 2µm, temperature sensitive
Silicon	1.2 - 8 µm	Good for NIR/SWIR, hard and stable	Opaque in visible, limited MIR range
CaF₂	0.13 - 8 µm	Broadband UV to MIR, low dispersion	Fragile, moisture sensitive

Not sure which material to choose?

Ask AI Optical Engineer

Optical Coating Options

AR NIR

AR for 1-3µm band.

Typical use: NIR imaging and sensing

AR MWIR

AR for 3-5µm band.

Typical use: MWIR thermal imaging

Uncoated

Raw Si. ~30% per surface (high n).

Typical use: Non-critical

How to Specify Your Coating

To select the right coating, please provide: (1) Operating wavelength, (2) Angle of incidence, (3) Required transmission or reflectivity, (4) Laser power density (if applicable), (5) Operating environment.

Engineering Considerations

Key factors to evaluate when specifying this optical component for your system.

Wavelength Range

Silicon has specific transmission characteristics. Verify compatibility with your operating wavelength.

Surface Quality

Specify based on application: 40-20 for general, 20-10 for precision, 10-5 for laser-grade.

Flatness

λ/4 standard. Tighter specifications available for wavefront-critical systems.

Environmental

Consider thermal, chemical, and mechanical environment when selecting window material.

Applications

CO₂ Laser Systems

Windows and lenses for CO₂ laser cutting, welding, and marking.

Thermal Imaging

Mid-IR and LWIR optics for thermal cameras and infrared systems.

FTIR Spectroscopy

Infrared optics for Fourier-transform infrared spectrometers.

Industrial Processing

High-power IR laser delivery and process monitoring.

Manufacturing & Customization

PhotonEdge supports optical component sourcing, engineering review, and qualified manufacturing through our optical manufacturing network. We coordinate production, coating, and inspection to deliver components that meet your specifications.

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Prototype

⚙️

Low Volume

🏭

Volume Production

📋

Custom Specification

Quality Assurance

Dimensional Inspection

Diameter, thickness, focal length verified per specification

Surface Quality

Scratch-dig inspection under calibrated illumination

Coating Verification

Spectrophotometric measurement of transmission/reflectance

Inspection documentation available according to project requirements. Certificates of Conformance, material test reports, and coating curves can be provided.

You May Also Need

Related Knowledge

Engineering Documentation

The following documentation is available upon request for qualified engineering projects:

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Dimensional Drawing

CAD & dimensional specs per your requirements

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Material Data Sheet

Material properties, transmission curves & certificates

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Coating Performance Curve

Spectrophotometric measurement data

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Inspection Report

Surface quality, flatness, centration & dimensional data

✅

Certificate of Conformance

CoC with full traceability per project requirements

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Custom Specification Sheet

Application-specific specification documentation

Documentation availability depends on project scope and order quantity. Request details during RFQ.

Frequently Asked Questions

What sizes are available?

Standard diameters range from 5mm to 100mm with thicknesses from 1mm to 50mm. Larger sizes and custom shapes are available upon request.

Can these windows be used in vacuum environments?

Most optical window materials are compatible with vacuum environments. Fused silica and sapphire have very low outgassing characteristics.

What surface quality do you recommend?

For laser applications, 10-5 is recommended. For general-purpose windows, 20-10 is acceptable and more economical.

Can I specify a custom shape?

Yes. Circular, rectangular, square, and custom shapes are available. Provide your drawing or dimensional requirements for a quotation.

What flatness should I specify?

λ/10 is standard for precision applications. For wavefront-critical systems, λ/20 or tighter is available. Note that tighter flatness directly affects cost.

How do I specify a custom window?

Provide: material, diameter/shape, thickness, wavelength, surface quality, flatness, coating requirements, and quantity.

Why is silicon opaque in visible?

Silicon has a bandgap that absorbs visible light. It becomes transparent above ~1.2µm.

Is Si temperature stable?

Yes. Silicon has low dn/dT (0.0001/K), better than germanium for thermal stability.

Not Sure Which Specification You Need?

Describe your optical system and our AI Optical Engineer will help identify the right specifications, materials, and coatings for your application.

Analyze My Requirement

Request an Engineering Quote

Provide your requirements and our engineering team will respond within 24 hours with a detailed quotation.

MaterialTransmissionDiameterThicknessSurface QualityRefractive IndexHardnessdn/dT

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