Silicon & Germanium Optical Window | MWIR & LWIR IR Windows - Felix Glass
Silicon & Germanium Optical Window
Silicon (Si) and Germanium (Ge) are the most widely adopted infrared optical substrates for mid-wave and long-wave infrared systems. Both can be fabricated into protective IR windows, domes and optical blanks, compatible with AR anti-reflection and DLC diamond-like carbon hard coatings for harsh environment applications.
Key Optical & Physical Properties
| Material | Transmission Range | Core Feature & Working Band |
|---|---|---|
| Silicon (Si) | 1.2 μm – 7 μm | MWIR, low density, good mechanical strength, cost effective |
| Germanium (Ge) | 2 μm – 14 μm | LWIR, high refractive index, ideal for long wave thermal imaging |
Common Optical Components We Fabricate
- Silicon IR windows, silicon domes and optical blanks for mid-infrared optical assemblies
- Germanium optical windows, Ge domes and Ge lenses for long-wave infrared thermal cameras
- Custom round, square, rectangular IR windows with tight dimensional & surface flatness tolerances
- Thin substrate windows for gas sensing, pyrometry and infrared detection modules
Available Coating Options
We provide specialized coatings optimized for Silicon and Germanium infrared materials:
- MWIR anti-reflection AR coating for Silicon optical windows
- LWIR broadband AR coating for Germanium windows & domes
- DLC diamond-like carbon coating for scratch, moisture and abrasion protection on Ge
- Multi-spectral AR coating for dual-band infrared optical systems
Typical Application Fields
- Infrared thermal imaging cameras, perimeter security & surveillance optics
- Industrial pyrometers, non-contact temperature measurement sensors
- FTIR infrared spectroscopy and gas detection analysis instruments
- Aerospace, drone and ruggedized military infrared sensor assemblies
- Medical infrared imaging and industrial online monitoring equipment
Machining Capacity & Quality Control
Felix Glass processes high-grade Silicon and Germanium infrared optical materials. Surface scratch-dig grade up to 20/10, surface flatness can reach λ/4 @ 632.8nm. We support custom drawings, prototype sampling and bulk serial production, with in-house coating service for infrared optical windows.
Datasheet & Custom Inquiry
Send your spectral requirement, drawing and coating specification for custom quotation of silicon or germanium optical windows.
Request Datasheet & Custom Quote



