Silicon Infrared Lenses
Single-crystal silicon lenses for mid-wave infrared (MWIR) optical systems. Lightweight alternative to germanium with superior thermal conductivity. Plano-convex, meniscus and aspheric designs for 3-5um thermal imaging and laser applications.
Key Specifications
Material Options
Select the optimal optical material based on your wavelength, power, thermal environment and mechanical requirements.
- Silicon (Si) — Lightweight MWIR material. Best thermal conductivity among IR materials. Standard for 3-5um systems.
- Germanium (Ge) — Higher index (n=4.0) for more compact designs. Covers MWIR + LWIR. Heavier.
- ZnSe (Alternative) — Broadband 0.6-18um. Visible alignment beam compatible. Softer material.
Coating Options
Coatings are engineered around your specific wavelength and operating conditions.
- AR @ 3-5um (MWIR) — R < 0.5% per surface. Standard for thermal imaging systems.
- BB AR MWIR — R < 1% across 3-5um. For broadband MWIR systems.
- DLC Overcoat — Hard protective layer. Recommended for field-deployed systems.
Manufacturing Tolerances
We optimize specifications to match your system requirements — not over-specify. Tighter tolerances increase cost without always improving system performance. Typical manufacturing capabilities:
- Surface quality: from 60-40 to 10-5 scratch-dig
- Surface flatness: from λ/4 to λ/20 per inch
- Dimensional tolerance: ±0.01mm to ±0.05mm
- Centration: <3 arc min standard, <30 arc sec precision
Inspection & Quality
Every component undergoes 100% inspection before shipment with full documentation including interferometer reports, spectral curves, surface quality images and dimensional data.
- Laser interferometry: λ/100 resolution
- Spectrophotometry: 190nm – 25μm
- Surface inspection: MIL-PRF-13830B compliant
- Dimensional metrology: ±0.01mm accuracy
Applications
- MWIR thermal imaging camera lenses
- IR gas sensing and analysis systems
- MWIR laser beam focusing and collimation
- Aerospace IR sensor optics (weight-optimized)
- Industrial process monitoring at 3-5um
- Free-space optical communication systems
Engineering Considerations
Si vs Ge for lens design: Silicon's lower refractive index (3.42 vs 4.0 for Ge) means slightly longer focal lengths for the same curvature, but the weight savings (56% lighter) is significant for large-aperture optics (>50mm diameter) and aerospace applications.
Thermal management advantage: Silicon's thermal conductivity (163 W/m-K) is 63% higher than germanium. For high-power laser or high-ambient-temperature applications, silicon lenses dissipate heat more effectively, reducing thermal lensing.
Opaque in visible: Silicon is opaque below 1.2um. Visible alignment is not possible. Use IR-sensitive cameras or coordinate measurement for system alignment.
Frequently Asked Questions
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Related Technical Resources
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