What Are Sapphire Lenses?
Sapphire lenses are optical components made from single-crystal aluminum oxide (Al₂O₃), offering exceptional mechanical durability, chemical resistance, and wide spectral transmission from UV to mid-IR (150 nm–5.5 μm). These lenses are used in demanding environments such as aerospace, military systems, medical endoscopes, and laser instrumentation.
- Inspection Equipment List and Metrology of Bote Optics
- Introduction of BOTE Key Equipment
- Catalog of Precision Optics
- Catalog of Imaging Optics
- ISO9001-2015 Certified
At Bote Optical Singapore, we offer custom sapphire lenses with high surface precision, various curvature options (convex, concave, aspheric), and coatings tailored to your application.
Sapphire Optical Properties Table
| Property | Value |
|---|---|
| Crystal Structure | Hexagonal (Rhombohedral) |
| Transmission Range | 150 nm – 5.5 µm |
| Refractive Index (at 1.0 µm) | ~1.76 |
| Hardness (Mohs Scale) | 9 (second only to diamond) |
| Density | 3.98 g/cm³ |
| Birefringence | Yes (uniaxial positive) |
| Thermal Conductivity | 35 W/(m·K) at room temperature |
| Maximum Operating Temperature | >1600 °C |
| Damage Threshold (Laser) | Very high |
✅ Sapphire’s unique combination of hardness, transparency, and thermal resilience makes it ideal for high-end optical engineering.
Sapphire IR Transmission Performance
Sapphire lenses are widely used in infrared optics, particularly between 0.75 µm to 5.5 µm, including:
- IR spectroscopy
- Thermal imaging systems
- IR sensors in harsh industrial or military settings
🔍 Transmission Graph Suggestion:
(Include a chart showing sapphire’s transmission curve across 150 nm–5.5 µm range, compared with fused silica or BK7.)
Optical Grade Sapphire: Why It Matters
Not all sapphire is created equal. Optical grade sapphire refers to high-purity, low-defect sapphire crystals that have been grown using methods like Kyropoulos or Czochralski growth. These materials exhibit:
- Minimal inclusions or birefringence
- High transmission across a broad spectrum
- Uniformity and high mechanical stability
At Bote Optical, our sapphire optics are processed from optical-grade ingots with strict quality control and interferometric testing to ensure λ/10 or better surface flatness when needed.
Applications of Sapphire Lenses
Sapphire lenses are chosen for environments where other materials may fail:
- 🔬 Medical Endoscopy & Imaging
- 🔥 High-Temperature Furnaces & IR Windows
- 🔫 Military Sights and Optics
- 💡 High-Power Lasers
- 🌌 Space Optics & Satellite Sensors
- 📸 Camera Lenses for Hazardous Areas
Why Sapphire Over Glass or Quartz?
| Comparison | Sapphire | Quartz | BK7 Glass |
|---|---|---|---|
| Hardness | 9 (Excellent) | ~7 (Good) | ~5.5 (Fair) |
| Max Temp Resistance | >1600°C | ~1000°C | ~500°C |
| IR Transmission | Excellent (to 5.5 µm) | Moderate (to 3.5 µm) | Poor |
| Scratch Resistance | Very High | Moderate | Low |
| Cost | Higher | Medium | Low |
Sapphire Lens Price – What Affects It?
The cost of sapphire lenses depends on several factors:
- 📏 Lens Size and Thickness
- 🔍 Surface Accuracy (λ/10 vs λ/4)
- 🧱 Coating Type (AR, IR, UV)
- 📦 Quantity Ordered
- 🧪 Custom Tolerances or Testing Required
Price Range Estimate:
| Lens Diameter | Estimated Unit Price (USD)* |
|---|---|
| Ø10 mm | $30–$80 |
| Ø25.4 mm | $80–$150 |
| Ø50.8 mm | $180–$300 |
Contact [email protected] for a custom quote.
Bote Optical: Trusted Sapphire Crystal Manufacturer
While we source optical-grade sapphire materials globally, all lens grinding, polishing, testing, and coating is conducted at our Nanjing facility, with Singapore-based quality checks and regional logistics.
✅ Our Capabilities:
- Custom lens shapes (plano-convex, biconvex, meniscus)
- Tight tolerance: ±0.01 mm in diameter, λ/10 flatness
- High-volume production or low MOQ prototyping
- AR/IR/DLC coatings available
- Worldwide shipping with export compliance
Frequently Asked Questions (FAQ)
Q1: What’s the main advantage of sapphire over fused silica?
A: Sapphire offers better scratch resistance, higher IR transmission, and higher thermal resistance than fused silica, especially in rugged environments.
Q2: Can sapphire lenses be used with CO₂ lasers?
A: Not typically. Sapphire does not transmit well at 10.6 µm. For CO₂ lasers, zinc selenide (ZnSe) or germanium is preferred. Read more →
Q3: Do you offer AR coatings for sapphire?
A: Yes. We offer AR coatings optimized for UV, visible, or IR bands depending on your application.
Q4: Can I request a custom sapphire lens prototype?
A: Absolutely. Whether you need a single precision lens or a production batch, we can deliver.
Order or Enquire Now
📧 Email: [email protected]
🌐 Website: www.bote.com.sg
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