Anwendungen
Optics & Photonics
Precision fused quartz and sapphire optical components for laser systems, spectroscopy, vacuum UV optics, and photonic research applications.
Fused Quartz & Sapphire for Optics & Photonics
The optical properties of fused quartz and sapphire — broad transmission window, low autofluorescence, high damage threshold, and exquisite polishability — make them the dominant substrate materials for precision optics from deep UV to mid-infrared.
Fused Quartz Optical Properties
| Property | Natural Fused Quartz | Synthetic Fused Silica |
|---|---|---|
| Transmission range | 200 nm – 3.5 μm | 150 nm – 3.5 μm |
| Refractive index (589 nm) | 1.4585 | 1.4585 |
| Homogeneity (Δn) | < 5 × 10⁻⁶ | < 1 × 10⁻⁶ |
| Birefringence (stress) | < 5 nm/cm (annealed) | < 2 nm/cm (annealed) |
| OH content (wet grade) | < 30 ppm | 800–1200 ppm |
| UV transmission (193 nm) | ~80% (2 mm) | > 90% (2 mm) |
| Laser damage threshold (355 nm) | > 10 J/cm² | > 20 J/cm² |
Sapphire Optical Properties
| Property | Value |
|---|---|
| Transmission range | 0.14 – 6.0 μm |
| Refractive index (589 nm) | nₒ = 1.768, nₑ = 1.760 |
| Birefringence | Inherent (uniaxial crystal) |
| Knoop hardness | 1800–2000 |
| Surface finish achievable | Ra < 0.1 nm |
| Laser damage threshold (1064 nm) | > 40 J/cm² |
Key Applications
Excimer Laser Windows & Optics (193 nm, 248 nm)
Synthetic fused silica is the material of choice for DUV optics — its superior UV transmission, low OH-induced absorption, and high laser damage threshold enable use in ArF and KrF lithography illumination systems.
| Specification | Value |
|---|---|
| UV transmission (193 nm, 10 mm path) | > 85% |
| Homogeneity | < 1 × 10⁻⁶ Δn |
| Birefringence | < 2 nm/cm |
| Surface roughness | Ra < 0.5 nm |
| Surface form | λ/10 at 633 nm |
IR Spectroscopy Windows (MgF₂ range overlap via sapphire)
Sapphire’s transmission to 6 μm fills the gap between fused silica (cutoff ~3.5 μm) and long-wave IR materials.
- FTIR cell windows: sapphire for aqueous samples (impervious to moisture)
- Mid-IR laser windows: 2.94 μm Er:YAG, 3–5 μm quantum cascade lasers
- Pyrometry: 4–5 μm band temperature measurement
Optical Fiber Preforms
Synthetic fused silica is the base material for silica optical fiber. Tuguan Semiconductor supplies:
- Synthetic silica tubes for Modified Chemical Vapor Deposition (MCVD) preform deposition
- High-OH wet-grade silica for near-IR transmission fibers
- Low-OH dry-grade silica for long-haul telecommunication preforms
Vacuum UV (VUV) Optics
Below 200 nm, only synthetic fused silica (and CaF₂) transmits adequately. Tuguan Semiconductor supplies VUV-grade synthetic silica with:
- OH content optimized for 150–200 nm transmission
- Surface roughness Ra < 0.2 nm
- Certified transmission at 157 nm (F₂ laser wavelength)
Custom Optical Fabrication
We manufacture to customer drawings or specifications:
| Component | Material | Specification |
|---|---|---|
| Windows (flat) | Fused silica / sapphire | Ra < 0.5 nm, λ/10 flatness |
| Prisms | Fused silica | Angular accuracy ±0.5 arc-min |
| Rods & cylinders | Fused silica / sapphire | OD ±0.02 mm |
| Lenses (plano-convex) | Fused silica | Surface form λ/4 |
| Custom shapes | Both | Per drawing |