Home Products SCHOTT® Lithosil Q Synthetic Fused Silica

SCHOTT® Lithosil Q Synthetic Fused Silica

SCHOTT® Lithosil Q is a high-purity synthetic fused silica material designed for demanding UV, optical, semiconductor, laser and scientific applications. With high SiO₂ purity above 99.99%, excellent deep-UV transmission from 170–2500 nm, low thermal expansion of 0.51 × 10⁻⁶ /°C and strong optical homogeneity up to Δn ≤ 1 × 10⁻⁶, Lithosil Q is suitable for precision components that require stable optical performance, low impurity levels and reliable resistance to thermal stress.

We supply customized SCHOTT® Lithosil Q fused silica components according to drawings, dimensions, thickness requirements and application conditions. Typical products include UV optical windows, semiconductor process windows, excimer laser optics, spectroscopy components, telescope lenses, mirror substrates and other high-precision fused silica parts for optical and industrial projects.

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Details Introduction

1. Basic Information

Item	Specification
Material Type	Synthetic Fused Silica
Brand	SCHOTT®
Grade	Lithosil Q
Typical OH Content	≈ 600–1200 ppm (High OH)
Density	2.20 g/cm³

2. Mechanical Properties

Item	Specification
Young’s Modulus	72.7 GPa
Shear Modulus	31.4 GPa
Poisson’s Ratio	0.17
Knoop Hardness	≈ 522 kg/mm²
Flexural Strength	≈ 67 MPa

3. Thermal Properties

Item	Specification
CTE (0–300°C)	0.51 × 10⁻⁶ /°C
Softening Point	≈ 1585°C
Annealing Point	≈ 1042°C
Strain Point	≈ 890°C
Thermal Conductivity	1.38 W/(m·K)

4. Optical Properties

Item	Specification
Refractive Index @ 587.6 nm	1.4585
Abbe Number	67.8
Transmission Range	170–2500 nm
UV Transmission	Excellent (Deep UV)
Homogeneity	Δn ≤ 1 × 10⁻⁶

5. Chemical Purity

Item	Specification
SiO₂ Content	> 99.99%
Metal Impurities	< 1 ppm (total)
Bubbles & Inclusions	Extremely Low
Chemical Resistance	Excellent (except HF)

6. Typical Applications

Field	Application
Semiconductor	Photolithography Optics, Process Windows
Laser	193 nm / 248 nm Excimer Laser Optics
Astronomy	Telescope Lenses & Mirror Substrates
Scientific	UV Spectroscopy & High-End Instrumentation

7. UV-Grade Fused Silica — Grade Comparison

Property	SCHOTT® Lithosil Q	Corning® 7980	Heraeus® Suprasil 1	Tosoh® ES-2000
Material Type	Synthetic Fused Silica	Synthetic Fused Silica	Synthetic Fused Silica	Synthetic Fused Silica
OH Content	600–1200 ppm	800–1000 ppm	600–1200 ppm	600–1000 ppm
Transmission Range	170–2500 nm	180–2500 nm	170–2500 nm	170–2500 nm
Homogeneity (Δn)	≤ 1 × 10⁻⁶	≤ 1 × 10⁻⁶	≤ 1 × 10⁻⁶	≤ 2 × 10⁻⁶
CTE (0–300°C)	0.51 × 10⁻⁶ /°C	0.52 × 10⁻⁶ /°C	0.51 × 10⁻⁶ /°C	0.51 × 10⁻⁶ /°C
Young’s Modulus	72.7 GPa	72.7 GPa	72.7 GPa	72.5 GPa
SiO₂ Purity	> 99.99%	> 99.99%	> 99.99%	> 99.99%
Brand Origin	Germany	USA	Germany	Japan
Industry Strength	Precision Optics & Astronomy	Semiconductor & UV Laser	European Optics & Laser	Semiconductor & Asia-Pacific