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How to Choose Quartz Glass: Complete Technical Guide to JGS1, JGS2, and JGS3?

Time:2026-10-04

When selecting optical materials for research and industrial applications, understanding JGS1 vs JGS2 vs JGS3 is essential. While all three are high-purity quartz glass grades, their spectral transmission ranges from deep ultraviolet (DUV) to mid-infrared (MIR) differ significantly.

However, selecting the correct optical grade is vital. Choosing the wrong grade can lead to unexpected transmission loss in the ultraviolet or infrared bands, thermal failure, or unnecessary procurement costs.

This technical guide covers the primary applications of quartz glass, provides an engineering specification sheet with translated parameters, and explains exactly how to select between JGS1, JGS2, and JGS3.

1. What is Quartz Glass and Why is It Used in Advanced Engineering?

Quartz glass is an amorphous, single-component glass made of high-purity silicon dioxide (SiO2 > 99.9%). Its strong silicon-oxygen (Si-O) molecular bonds give it unique advantages over standard industrial glass:

Extreme Thermal Shock Resistance: An exceptionally low coefficient of thermal expansion (5.2 – 5.8 x 10^-7 / K) allows it to withstand abrupt temperature shifts from 1100 deg C directly into cold water without cracking.
Broad Transmission Range: Optical transparency spans from the deep ultraviolet (DUV) through visible light and into the mid-infrared (MIR) spectrum (185 nm to 3500 nm).
High Working Temperature: The deformation point reaches 1200 deg C, with continuous operating stability up to 1100 deg C.
Superior Chemical Stability: Inert to virtually all acids (except hydrofluoric acid and hot concentrated alkali) with zero impurity diffusion at elevated temperatures.
Excellent Dielectric Insulation: Ultra-high volume resistivity (1 x 10^16 Ohm-cm at 20 deg C) with minimal dielectric loss across high-frequency RF fields (10 GHz).

2. Key Applications of Quartz Glass

A. Laboratory and Academic Research

Spectrophotometry Cuvettes: Deep-UV transmission down to 185 nm enables high-precision absorption spectroscopy.
High-Temperature Reaction Tubes: Essential for tube furnaces, chemical vapor deposition (CVD), and vacuum chambers.
Photochemical Reaction Vessels: Outstanding laser damage threshold under continuous irradiation.

B. Optical and Laser Systems

Laser Windows and Lens Substrates: Bubble-free material with high optical homogeneity.
Prisms, Mirrors, and Optical Filters: Minimal thermal expansion prevents focal plane drift.

C. Semiconductor and Photovoltaic Manufacturing

Wafer Carriers, Boats, and Flanges: Ultra-low trace metal content protects semiconductor yield.
Photolithography Windows: High DUV transparency for precision exposure systems.

D. Electronics and Display Panels

Conductive Glass Substrates (ITO / FTO Coatings): Acts as a heat-resistant substrate for transparent conductive films.
Sensor Protection Windows: Protects optical sensors, photodetectors, and thermal imaging cameras.

3. Comprehensive Quartz Glass Technical Specification Sheet

Table 1: Chemical Properties

Items	Standard Values	Engineering Notes
Main Composition	Silicon Dioxide (SiO2)	Single-component high-purity glass matrix
Purity (SiO2 Content)	> 99.9%	Ultra-low trace metal impurities
Corrosion Resistance	Excellent	Resistant to most acids; not resistant to hydrofluoric acid (HF), high-temperature concentrated alkali, or molten alkali.
Chemical Stability	Extremely High	High chemical inertness at room temperature; resistant to chemical reactions.
High Temperature Chemical Property	Stable up to 1100 deg C	No precipitation and no impurity diffusion at elevated temperatures.

Table 2: Electrical Properties

Items	Standard Values	Test Condition / Notes
Resistivity	1 x 10^16 Ohm-cm	Measured at 20 deg C
Insulation Strength	250 – 400 kV/cm	High-voltage dielectric barrier
Dielectric Constant	3.7 – 3.9	Tested at 10 GHz
Dielectric Absorption Coefficient	< 4 x 10^-4	Minimal power dissipation
Electricity Loss Coefficient	< 1 x 10^-4	High-frequency RF stability

Table 3: Physical & Thermal Properties

Items	Standard Values	Engineering Notes
Mohs Hardness	6 – 7	Scratch resistant
Density	2.2 g/cm3	Lightweight structural material
Heat Conductivity	1.0 – 1.2 W/(m.K)	Measured at 1000 deg C
Thermal Expansion Coefficient (CTE)	5.2 – 5.8 x 10^-7 / K	Exceptional thermal shock resistance
Deformation Point (Heat Resistance)	1200 deg C	Maximum structural transition limit
Optical Transparency	> 90%	Across primary transmission band

Table 4: Mechanical Properties

Items	Standard Values	Testing Condition / Footnotes
Compressive Strength	1100 MPa	Highly resistant to pressure
Bending Strength (Flexural)	67 MPa	Estimated by extrapolation; depends on surface polishing
Tensile Strength	48 MPa	Estimated by extrapolation; depends on edge condition
Poisson’s Ratio (v)	0.14 – 0.17	Standard elastic deformation ratio

Note: Unless otherwise specified, all values refer to measurements taken at room temperature (<= 25 deg C).

Table 5: Thermal Behavior Reference (Expansion & Viscosity Trends)

Measurement Item	Temperature Range	Curve Trend & Engineering Characteristics
CTE vs. Temperature	-200 deg C to 1000 deg C	Increases rapidly from -10.0 x 10^-7/K at -200 deg C to 6.0 x 10^-7/K at 0 deg C, then stabilizes between 5.2 and 6.5 x 10^-7/K from 200 deg C to 1000 deg C.
Viscosity vs. Temperature	1000 deg C to 1800 deg C	Log10 viscosity decreases smoothly and linearly from 14.0 dPa.s at 1000 deg C down to 7.4 dPa.s at 1800 deg C.

4. Optical Comparison Matrix: JGS1 vs JGS2 vs JGS3

Table 6: Optical Comparison Matrix (JGS1 vs JGS2 vs JGS3)

Grade	Transmission Range	Key Transmittance Specs	Absorption Peak (OH-)	Optical Features & Material	Primary Applications
JGS1 (Synthetic Fused Silica)	185 nm – 2500 nm	• 185 nm: > 85% • 220 nm: > 85% • 240 nm: > 87% • 300 – 2500 nm: > 90%	2600 – 2800 nm (Strong OH- absorption band around 2730 nm)	• Excellent Deep-UV transmission (185-220 nm) • Bubble-free, high homogeneity • Made by SiCl4 flame hydrolysis	• DUV Optics & Lithography • Laser Windows & Prisms • UV Spectrophotometry Cells • High-end Lab Windows
JGS2 (Fused Quartz)	220 nm – 2500 nm	• 220 nm: > 80% • 240 nm: > 75% • 300 – 2500 nm: > 90%	2600 – 2800 nm (Strong OH- absorption band, same as JGS1)	• Almost opaque below 220 nm • High cost-to-performance ratio • Minor micro-bubbles permissible	• Standard Optical Windows • Sight Glasses & Viewports • UV Curing Lamp Envelopes • General Laboratory Glass
JGS3 (Infrared Optical Quartz)	260 nm – 3500 nm	• Extended IR up to 3500 nm • Weak UV below 260 nm • Stable in visible spectrum	No absorption peak in 2600-2800 nm (Ultra-low OH- content < 5 ppm)	• Optimal infrared transmission • Strong absorption below 260 nm • Made by vacuum electro-fusion	• Thermal Imaging Windows • IR Spectroscopy Windows • Pyrometer Sight Glass • Gas Analysis Chambers

Quick 3-Step Selection Guide

Do you need Deep Ultraviolet (DUV) light transmission between 185 nm and 220 nm?
- Choose JGS1. It is the premier choice for laser optics, lithography blanks, and UV analytical instruments where zero fluorescence and bubble-free optical clarity are mandatory.
Do you need Infrared (IR) transmission extending from 2500 nm up to 3500 nm without OH- absorption loss?
- Choose JGS3. JGS3 eliminates the 2.73 micron water absorption dip, making it ideal for thermal imaging, infrared sensing, pyrometer viewports, and gas analysis.
Is your operating wavelength within the standard UV-Visible-NIR range (260 nm to 2000 nm) where cost efficiency is important?
- Choose JGS2. It offers balanced optical and mechanical characteristics for sight glasses, UV curing fixtures, and general laboratory glassware at a lower cost than synthetic silica.In summary, the choice of JGS1 vs JGS2 vs JGS3 depends on your specific operational wavelength.

5. Custom Quartz Glass Fabrication Capabilities

Choosing the right quartz grade is only the first step; high-precision machining determines final component performance.

At Shenzhen Chenshi-Tech Co., Ltd. (CHENSHI-TECH), we supply custom quartz components and electronic glass panels for research institutes, universities, and industrial manufacturers:

Available Materials: JGS1 (Synthetic Silica), JGS2 (Optical Quartz), JGS3 (Infrared Quartz), High-Borosilicate Glass, and Conductive Glass (ITO / FTO).
Machining Capabilities: CNC profiling, chamfering, hole drilling, step edge polishing, optical double-sided polishing (Surface accuracy: Lambda/4 to Lambda/10; Scratch-Dig: 40-20 or 20-10), and custom anti-reflective (AR) / dielectric coatings.
Custom Sizing: Thickness from 0.2 mm to 50 mm, custom round wafers, square plates, stepped glass covers, and custom CNC cutouts.

Here are frequently asked technical questions regarding JGS1 vs JGS2 vs JGS3 selection.

Frequently Asked Questions (FAQ)

Q1: What is the main difference between Fused Quartz and Fused Silica?

A: Fused Quartz (such as JGS2 and JGS3) is manufactured by melting natural high-purity quartz crystal. Fused Silica (such as JGS1) is synthetically produced by the chemical flame hydrolysis of silicon tetrachloride (SiCl4), delivering superior chemical purity, zero fluorescence, and higher UV transparency.

Q2: Why does JGS1 show an absorption dip around 2700 nm?

A: JGS1 contains residual hydroxyl groups (OH-) introduced during flame combustion synthesis. These OH- groups cause molecular vibrational absorption across the 2600 nm to 2800 nm infrared band.

Q3: Can quartz glass be tempered like standard float glass?

A: No. Quartz glass cannot be thermally tempered because its coefficient of thermal expansion is too low (5.5 x 10^-7 / K) to establish the necessary surface compressive stress layer. However, its natural compressive strength (1100 MPa) is already far higher than standard annealed glass.

Q4: What is the maximum safe operating temperature for quartz glass?

A: Quartz glass can operate continuously at temperatures up to 1100 deg C and withstand short-term exposure up to its deformation point of 1200 deg C without structural degradation.

Need a Custom Quote or Technical Advice?

Contact the CHENSHI-TECH engineering team to review your technical drawings, tolerances, and optical requirements.

Company: Shenzhen Chenshi-Tech Co., Ltd.
Inquiry: Request a Quote for Custom Quartz Glass Components