Quartz Glass Window UV Fused Silica Optical Viewport Custom Size Coating Available

Quartz Glass Window | UV Fused Silica Optical Viewport | Custom Size & Coating Available

Overview

Quartz glass windows, also known as fused silica windows or quartz optical windows, are precision flat components made from high-purity silicon dioxide (SiO₂). They are widely used in optical, industrial, and scientific applications due to their outstanding thermal stability, high UV to IR transmission, low thermal expansion, and excellent chemical resistance.

Quartz windows are available in various grades—such as JGS1, JGS2, and JGS3 in China—depending on the required UV/VIS/IR transmission, internal defects, and purity. These windows are often used as viewports, protective covers, or optical transmission mediums in high-demand environments such as vacuum chambers, laser systems, and analytical instruments.

Production Principle

The manufacturing process of quartz glass windows primarily involves the following steps:

1. Raw Material Preparation
   High-purity silica (often >99.99%) is prepared, usually in the form of natural quartz powder or synthetically derived silicon tetrachloride (SiCl₄) gas.

2. Melting Process
   The raw material is melted using one of the following techniques:

   • Flame fusion (for synthetic quartz): A chemical vapor deposition (CVD) method where silicon compounds are oxidized in a flame and deposited as SiO₂.

   • Electric fusion (for natural quartz): Natural quartz sand is melted in a high-temperature electric furnace.

3. Blank Shaping
   The fused quartz is shaped into blocks or plates and then annealed to remove internal stresses.

4. Cutting and Grinding
   The glass blanks are cut into specific shapes and sizes using diamond saws or CNC tools.

5. Polishing
   Optical-grade surfaces are achieved via double-sided polishing or precision lapping to achieve high surface flatness, parallelism, and low surface roughness.

6. Cleaning and Inspection
   Final cleaning is performed using ultrasonic or chemical baths, followed by visual and spectroscopic inspection to meet transmission and cosmetic specifications.

Applications

Quartz glass windows are indispensable in numerous high-performance applications:

• Laser Systems
  Used as output couplers or protective windows due to high damage threshold and thermal stability.

• Semiconductor Processing
  Serve as viewports in plasma etching, ion implantation, and CVD chambers due to their excellent resistance to chemical corrosion and thermal shock.

• UV Sterilization and Disinfection
  Quartz windows are transparent to UV-C light, making them ideal covers for UV lamps in sterilization systems.

• Scientific Instrumentation
  Used in spectroscopy, telescopes, and photonics equipment where high optical clarity and low absorption are essential.

• Aerospace and Defense
  Provide radiation resistance and stability in harsh environmental conditions.

• Medical and Analytical Devices
  Protect sensitive optics in imaging systems and flow cells for UV/VIS analysis.

FAQ

Q1: What is the difference between JGS1, JGS2, and JGS3 quartz glass?
A:

• JGS1: UV-grade fused silica with high transmittance from 185–2500 nm; suitable for UV optics.

• JGS2: Standard optical quartz for 220–2500 nm; commonly used in general optics.

• JGS3: Infrared-grade quartz with transmission mainly in the visible to near-IR range; limited UV response.

Q2: Can quartz windows withstand high temperatures?
A:Yes. Fused quartz can operate continuously up to 1100°C and withstand short-term exposure beyond that, making it ideal for high-temperature environments.

Q3: Are quartz windows suitable for vacuum applications?
A:Absolutely. Quartz has extremely low outgassing and maintains structural integrity under vacuum and thermal cycling, making it ideal for UHV (ultra-high vacuum) viewports.

Q4: What surface finish is available?
A:Windows are typically polished to a surface roughness of <10 Å RMS. Flatness can reach λ/10 or better upon request.

Q5: How do quartz windows compare to other glass materials like borosilicate?
A:Quartz glass outperforms borosilicate in UV transmission, thermal resistance, and chemical durability, but is more expensive due to its high purity and processing complexity.

Q6: Can quartz windows be customized?
A:Yes. They can be customized in terms of size, thickness, coating (AR, HR, etc.), and shape (round, square, elliptical), depending on specific application requirements.