Product Description
High-Quality 5″ Diameter UV-grade Fused Silica Optical Window – 8.5 mm Thick, Plano-Plano, Uncoated
For sale: A precision-engineered plano-plano optical window, measuring 5 inches (127 mm) in diameter and 8.5 mm thick. This high-purity fused silica (UV-grade quartz) component is in excellent condition, with polished flat surfaces free of scratches, digs, or inclusions, and a ground/frosted edge for safe handling and reduced stray light.
UV-grade fused silica is the material of choice for demanding optical applications requiring exceptional transmission from the deep ultraviolet through the near-infrared. Its high purity, low thermal expansion, and resistance to radiation and fluorescence make it ideal for laser systems, vacuum viewports, and precision metrology .
Key Specifications
| Specification | Details |
|---|---|
| Material | UV-grade fused silica (synthetic amorphous SiO₂) |
| Diameter | 5 inches (127 mm) |
| Thickness | 8.5 mm |
| Geometry | Plano-plano (both surfaces flat and parallel, no optical power) |
| Surface Flatness | λ/10 @ 632.8 nm |
| Surface Quality | 20-10 scratch-dig per MIL-PRF-13830 |
| Clear Aperture | >90% of central diameter |
| Parallelism | <30 arc seconds (typical for precision windows) |
| Coatings | Uncoated (both sides) |
| Spectral Range | 195 nm – 2100 nm (deep UV to near-IR) |
| Transmission | >90% uncoated across most of range |
| Thermal Expansion | Extremely low coefficient |
| Edge Finish | Ground/frosted for safe handling, reduced stray light |
| Condition | Like-new, surplus from professional lab environment |
| Inspection | Tested for clarity and transmission |
Material Advantages – UV-Grade Fused Silica
UV-grade fused silica offers exceptional properties for precision optical applications :
Optical Performance:
-
Broadband Transmission: 195–2100 nm, covering deep UV through visible to near-IR
-
No Fluorescence: Will not fluoresce under UV light – critical for spectroscopy and fluorescence imaging
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Low Autofluorescence: Extremely low bulk scatter compared to other optical glasses
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Excellent Homogeneity: Uniform refractive index throughout
Physical & Thermal Properties:
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Very Low Thermal Expansion: Maintains figure under temperature changes – ideal for laser systems
-
High Thermal Shock Resistance: Can withstand rapid temperature changes
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Radiation Resistant: Suitable for space and high-radiation environments
Laser Applications:
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High Laser Damage Threshold: Extreme purity eliminates microscopic defect sites that could lead to laser damage
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Low Absorption: Minimal heating under high-power beams
Purity:
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Synthetic Material: Flame hydrolysis process ensures highest purity, free from impurities found in natural quartz
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No Orientation Issues: Unlike crystalline quartz, fused silica is isotropic with no temperature instability
Surface Quality & Flatness
20-10 Scratch-Dig :
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Scratch: 20 (very fine, barely visible under magnification)
-
Dig: 10 (tiny imperfections, 0.1mm diameter max)
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This is the highest standard commercial surface quality, suitable for demanding laser and imaging applications
λ/10 Flatness :
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Surface figure accuracy of λ/10 at 632.8 nm
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Near-diffraction-limited performance
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Suitable for interferometry, beam expansion, and precision imaging
Parallelism:
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<30 arc seconds typical for precision windows
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Minimizes beam deviation in transmission
Thickness Advantage – 8.5mm
This window’s 8.5mm thickness provides:
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Enhanced Mechanical Rigidity: Suitable for pressure/vacuum differential applications
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Reduced Flexure: Maintains flatness under mounting stress
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Robust Handling: Less susceptible to breakage during integration
Applications
Vacuum Chamber Viewports:
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Ideal for high and ultra-high vacuum (UHV) systems
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Scientific instruments, electron microscopes, spectroscopy systems
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Can withstand pressure differentials while maintaining optical integrity
Laser Systems:
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Protective windows in high-power laser setups (research, cutting, welding)
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High laser damage threshold from extreme purity
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Suitable for intracavity applications
Optical Benches & Metrology:
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Substrates or covers in interferometers and imaging setups
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Reference flats for flatness verification
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Barriers against dust, humidity, or contaminants
Environmental Chambers:
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Materials science, biology, or chemistry labs
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Enables clear observation while isolating samples
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UV-grade transmission for photochemistry studies
Custom Optics Projects:
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Beam path enclosures
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Substrates for custom coatings
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Newton’s rings demonstrations for flatness verification
Multiphoton Imaging:
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Low autofluorescence makes it ideal for multiphoton microscopy systems
Why Uncoated?
The window is uncoated, offering maximum flexibility:
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Versatile Use: Suitable for a broad range of wavelengths without coating restrictions
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Custom Coatings: User can apply custom AR or reflective coatings optimized for specific applications
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High Transmission: Uncoated fused silica still offers >90% transmission across most of its range
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No Coating to Fail: Eliminates risk of coating damage in harsh environments
Condition
EXCELLENT – LIKE-NEW
SURFACES: Clean, polished, no visible scratches, digs, or inclusions
EDGE: Ground/frosted finish – safe handling, reduced stray light
TRANSMISSION: Verified for clarity
STORED: Protected in lab environment
READY FOR IMMEDIATE INTEGRATION
⚠ HANDLING NOTE: This is a precision optical component. Handle only by edges with clean gloves. Never touch polished surfaces. Store in clean, dry environment when not in use.



