Double-Side Polishing Fused Silica – Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); Double-Side Polishing to TTV under 3 um. No minimum order; DFM review included with every RFQ.
We DSP-polish Fused Silica daily, in thicknesses from 0.1 – 10 mm. The controlling numbers: TTV under 3 um working tolerance, Ra below 0.5 nm both faces minimum features, and 60/40 to 20/10 both faces off the machine. Where the drawing asks for more, downstream lapping and polishing take over.
Specifications at a glance
| Material | Fused Silica (JGS1 (UV), JGS2 (standard), JGS3 (IR)) |
|---|---|
| Thermal expansion (CTE) | 0.55 x 10^-6 /K |
| Service temperature | 1,100 C continuous |
| Transmission range | 185 nm – 2.5 um |
| Density | 2.20 g/cm3 |
| Knoop hardness | 500 kg/mm2 |
| Refractive index | 1.458 @ 587 nm |
| Stock thickness | 0.10 – 50 mm |
| Maximum blank size | 450 x 450 mm |
| Process | Double-Side Polishing |
| Working tolerance | TTV under 3 um |
| Minimum feature | Ra below 0.5 nm both faces |
| Surface finish | 60/40 to 20/10 both faces |
| Thickness window | 0.1 – 10 mm |
| Edge condition | edge-rounded before DSP |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
Double-Side Polishing earns its place through wafer-grade parallelism and sub-nanometer roughness on both faces simultaneously. Its boundary condition – parts must be round or near-round; strongly asymmetric outlines wedge in the carriers – is the first thing our DFM review checks.
Beyond this page, Fused Silica routinely runs through cnc machining, drilling, coring, sandblasting in our shop – most real parts combine two or three of these steps.
Design guidance
Three items decide most of the cost and lead time on this work:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Process boundary: parts must be round or near-round; strongly asymmetric outlines wedge in the carriers.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
The full rules live in our tolerance design guide and holes and edges design guide.
Application context
The recurring buyers of double-side polishing fused silica: optical sensors (sensor windows, filter caps, lens covers); medical diagnostics (flow cells, slides, microplate bottoms, cuvette windows); microfluidic devices (chips, manifolds, via plates, bonded stacks). Background reading on the underlying material science: RP Photonics: fused silica.
The fastest route to a quote is geometry: use the 3D configurator below, or the site-wide custom glass machining 3D builder for fully custom parts.
Related reading on this site: fused silica material guide, fused silica wafer applications, holes and edges design guide.
Frequently asked questions
What tolerances are achievable on Fused Silica parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Its hardness and brittleness demand diamond tooling and controlled feeds.
What thickness range do you stock for Fused Silica?
Standard stock spans 0.10 – 50 mm, with blanks up to 450 x 450 mm. Other formats are sourced per order.
How does Fused Silica behave under heat?
CTE is 0.55 x 10^-6 /K and continuous service reaches 1,100 C continuous, which is what drives its use where near-zero thermal expansion matters.
What accuracy does double-side polishing hold?
TTV under 3 um with minimum features of Ra below 0.5 nm both faces. Parts must be round or near-round; strongly asymmetric outlines wedge in the carriers.
What equipment runs the double-side polishing work?
Planetary double-side polishers with carrier plates.
Specifications on this page were last reviewed by our engineering team in July 2026.