Quick answer: Fused Silica With Cavities covers Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); pockets with 5 um floor flatness available. Prototypes ship in 5-10 working days.
When a drawing calls out Fused Silica, three numbers matter before any machining starts: CTE of 0.55 x 10^-6 /K, service temperature to 1,100 C continuous, and a transmission window of 185 nm – 2.5 um. fused silica with cavities here begin with those numbers and end with dimensional reports.
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 |
| Feature | Cavities |
| Capability | pockets with 5 um floor flatness available |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Manufacturing capability
One material, many routes: on Fused Silica we also quote edge grinding, ultrasonic machining, grinding, etching, and multi-step drawings are the norm rather than the exception.
These features are produced by ultrasonic machining or etching or cnc machining. Capability: pockets with 5 um floor flatness available. Design rule worth copying onto the drawing: corner radius R0.5 mm minimum for milled pockets.
Getting the drawing right
Before sending the RFQ, check these against your drawing:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Feature rule: corner radius R0.5 mm minimum for milled pockets.
- 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.
For the complete framework, see the tolerance design guide and the holes and edges design guide.
Who orders this
Orders for fused silica with cavities cluster in machine vision (camera windows, ring-light diffusers, calibration plates); optical sensors (sensor windows, filter caps, lens covers); laser systems (windows, beam splitters, debris shields). Background reading on the underlying material science: RP Photonics: fused silica.
Dimensions still moving? Configure this part live in the 3D + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
Useful companion pages: fused silica wafers 2-12 inch, CNC machining capability, ultra-thin glass materials.
Buyer questions, answered
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 is the design rule for cavities?
Corner radius R0.5 mm minimum for milled pockets.
Is there a minimum order for fused silica with cavities?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
Specifications on this page were last reviewed by our engineering team in August 2026.