Custom Sapphire Optical Window

Custom Sapphire Optical Window

Custom Sapphire Optical Window Manufacturer

High Hardness Sapphire Window | UV-Vis-IR Transparent | Pressure & Seawater Resistant

Felix Glass supplies custom single-crystal sapphire optical windows for underwater ROV, aerospace, laser, surveillance and rugged sensor systems. Sapphire delivers superior hardness, thermal shock resistance and chemical stability, compatible with AR, DLC and combined AR+DLC coatings.

Felix Glass custom sapphire optical window for subsea, aerospace and laser sensor protection

Sapphire Optical Window | Single Crystal Sapphire
OEM Manufacturing | AR / DLC Coating | Custom Specifications

Material & Grade Overview

Single-crystal sapphire (Al₂O₃) is a premium hard optical substrate transmitting from UV through visible, NIR and mid-wave IR. It features outstanding Mohs 9 hardness, seawater corrosion resistance, high pressure bearing capacity and excellent thermal shock performance. Compared with ZnS, fused silica and silicon, sapphire is the preferred choice for long-life subsea, abrasive and high-reliability airborne applications. Material substrate does not equal final performance grade. Specify wavelength, pressure rating and coating for accurate quotation.

Key Specifications & Custom Options

Substrate Material Single Crystal Sapphire (Al₂O₃)
Shape Round window, square / rectangular plate, disc, blanks, custom profile
Size Range Dia 5mm‑300mm, custom thickness, edge flange & O-ring groove
Surface Quality 20‑10 /40‑20 scratch‑dig, customized per customer drawing
Working Wavelength Band 0.2–5.0μm, UV / Vis / NIR / MWIR broadband transmission
Coating Options Uncoated, UV AR, VIS-NIR AR, MWIR AR, DLC hard coating, AR+DLC combined
Custom Machining Chamfer, drilling, counterbore, O-ring groove, stepped flange, edge polishing
Inspection Interferometer, spectrophotometer, hydrostatic pressure test optional, material certificate available

Manufacturing & Inspection Evidence

ZYGO interferometer inspection for sapphire optical window

Interferometer Inspection

Precision polishing for sapphire window plate

Precision Polishing

Finished custom sapphire optical window

Finished Sapphire Window

All sapphire windows are inspected for surface figure, transmittance and scratch-dig quality. Pressure testing is available for subsea-rated components.

Typical Application

  • Subsea ROV, underwater camera and deep-sea sensor protective windows
  • Aerospace, gimbal, airborne EO/IR multi-sensor payloads
  • UV laser, high-power laser, flame detection and industrial optical monitoring
  • Harsh outdoor, abrasive and corrosive environment optical protection

Coating Selection Guide

AR coating boosts transmission for target wavebands. DLC coating adds extra scratch and chemical resistance for marine and sandy environments. AR+DLC combined coating is recommended for subsea sapphire windows where both high transmission and ruggedness are required. Learn more about infrared optical coating technology.

Order & Quotation Requirements (Valid RFQ Checklist)

To generate an accurate quotation within 24 hours, please prepare below information:

  • 2D/3D engineering drawing (PDF / STEP / IGES preferred)
  • C-axis orientation requirement (if specified)
  • Working wavelength, dimension, thickness, flange & O-ring specs
  • Coating specification, pressure rating and environmental conditions
  • Quantity: prototype sample / pilot batch / mass‑production volume
Send Drawing For Quote

FAQ Snippets

Why choose sapphire instead of ZnS or fused silica for subsea?

Sapphire is Mohs 9 hard, seawater resistant and pressure-capable. ZnS is soft and prone to moisture attack; fused silica lacks mid-IR transmission for thermal imaging.

Does sapphire transmit 8–14μm LWIR thermal band?

Sapphire cuts off around 5μm. It is not suitable for pure LWIR thermal-only systems; ZnS is the standard for 8–14μm thermal imaging.

Can you machine sapphire windows with holes and O-ring grooves?

Yes. We can drill, counterbore, machine O-ring grooves and stepped flanges per your drawing, with full inspection after precision machining.

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