GW31 Sapphire Standard-Precision Flat Optical Window

Overview

The GW31 Sapphire Standard-Precision Flat Optical Window is a high-performance, single-crystal aluminum oxide (Al₂O₃) optical component engineered for demanding ultraviolet (UV) through mid-infrared (MIR) transmission applications. Unlike fused silica or BK7 glass, sapphire exhibits exceptional mechanical robustness, chemical inertness, and broad spectral transmittance—from deep UV (150 nm) to beyond 5.5 µm—making it uniquely suited for harsh environments where thermal stability, abrasion resistance, and vacuum compatibility are critical. The GW31 series adheres to ISO 10110-3 surface quality standards (40–20 scratch-dig), with surface flatness specified at λ/4 at 633 nm and parallelism controlled to <30 arcseconds. Its monolithic crystalline structure ensures zero birefringence under isotropic stress conditions and eliminates the risk of delamination common in coated multilayer substrates. Designed for integration into spectrometers, laser cavities, vacuum viewports, semiconductor process chambers, and aerospace-grade sensor housings, the GW31 window maintains optical integrity across wide temperature ranges (–270 °C to +1000 °C short-term) and aggressive cleaning protocols.

Key Features

• Single-crystal sapphire substrate with certified crystallographic orientation (C-plane standard)
• Standard thickness tolerance: ±0.05 mm; diameter tolerance: ±0.05 mm
• Surface flatness: λ/4 @ 633 nm (measured via interferometry per ISO 10110-5)
• Parallelism maintained to <30 arcseconds—critical for collimated beam preservation
• Available with broadband anti-reflection (BBAR) coatings optimized for UV (240–400 nm), VIS (400–700 nm), NIR (700–1100 nm), or SWIR (1100–2500 nm) spectral bands
• High laser-induced damage threshold (LIDT): >500 MW/cm² (1064 nm, 10 ns, 10 Hz)
• Hermetically sealable—compatible with UHV systems down to 1×10⁻¹⁰ mbar

Sample Compatibility & Compliance

The GW31 window is compatible with standard optical mounting hardware including kinematic lens mounts, vacuum flanges (CF, KF, ISO-K), and epoxy-free clamping solutions. It meets material compliance requirements for Class 100 cleanroom handling (ISO 14644-1) and passes ASTM F2733-19 for particulate shedding under vibrational stress. All sapphire blanks are sourced from certified crystal growers and undergo full traceability documentation (batch ID, crystal growth method, annealing history). The product conforms to RoHS 2015/863/EU and REACH SVHC screening. For regulated industries—including medical device optics and defense-grade EO/IR systems—the GW31 supports full material certification packages (MIL-PRF-13830B, MIL-DTL-48497A) upon request.

Software & Data Management

While the GW31 is a passive optical component, its metrological specifications are fully integrated into industry-standard optical design and tolerancing workflows. Zemax OpticStudio and CODE V users may import native .ZBF or .DAT files containing measured surface map data (available on request). Each batch includes a Certificate of Conformance (CoC) with interferometric surface error maps, spectral transmission curves (200–5500 nm, ±0.5 nm resolution), and dimensional verification reports traceable to NIST-calibrated CMM and optical profilometers. Digital records comply with FDA 21 CFR Part 11 requirements when delivered via secure client portal with audit trail logging.

Applications

• UV-VIS-NIR spectrophotometer entrance/exit windows requiring high throughput and low fluorescence
• Laser system protection windows for excimer (193 nm), Nd:YAG (1064 nm), and quantum cascade lasers (4–12 µm)
• High-pressure and high-temperature combustion diagnostics viewports
• Space-qualified instrumentation for Earth observation and planetary science payloads
• Biomedical endoscopy and OCT probe front elements exposed to sterilization cycles
• Industrial machine vision lenses operating in abrasive or corrosive factory environments

FAQ

Is the GW31 window suitable for vacuum ultraviolet (VUV) applications below 190 nm?
Yes—sapphire’s intrinsic transmission extends to ~150 nm; however, surface oxidation and hydrocarbon contamination significantly reduce VUV throughput. For sustained VUV performance, specify optional plasma cleaning and in-situ bake-out support.
Can custom diameters or thicknesses be manufactured?
Yes—custom geometries up to Ø50 mm and thicknesses from 0.3 mm to 5.0 mm are available under OEM agreements with minimum order quantities and extended lead times.
What coating durability testing has been performed?
All AR-coated variants undergo MIL-C-48497A abrasion testing (rubbing with CS-10 wheels, 1000 cycles), humidity exposure (85% RH, 1000 h), and thermal cycling (–40 °C to +85 °C, 200 cycles) per ISO 9211-4.
Is there batch-to-batch variation in transmission performance?
No—each production lot undergoes full spectral characterization; typical deviation in peak transmission is ≤0.3% across the VIS-NIR band (400–1000 nm) when measured under identical conditions.
Do you provide mounting fixtures or kinematic adapters?
Yes—standard SM-threaded retaining rings (SM05, SM1, SM2), vacuum-compatible compression mounts, and O-ring groove configurations are available as configurable accessories.