KEWLAB KW31-012 Sapphire Precision Flat Window

Overview

The KEWLAB KW31-012 Sapphire Precision Flat Window is a high-stability optical component engineered for demanding applications in UV–visible–NIR spectral transmission, vacuum-compatible environments, and harsh-condition optical systems. Fabricated from single-crystal, optical-grade sapphire (Al₂O₃), this window exhibits exceptional hardness (Mohs 9), chemical inertness, thermal stability (up to 2000 °C melting point), and broad spectral transmittance from ~150 nm to >5.5 µm. Its precision-ground and polished surfaces conform to λ/1–λ/2 surface figure at 633 nm He–Ne wavelength—ensuring minimal wavefront distortion for interferometric, laser cavity, and metrology-grade setups. The absence of anti-reflection or protective coatings preserves intrinsic material performance while enabling user-specific custom coating integration downstream.

Key Features

• Optical-grade sapphire substrate with certified crystalline homogeneity and low birefringence (< 5 nm/cm), suitable for polarized light applications.
• Surface figure tolerance of λ/1–λ/2 @ 633 nm, verified via phase-shifting interferometry (PSI) per ISO 10110-5.
• Parallelism controlled to < 3 arcminutes, minimizing beam deviation and angular error in collimated optical paths.
• Surface quality rated 5–5 per MIL-PRF-13830B standard—indicating ≤5 scratches and ≤5 digs per defined inspection area under 10× magnification.
• Tight dimensional tolerances: diameter +0.0 / –0.1 mm and thickness ±0.1 mm, supporting precise mechanical mounting in kinematic or vacuum flange assemblies.
• Consistent 0.1 mm × 45° edge chamfer applied to all peripheries to mitigate chipping during handling and clamping.

Sample Compatibility & Compliance

This window is compatible with standard optical mounts (e.g., SM1-threaded lens tubes, kinematic mirror mounts) and vacuum feedthrough housings rated up to 10⁻⁷ mbar. Its sapphire composition complies with ASTM F1710 (Standard Specification for Sapphire Optical Components) and meets RoHS Directive 2011/65/EU requirements. While not supplied with certification documentation by default, batch traceability and optional ISO/IEC 17025-compliant calibration reports—including interferometric surface map data and spectral transmittance curves (200–2500 nm)—are available upon request for GLP/GMP-aligned laboratories.

Software & Data Management

As a passive optical component, the KW31-012 requires no embedded firmware or driver software. However, its metrological specifications are fully compatible with industry-standard optical design and simulation platforms including Zemax OpticStudio, CODE V, and FRED. Surface figure data (in ZYGO .dat or ISO 10110-5 compliant ASCII format) can be provided for integration into tolerance analysis workflows. For quality assurance documentation, KEWLAB supports electronic delivery of inspection certificates aligned with ISO 9001:2015 manufacturing controls.

Applications

• Laser system windows for excimer (193 nm), Nd:YAG (1064 nm), and CO₂ (10.6 µm) sources requiring high damage threshold (>1 GW/cm² for nanosecond pulses).
• Vacuum chamber viewports in UHV R&D environments where outgassing rates must remain below 1×10⁻¹² mbar·L/s·cm² (per ASTM E595).
• Environmental sensor housings exposed to abrasion, corrosion, or high-pressure conditions (e.g., underwater spectroscopy, combustion diagnostics).
• Reference-grade flatness standards in optical shop testing, used alongside Fizeau interferometers for calibration of test plates or null optics.
• Front-surface protection elements for sensitive detectors (e.g., InGaAs arrays, PMTs) operating in industrial or aerospace settings.

FAQ

Is this window suitable for deep-UV applications below 200 nm?
Yes—optical-grade sapphire transmits down to ~150 nm; however, atmospheric oxygen absorption and surface contamination significantly affect throughput below 190 nm. Operation in purged N₂ or vacuum environments is recommended.
Can I request AR coating on this part post-purchase?
Yes. KEWLAB offers optional broadband (350–700 nm) or laser-line (e.g., 532 nm, 1064 nm) MgF₂ or Ta₂O₅/SiO₂ multilayer coatings. Lead time and minimum order quantities apply.
What is the typical surface roughness (Ra) of the polished faces?
Measured Ra is typically ≤0.8 nm over 80×80 µm scan areas, as confirmed by white-light interferometry per ISO 25178.
Does the product include a certificate of conformance?
A basic CoC listing material grade, dimensions, and surface specifications is included. Full metrology reports with interferogram data require separate quotation.
Are custom diameters or thicknesses available?
Yes—KEWLAB maintains standard offerings from Ø3 mm to Ø50 mm and thicknesses from 0.5 mm to 10 mm, all held to equivalent surface and dimensional tolerances. Custom geometries (e.g., rectangular, wedge-shaped) are supported under NDA.