Standard FLIR Grade ZnS Dome & Window | LWIR Thermal Imaging Optics

Standard FLIR Grade CVD ZnS – Cost-Effective LWIR Thermal Imaging Optics

Standard FLIR grade CVD ZnS (regular grade zinc sulfide) is the industry baseline material for 8–12μm long-wave infrared thermal imaging front optics. Produced via pure CVD deposition without HIP post-processing, this yellow-tinted polycrystalline ZnS delivers high mechanical toughness, excellent outdoor moisture stability, and flat LWIR transmission for FLIR thermal cameras, UAV turrets, vehicle-mounted gimbals and industrial thermography sensors. We manufacture FLIR ZnS hemispherical domes, flat windows and plano-convex lenses with tight dimensional tolerances and optional LWIR anti-reflection coatings. Check full engineering specs.

Material Definition: FLIR Grade vs Multispectral CLEARTRAN ZnS

FLIR grade is raw CVD-grown ZnS with no hot isostatic pressing treatment, optimized exclusively for LWIR thermal bands rather than visible+infrared multispectral applications. This grade avoids the extra cost of HIP processing while retaining high fracture resistance for exposed outdoor sensor front windows.

• Raw CVD polycrystalline zinc sulfide, no post-HIP treatment
• Primary transmission window: 7–13μm LWIR thermal imaging band
• Yellow-orange natural tint, opaque to visible light
• High mechanical strength for gimbal vibration & harsh outdoor deployment
• Strict batch separation from multispectral CLEARTRAN ZnS to avoid material mixing

Optical Performance Specifications (8–12μm LWIR Baseline)

All standard FLIR ZnS components follow fixed optical baselines to guarantee consistent thermal imaging clarity without ghosting or transmission drop-off.

• Working Wavelength: 8–12μm long-wave infrared
• Uncoated Bulk Transmission: ≥72% single substrate
• Dual-Side AR Coated Transmittance: ≥95% across full LWIR band
• Refractive Index: n=2.192 @10μm for optical path simulation
• Surface Quality: 60-40 scratch-dig (default industrial thermal camera grade)
• Surface Flatness/Figure: λ/4 @632.8nm full aperture
• Wavefront Uniformity: Low distortion for uncooled thermal sensor integration

Dimensional Machining Tolerances for Domes & Windows

Precision machining ensures perfect sealing fit inside EO/IR turret housings and thermal camera enclosures.

LWIR AR & DLC Hard Coating Options

Coating formulas are strictly tuned for FLIR thermal imaging bands, different from multispectral infrared coating recipes.

• Primary Coating: Broadband LWIR AR coating (8–14μm)
• Average Transmittance: ≥96% after dual-side coating
• Incidence Angle Compatibility: 0°–35° off-axis rays
• Durability Standard: MIL-C-48497 adhesion & humidity test passed
• Upgrade Option: DLC diamond-like carbon hard coating for scratch, dust and rain erosion resistance for outdoor field units

Mechanical & Environmental Operating Limits

These material limits are mandatory for system integration in UAV, vehicle-mounted and field surveillance hardware.

• Operating Temperature Range: -55℃ ~ +130℃
• Thermal Expansion Coefficient: 6.6×10⁻⁶ /K
• Knoop Hardness: 160 HK, high impact resistance
• Chemical Stability: Water-insoluble, stable under 95% RH high humidity
• Vibration Resistance: Suitable for airborne gimbal & mobile vehicle thermal cameras

Common Application Scenarios for FLIR Grade ZnS Optics

• Uncooled LWIR thermal camera front protective domes & windows
• UAV drone EO/IR sensor turret outer optical housing
• Vehicle-mounted thermal surveillance gimbal optics
• Industrial predictive maintenance thermal imager protective windows
• Border security outdoor thermal imaging sensor domes

Production Drawing Requirements & Inspection Certification

We require complete dimensional drawings before production; every finished part ships with full inspection documentation for engineering traceability.

• Required drawing data: OD, thickness, curvature, flange dimensions, sealing surface specs
• Coating specification: Coated surfaces, reserved uncoated sealing zones, LWIR band requirement
• Inspection report content: Raw material grade certificate, dimensional tolerance test, scratch-dig inspection, 8–12μm spectral transmission curve, coating adhesion test record

RFQ Workflow for Custom FLIR ZnS Domes & Windows

Send your technical drawings, application environment, coating requirements and order quantity. Our optical engineering team reviews your optical path design, confirms FLIR grade material suitability, optimizes tolerances and coating schemes, then issues a locked engineering quotation for prototype and mass production. Submit your RFQ now.