high transmittance germanium ir window With AR+DLC Dual Protective Coating

 

Felix Glass germanium ir window is made of high-purity single crystal germanium substrate, the core optical material for 8–14μm long-wave infrared thermal imaging systems. Germanium features ultra-low absorption within LWIR band, completely blocks visible light to avoid stray light interference, and delivers stable thermal performance for continuous industrial infrared detection.

 

Dual composite coating of AR anti-reflection film + DLC diamond-like carbon hard film is deposited on both surfaces. AR coating maximizes long-wave infrared transmittance, while DLC layer provides high hardness scratch, moisture and oxidation resistance, solving the soft substrate defect of bare germanium and extending service life in harsh outdoor environments. Flat polished plane ensures no optical distortion for thermal imaging sensor detection.

 

 

- Base Material: Single crystal germanium (Ge)

- Main Working Band: 8 μm – 14 μm long-wave infrared (LWIR)

- Coating Structure: Dual-side AR anti-reflection coating + DLC hard protective coating

- Average Transmittance: >90% @8–14μm after AR+DLC coating

- Single-Surface Reflectance: <1.3% within target LWIR spectrum

- Visible Light Performance: 100% opaque to 0.4–0.7μm visible light, eliminate visible stray light

- Shape: Custom round, square, rectangular flat window

- Thickness Range: 1mm ~ 12mm customizable

- Surface Quality: Standard 60-40 scratch-dig, upgradeable to 40-20 high precision

- Operating Temperature: -40℃ ~ +120℃ stable thermal performance

 

1. Single crystal germanium substrate with ultra-low LWIR absorption, excellent long-wave infrared light throughput for thermal imaging

2. Dual AR+DLC composite coating, combines high transmittance and hard scratch/moisture protection, solves soft Ge substrate wear problem

3. Naturally blocks all visible light, effectively suppress visible stray light interference to improve thermal imaging picture purity

4. Flat ultra-precision polished surface, no beam distortion, stable detection precision for long-distance temperature measurement

5. Fully customizable outline, thickness and coating spectrum to match industrial thermal camera, night vision and infrared spectrometer systems

6. Stable thermal expansion coefficient, no surface deformation under continuous high-temperature industrial detection load

 

 

- Vehicle-mounted LWIR night vision thermal imaging cameras

- Industrial online high-temperature infrared temperature measurement equipment

- Security perimeter thermal detection surveillance cameras

- Handheld infrared thermal imagers & thermal monoculars

- Laboratory 8–14μm Fourier transform infrared spectrometers

- Mining, metallurgy high-temperature infrared monitoring optical windows

 

We provide full one-stop germanium optical processing including single crystal blank cutting, ultra-precision flat polishing, dual AR+DLC composite coating, edge deburring, strict 8–14μm spectral transmittance testing and surface hardness inspection.

Prototype sampling, small-batch trial production and mass manufacturing are supported. Every AR+DLC coated germanium window is fully tested to meet customer-specified spectral, dimensional and coating hardness requirements before delivery.

 

 

AR coating reduces infrared surface reflection to improve 8–14μm transmittance; DLC diamond-like carbon hard film increases surface hardness, resisting scratch, water vapor and oxidation to protect soft germanium substrate.

Germanium fully blocks visible light to eliminate stray light interference, ideal for single-band LWIR thermal imaging; ZnSe transmits visible light, only suitable for multi-spectrum dual-band systems.

Yes, we support custom round/rectangular outline, thickness, and AR+DLC coating optimized for 8–14μm long-wave infrared thermal imaging wavelength.

It fits vehicle night vision thermal cameras, industrial online temperature measuring equipment, handheld thermal imagers and laboratory LWIR infrared spectrometers.

We supply prototype sampling, small trial batches and large-scale manufacturing, all germanium windows pass full spectral transmittance and surface hardness inspection before shipment.