MiXran Meg1075 Germanium (Ge) Planar Optical Window
| Brand | MiXran |
|---|---|
| Model | Meg1075 |
| Material | Single-Crystal Germanium (Ge) |
| Surface Flatness | λ/4 @ 633 nm |
| Parallelism | < 10 arcsec |
| Clear Aperture | ≥ 90% of diameter |
| Thickness Tolerance | ±0.05 mm |
| Diameter Options | Φ10.0, Φ12.5, Φ12.7, Φ25.0, Φ25.4, Φ40.0, Φ50.0 mm |
| Thickness Options | 1 mm, 2 mm, 3 mm |
| AR Coating | Broadband Anti-Reflection (BBAR) for 8–12 µm (Ravg < 1.5%) |
| Substrate Grade | IR-grade, polished both sides |
| Compliance | ISO 10110-3, MIL-O-13830A surface quality (scratch-dig 20-10) |
| Operating Temperature Range | –40 °C to +60 °C |
| Damage Threshold | > 500 MW/cm² (10 ns, 1064 nm) |
Overview
The MiXran Meg1075 Germanium (Ge) Planar Optical Window is a precision-engineered infrared transmissive component designed for demanding mid-wave to long-wave infrared (MWIR–LWIR) optical systems. Fabricated from high-purity, single-crystal germanium with controlled dopant levels and low dislocation density, the Meg1075 window exhibits exceptional transmission (>50% at 2–12 µm, peak >60% at 8–12 µm) and minimal absorption in the thermal imaging band. Its planar geometry—combined with λ/4 surface flatness and sub-10 arcsec parallelism—ensures minimal wavefront distortion and beam deviation, making it suitable for collimated beam paths in FTIR spectrometers, CO₂ laser delivery systems, thermal camera front elements, and uncooled microbolometer housings. Germanium’s high refractive index (~4.0 at 10 µm) necessitates anti-reflection coating for optimal throughput; the standard BBAR coating on the Meg1075 is optimized specifically for the 8–12 µm atmospheric window, achieving Ravg < 1.5% across the full band.
Key Features
- IR-grade single-crystal germanium substrate with certified crystallinity and low impurity content per ASTM F1567 specifications
- Double-side polished surfaces meeting ISO 10110-3 surface quality standards (scratch-dig 20-10)
- λ/4 surface flatness at 633 nm, verified via interferometric testing with ZYGO or equivalent metrology
- Tight parallelism control (< 10 arcsec), critical for minimizing etalon effects in multi-pass or cavity-based IR systems
- Broadband anti-reflection coating deposited via ion-assisted e-beam evaporation for durability and environmental stability
- Thermally robust design: operational up to +60 °C without measurable birefringence or coating delamination
- Available in seven standard diameters (Φ10.0 to Φ50.0 mm) and three thicknesses (1, 2, and 3 mm), enabling system-level mechanical integration flexibility
Sample Compatibility & Compliance
The Meg1075 window is compatible with standard optomechanical mounts including SM1 (1.035″-40), SM2 (2.035″-40), and custom flange interfaces. All substrates undergo full spectral transmission verification (2–14 µm) using a calibrated FTIR spectrometer (e.g., Bruker VERTEX 80v) prior to coating. Coating adhesion is validated per MIL-C-48497A and humidity resistance tested per ISO 9211-3. The product conforms to ISO 9001:2015 manufacturing controls and supports traceable calibration documentation upon request. While not inherently FDA-regulated, its material purity and coating process are compatible with Class I and IIa medical device optical subsystems requiring IR transmission (e.g., non-contact thermography modules).
Software & Data Management
No embedded firmware or software is associated with the Meg1075, as it is a passive optical component. However, spectral transmission data (CSV and SDF formats), interferometric surface maps (ZEMAX-compatible .ZRD files), and coating reflectance curves are supplied digitally with each batch-certified shipment. These datasets integrate directly into optical design platforms including Zemax OpticStudio, CODE V, and FRED for tolerance analysis, ghost image prediction, and thermal deformation modeling. Traceability records—including lot number, crystal growth date, polishing batch ID, and coating run log—are archived for 10 years and available under GLP-compliant audit protocols.
Applications
- Front-element windows for uncooled LWIR cameras operating in the 8–14 µm band
- Pressure-sealed viewport assemblies in industrial gas analyzers (e.g., methane, SF₆ detection)
- Beam isolation and harmonic separation optics in pulsed CO₂ laser systems (9.2–10.8 µm)
- Reference windows in Fourier-transform infrared (FTIR) spectrophotometers compliant with ASTM E1421 and ISO 13773
- Environmental sensor housings requiring high moisture resistance and stable transmission over temperature cycling (–40 °C to +60 °C)
- Optical bench components in quantum cascade laser (QCL) spectroscopy setups
FAQ
What is the maximum operating temperature for the Meg1075 Ge window before transmission degradation occurs?
Germanium begins exhibiting significant free-carrier absorption above ~60 °C; therefore, continuous operation is rated to +60 °C. Short-term exposure up to +80 °C is permissible but requires derating of transmitted power density by 30% to avoid localized thermal lensing.
Is the BBAR coating durable enough for field-deployed outdoor sensors?
Yes—the ion-assisted e-beam coating meets MIL-C-48497A abrasion class 3 and passes 100-hour salt fog (ASTM B117) and 500-cycle humidity cycling (IEC 60068-2-30) without adhesion loss or spectral shift.
Can custom diameters or thicknesses be manufactured?
Yes—MiXran offers OEM fabrication services for non-standard geometries, including wedge windows, meniscus profiles, and metallized edge seals, subject to minimum order quantities and lead time confirmation.
Does the Meg1075 comply with RoHS or REACH requirements?
Yes—all germanium substrates and coating materials are fully RoHS 2015/863/EU and REACH SVHC-compliant; full substance declarations are provided upon request.
How is surface quality verified during final inspection?
Each unit undergoes automated dark-field inspection per MIL-O-13830A using a 5-megapixel telecentric imaging system, followed by manual verification under 100× magnification; defect maps are archived with the certificate of conformance.
