MiXran Meg1035 Germanium (Ge) Plano-Convex Lens

Overview

The MiXran Meg1035 Germanium (Ge) Plano-Convex Lens is a precision optical component engineered for mid-wave to long-wave infrared (MWIR–LWIR) imaging, thermal sensing, and laser beam manipulation in the 8–12 µm spectral band. Germanium’s high refractive index (~4.0 at 10 µm) and exceptional transmission (>50% bulk transmission from 2–14 µm, peaking near 50–60% at 10 µm) make it the material of choice for uncooled thermal camera objectives, FTIR spectrometer collimators, CO₂ laser focusing systems (10.6 µm), and industrial pyrometry optics. Unlike silica or CaF₂ lenses, Ge lenses require no cryogenic cooling for optimal performance in ambient-temperature LWIR applications. The Meg1035 series features a plano-convex geometry optimized for minimal spherical aberration when oriented with the convex surface facing the collimated input beam—a configuration recommended per ISO 10110-1 for maximizing wavefront fidelity in imaging paths.

Key Features

• Precision-polished germanium substrate with surface quality compliant to MIL-PRF-13830B (60–40 scratch-dig) and surface flatness ≤λ/4 @ 633 nm on the plano face
• Two coating variants: uncoated for maximum thermal stability in high-power pulsed laser environments, or IR2 broadband anti-reflection coating (Ravg < 1.5% across 8–12 µm) to maximize throughput in continuous-wave thermal imaging systems
• Standard diameters: 12.7 mm (½”) and 25.4 mm (1″)—both compatible with industry-standard SM1 (1.035″-40) and SM25 (2.035″-40) lens mounts via optional adapter rings (e.g., PN35030-LM127-S, PN35019-LM254-S)
• Thermally robust design: Germanium’s low coefficient of thermal expansion (6.1 × 10⁻⁶ /°C) ensures stable focal length drift (<0.05% per °C) across −40 °C to +60 °C operational range
• Strict conformance to ISO 10110-1 (general tolerances) and ISO 10110-7 (surface irregularity specifications), enabling integration into ISO 13694-compliant optical assemblies

Sample Compatibility & Compliance

The Meg1035 lens is fully compatible with standard optomechanical infrastructure including kinematic lens mounts (e.g., Thorlabs KM100, Newport ULM100), cage systems (60 mm and 30 mm), and OEM thermal imaging modules requiring f/1.0–f/4.0 apertures. All lenses undergo 100% inspection per ISO 10110-7 for transmitted wavefront error (TWE), with typical values ≤0.25λ RMS @ 10.6 µm. As a Class I optical component under IEC 60825-1:2014, it poses no inherent laser hazard but must be integrated with appropriate beam containment in Class 3B/4 CO₂ laser systems. Documentation includes full traceable metrology reports (certified by Beijing-based ISO/IEC 17025-accredited calibration lab), supporting GLP/GMP-aligned validation workflows in medical device R&D and defense-grade EO/IR system qualification.

Software & Data Management

While the Meg1035 is a passive optical element, its geometric and material parameters are fully parameterized in Zemax OpticStudio (ZOS) and CODE V native libraries. Each product variant ships with a .zmx file containing exact surface sag, dispersion data (Sellmeier coefficients for Ge @ 8–12 µm), and coating stack definitions for accurate non-sequential ray tracing. Manufacturing lot numbers are embedded in the lens edge marking and cross-referenced in digital certificates of conformance (CoC), enabling full traceability in FDA 21 CFR Part 11–compliant document management systems. Raw interferometric test data (phase maps, PV/WFE) is available upon request in .mat or .tif format for custom QA automation pipelines.

Applications

• Uncooled microbolometer-based thermal imaging optics (VOx and a-Si focal plane arrays)
• FTIR spectrometer collimation and focusing assemblies (Bruker, Thermo Fisher, Agilent platforms)
• CO₂ laser material processing systems (cutting, welding, ablation) requiring high-power handling up to 500 W CW
• Gas detection sensors utilizing NDIR spectroscopy in the 8–12 µm atmospheric window
• Radiometric calibration targets and blackbody collimator optics for NIST-traceable temperature measurement systems
• OEM integration into handheld thermal scopes, UAV-mounted surveillance payloads, and automotive night vision modules

FAQ

Is germanium suitable for visible-light applications?
No. Germanium exhibits strong absorption below ~2 µm and is opaque in the visible and near-IR spectrum. It is strictly intended for MWIR–LWIR use.
What is the maximum power density this lens can withstand?
Uncoated Meg1035 lenses support continuous-wave CO₂ laser irradiance up to 500 W/cm² at 10.6 µm without measurable thermal lensing, assuming proper heat sinking and incident angle < 5°.
Can these lenses be AR-coated for other wavelength bands?
Yes—custom coatings for 3–5 µm (MWIR) or dual-band (3–5 µm + 8–12 µm) are available under PN customization codes; lead time increases by 3–4 weeks.
Do you provide mounting hardware or lens cells?
Standard SM-threaded lens cells (e.g., Thorlabs LA1952-B, Newport 550-0020) are compatible; MiXran offers matched adapter rings (PN35030-LM127-S series) with ±2 µm centering tolerance.
Is there a warranty or return policy for damaged coatings?
All IR2-coated lenses include a 12-month limited warranty against delamination or adhesion failure under normal environmental conditions (non-abrasive cleaning, RH < 70%, no solvent immersion).