Rocky Mountain Instrument Co.

FLIR / Thermal Imaging Optics

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To keep up with the rapidly evolving capabilities of next-generation IR sensors and detectors, optical component manufacturers must stay on the leading edge of manufacturing technologies to support the increasing technical requirements of the FLIR community. RMI brings over 30 years of continuous advancements in IR production capabilities delivering on difficult custom solutions including diamond turned IR aspheric lenses, large IR elements (up to 12” dia), environmentally durable MWIR & LWIR coatings as well as IR opto-mechanical assemblies, offering a full-service, one stop shop for IR imaging system OEMs.

Diamond Turning Capabilities

RMI understands that critical design considerations for high performance FLIR optical systems include savings in weight, space and cost. Infrared optical elements featuring aspheric lens surfaces boost the imaging performance and efficiency of optical system designs by allowing for the combination, and thereby reduction, of the number of optical elements while still obtaining full coverage of the detector. RMI’s precision, 3-Axis Diamond-Point Turning (X,Y,C) produces flawless custom aspheric lens surfaces on a wide range of IR substrates to allow designers to reach their performance goals.

250UPL with Doors Open box DT Metal
Materials Surface Figures Specifications
Germanium Aspherical Up to 350mm diameter
Silicon Spherical Form accuracy of <10nm
CaF2 Cylindrical Surface figure of λ/4- λ/10
ClearTran / Zinc Sulfide Off-Axis Parabolic Surface quality S/D 60-40
Zinc Selenide Freeform Roughness ~ 10-20nm

IR Thin-Film Coatings

With over 30 years of IR coating experience, RMI possesses unrivaled, full-service custom coating capabilities with expertise across the widest range of coating materials and deposition techniques. RMI’s thin-fim FLIR coatings feature thorium-free designs that are specially tuned to maximize transmission and enhance image quality in the MWIR (3-6 micron), LWIR (6-15 micron), and SWIR (0.9-1.7 Micron) wavelength ranges. RMI specializes in environmentally durable IR coatings that can withstand our comprehensive battery of in-house testing. Additionally, RMI excels at solving difficult custom IR coating challenges and can handle large IR optical substrates requiring coatings up to 12” in diameter.

ir coating coating tech
IR Application Specialties Coating Types Coating Methods
IR Imaging Dielectric Electron Beam Evaporation
0.9-1.7 μm (SWIR) Metallic Thermal Evaporation
3-6 μm (MWIR) Metal / Dielectric Hybrid Ion-Assisted Deposition (IAD)
6-15 μm (LWIR) Diamond-Like Carbon (DLC) Magnetron Sputtering

Environmental Testing


Mission critical FLIR optics must perform at their best no matter what the conditions, so RMI rigorously tests each IR optical element through an exhaustive battery of in-house environmental tests. Recognizing the unique challenge that FLIR systems (in particular Airborne Imaging Systems) face in gathering light in the most extreme and harsh environmental conditions, RMI has developed comprehensive testing and certification procedures around various MIL-SPEC and ISO standards.

Comprehensive Testing

Test Type Specification
Humidity Optics are exposed to 50°C/95% humidity for 24hrs standard
Abrasion Moderate and severe tested by rubbing a cheesecloth over the optic
Adhesion Coated surface tested with cellophane tape and quickly removed
Salt Fog/Spray 24hr standard
Salt Solubility Optics are immersed in saline solution for 24 hrs
Water Solubility Optics are immersed in distilled water for 24 hrs
Solvent Solubility Acetone, Ethanol
Temperature Extremes (+80/-65°C) Standard
Temp Cycling (±2°C/minute standard)

RMI Testing Standards

Specifications Description
Mil-PRF-13830B Manufacture, assembly and inspection of finished optical components
Mil-C-675 Durability and abrasion resistance, salt solubility, severe abrasion, and salt fog
Mil-C-48497 Durability requirements for single layer and multilayer interference coatings
Mil-F-48616 General performance and durability requirements for this film coated optical elements
Mil-M-13805 Coating quality adhesion
ISO 9022 Test for the ability to resist the influence of salt mist
ISO 9211 Standard form for surface treatments of components and substrates on optical coatings