Thin Film Coatings

Performance Thin Film Coatings & Thin Film Technology

Thin film coatings are ultra-thin layers deposited on optical components to control reflection, transmission, polarization, and environmental durability. In EOIR systems, they enable high optical transmission and long-life protection for lenses, mirrors, sensors, and windows.

Coatings Engineered for Active and Passive Devices

Thin films play a critical role in system performance. Clear Align designs and manufactures thin film coatings with improved transmission or throughput, and stability under shock, vibration, temperature swing, salt fog, dust, and sand.

Thin film coating methods we employ chemical vapor deposition (CVD) including ion assist and specialized hard carbon. Spin coating is integrated into most process flows to ensure uniform layers and very low vacuum can be used.

Process selection is driven by the target material, required number of layers, and quality assured criteria and we use crystal monitoring for precise chamber management.

Optical Coating Design & Verification

Our in-house team designs our thin film coating methods and coatings formulas that spans the multispectral environment which includes UV, visible, NIR, SWIR, MWIR, and LWIR with oxides, metals, and select rare-earth materials to tune spectral bands. We model thin film deposition techniques to manage thin film morphology, substrate surface adhesion, mechanical properties (stress, hardness), and coating thickness while minimizing coating defects.

Performance of your coating depends on:

  • Processing discipline (cleanliness, fixturing, bakeouts)
  • Number of layers and tight film thickness tolerances
  • Refractive-index contrast and surface diffusion behavior
  • Matching coating material to substrate surface (e.g., germanium vs. sapphire)
  • Thin film morphology which describes the structural characteristics of thin layers of material, encompassing aspects like surface roughness, internal void networks, and the overall arrangement of grains and columns.

We validate designs through in-line and post-process deposition process checks, spectral verification, and environmental screening.

Critical Pre- and Post- Coating Steps

Precision Cleaning

We begin with automated ultrasonic lines to deliver a meticulous substrate surface that promotes adhesion and long-term reliability.

Inspection & Standards

Each deposited film is inspected to ANSI, MIL-SPEC, and ISO 10110. This replaces guesswork with standardized acceptance criteria and traceable quality records.

Protective Coatings: DLC & Hard Coats

Diamond-Like Carbon (DLC) and other hard coatings safeguard optics in extreme environments. Tight coating thickness control governs transmittance, emissivity, and abrasion resistance. MWIR/LWIR windows for maritime salt spray, desert sand/stone impact, and high-duty cleaning cycles.

We qualify coatings via standardized environmental, mechanical, and chemical stress protocols to ensure field performance.

AR Coatings & Spectral Filters

Anti-Reflective (AR)

Our AR portfolio reduces Fresnel loss and ghosting across the visible and infrared. Ion-assisted processes, crystal monitoring, and real-time rate control deliver uniform film coating on flat and curved optics, with custom tooling for complex geometries.

Notch Filters

Notch filters block narrow wavelength bands while passing others, supporting laser safety, spectroscopy, microscopy, and instrument stray-light suppression. We offer single and multi-band notch designs across UV–LWIR.

Deposition Methods We Use (and How We Choose)

CVD: When a chemical reaction route yields the needed microstructure or barrier properties. We do not offer ALD, PLD, Dip coating or flexible substrates. Our process portfolio focuses on PVD/CVD and scalable operations.

Precision at Scale

We support prototype to production with multi-chamber capacity and in-house spectrophotometry to keep spectral bands, layer thickness, and adhesion in tolerance. Our tooling library have over 30,000 custom fixtures and we have an in-house machine shop for quick fixture designs on quick-turn programs.

Where These Coatings Operate

  • EO/IR imaging systems including border surveillance, maritime patrol, gimbals
  • Protective windows and domes for harsh environments including military vehicles.
  • Notch and bandpass filters for laser-based instruments and laser eye safety
  • Anti-reflective coatings for high-NA assemblies and compact ISR payloads.

Pairing Materials Science + Process Control

By pairing deposition techniques with rigorous deposition process controls, we shape microstructure (grain size, grain boundaries), stress, and adhesion to achieve the mechanical properties and spectral performance you need—without over-engineering or cost creep. The result is the right coating, the right coating, and the right lifetime for your mission.

Chalcogenides, Specialty Glasses and Military Optics with Unique Requirements

We apply deep expertise in the basic properties of thin films and the surface science of specialty chalcogenide substrates. Our team maintains precise control of vacuum chamber conditions and deposition temperature to ensure uniformity in advanced deposition processes for mass production. Clear Align works with a wide range of glass substrates and delivers both metallic films and custom films deposited for demanding defense applications, including tank windows and other specialty optics engineered for extreme environments.

Flawless Results: Advanced Automated Cleaning Systems

We are experts in depositing thin films on bulk materials, and it begins with automated ultrasonic cleaning that provides a meticulous surface for optical coatings.  This process is critical to adhesion and long-term reliability. 

Optical Coatings Inspection

Our coating process utilized modernized inspection techniques and equipment and inspect to ANSI, MILSPEC, and ISO 10110 standards. This disciplined process eliminates guesswork for inspectors and offer standardized quality control.

Unique Capability: Advanced Dual-Band, Broadband, and Multiband Coatings

Clear Align offers specialized evaporation process expertise in the design and production of dual-band, broadband, and multiband optical coatings, enabling performance across multiple spectral bands including VIS, NIR, SWIR, MWIR, and LWIR. These advanced coatings are applied to a wide range of specialty optical materials, such as germanium, chalcogenide glass, sapphire, and silicon, supporting next-generation imaging systems with stringent spectral and environmental requirements. Our precision deposition techniques and in-house metrology ensure tight control over spectral response, durability, and adhesion—critical for maintaining optical performance in extreme operational environments. This capability positions Clear Align to meet emerging customer needs in multi-sensor fusion, free-space optical communication, and compact ISR platforms, where maximizing optical throughput and minimizing reflection losses across multiple bands is essential to mission success. Precision at Scale: Your High-Volume Coating Partner.

Effect of Coating on Center Thickness

Ultimate thickness of coating can modify your lens center thickness and that will vary with wavelengths. Please note we measure CT prior to coating. Shorter wavebands such as Visible and SWIR have thinner coatings that may have no effect, while LWIR and MWIR can be thicker and this should be taken into account during your design phase.

Partner With Clear Align for Your Coating Solution

From thin films for high-performance ISR platforms we serve extreme defense environments, and balance film thickness, durability, and spectral precision. Our expertise spans bulk material, specialty glasses, and plastics—applied with advanced chemical deposition methods and very low-pressure vacuum processes.

Work with our esteemed team to design your coating solution. Whether you need to maximize transmission in visible and SWIR, or engineer rugged coatings for MWIR and LWIR, we provide coatings tuned to your exact mission parameters.

Let’s build coatings that perform where it matters most—contact Clear Align today to start your program

Qualification and Inspection Available:

  • 8.1 MIL-M-13508C: Military Specification - Mirror, Front Surfaced Aluminized for Optical Elements
  • 8.2 MIL-F-48616: Military Specification - Filter (Coatings), Infrared Interference: General Specification
  • 8.3 MIL-C-48497A: Military Specification - Coating Single or Multilayer, Interference Durability Requirements
  • 8.4 MIL-C-14806A: Military Specification - Coating Reflection Reducing for Instrument Cover Glasses and Lightning Wedges 
  • 8.5 MIL-C-675C: Military Specification - Coating of Glass Optical Elements (Anti-Reflection)
  • 8.6 MIL-PRF-13830B: Optical Components for Fire Control Instruments; General Specification Governing the Manufacture, Assembly, and Inspection
  • 8.7 MIL-STD-810G: Department of Defense Test Method Standard: Environmental Engineering Considerations and Laboratory Tests 
  • 8.7.1 MIL-STD-810C
  • 8.7.2 MIL-STD-810D
  • 8.7.3 MIL-STD-810E
  • 8.7.4 MIL-STD-810G 
  • 8.8 ISO 9211-3: Optics and Optical Instruments - Optical Coatings - Part 3: Environmental Durability
  • 8.8.1 Application Categories and Recommended Tests for Environmental Durability
  • 8.8.2 Thermal Cycle Acceptance Tests According to the Standard
  • 8.9 TS-1888: Technical Specification for Infrared Optical Coatings

Clear Align routinely fabricates and coats these materials and many others:

  • Acrylic(PMMA)
  • AMTIR
  • Barium Fluoride (BaF2)
  • Brass
  • Bronze
  • Bronze
  • Calcium Fluoride (CaF2)
  • Chalcogenide Glass (IRG, IG)
  • Copper
  • Fused Quartz
  • Fused Silica
  • Gallium Arsenide
  • GASIR (calcogenized glass)
  • Germanium (Ge)
  • Gold (Au)
  • GRIN
  • IRG24
  • IRG26
  • Indium Antimonide
  • Lithium Fluoride
  • MgF2
  • MS Zinc Sulfide (Cleartran)
  • N-BAK1
  • N-BAK4
  • N-BK7
  • Nickel
  • N-SF10
  • N-SF11
  • N-SF2
  • N-SF5
  • N-SF8
  • N-SK11
  • OPK
  • PMMA
  • Polycarbonate
  • Polymers
  • Polystyrene
  • Rexolite (Polystyrene)
  • Sapphire
  • Silicon
  • Silver
  • Zeonex (E48R, 480R, 480)
  • Zeonex Aluminum
  • Zinc Selenide