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

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.

Spectral Filters & AR Coatings

AR Coatings & Spectral Filters

Anti-Reflective (AR): Reduce 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: 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 (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.

Over three decades of design and fabrication of thin film coating enables us to develop a broad array solutions. we udevelopment of anti-reflective coatings , known for efficiency in achieving uniform coatings on substrates. Ion assist and crystal monitoring allows for the precise control of material deposition by layering one atomic layer at a time, ensuring thorough saturation on the substrate for desired performance. We are able to offer coating services on a wide range of substrate materials and maintain a library of over 30,000 coating fixtures that enable quick-turn programs.

Unique geometries are no problem as we design and fabricate tooling in-house as needed. Our design software enables us to create the best coating solution for your needs. We also offer small run prototyping services and in-house qualification testing to be certain that our coatings are qualifed.

Precision at Scale: Your High-Volume Coating Partner

We specialize in high-volume production with 17 advanced coating chambers and 7 in-house spectrophotometers, ensuring precision and consistency at scale. Our streamlined processes and cutting-edge technology make us your ideal partner for large-scale optical coating and metallization needs, delivering quality and reliability every time.

Deposition Process

The deposition process of thin films involves several critical steps to ensure the desired film characteristics and performance. These steps include:

  • Substrate Preparation: The substrate surface is meticulously cleaned and prepared to ensure proper adhesion and uniformity. This step is crucial as any contaminants or irregularities on the substrate can affect the quality and performance of the deposited film.
    Deposition: The target material is deposited onto the substrate using a specific thin film deposition method such as sputtering, evaporation, or chemical vapor deposition. Each method has its advantages and is chosen based on the desired film properties and application requirements.
  • Film Growth: During this phase, the deposited material grows into a thin film on the substrate surface. The growth process is influenced by factors such as temperature, pressure, and deposition rate, which are carefully controlled to achieve the desired film thickness and morphology.
  • Post-Deposition Processing: After deposition, the thin film may undergo additional processing steps such as annealing, etching, or patterning. These processes can enhance the film’s properties, such as its mechanical strength, electrical conductivity, or optical performance, and are tailored to meet specific application needs.

Coating Methods

Thin film coating methods are essential techniques used to deposit thin films onto a substrate, and selecting the appropriate method based on factors like coating liquid, film thickness, and production speed is crucial. Among the most prominent methods are physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD).

Thin Film Design and Technology

Thin film design and technology involve the use of various advanced techniques to control the properties and performance of thin films. Some of the key techniques include:

  • Atomic Layer Deposition (ALD): This technique involves the deposition of thin films one atomic layer at a time, allowing for precise control over film thickness and composition. ALD is widely used in applications requiring ultra-thin, conformal coatings with excellent uniformity and step coverage.
  • Pulsed Laser Deposition (PLD): This technique utilizes high-energy laser pulses to vaporize the target material and deposit it onto the substrate. PLD offers precise control over the deposition process, making it ideal for creating high-quality thin films with specific properties, such as high purity and uniformity.
  • Spin Coating: This technique involves the use of a spinning substrate to deposit thin films. A solution containing the coating material is applied to the center of the substrate, which is then spun at high speed to spread the solution evenly across the surface. Spin coating is commonly used for creating uniform thin films in applications such as photoresists and organic electronics.
  • Chemical Vapor Deposition (CVD): This technique involves the use of chemical reactions to deposit thin films. A gaseous precursor undergoes a chemical reaction on the substrate surface, resulting in the formation of a solid thin film. CVD is highly valued for its ability to produce high-quality films with excellent adhesion and uniformity, making it suitable for a wide range of applications, including semiconductors and protective coatings.

By leveraging these advanced techniques, thin film technology continues to evolve, enabling the development of innovative solutions and enhancing the performance of various devices across multiple industries.

Properties of Thin Films

Thin films have distinct mechanical properties influenced by deposition methods, substrate surface, and thickness. They often exhibit high hardness, strength, and toughness, ideal for applications like protective coatings and MEMS. By adjusting deposition techniques and film thickness, these properties can be precisely tailored for specific industry needs.

Thin Film Applications

Thin films have revolutionized various industries, offering innovative solutions and enhancing the performance of numerous devices. Their applications span across electronics, optics, and energy sectors, showcasing their versatility and importance.

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

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