CUSTOM INFRARED WINDOW FABRICATION
Infrared windows are used in camera turrets for aircraft, marine and ground based surveillance systems, sensing applications, IR imaging and other electro optical payloads. IR windows in FLIR instruments, FTIR spectroscopy, and mineral and gas detection systems serve a range of markets including military & defense, medical, industrial, and commercial applications.
Sydor Optics is one of the leading firms polishing flat IR materials. Whether your infrared application is in the NIR (0.75µm – 1µm), the SWIR (1µm – 2.7µm), the MWIR (3µm – 5µm) or the LWIR (8µm – 12µm) spectrum, we are able to shape and polish infrared materials best suited to imaging requirements. Sydor Optics has experience producing IR components in silicon, germanium, sapphire, silica, and zinc sulfide / zinc selenide. We have manufacturing processes and metrology tools to produce and accurately measure coated or uncoated components. Our capabilities include:
- Double-sided polishing for exceptional transmitted wavefront and parallelism.
- Metrology to measure transmitted wavefront of IR windows, as the parts are used, and taking into account the two surfaces and material homogeneity.
- Ability to measure windows up to 14”, ~350mm.
- High-volume production of IR products.
Demonstrating Transmitted Wavefront with an IR Interferometer
Our IR Interferometer allows Sydor to ensure that the IR windows we produce will perform as designed at specified transmitted wavefront. The IR Interferometer allows us to test and measure the window’s performance at 3.39μm and calculate the transmitted wavefront for other IR wavelengths, allowing us to precisely qualify the IR window.
Our IR Interferometer can measure windows up to 14”, ~350mm, which allows us to ensure we meet specification on even the largest IR window requests.
AVAILABLE MATERIAL TYPES
Based upon customer demand, Sydor Optics offers Optical Windows made from the following optical substrate materials. Of course, if you don’t see a material you need, please contact a Sales Engineer, who will gladly discuss additional options that may be available.
- Crystal
- Magnesium Fluoride (MgF2)
Popular Materials - Fused SilicaPopular Materials
- IR Materials
- Sapphire
- Zinc Selenide
Popular Materials - Low ExpansionPopular Materials
ABOUT THE IR MATERIALS AVAILABLE
Silicon Characteristics
- Cubic in nature and will not exhibit birefringence
- High environmental durability
- Silicon is lower in density making it ideal for weight-sensitive applications when compared to other popular IR materials such as germanium and zinc selenide
- Thermal stability
- More cost-effective for mid-wave applications than other IR materials
Germanium Characteristics
- Highest refractive index and lowest optical dispersion of commonly available IR-transmitting materials
- Germanium is relatively hard with high-density, making it ideal for IR applications requiring rugged optics
- Generally, an anti-reflection coating is recommended on germanium windows for sufficient transmission in the region of interest
- Subject to decreases in transmission as temperature increases, therefore, it must be used at temperatures below 100°C
- Germanium makes an effective 50:50 beamsplitter without the need for coatings
Sapphire Characteristics
- Not reactive with air, water, heat, oxidizers, corrosives, or non-corrosives
- Extremely hard and durable
- High melting point of 2,040°C
- Very low transmitted wave distortion
- Wide optical transmission range
IR-Grade Fused Silica Characteristics
- A very low coefficient of thermal expansion
- Outstanding transmittance in the UV, DUV, visible, and Infrared spectrums
- Refractive index from 1.440791 – 1.588999
- Excellent performance in applications that use the 2µm wavelength spectrum
Zinc Sulfide Characteristics
- Reduces scatter and offers low absorption
- Excellent transmission from 0.36 to 12µm
- Generally a lower cost compared to other IR materials
- The multispectral version is especially appropriate for applications in multiple spectrums that require a single aperture for beam path for several wavebands
Zinc Selenide Characteristics
- Appropriate choice for CO2 lasers and thermometry and spectroscopy
- Extremely low coefficient of thermal expansion
- Excellent homogeneity and uniformity in a wide range of spectrums
Specifications | Measurements |
---|---|
Diameter | ≤ 600mm |
Length / Width | ≤ 450mm x 450mm |
Thickness | ≤ 100mm |
Thickness Tolerance | ± 0.010mm [Precision] ± 0.10mm [Standard] |
Cosmetics (MIL-PRF-13830B) | Down to 10-5 [Precision] 60-40 [Standard] |
Surface Roughness | ≥ 3 Ǻ rms |
Parallelism | ≥ 1 arc second |
Reflected Wavefront Error (RWE) - before coating | ≤ 1/20 wave over clear aperture [Precision] ≤ 1 wave [Standard] |
Transmitted Wavefront Error (TWE) - before coating *Interferometric Scale Factor (ISF) of 0.5 – Single-Pass | ≤ 1/20 wave over clear aperture [Precision] ≤ 1 wave [Standard] |
Clear Aperture | ≥ 90% [Precision] ≤ 85% [Standard] |
Infrared (IR) Windows
Infrared windows are often used in FLIR, FTIR spectroscopy, medical systems, thermal imaging, or other optics applications within the infrared light spectrum. IR windows can help protect your employees and equipment. Sydor Optics can custom manufacture IR windows in a variety of shapes, sizes, substrates, and coatings for various infrared applications. AR coating is available for one or both surfaces.
Window Shapes
Sydor Optics can manufacture custom optical windows — with various shapes and sizes — using CNC Glass Machining or Laser Machining capabilities to meet your specific needs
Some of the standard optical window shapes that Sydor Optics customers frequently order include:
- Circular Windows
- Square Windows
- Rectangular Windows
- Elliptical Windows
- Custom Window Shapes
BENEFITS OF DOUBLE-SIDED GRINDING AND POLISHING INFRARED WINDOWS AT SYDOR OPTICS
Production Volume – Quickly
Excellent Transmitted Wavefront
Engineering value into your precision flat optics
IR MATERIAL APPLICATIONS
Defense
For handheld, ground-based vehicles and aircraft & marine-mounted vehicles:
- Thermal imaging
- Night vision
- Targeting sights
- Camera turrets for VIS & IR imaging
- EO/IR surveillance systems
- Threat warning instruments
Law Enforcement
For handheld, ground-based vehicles and aircraft & marine-mounted vehicles:
- Thermal imaging
- Night vision
Search & Rescue
For handheld, ground-based vehicles and aircraft & marine-mounted vehicles:
- Thermal imaging for firefighting
- Night vision
Commercial/Industrial
- Power line maintenance
- Process control
- Mineral & gas detection
- Agriculture