Europe, UK, Asia & RoW: [email protected] +44 (0)1622 859444 | USA & Canada: [email protected] +1 401-583-7846

Optics for Infrared (IR)

There are generally three major wavelengths ranges that are worked with when optical systems are applied within the Earth’s atmosphere. They are:

Short-wave infrared (SWIR), or near-infrared (NIR), which covers 0.7 – 3.0 micrometers.

Mid-wave infrared (MWIR), which covers 3.0 – 5.0 micrometers.

Long-wave infrared (LWIR), which covers 8.0 – 14 micrometers.

Wavelength ranges between these ones cannot be used in the Earth’s atmosphere due to absorption by various molecules.

Infrared Image

Optical components Defence, Security & Aerospace industries

Custom Optic Solutions

Knight Optical are global leaders in custom optical solutions. We have a team of Science and Business graduates complimented by a management team with years of experience. We work closely with our customers to achieve their specific goals in the design and manufacture of custom optics and mechanics to their exact requirements.

Custom Optics

Stock Optic Solutions

We also hold a large inventory of stock optical components for use in ultra-violet, visible, near infrared and far-infrared applications that can be customized at short notice to meet your specific requirements.

Stock Optics

stock optical components for university research

Flexibility in Manufacturing

Knight Optical can produce a vast number of optical components such as; lenses, prisms, windows and filters using IR materials. This flexibility enables us to make your design ideas a reality. Components can have a variety of different coatings applied such as; broad band anti-reflective (BBAR) coating and diamond-like coating (DLC).


IR Materials

Whatever you IR application Knight Optical can provide the optical solution for you. Knight Optical can produce components from any material listed below.

Material Symbol Transmission Range (μm) Refractive Index Density g/cm2
Barium Fluoride BaF2 0.25 – 9.5 1.455@4µm 4.89
Cadmium Telluride CdTe 1.0 – 2.5 2.693@4µm 5.85
Calcium Fluoride CaF2 0.13 – 10 1.4096@4µm 3.18
Caesium Bromide CsBr 0.35 – 32 1.668@4µm 4.44
Caesium Iodide CsI 0.42 – 40 1.743@4µm 4.51
Gallium Arsenide GaAs 2.0 – 15 3.307@4µm 5.31
Germanium Ge 2.0 – 14 4.025@4µm 5.323
Lithium Fluoride LiF 0.12 – 8.5 1.349@4µm 2.639
Magnesium Fluoride MgF2 0.11 – 7.5 1.349@4µm 3.18
Potassium Bromide KBr 0.26 – 2 1.535@4µm 2.754
Potassium Chloride KCl 0.3 – 21 1.472@4µm 1.989
Sapphire Al2O3 0.17 – 5.5 [email protected]µm 3.98
Sillicon Si 1.2 – 7.0 and 25 – 300 3.4289@4µm 2.329
Sodium Chloride NaCl 0.23 – 12 1.522@4µm 2.165
Thallium Bromoiodide KRS-5 0.7 – 32 2.382@4µm 7.371
Thallium Bromoiodide KRS-5 0.7 – 32 2.382@4µm 7.371
Zinc Selenide ZnSe 0.6 – 16 2.4332@4µm 5.27
Zinc Sulphide ZnS 3 – 12 2.252@4µm 4.09
Zinc Sulphide (Clear) ZnS 0.4 – 12 2.252@4µm 4.09
AMTIR-1 Ge-As-Se 0.7 – 12 2.49715@10µm 4.43
AMTIR-2 As-Se 1.0 – 14 2.7703@10µm 4.66
AMTIR-3 GE-Sb-Se 1.0 – 12 2.6027@10µm 4.67
AMTIR-4 As-Se 1.0 – 12 2.646@10µm 4.49
AMTIR-5 As-Se 1.0 – 12 2.7423@10µm 4.51
AMTIR-6 As-S 0.6 – 8.0 2.3807@10µm 3.2

Understanding Quality

Our rigorous testing procedures – using advanced metrology equipment and skilled QA inspectors – ensure all our products satisfy even the most specific requirements. This applies to one-off custom parts and large production runs. Every single component we supply is proven to perform. We will also provide you with all the information you require for your documentation. We can reassure you that there is transparency on your ordered items including a metrology report and a certificate of conformance to quality standards. We are able to provide you with as much information as required to ensure that legal obligations are met, allowing your instrument to be approved for use as soon as possible.

Whether you want us to manufacture optical components based on your technical drawings, or need us to design parts or systems for your brief, we have the resources to make your concepts a reality. We always start by understanding your particular needs and expectations, and work to ISO 10110, BS 4301-1991, and MIL-PRF-13830B, to produce optical components and sub-assemblies at the correct quality, on time and within budget.

Knight Optical value every one of our customers, and therefore you will be assigned a dedicated account manager, who cares as much about your project as you do. They make the process of getting a quotation to receiving an order, as smooth as possible. We go above and beyond ensuring that your supply chain experience is as stress-free as possible.

Commonly Ordered Optics

Our 2022/2023 Catalogue

Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.
Click below to view our digital catalogue now.

view our catalogue