UV AND IR Optical Windows

UV AND IR OPTICAL WINDOWS

Full Range UV and IR Optical Window Solutions

Advanced Optics manufactures UV and IR optical windows to meet your needs when your design requires more than one of our visible spectrum windows. We manufacture high-quality optical windows that are available in both commercial grade and precision polished options. With a transmission range spanning from 180nm to 14µc, our windows will provide exceptional results for your specific application.

UV Optical Window Solutions

We produce UV optical windows using UV Grade Fused Silica, a material that provides numerous advantages such as:

A high degree of purity
Superior environmental durability
A low coefficient of thermal expansion
Outstanding resistance to thermal shock
Excellent transmission from the UV to the NIR (180nm – 2,500nm)
Exceptional hardness for demanding applications that require a high degree of flatness.

Due to these distinct qualities, fused silica windows are highly sought-after across a diverse range of industries, ranging from aerospace, astronomy, military and commercial avionics, medical and scientific instrumentation, academics and research, to industrial applications. These windows are particularly valuable in laser applications, serving as vacuum windows, and as substrates for UV and IR transmitting optics, as well as other applications.

IR Optical Window Solutions

Advanced Optics provides a wide range of substrates suited for use in the IR spectrum. Each substrate has unique properties and benefits and is designed to work within a specific wavelength range.

Material	Wavelength Range	Refractive Index	Abbe Number (vd)	Density (g/cm3)	Coefficient of Thermal Expansion (x10-6C)	Knoops Hardnes(kg/mm2)	Benefits	Disadvantages
Calcium Fluoride (CaF2)	180nm – 9.5µm	1.43	94.99	3.18	18.85	158.3	Low dispersion and fluorescence Low absorption coefficient No OH absorption and no infrared impurity absorption bands High damage threshold Practically insoluble in water A low index of refraction allows the material to be used without the need for an AR coating	Susceptible to scratches Mildly impacted by thermal shock
Fused Silica	180-2.5µm IR grades up to 3.6	1.46	67.8	2.2		640	Available in various glass codes and grades Superior environmental durability Low coefficient of thermal expansion IR grades contain fewer OH-ions resulting in higher transmission across the NIR spectrum	7980 grade has an OH band that causes strong absorption at 2.7 µm.
Germanium (Ge)	2-14µm	4.00	N/A	5.33	6.1	780	Good transmission range Durable and chemically resistant, making it suitable for use in harsh environments Blocks UV-VIS wavelengths while transmitting infrared between 2-14µc	Expensive and hard to produce, making it uneconomical for mass production Brittle and susceptible to shattering upon heavy impact Not suitable for low-cost applications Due to its mechanical properties, it is difficult to fabricate large custom pieces and shape specific geometries
Sapphire (Al2O3)	150nm – 5.5µc	1.754	72.2	3.98	5.4	2000	The second hardest natural material after diamond Extraordinarily scratch resistant Highly durable, even in harsh environments High electrical resistance Extremely high melt temperature Chemically inert Resistant to chemicals with the exception of hot caustics	Expensive and hard to produce, making it uneconomical for mass production Brittle and susceptible to shattering upon heavy impact Not suitable for low-cost applications Due to its mechanical properties, it is difficult to fabricate large custom pieces and shape specific geometries
Silicon (Si)	1.2-7µm	3.4	N/A	2.3	2.5	1130	Low cost Low density makes it suitable for weight-sensitive applications. May be AR coated to improve transmission Not water soluble Good chemical resistance Exceptional abrasion resistance	Strong absorption in the mid-IR due to impurities, Ge and ZnSe may be better alternatives
Zinc Selenide (ZnSe)	1-14µm	2.403	N/A	5.27	7.1	110	Exceptionally low IR absorption Low dispersion and absorption coefficient Incredibly resistant to thermal shock Can be AR coated to enhance transmission and lower reflectance	Not recommended for harsh environments Relatively soft material Sensitive to scratches

UV-IR Window Selection

When choosing a UV or IR optical window, it is essential to carefully assess the physical and optical properties of each material and its suitability for your specific application. Special consideration should be given to each of the following:

Desired wavelength of use and transmission requirements.
Physical properties such as density, coefficient of thermal expansion, and hardness of the material and how they may affect your application.
Optical properties such as the transmission range, refractive index, and Abbe number of the material under consideration and their impact on your application.
Environment in which the window will be used.

For an optical window to perform as expected, having a good understanding of your application (as well as specifying the correct optical characteristics) is essential to reducing costs and procuring the perfect optical window.

Careful consideration should be given to the following and provided when requesting an optical window.

Determine Physical Characteristics

Shape

Tolerances for LxWxT or Diameter

Scratch and Dig

Edge Bevels

Establish Accuracy

Surface Quality:
Commercial polish, 1/2, 1/4, 1/10, or 1/20 wave

Parallelism:
Wedged or Parallel
Parallelism available to < 2 arc seconds

Clear Aperture

Choose Coating

Wavelength or wavelength range of interest

Percentage of reflectivityrequired at a specific wavelength(s) at a specific AOI (angle of incidence)

For more detailed information on how to properly specify an optical window, please visit our page: 10 Steps to Consider when Designing Your Optical Window.

Careful consideration of each step will enable the manufacturer of your optical window to clearly understand your requirements and provide you with a faster and more accurate quotation.