Vacuum Viewports

ANCORP offers a wide selection of vacuum viewports with borosilicate glass, quartz, fused silica, sapphire, zinc selenide, magnesium fluoride, and calcium fluoride windows and designs rated for high and ultra-high vacuum (UHV) applications.


Viewport Applications

Viewports, also known as windows or sight glasses, are commonly used to observe or illuminate processes inside a vacuum chamber. In optical applications, viewports transmit electromagnetic radiation into or out of a vacuum chamber. Other applications benefitting from the equipment of a vacuum viewport to a system include general viewing, precision lasers, infrared imaging, and research utilizing harsh environments and thermal shock.


Viewport selection is typically based on requirements for flange type, transmission range, thermal stability, durability, and other optical and physical properties of the window material.


Viewport Window Material Selection

    • Borosilicate glass offers a wide, distortion-free viewing area and is best suited for general purposes such as viewing inside a chamber.
    • Fused silica has high transmission in the ultraviolet (UV) range and excellent thermal and optical properties, making it ideal for use in precision optics and laser applications.
    • Sapphire offers a broad transmission range from UV to near infrared (NIR) and is excellent for use in harsh environments or high temperatures.
    • Zinc selenide has high transmission in the infrared range and is used in IR applications such as thermal imaging.
    • Magnesium fluoride transmits across a wide range from the vacuum ultraviolet (VUV) to mid-IR and is resistant to physical stress and thermal shock.
    • Calcium fluoride has a wide transmission range from UV to IR and has good chemical and laser damage resistance.
    • Weldable viewports feature replaceable elastomer-sealed fused quartz or borosilicate windows and are an excellent choice for attaching an observation window to high vacuum (1×10-8) coating systems.