What is an optical window?

An optical window is a flat, parallel, optically transparent component used to separate two specific environments from each other while maximizing the transmission of light.

Classification of optical Windows

Fused silica Windows

According to the spectral region, quartz glass is divided into JGS1, JGS2, JGS3. JGS1 is Fused Silica with UV-Quality.It has high transmittance in the 180-2500nm wave band.JGS2 with a transmission rate of more than 93.5% is transparent in the 220-2500 nm band. Fused silica is resistant to high temperatures up to a maximum operating temperature of 1450 ℃；resistant to acid corrosion and hardly reacts with acids; low coefficient of thermal expansion and can withstand severe temperature changes.

N-BK7, H-K9L Windows

The chemical properties of N-BK7and H-K9Lare very stable, scratch and corrosion resistant.N-BK7 and H-K9L are easy to be ground and polished and is a kind of high-quality optical material.BK7 has high homogeneity, with low content of bubbles and magazines.

Silicon Windows

The density of silicon substrate is low.It is half the density of germanium or zinc selenide.The weight of silicon is relatively light, which is suitable for applications requiring weight.  Optical elements made of silicon are harder and less fragile than optical elements made of germanium.

Fluoride Windows

Fluoride materials have a high transmittance in the ultraviolet to far infrared range（calcium fluoride high transmission range 180 nm-8.0 µm, magnesium fluoride high transmission range 200 nm to 6.0 µm), high mechanical and environmental stability.

Application field

Optical windows are usually used as a external protective barrier to protect optical detectors, sensors, optical lenses from the light transmission.

Optical windows are commonly used in biomedicine, scientific research, underwater imaging, aerospace, optical instruments, laser optics, military defense, and other fields.