220-0206E 25.4 mm Dia. N-BK7 Precision Round Window; t=6 mm Uncoated

The 220-0206E is a precision round window offered by EKSMA Optics, a leading vendor in the optical components industry. This window, designed for use with lasers, boasts a base shape of a circle with a diameter of 25.4 mm, making it suitable for a wide range of applications.

The window is made from N-BK7, a popular glass type in the optical industry, known for its excellent optical properties. This Schott glass variant is particularly praised for its low dispersion and high Abbe number, making it an ideal choice for applications that require high precision and minimal distortion.

The window has a thickness of 6 mm, which is a standard size for many optical applications. Despite its thickness, the window remains lightweight and easy to handle, making it a practical choice for various setups.

The window is uncoated, meaning it does not have any additional layers applied to its surface. While coatings can enhance certain properties of an optical element, an uncoated window offers the benefit of simplicity and versatility, making it suitable for a wide range of wavelengths. In this case, the window is designed for use with a wavelength of 633 nm.

The window's geometry is that of a thin lens, which is a lens with a thickness much smaller than its diameter. This geometry is often used in optical systems where the lens's material properties are more important than its thickness.