220-0462M 40.0 mm Dia. N-BK7 Precision Round Window; t=6 mm Uncoated

The 220-0462M is a precision round window offered by EKSMA Optics, a leading vendor in the field of optical components. This window, designed for use with lasers, boasts a base shape of a circle with a generous diameter of 40.0 mm, providing a large aperture for beam transmission.

The window is fabricated from N-BK7, a high-quality borosilicate glass known for its excellent optical properties. This material, also known as Schott glass, is renowned for its low auto-fluorescence, high homogeneity, and exceptional transmission in the visible and near-infrared spectral ranges. The window's thickness is 6 mm, striking a balance between robustness and light transmission.

The window is uncoated, meaning it does not have any anti-reflective or other coatings applied to its surfaces. This can be advantageous in certain applications where the natural reflectivity of the glass surface is desired or where cost considerations are a factor. However, it's important to note that uncoated windows can have higher reflectivity, which may impact performance in high-transmission applications.

This window is classified as a flat window, indicating that its surfaces are parallel and there is no curvature. This design is suitable for applications where no focusing or collimation of the beam is required.

The window's geometry and material make it suitable for use with wavelengths of 633 nm, although it can potentially be used with other wavelengths depending on the specific application requirements.