49-621 12.5 x 12.5 mm N-BK7 Precision Protective Flat Window; t=3 mm Uncoated

The 49-621 is a 12.5 x 12.5 mm N-BK7 Precision Protective Flat Window, with a thickness of 3 mm and no coating. This window is sourced from the renowned optical vendor, Edmund Optics.

This optical element is a flat window, a type of window that is characterized by its planar geometry, designed to protect optical surfaces from environmental contaminants and damage. The window's base shape is rectangular, making it suitable for applications where a rectangular aperture is required.

The window is made from N-BK7, a popular borosilicate crown glass known for its excellent optical properties. This material is often chosen for its high Abbe number, low coefficient of thermal expansion, and excellent transmittance across a wide spectrum, making it ideal for a variety of optical applications.

The window has a thickness of 3 mm, providing a good balance between mechanical strength and optical performance. The uncoated surface ensures broadband transmittance but may be more susceptible to environmental effects such as dirt, dust, or moisture.

This window is designed for use at a wavelength of 587.6 nm, although it can be used across a broader spectrum depending on the specific requirements of the application. The window's shape is that of a thin lens, indicating that it has been manufactured to tight tolerances and can be used in high-precision optical systems.