The 210-0203M is a Flat Round Window, offered by EKSMA Optics, with a diameter of 25.0 mm and a thickness of 3 mm. This window is made of N-BK7, a popular glass type in the optical industry, known for its excellent optical properties and high damage threshold. The window is uncoated, meaning it does not have any anti-reflective or other coatings applied to its surfaces.
The window's geometry is defined by its diameter and thickness. With a diameter of 25.0 mm, it is suitable for a wide range of applications where a small, flat window is required. The thickness of 3 mm provides sufficient structural integrity while minimizing optical distortion.
This window is designed for use at a wavelength of 633 nm, making it suitable for applications that use red lasers, such as alignment, barcode scanning, and spectroscopy. The window's shape is that of a thin lens, which means it has been ground and polished to a precise curvature, although in this case, the curvature is so slight as to be virtually unnoticeable.