39-270 50.8 mm Dia. AR Coated Sapphire Protective Flat Window; t=3.15 mm NIR II 750-1550nm

The 39-270 is a 50.8 mm diameter flat window designed for use in the near-infrared (NIR) spectrum, specifically between 750 and 1550 nanometers. This window is sourced from Edmund Optics, a reputable vendor known for their high-quality optical components.

The window is made from sapphire, a material with the chemical formula Al2O3, and has a thickness of 3.15 mm. Sapphire is chosen for its excellent optical properties, including a high refractive index and low absorption across a wide range of wavelengths. It is also highly resistant to scratching and environmental damage, making it an ideal choice for protective windows.

Both the front and back surfaces of the window are coated with the EDM NIR-II standard curve coating. This anti-reflective (AR) coating is designed to reduce surface reflections and improve transmission in the NIR spectrum. The coating is specifically tailored to the NIR-II range, ensuring optimal performance in this specific wavelength band.

The window is shaped as a thin lens, which can be beneficial in certain optical systems where a flat window may introduce unwanted aberrations. However, the lens shape does not introduce any focusing or diverging properties to the window.

The window is currently in stock and can be purchased directly from the Edmund Optics website using the provided weblink.