Optical prism

Optical prisms differ in terms of physical dimensions, material specifications, and special coatings. Typically, suppliers specify a prism's largest dimension in millimeters (mm).  Several prism materials are commonly available. BK7 glass is a borosilicate crown glass with a wavelength range of 330 nm - 2100 nm and an angular dispersion of 0°42'37". It is relatively hard and does not scratch easily. F2 glass provides excellent chemical resistance and is often used as a second glass in achromatic lenses. It has a wavelength range of 350 nm - 2200 nm and an angular dispersion of 1°40'45". SF10 glass is a high-index material with a wavelength range of 400 nm - 2400 nm and an angular dispersion of 2°58'25". Optical prisms that are made of UV-grade fused silica are also available. They provided better transmission in the ultraviolet (UV) region than crown glass and provide both a wavelength range of 200 - 2500 nm and an angular dispersion of 0°34'01". Some optical prisms use reflective coatings to help reduce the loss of light due to transmission. Others use antireflective coatings to reduce the loss of light due to reflection.