Refraction of light beams passing through a glass block #2

Image illustrating the refraction of light beams passing through a glass block. This simulation shows three beams of monochromatic light striking a glass block at different angles. The rays are refracted (bent) as they enter the prism and again as they leave it. Because the surfaces of the block are parallel, the two refractions cancel out and the rays emerge in the same direction as they entered (but shifted somewhat). This differs from version #1 in having narrower and more defined light beams.