Total internal reflection: 45 deg-45 deg-90 deg prism using arc lamp.

Total internal reflection: 45 deg -45 deg -90 deg prism using arc lamp. This apparatus is designed to show ray optics such as reflection, refraction and total internal reflection in prisms. White light from a carbon arc shines through a slit, producing a ray that is beamed into a prism mounted on a large white rotateable disk marked with degrees. The ray also glances against the disk, making it visible to the class. There are several Lucite (and glass) prisms that can be used: 45 deg -45 deg -90, 60 deg -60 deg -60 deg , and 45 deg -62.5 deg -62.5 deg . Note: Blackboard optics, X, shows basically the same things and is more easily viewed by a large class.