PRISM

What is a Prism?

Prism is a solid figure having two triangular bases and three rectangular surfaces and is the closed surface. The angle between each surface is the angle of the prism.

Here the opposite surfaces are equal surfaces and are parallel.  We notice that here there are two refracting surfaces which means the surface where refraction of light takes place.

Refraction Through a Prism

• Prism, in optics, piece of glass or other transparent material cut with precise angles and plane faces, useful for analyzing and reflecting light.
• An ordinary triangular prism can separate white light into its constituent colors, called a spectrum. Each colors, or wavelength, making up the white light is bent, or refracted, a different amount; the shorter wavelengths (those toward the violet end of the spectrum) are bent the most, and the longer wavelengths (those toward the red end of the spectrum) are bent the least.
• Prisms of this kind are used in certain spectroscopes, instruments for analyzing light and for determining the identity and structure of materials that emit or absorb light
• Prisms can reverse the direction of light by internal reflection, and for this purpose they are useful in binoculars.
• Prisms are made in many different forms and shapes, depending on the application. The Porro prism, for example, consists of two prisms arranged both to invert and to reverse an image and are used in many optical viewing instruments, such as periscopes, binoculars, and monoculars.
• The Nicol prism consists of two specially cut calcite prisms bonded together with an adhesive known as Canada balsam. This prism transmits waves vibrating in one direction only and thus produces a plane-polarized beam from ordinary light.