In optical devices, a piece of glass or other transparent material cut at a precise angle and plane can be used to analyze and reflect light. When light moves from one medium to another, the speed changes, the path of the light is bent, and part of the light is reflected. Sometimes only the surface reflection of the prism is used instead of dispersion. If the angle of the light inside the prism when it reaches the surface is steep, total reflection will occur, and all light will be reflected back inside.
In optical devices, a piece of glass or other transparent material cut at a precise angle and plane can be used to analyze and reflect light. When light moves from one medium to another, the speed changes, the path of the light is bent, and part of the light is reflected. Sometimes only the surface reflection of the prism is used instead of dispersion. If the angle of the light inside the prism when it reaches the surface is steep, total reflection will occur, and all light will be reflected back inside.
Ordinary triangular prisms can separate white light into its constituent colors, called frequency spectrum. Each color or wavelength that makes up white light is bent or refracted, but the amount is different. Shorter wavelengths (wavelengths toward the purple end of the spectrum) bend the most, while longer wavelengths (wavelengths toward the red end of the spectrum) bend the least. This type of prism is used in some spectroscopes, instruments that analyze light and determine the identity and structure of materials that emit or absorb light.
Optical prisms refract light to reflect (reflection prism), disperse (dispersion prism) or split (beam splitter) light.
The prism is usually made of glass, but any material can be used as long as the material is transparent and suitable for the design wavelength. Common materials include glass, plastic and fluorite.
Optical prisms can reverse the direction of light through internal reflection, so they are useful in binoculars.
Optical prisms can be made in many different forms and shapes. For example, the Porro prism is composed of two prisms. The two prisms can invert the image as well as the image, and are used in many optical observation instruments, such as periscopes, binoculars and monoculars.
Post time: Oct-20-2021