Unit 3 Optics. What is Light?. Electromagnetic Spectrum. is energy that moves in the form of waves electromagnetic spectrum ranges from short (x-ray and gamma) wavelengths to long (radio) wavelengths
Incandescence: is the emission of light from a hot body due to its temperature.
Fluoresence: emission of light by a substance that has absorbed other electromagnetic radiation...
Electroluminescence: a material emits light in response to the passage of an electric current.
1. Single ray parallel to principal axis. What happens?
2. Single ray through the focus point. What happens?
3. Single ray through the center of curvature. What happens?
Refraction is the change in direction of light as it passes at an angle from one medium into another...e.g.air into water
As light (or any wave) changes speed, it changes direction…unless it hits the new medium straight on at a perfect angle of 90.
When a ray of light passes into a slower, more optically dense medium, the ray of light bends towards the normal. (example air glass)
Diamonds have a very high index of refraction that makes total internal reflection easier. But the cut of the diamond is also important. 45 angle!
ray that is parallel to the principal axis is refracted through the principal focus (F – opposite side of lens from the object)
An upright image has a positive magnification