Basic Optical Devices Mirrors Lenses Prisms And Diffraction

Basic Optical Devices Mirrors, Lenses Prisms, And Diffraction Gratings

Basic Optical Devices are used to… 1. Change the Direction of a Ray of Light 2. Gather parallel rays of light and focus them at a point 3. Disperse white light into a spectrum 4. Create an Image which is… • Real and can be Projected onto a screen, (its really there!) or • Virtual which cannot be projected (its not really there!)

Mirrors are reflecting surfaces There are 3 basic types of mirrors by shape; • Flat: Used to change the direction of a ray, can create a virtual image of equal size • Convex: (Curves out) Can create a smaller virtual image, rarely used in telescopes • Concave: (Curves in) Used to gather light, focus it, and to create virtual and real images of various sizes

Lenses are curved pieces of glass, plastic or crystal. There are two types of lenses: • Diverging which have at least one Concave side: They can create a smaller virtual image, used in telescopes as part of a compound lens • Converging which have at least one Convex side: They are used to gather light, focus it, and to create virtual and real images of various sizes

Prisms are flat sided pieces of glass, plastic or crystal, They are used to: • disperse white light into a spectrum. • change the direction of a ray of light Diffraction Gratings are a series of parallel slits usually in a plastic film. They use diffraction to disperse white light into a spectrum A Spectroscope is a devise that uses a prism or diffraction grating to study spectra