Download Basic Optical Devices

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
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
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
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
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