1. Chapter 14: Light Section 4: Using Light
Polarized light: light waves vibrate in only one direction after passing through a polarizing filter

3. Holography: process used to create a three-dimensional photographic image of an object
1. Illuminating objects with laser light produces holograms.
2. Holographic images are difficult to copy

5. When laser light must travel long distances or to hard-to-reach places, optical fibers are used.
Total internal reflection: light strikes a surface between two materials and is completely reflected back to the first material

6. http://www. optics. arizona

7. http://i. cnn. net/cnn/SPECIALS/2004/explorers/images/profiles/top/top

8. 2. Uses of optical fibers
Communication: send enormous numbers of messages in coded light beams
Medicine: internally explore the body

9. D. Optical scanners: read intensities of reflected light and convert the information to digital signals.
1. Used in stores to read price on pattern called a bar code
2. Used in U.S. Postal Service to sort mail and keep track of deliveries
3. Used in photocopy machines and fax machines

12. http://pro. corbis. com/images/42-17625420. jpg