Chapter 15--Lasers Lights
Define electromagnetic wave.
What is light?
Name four conventional sources of light.
What is an incandescent lamp?
What is a flourescent lamp?
What is a light-emitting diode (LED)?
What is laser light?
How do lasers work?
What are the four classes of lasers?
Name four types of lasers.
How can lasers be used for communication?
How can lasers be used for manufacturing?
How can lasers be used for construction?
How can lasers be used for healthcare?
How can lasers be used in business?
How can lasers be used at home?
Chapter 15--Lasers Lights
wave produced by the motion of electrically charge particles
Light is a form of energy. Light travels in waves. Light does not need a medium.
It can travel through a vacuum. Light waves are part of the electromagnetic
Incandescent lamp
Flourescent lamp
Light-emitting diode (LED)
Laser light
These light sources use a very thin wire, called a filament, that is heated when
electricity flows through it
The heated filament glows and emits photons, which produce light
Electrons flow through a sealed glass tube. Some of the mercury inside
changes from a liquid to a gas. Ultraviolet photons are released. The ultraviolet
photons strike the phosphor coating, which then emits visible light
Diodes allow electricity to flow in only one direction. As electricity flows from
the cathode (positive lead) to the anode (negative lead), photons are released
Laser light is monochromatic (single color) directional—it does not spread like
ordinary light coherent (single wavelength) bright—it produces more light than
ordinary sources with the same amount of energy
Excitation mechanism provides power. Active medium changes the energy to
light and amplifies it. Feedback mechanism builds the strength of the laser
beam
Class I—used in checkout scanners, laser printers, and CD and DVD players
Class II—used in some technology education classes
Class III—used in office scanners or in light shows
Class IV—used in cutting, welding, and surgery
Ruby lasers use a solid piece of ruby as the active medium.
Carbon dioxide gas is the active medium in a carbon dioxide laser.
Semiconductor lasers use electronic components as their active medium.
Helium-neon lasers use a mixture of the two gases
Sending signals through fiber optic cables
Creating holograms
Cutting
Welding
Drilling
Engraving
Measurements for surveying
Alignment of utility pipes and tunnels
Leveling
Precision surgery
Viewing inside the body through fiber optic cables
Reading UPC codes
Laser printers
Lasers in the Home
Laser printers
Reading and burning CDs and DVDs