1. Laser Light
overview

2. Lasers Lasers are special sources of light energy
Lasers are used in many fields
medicine
manufacturing
communications
construction
Come in a variety of sizes and types

3. What are the parts of a laser?
Three main components make up a laser
laser substance- gives off light when energy is put into it
may be a solid, liquid, or gas
commonly helium-neon gas is used
optical cavity- where the laser substance is kept
usually tubelike in shape
has mirrors at both ends
pump- supplies the energy to the laser substance
the power supply or light source that delivers the energy
most gas lasers have electrical pumps (battery)
solid and liquid lasers have optical pumps
radiation from an intense light source is absorbed by the laser substance

4. Different types of laser pumps

5. What are some common lasers?
Helium-Neon Laser
one of the most common gas lasers
relatively inexpensive
supermarket scanners, high school science labs
Carbon Dioxide Laser
found in manufacturing situations
drill metal, weld, cut cloth, monitor air pollution
produce infrared wavelengths so the beams aren’t visible
special precautions are required

6. What are some common lasers?
Argon Laser
emit light in the blue and green spectrum
used in laser light shows and medicine
tattoo removal
treating detached retinas
Neodymium – YAG Laser
solid yttrium aluminum garnet is the laser substance
optically pumped
electrical current passes through a tungsten-iodide pumping lamp to provide the light energy

7. Common Lasers Dye Laser Uses liquid dye as its laser substance
tunable – wavelength can be changed to emit different visible wavelengths
the dye solution flows into the optical cavity where it’s pumped by a xenon flashlamp

8. What is so special about laser light?
Laser light consists of one color or wavelength
Laser light is collimated
spreads out very little
Laser light is Coherent
all light waves have the same wavelength and they travel in phase with one another

9. What is Radiant Power?
Laser light is very intense compared to light from ordinary power
Radiant power is the amount of radiant energy delivered in a given time

10. Example: Comparison of Output Power for 2 lasers

11. What is meant by power density?
Power Density- the amount of power delivered per unit area
Lasers are generally directed at a target
a seam to be welded
inside of an eye
The size of a target area makes a big difference in the effect of the power delivered.

12. Example: Calculating Power Density

13. Calculating Power Density cont.

14. Irradiance
Another word for power density is irradiance