Laser Light overview

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

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

Different types of laser pumps

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

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

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

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

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

Example: Comparison of Output Power for 2 lasers

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.

Example: Calculating Power Density

Calculating Power Density cont.

Irradiance Another word for power density is irradiance