What is Laser?

The acronym laser stands for "light amplification by stimulated emission of radiation." Lasers work as a result of resonant effects. The output of a laser is a coherent electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the same frequency and phase.

Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam." Laser beams can be focused to very tiny spots, achieving a very high irradiance. Or they can be launched into a beam of very low divergence in order to concentrate their power at a large distance.

USES OF LASER 

• Bar code readers in stores use lasers.
• CD and DVD players use lasers.
• Lasers carry TV and telephone signals over special cables.
• Doctors use lasers to do delicate surgery, such as eye surgery.
• Workers in clothing factories use lasers to cut through hundreds of layers of fabric at once.
• Metal workers use lasers to cut and weld metal into everything from street light poles to cars.

LASER BEAM USE IN MILITARY DEFENSE IN THE US

The US Air Force airborne laser, (ABL), designated YAL-1A, is a high-energy laser weapon system for the destruction of tactical theatre ballistic missiles, which is carried on a modified Boeing 747-400F freighter aircraft.

The ABL is being developed by the Air Force Research Laboratory and Team ABL, comprising Boeing, TRW (now Northrop Grumman Space Technologies) and Lockheed Martin.

COMMON LASERS AND IPL USED IN DERMATOLOGIC SURGERY

CARBON DIOXIDE (CO2) LASER - The CO2 laser system can be used in three ways: "focused" for cutting skin without bleeding; "defocused" for superficially vaporizing skin; and "ultra pulsed" for facial resurfacing.

First, by delivering very powerful, rapid pulsing or scanning of the latest generation of CO2 lasers, known as focused, dermatologic surgeons are able to resurface the skin for cosmetic improvement. This technique removes fine lines and wrinkles of the face, smoothes acne scars, and rejuvenates aging and sun-damaged skin as it contours the skin surface.

Second, when the CO2 laser's energy is defocused and not continuous (pulsed), the dermatologic surgeon can treat warts, shallow tumors and certain precancerous conditions.