Laser Technology Flashcards
What does LASER stands for?
The word “LASER” is an acronym for Light Amplification by Stimulated Emission of Radiation.
How would you define a laser device?
A laser is a device that generates an intense beam of coherent monochromatic light (or other electromagnetic radiation) by stimulated emission of photons from excited atoms or molecules.
Who invented the laser?
Theodore Maiman, an American engineer and physicist.
When was the laser invented?
1960
What was the first application of the laser?
The first commercial application was in 1967 when a CO2 laser beam was used to cut through a sheet of steel 1 mm thick.
Between 1970 and 2000, what was laser technology used for? (4)
1) American military employed lasers to mark targets for smart bombs.
2) Laser scanners were used to read retail bar codes.
3) Eye surgeons used lasers to weld detached retinas back into place.
4) The handheld laser pointer became practical in the late 1980s.
How will laser technology involve/improve?
1)An increased number of laser wavelengths.
2)Modifications of laser light pulse rates or shapes.
3)Radically new laser systems, like the quantum cascade laser.
Give the three properties of laser light
It only emits ONE wavelength (monochromatic)
It emits light in only one direction (directed)
It is coherent (the wave train is much longer).
How does a laser work?
The particles in the medium are excited by an energy / pumping source and jump to a higher energy level. To come back to their original state of energy, they give off / release the energy surplus as a light photon which stimulates other excited atoms. This creates a cascade of photons that is reflected back and forth between two mirrors to create a laser beam.
Define light
Electromagnetic radiation that is visible, i.e perceivable by the unaided human eye as colors between red and violet, having frequencies between 400 terahertz and 790 terahertz and wavelengths between 750 nanometers and 380 nanometers. Also called visible light.
What is the difference between wavelength and frequency
Wavelength: The distance between one peak (or crest) of a wave to the next corresponding peak/crest, or between any two adjacent corresponding points.
Frequency: The number of complete cycles / oscillations of a wave that occur per unit of time. The SI unit of frequency is the hertz. The one hertz means the wave completed one cycle in one second.
How does frequency relate to wavelength?
The formula is v = fλ, where v stands for velocity, f for frequency and λ for wavelength.
Frequency and wavelength are inversely proportional. that means the higher the frequency, the shorter the wavelength.
What is the difference between velocity and speed?
Speed is displacement (=distance travelled) per unit of time. Speed is a scalar quantity.
Velocity is displacement (= distance travelled) per unit of time in a given direction.
Directionality associated with velocity makes it a vector quantity.
What are the components of a laser?
A laser device consists of / is composed of / is made up of a central cavity filled with a medium (e.g. a gas, a liquid or a solid) and two mirrors, a total reflector and a partial reflector.
What for is laser pioneer James Wynne known for?
James Wynne is believed to have discovered possible applications of the excimer laser in plastic surgery to remove third-degree scars.
