Lasers
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What is a laser?
A laser is a source of light that only has one color (wavelength), unlike white light, which is made up of all colors in the spectrum and many wavelengths. Lasers are tightly focused, meaning that it can be very narrow and does not diverge much. This is why laser beams are so thin.
What does light stand for and how does it work?
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Lasers concentrates light particles (photons) over and over again until it becomes a laser beam. The atoms/electrons get “excited” and move around. When they slow down and goes back to ground state, it releases a kind of particle-photons.
These photons stick together or “coherent”, and move as one wavelength, so that lasers are very different to sources of ordinary light, which spreads out. These photons bounce back and forth until they get so powerful it becomes a laser.
What are lasers used for?
Lasers are used widely for many things. They are used in surgery to burn tissue as they are concentrated light sources. It is also used in a CD player to read contents on the CD. Manufacturers also have machines that utilizes lasers to cut through objects. In supermarkets, lasers are used to scan bar codes on the foods packaging.
Who invented laser?
Lasers was first invented by Charles Townes and his university students in 1954. They invented a “maser”, which had the same principle except it was invisible microwaves. This is because the microwave is part of the electromagnetic spectrum, same as radio waves, gamma rays, X-rays, etc. After his success, Townes and Arthur Schawlow invented the first laser.