The Short Answer:
A laser produces a very narrow beam of light that is useful in many technologies and instruments. The letters in the word laser stand for Light Amplification by Stimulated Emission of Radiation.
The letters in the word laser stand for Light Amplification by Stimulated Emission of Radiation. A laser is an unusual light source. It is quite different from a light bulb or a flash light. Lasers produce a very narrow beam of light. This type of light is useful for lots of technologies and instruments—even some that you might use at home!
How does a laser work?
Light travels in waves, and the distance between the peaks of a wave is called the wavelength.
Each color of light has a different wavelength. For example, blue light has a shorter wavelength than red light. Sunlight—and the typical light from a lightbulb—is made up of light with many different wavelengths. Our eyes see this mixture of wavelengths as white light.
This animation shows a representation of the different wavelengths present in sunlight. When all of the different wavelengths (colors) come together, you get white light. Image credit: NASA
A laser is different. Lasers do not occur in nature. However, we have figured ways to artificially create this special type of light. Lasers produce a narrow beam of light in which all of the light waves have very similar wavelengths. The laser’s light waves travel together with their peaks all lined up, or in phase. This is why laser beams are very narrow, very bright, and can be focused into a very tiny spot.
This animation is a representation of in phase laser light waves. Image credit: NASA
Because laser light stays focused and does not spread out much (like a flashlight would), laser beams can travel very long distances. They can also concentrate a lot of energy on a very small area.
This animation shows how a laser can focus all of its light into one small point. Credit: NASA
Lasers have many uses. They are used in precision tools and can cut through diamonds or thick metal. They can also be designed to help in delicate surgeries. Lasers are used for recording and retrieving information. They are used in communications and in carrying TV and internet signals. We also find them in laser printers, bar code scanners, and DVD players. They also help to make parts for computers and other electronics.
Lasers are also used in instruments called spectrometers. Spectrometers can help scientists figure out what things are made of. For example, the Curiosity rover uses a laser spectrometer to see what kinds of chemicals are in certain rocks on Mars.
This is a picture of Martian soil before (left) and after (right) it was zapped by the Curiosity rover’s laser instrument called ChemCam. By zapping tiny holes in Martian soil and rock, ChemCam can determine what the material is made of. Image credit: NASA/JPL-Caltech/LANL/ CNES/IRAP/LPGN/CNRS
NASA missions have used lasers to study the gases in Earth’s atmosphere. Lasers have also been used in instruments that map the surfaces of planets, moons, and asteroids.
Scientists have even measured the distance between the moon and Earth using lasers! By measuring the amount of time it takes for a laser beam to travel to the moon and back, astronomers can tell exactly how far away it is!
article last updated February 4, 2021
FAQs
A laser is an unusual light source. It is quite different from a light bulb or a flash light. Lasers produce a very narrow beam of light. This type of light is useful for lots of technologies and instruments—even some that you might use at home!
What is a laser kid definition? ›
A laser is an instrument that can produce a powerful beam of light. The word laser stands for the scientific words that explain how a laser beam is produced: “light amplification by the stimulated emission of radiation.”
Does NASA have a space laser? ›
ATLAS carries two lasers, one primary and one backup. The laser light is at 532 nanometers, a bright green on the visible spectrum. It is fast-firing – it sends 10,000 pulses per second, as compared to the laser on the first ICESat, which sent 40 pulses per second.
What is laser in simple words? ›
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.
What is a laser used for? ›
Today, lasers come in many sizes, shapes, colors, and levels of power, and are used for everything from surgery in hospitals, to bar code scanners at the grocery store, and even playing music, movies, and video games at home.
Is laser OK for kids? ›
What they may not know is this: When operated unsafely, or without certain controls, the highly concentrated light from lasers — even those in toys — can be dangerous, causing serious eye injuries and even blindness. And not just to the person using a laser, but to anyone within range of the laser beam.
Why are lasers banned in school? ›
The principal of at least one school says he has proof that laser pointers can cause permanent eye damage. Cole Brownlee, a 7th grader at Maple Park Middle School in Kansas City, Mo., suffered permanent retinal damage in December after another student shone a laser light in his eye, according to his principal.
Is it lazer or laser? ›
Answer : The word "LASER" is an acronym. It stands for "Light Amplification By Stimulated Emission Of Radiation". The word "Laser" is as fine a term for it as "laser". But the word "lazer" is not a legitimate word.
What is the English word laser? ›
la·ser ˈlā-zər. often attributive. Synonyms of laser. 1. : a device that utilizes the natural oscillations of atoms or molecules between energy levels for generating a beam of coherent electromagnetic radiation usually in the ultraviolet, visible, or infrared regions of the spectrum.
What is laser cutting in simple words? ›
Laser Cutting is a non-contact process which utilizes a laser to cut materials, resulting in high quality, dimensionally accurate cuts. The process works by directing the laser beam through a nozzle to the workpiece. A combination of heat and pressure creates the cutting action.
No particular color is intrinsically more powerful than any other. A 100mW blue light laser is as powerful as a 100mW red light laser, and as a 100mW gamma ray laser.
Is laser therapy safe? ›
While laser therapy is generally considered a safe and effective treatment option, there are potential risks associated with its use. Some of the potential risks of this therapy include the following: Skin irritation or burns from exposure to the laser. Eye damage or vision loss from exposure to the laser.
How are lasers used in real life? ›
Lasers are key components of many of the products that we use every day. Consumer products like Blu-Ray and DVD players rely on laser technology to read information from the disks. Bar code scanners rely on lasers for information processing. Lasers are also used in many surgical procedures such as LASIK eye surgery.
What are the definitions of Lazer? ›
laser. / lā′zər / Short for light amplification by stimulated emission of radiation. A device that creates and amplifies electromagnetic radiation of a specific frequency through the process of stimulated emission .
What is a laser cutter for kids? ›
Lasers cut by burning through the material and are incredibly precise. They can be used on cardboard, paper, wood, foam, acrylic plastics as well as on some metals and glass. It's useful to remember that it's possible to cut out and etch within the same project. The first thing you need to do is to create your design.
