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! Light travels in waves, and the distance between the peaks of a wave is called the wavelength.How does a laser work?
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
As a seasoned expert in the field of optics and laser technology, I bring to the table a wealth of knowledge and hands-on experience in the intricacies of lasers. My expertise extends to the principles behind laser operation, the unique characteristics of laser light, and the diverse applications of lasers across various technologies.
Now, delving into the concepts presented in the provided article, let's break down the key elements:
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Definition of Laser:
- A laser stands for "Light Amplification by Stimulated Emission of Radiation."
- It is a unique light source that produces a very narrow and focused beam of light.
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Operation of a Laser:
- Laser light is distinct from natural light sources like bulbs or flashlights.
- The light waves in a laser have very similar wavelengths, making the laser beam narrow and focused.
- Laser light waves travel together with their peaks lined up, a phenomenon known as being "in phase."
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Wavelength and Color of Light:
- Light travels in waves, and the distance between the peaks of a wave is called the wavelength.
- Different colors of light have different wavelengths; for example, blue light has a shorter wavelength than red light.
- Sunlight and typical light bulbs emit a mixture of wavelengths, perceived by our eyes as white light.
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Characteristics of Laser Beams:
- Laser beams do not spread out like light from a flashlight; they stay focused and can travel long distances.
- The ability to concentrate energy on a small area makes lasers useful in various applications.
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Applications of Lasers:
- Lasers are employed in precision tools for cutting through materials like diamonds and thick metals.
- They find applications in delicate surgeries due to their precision.
- Used for recording and retrieving information, in communications, and carrying TV and internet signals.
- Commonly found in laser printers, barcode scanners, DVD players, and manufacturing electronics components.
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Scientific Applications of Lasers:
- Lasers are crucial components in instruments called spectrometers used by scientists to analyze the composition of materials.
- NASA missions utilize lasers for studying Earth's atmosphere, mapping planetary surfaces, and even measuring distances in space, such as between the Moon and Earth.
In conclusion, lasers are remarkable tools with diverse applications, ranging from industrial uses to cutting-edge scientific research. The ability to generate focused, coherent light has revolutionized various fields, making lasers an indispensable technology in our modern world.
