Stimulated emission in 1000mw Laser Pointer makes electrons produce a cascade of identical photons - identical in energy, frequency, wavelength - and that's why laser light is monochromatic. The photons produced are equivalent to waves of light whose crests and troughs line up (in other words, they are "in phase") and that's what makes laser light coherent.
The high power laser pointer is another popular type, favored by electronics hobbyists because of its moderate cost. As its name implies, it has a cavity filled with helium and neon gases. The output of the device is bright crimson. Other gases can be used instead of helium and neon, producing beams of different wavelengths. Argon produces a laser with blue visible output. A mixture of nitrogen, carbon dioxide, and helium produces IR output.
But burning laser pointer play a pivotal role in our everyday lives, too. The fact is, they show up in an amazing range of products and technologies. You'll find them in everything from CD players to dental drills to high-speed metal cutting mac-hines to measuring systems. Tattoo removal, hair replacement, eye surgery -- they all use lasers. But what is a laser? What makes a laser beam different from the beam of a flashlight? Specifically, what makes a laser light different from other kinds of light? How are lasers classified?
- Where the light waves in a flashlight beam are all jumbled up (with the crests of some beams mixed with the troughs of others), the waves in laser light are exactly in step: the crest of every wave is lined up with the crest of every other wave. We say laser light is coherent. Think of a flashlight beam as a crowd of commuters, pushing and shoving, jostling their way down the platform of a railroad station; by comparison, a laser beam is like a parade of soldiers all marching precisely in step.
Before you can understand how a 300mw Green Laser Pointer works, you need to know how an atom can give off light. If you're not sure how this happens, take a look at the box how atoms make light in our introductory article about light.
- Laserfest: A superb website set up to mark the 50th anniversary of the laser's invention. Includes excellent videos by laser pioneers, including Charles Townes and Theodore Maiman, and many other useful articles and resources.
Cutting tools based on CO2 lasers are widely used in industry: they're precise, easy-to-automate, and, unlike knives, never need sharpening. Where pieces of cloth were once cut by hand to make things like denim jeans, now fabrics are chopped by robot-guided lasers. They're faster and more accurate than humans and can cut multiple thicknesses of fabric at once, which improves efficiency and productivity. The same precision is equally important in medicine: doctors routinely use lasers on their patients' bodies. for everything from blasting cancer tumors and cauterizing blood vessels to correcting problems with people's vision (laser-eye surgery, fixing detached retinas, and cataract treatments all involve lasers).