Laser

By A Sixth Grader

Intro

The word laser is an acronym for light amplification by stimulated emission of radiation.  Some lasers can appear to shine at the stars.  These lasers point at certain places on the atmosphere, and look as if they point the stars.  Some beams can be as small as a few millimeters.  These are the kind of lasers that are used to read bar codes, DVDs, and CDs.  According to Wikipedia.org, A laser is an electronic-optical device that emits coherent light radiation. (Wikipedia.org).  This report will cover the history of lasers, how they work, what they do, and how much they can cost.

What is a Laser?

      

         What is laser light? Laser light is not the same as a flash-

light or the sun's light.  The light produced from a laser is actually photons.  This light is monochromatic, meaning it consists of one color.  Regular, white light is made up of the color spectrum (ROYGBiV). Another thing that makes ordinary light differ from laser light is that ordinary light travels in all directions.  This can be illustrated by activating a flashlight.  When a flashlight beam appears, it spreads out, and as it goes farther and farther, it gets wider and wider.  When a laser beam is shone, it goes in only one, strait, line, and is only one color.  You can see this when a laser beam is shone in the dust, or other powders.  When you shine a laser beam in dust, whole laser beam is visible and you can see that it travels in one, strait line

History

       Who invented the first laser? This first person ever to make a laser was made by Theodore H. Maiman, however, he would not get all the credit for the laser.  Many people were involved in the making of the laser.  Some of there people are: Albert Einstein, Rudolph W. Landenburg, Valentin A. Fabrikant, Willis E. Lamb, R. C. Retherford, Alfred Kastler, Charles H. Townes, and many others.  Even though all of these people helped in the making of the laser, Albert Einstien started the whole deal.  He would be credited for the roots of the invention.  He wrote a paper called Zur Quantentheorie der Strahlung (On the Quantum Theory of Radiation) he put down the foundation of the laser and the maser, its predecessor.  The maser came before the laser and is, like the laser, is an acronym.  Maser stands for Microwave Amplification by Stimulated Emission of Radiation.

         How has the laser improved over time? The laser has improved in many ways since its beginning. According to wikipedia.org "Since the early period of laser history, laser research has produced a variety of improved and specialized laser types, optimized for different performance goals, including:

 

    * New wavelength bands

    * Maximum average output power

    * Maximum peak output power

    * Minimum output pulse duration

    * Maximum power efficiency

    * Maximum charging

    * Maximum firing

 

and this research continues to this day. (Wikpedia.org.) Lasers most certainly have improved overtime.  Lasers are now attached to military planes, can shine 2 miles in the sky, and to top that, can appear on the atmosphere.

How it Works

       How does a laser work? The laser works in four main steps.  The first is when the flash quartz tube makes high voltage electricity and causes some of the atoms in the ruby to go to a higher energy level.  When this happens, particles of light called photons are emitted in every direction.  According to Mary Bellis from About.com, "photons from one atom stimulate emission of photons from other atoms and the light intensity is rapidly amplified." (Mary Bellis from About.com) After this, because of the two mirrors located the ends, the photons go back and forth, and continue the process of stimulated emission and amplification.  As you can see from the picture above, the 100% reflecting mirror is on the end closest to the switch, and the 95% reflecting mirror is on the other end.  The last step is when the beam is created.  The beam is created when photons pass through the part of the 95% mirror that does not reflect (the remaining 5%) and goes out, making the beam.

         How far can a laser beam shine? Some lasers can only point a few feet, some point up to 6,000 feet, and some can appear on the atmosphere.  Laser beams can shine very far.

Applications

       How are lasers used? The laser is used for many things. Some of these things are laser cutting, laser printing, and lasik surgery.  The laser is also capable of reading things, such as CDs, DVDs, and bar codes.  The laser can also cut through things.  In clothing factories, they use lasers to cut through lots of layers of cloth, and people that work with metal use lasers to weld it into lots of different things.  Some lasers have actually been put on military planes that can destroy a communication towers and stop a moving truck.  This plane is the one at the right.  Some other things that lasers do are tattoo removal and hair replacement.
         What can you do with a laser pointer?
Laser pointer are very fun to play with.  Some of the best pointers are able to be shine into the night sky, and appear on the atmosphere.  These pointers are very good, because you can point out constellations.  A teacher from an elementary school said how cool it would be to have a night with her classes, get a laser pointer and point out constellations with her students.  You could also hike up foothills and point out houses, buildings ect. in you neighborhood.  These pointers are also very handy for presentations.  In 1st to 3rd grade, my teacher would use his pointer to point things out on the wall that we needed to see.  In a city council meeting, one person used a pointer in his presentation.  Laser pointers are very fun to use, and, are very useful.  Unfortunately, just as cool as lasers are, they can also be used for bad things.  Lasers can blind people, as you can on the wrapper of the laser.

Buying One

       How much money does a laser pointer cost? Laser pointers can very in price from $50.00 to $800.00.   A laser pointer that cannot go as far, but still works would cost somewhere from $12.00 to $20.00.  A laser pointer that appears to point into the night sky would cost from $200.00 to $300.00

Conclusion

       Lasers are very fun and can be used for many purposes.  We use lasers more than you think, and can benefit from them everyday.

Bibliography

http://en.wikipedia.org/wiki/Laser#History

Wikipedia

Laser

April 29, 2008

 

http://spaceplace.nasa.gov/en/kids/laser/index.shtml

 

What is a Laser?

April 30, 2008

 

http://www.theregister.co.uk/2007/12/11/boeing_atl_advanced_tactical_laser_fitted/

Page, Lewis

Boeing announces 'Laser Gunship' completion

May 1, 2008

 

http://science.howstuffworks.com/laser.htm

Weschler, Matthew

How Lasers Work

May 1, 2008

 

http://inventors.about.com/od/lstartinventions/ss/LaserWorks_2.htm

Bellis, Mary

How a Laser Works

May 6, 2008

 

http://www.2shopper.com/category_s/965.htm

 

High Power Green Laser Pointers- Green Laser Beam Class IIIa

May 8, 2008

 

http://en.wikipedia.org/wiki/Laser#Recent_innovations

Wikipedia

 

 

 

A sixth grader

http://images.google.com/imgres?imgurl=http ://www.laserist.org/ldi2007/images/TimWalsh/ WallOfLasers_1024w.jpg&imgrefurl=http://www .laserist.org/ldi2007/tw-report.htm&h=683&w=  1024&sz=167&hl=en&start=24&um=1&tbnid=yTJNg3jgT0-yHM:&tbnh=100&tbnw=150&prev=/images% 3Fq%3Dlasers%26start%3D20%26ndsp%3D2 0%26um%3D1%26hl%3Den%26safe%3Dactive%26sa%3DN

http://regmedia.co.uk/2007/12/11/advanced_tactical_laser.jpg

http://inventors.about.com/od/lstartinventions/ss/LaserWorks.htm