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C:\fakepath\ted 111 powerpoint

  1. 1. Lasers<br />The history of lasers and their every day applications<br />
  2. 2. LASER- Light amplification by stimulated emission of radiation <br />A Laser is a mechanism for emitting electromagnetic radiation.<br />A Laser usually emits light or visible light through a process called stimulated emission.<br />
  3. 3. History<br />Albert Einstein established the idea of the LASER and MASER in 1917.<br />In a paper entitled “On the Quantum Theory of Radiation,” Einstein states that LASER and MASER technology is possible via a re-derivation of Max Planck’s law of radiation.<br />Planck’s law was based off of Einstein’s coefficient's for the absorption, spontaneous emission, and stimulated emission of electromagnetic radiation.<br />Rudolf W. Ladenburg confirmed the existences of the phenomena of stimulated emission and negative absorption in 1928.<br />
  4. 4. History<br />R. C. Retherfordand Willis E. Lamb discovered stimulated emissions in the hydrogen spectra, and effected the first demonstration of stimulated emission in 1947.<br />in 1950, Alfred Kastler proposed a method known as optical pumping, which was experimentally confirmed by Kastler, Brossel, and Winter two years later.<br />Alfred Kastler would eventually receive the Nobel Prize for Physics in 1966 for his method of optical pumping.<br />The first functional laser was demonstrated at the Hughes Research Laboratorieson May 16, 1960, by Theodore Maiman.<br />
  5. 5. MASER<br />“A MASERis a device that produces coherent electromagnetic waves through amplification by stimulated emission<br />The Principles of the maser were described by Nikolay Basov and Alexander Prokhorov of the USSR in 1952, and officially published in October of 1954.<br />However, it was Charles H. Townes, J. P. Gordon, and H. J. Zeiger who built the first maser in 1953 at Columbia University.<br />Their device used stimulated emission in a stream of energized ammonia molecules to produce amplification of microwaves at a frequency of 24 gigahertz.<br />Later, Townes worked with Arthur L. Schawlow to describe the principle of the optical maser, or laser.<br />
  6. 6. MASER<br />The design of the maser is based on Albert Einstein’s principle of stimulated emission.<br />When atoms are put into an excited state, they can amplify radiation at the proper frequency.<br />The feedback produced by putting an amplifying medium in a resonant cavity is what is known as coherent radiation.<br />
  7. 7. How L.A.S.E.R.s Work<br />The Lstands for Light, a laser utilizes the forces of light into a beam and directs this light for its power.<br />The A stands for Amplification, this refers to magnifying the light in order to make it more or less intense.<br />The S stands for Stimulation, which is where the light comes from.<br />Atoms are made of electrons, which when excited reach an elevated state, much higher then their normal state.<br />The electrons in turn release their excess energy by giving off a photon of light, and then return to their normal state.<br />When electrons of a particular substance are stimulated by light, get charged up and in turn release photons of the same color.<br />
  8. 8. How L.A.S.E.R.s Work<br />TheEstands for Emission, which is the release of light energy.<br />The R stands for Radiation, which is the entire process of the stimulated emission of the photons.<br />A LASER is finally created when the process above is carried out in a controlled environment, using mirrors and lenses to collect the released photons.<br />
  9. 9. Types of Lasers<br />Solid State Lasers:<br />This laser uses solid substance material, solid material that is used for lasing is generally stimulated by a flashlight or other type of light.<br />You will get solid lasers that are in a continuous beam or a pulsed beam depending on whether the stimulation is continuous or intermittent.<br />A few examples of solid lasing material are neodymium, ruby, and titanium sapphire.<br />Gas State Lasers:<br />In a Gas State Laser, the lasing material is in a gaseous state.<br />The two most common gases used to create gas lasers are Helium and Helium-neon.<br />Gas Lasers are typically red in color.<br />
  10. 10. Types of Lasers<br />ExcimerLasers:<br />This type of laser is made by employing gases to create the laser.<br />Reactive gases are combined with inert gases, resulting in the release of a simulated molecule known as dimer.<br />The dimer produces ultraviolet lasers upon lasing.<br />Because of this, the term Excimer comes from excited dimer.<br />Some examples of gases used are chlorine and fluorine (Reactive), and argon, xenon, and krypton (Inert)<br />Semi-conductor Lasers:<br />These lasers are not solid state lasers, also known as diode lasers.<br />Because a semi-conductor laser is not very powerful on its own, it is usually used in conjunction with other lasers.<br />
  11. 11. Special Properties of Lasers<br />Color of the Laser Light<br />The kind of light we all see on a daily basis are forms of white light.<br />Sunlight, light from a light bulb, etc. are all forms of white light, but not just white.<br />Laser light is not the same however, it is only one solid color.<br />This means that laser light is monochromatic and not polychromatic. <br />Invisible Laser Light<br />There are lasers such as ultraviolet and infrared that give off light not visible to the naked eye.<br />Invisible laser lights are used predominantly for protective security and alarm systems.<br />
  12. 12. Special Properties of Lasers<br />Organizational Properties<br />The photons of light other than laser light are unorganized and random.<br />The photons of laser light, however, are very organized and consistent.<br />The photons of both laser light and non laser light travel together at the same speed and in perfect alignment.<br />Focus of Laser Light<br />Because laser work on the principle of stimulated emissions of photons, , the light itself becomes very focused and intense. <br />The photons are released through their environment through very small openings, allowing the light to be focused and directed effectivly.<br />
  13. 13. Lasers in the Medical World<br />Laser Eye Surgery<br />Lasers have been shown to be effective for treating such things as far sightedness and cataracts.<br />Because of the minute and direct laser beam used, it can easily and safely correct the damaged tissue while leaving the surrounding tissue in good shape.<br /> Laser Ulcer Removal<br />Lasers have proven very useful when removing stomach ulcers.<br />The laser beam is used to make a tiny incision in order to reach the ulcer, and because the ulcer burns the incision, the cut clots and seals immediately.<br />Because of this, blood lose is minimal and healing time is also faster.<br />
  14. 14. Lasers in the Medical World<br />
  15. 15. Lasers and Electronics<br />Compact Disc Players<br />Compact discs are used to store things such as music, and are played using a CD player.<br />It is a laser that enables you to hear the music stored on the CD<br />All CD’s have tiny lasers, which reads the digital codes and information and translates it into music.<br />Supermarket Scanners<br />Supermarkets scanners are nothing more then laser scanning devices.<br />These lasers read the information on the bar code.<br />The information from the bar code is then processed through the computer data base.<br />
  16. 16. Lasers and Electronics<br />
  17. 17. Bibliography<br />http://www.howstuffworks.com/laser.htm<br />http://en.wikipedia.org/wiki/Laser<br />http://hyperphysics.phy-astr.gsu.edu/Hbase/optmod/lasapp.html<br />http://en.wikipedia.org/wiki/Maser<br />http://focus.aps.org/files/focus/v15/st4/pic-v15-st4-1.jpg<br />http://www.youtube.com/watch?v=48WkYbkhJO4<br />