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Laser & it's applications

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Laser & Its Application
Laser & Its Application
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Laser & it's applications

  1. 1. Guiding Light Laser Technology…  Introduction  History of the Laser  Types of Laser  How the Laser works  Applications of the Laser Technology  Military  Medical  Industrial  Entertainment  Holography  Reference
  2. 2. Introduction In the Beginning There Was Light Industrial Cutting Tools CD & DVD Players Dental Drills Lasik eye Surgery Tattoo Removal Surgical Cutting Tool Printers
  3. 3.  The laser was developed about fifty years ago.  Arthur Schawlow and Charles Townes could have had no possible way of knowing the profound effects.  Most people don’t recognize that laser technology is already present as an integral part of our daily lives, allowing us to listen to CD’s, watch DVD’s, and play computer games.  Additionally, lasers are becoming increasingly visible in medicine in ophthalmologic, cosmetic, and general surgery.  This presentation focuses on giving the viewer better insight to the impacts this technology has had on society as a whole as well as an understanding of the functions lasers play in our daily lives. Introduction
  4. 4. Flashes of Brilliance “A splendid light has dawned on me.” – Albert Einstein In 1917 Einstein published ideas on stimulated emission of radiation. These ideas laid the basic foundation for the invention of the laser years later.  While investigating what is now known as the photo- electric effect, Einstein noted a statistical tendency which caused photons (particles of light), to want to move together.  Einstein was also able to prove that these emitted photons all traveled in the same direction and with the same frequency as the original photon.
  5. 5. Arthur L. Schawlow Charles H. Townes The laser is credited as being invented in 1958 by Charles H.Townes & Arthur L.Schawlow. Townes coined the term “laser” with help from his students. The main differentiating factor between the two devices is that the laser uses light waves as opposed to the microwaves utilized by the maser.  Laser = Einstein’ Theories + Right Type of Atoms + Reflecting Mirrors Flashes of Brilliance
  6. 6. Types of Laser Outputs  Continuous-Wave (CW) Continuous with respect to time. Higher level must be long-lived relative to lower level, else the laser is self- terminating.  Pulsed (not continuous) Higher peak powers (kW to > MW). Nanosecond pulse widths are typical  Q-Switched “Giant pulse laser” Spoil the cavity resonance so that the lasing threshold is greatly exceeded. Then let it out all at once. Hundreds of MW/pulse achieved.  Mode-Locked Picosecond or less laser pulses. Force all longitudinal modes to be coherent. Generates short (ps or less) and intense (MW) pulses.
  7. 7. Common Laser System
  8. 8. LASERS Semiconductor Solid state Liquid Gas LasersDiode Laser Solid state Liquid Neodymium Yag Laser Ruby laser Gaseous Varieties of Lasers
  9. 9. Courtesy of Los Alamos National Laboratory Rear Mirror Adjustment Knobs Safety Shutter Polarizer Assembly (optional) Coolant Beam Tube Adjustment Knob Output Mirror Beam Beam Tube Q-switch (optional) Nd:YAG Laser Rod Flashlamps Pump Cavity Laser Cavity Medium ~ Neodymium-Doped Yttrium Aluminum Garnet Crystal State ~ Solid Excitation Beam ~ Diode Laser 1064 nm infrared Uses ~ Cataract ,Glaucoma , Gingivectomy surgeries Neodymium YAG Laser
  10. 10. QD Lasers Optics Datacomnetwork Telecomnetwork High speed QDL Advantages • Directly Modulated Quantum Dot Lasers • Data com application • Rate of 10Gb/s • Mode-Locked Quantum Dot Lasers • Short optical pulses • Narrow spectral width • Broad gain spectrum • Very low α factor-low chirp • InP Based Quantum Dot Lasers • Low emission wavelength • Wide temperature range • Used for data transmission Quantum Dot Laser
  11. 11. Varieties of Lasers Laser type Wavelengths (nm) Power Output Helium–neon 633,1152 0.1–50 mW CW Argon–ion 351–529 several 5 mW–25 W CW Helium–cadmium 325-442 1–50 mW CW Dye (Ar pump) 400–1000 5 W CW, tunable Yd:YAG 1064 0.1–500 W Pulsed Nd:YAG 1064 0.5–1000 W CW CO2 10600 1–100 W CW GaAlAs 750–900 1–100 mW CW InGaAsP 1100–1600 1–100 mW CW Ti:sapphire 700–1100 0.1–1 W CW, tunable
  12. 12. Gamma Rays X-Rays Ultra- Visible violet Infrared Micro- waves Radar waves TV waves Radio waves 10-13 10-12 10-11 10-10 10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 1021 10 Wavelength (m) LASERS Far Infrared 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 10600 Wavelength (nm) ArF 193 XeCl 308 HeNe 633 2 Ruby 694 Alexandrite CO2 10600 Communication Diode 1550KrF 248 Ar 488/515 GaAs 905 Nd:YAG 1064Nd:YAG 532 755 Ultraviolet Retinal Hazard Region Far InfrarVisible Near Infrared Electromagnetic Spectrum
  13. 13. Shedding Some Light… How the Laser Works Flash Tube Partially Reflective Mirror Mirrored Surface Atoms become excited The flash tube fires light at the ruby rod. The light excites the atoms. Emitted Light Some of these atoms emit photons.
  14. 14.  Monochromatic, single-phase, calumniated light leaves the ruby through the half-silvered mirror ~ laser light!  Some of these photons run in a direction parallel to the ruby's axis.  So, they bounce back and forth off the mirrors. As they pass through the crystal, they stimulate emission in other atoms. Shedding Some Light… How the Laser Works
  15. 15. Applications of Laser The Weighty Implications of Laser Technology Applications of Laser Technology  Medical  Optical & General surgery  Tattoo removal  Military  Weapons  Radar  Entertainment  CD & DVD Players  Video Game system  Telecommunications  Holograms  Satellites  Computer Mouse  Industries  Metal cutting  Welding
  16. 16.  However, laser technology has also helped advance the U.S. military by offering new possibilities in warfare, such as: Non-Lethal Weapons Lasers & Military Ominous lights
  17. 17.  The Reagan Star-Wars era program did much to initially support laser weapons research, resulting in many of today’s military advancements.  Optical Guidance, Night Vision & Thermal homing missiles  Lasers are used to drive fusion machines fueling thermonuclear explosions and used in most nuclear devices.  The most potent and deadly application of laser technology is the Space Based Laser.  As tensions over the growing arsenals of nations grow, arms agreements have done little to slow down the development of these technologies. Lasers & Military Ominous lights
  18. 18.  High-intensity lasers can be used in Omni-directional bombs or flares which can flash-blind personnel as well as degrade sensors and night vision devices.  Low energy lasers can be directed or aimed at specific targets to blind personnel or sensors either temporarily or permanently. The most advanced blinding lasers oscillate between numerous colors to make goggles and other countermeasure ineffective.  Lasers can also be used to make a gun or other weapon too hot to hold. Lasers & Military Ominous lights THERMAL IMAGING
  19. 19.  Although military applications of Laser Technology have such potentially devastating implications for humanity.  Without the national security that these weapons provide, our country would be vulnerable to outside attack.  However, it is up to us to decide whether our vision for the future is the endless quest for military superiority, or whether our ultimate goal is peace on earth. Lasers & Military Ominous lights
  20. 20.  Advantages for the Laser as a Medical Cutting Tool  The laser is extremely precise, and can be tuned to work on a micro-level, barely visible to the human eye.  Reduces pain & trauma for the patient.  Lasers can be inserted inside the body with little risk or discomfort.  Certain conditions which were once inoperable due to the accuracy of incisions necessary are now possible.  Incisions can be guided by computers.  Speeds healing – thereby shortening costly hospital stays.  compact lasers can be inserted inside the body with little risk or discomfort, going places and performing surgeries that were not humanly possible before. Lasers & Medicine Going where no man has gone before
  21. 21. Lasers & Medicine Going where no man has gone before  Advantages for the Laser as a Medical Cutting Tool  The precision and accuracy with which lasers can cut is so exact that it would be impossible for a human to recreate. Pictured on the right is a human hair treated by an excimaer laser- the cuts are so tiny that they would not be visible to the human eye! The excimaer laser is typically used to perform Lasik eye surgery.  The laser as a cutting tool also has considerable industrial implications.  Lasers guided by computers can eliminate human error in surgery.
  22. 22. Lasers & Medicine Going where no man has gone before  Laser Technology’s Contribution to Ophthalmology  Advances in laser technology have made substantial improvements in the field of ophthalmology.  Prior to these advances the solutions for those genetically pre-disposed to bad eyesight were limited:  Glasses ~ which are bulky and often carry social stigma  Contacts – which often leave eyes susceptible to infection, require daily cleaning, and cannot be worn comfortably overnight or for extended periods of time
  23. 23. What is Laser Surgery ?  The goal in laser eye surgery is to reshape the cornea, changing the focal point of the eye. Ideally the focal point is changed so it focuses perfectly on the retina. Lasers & Medicine Going where no man has gone before If you are nearsighted, the image comes into focus before it hits your retina. If you are farsighted, the image doesn’t come into focus before it hits your retina. In a good eye the image is focused on the retina.
  24. 24. After applying anesthetizing drops, the surgeon marks the eye to indicate where the flap will be cut and then replaced. A suction ring holds the eye still and pressurizes it so it is firm enough to cut. The microkeratome slices a tiny flap in the cornea. The flap is moved out of the way, but it is still attached. The laser removes tissue to reshape the cornea. The flap is replaced on the eye. Lasers & Medicine Going where no man has gone before How does Laser Surgery Works ?
  25. 25. Lasers & Industry Something Heavy  Lasers are used now for cutting, drilling and welding of metals and other materials.  LIDAR - Light Detection & Ranging (Mines)  Laser light is used to collect the information about the prefixed prices of various products in shops and business establishments from the bar- code printed on the product.
  26. 26.  One of the most popular applications of laser technology, the Compact Disc Player, marked a revolution in digital video and sound technology. Lasers & Entertainment The Bright Side & The Dark Side
  27. 27.  The CD Player works by using a laser beam to determine the lengths of a series of tiny ridges inside a compact disk.  The music is digitally encoded in the ridge lengths which are measured by the reflected laser. Lasers & Entertainment The Bright Side & The Dark Side How does CD Player Works ? Inside a CD or DVD Player
  28. 28. Lasers & Holography Production of Holo things  Possible medical applications using the technology  Surgical procedures (using tracking capabilities)  Rehabilitation techniques & Gaming  Holography is the production of holograms by the use of laser.
  29. 29. Lasers & Safety eyewear Be careful
  30. 30. Reference  How Stuff Works (howstuffworks.com)  Wikipedia (wikipedia.org)  Principle of Physics (Book by Dr. Serway)

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