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ppt on Laser:Brief study
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Laser ppt.

  1. 1. PRESENTED BY: shivam pandey LASERS
  2. 2. LL Light AA Amplification by SS Stimulated EE Emission of RR Radiation
  3. 3. A laser is a device thatA laser is a device that transforms light of varioustransforms light of various frequencies into a chromaticfrequencies into a chromatic radiation in the visible, infrared,radiation in the visible, infrared, and ultraviolet regions with alland ultraviolet regions with all the waves in phase capable ofthe waves in phase capable of mobilizing immense heat andmobilizing immense heat and power when focused at closepower when focused at close range.range. WHAT IS A LASER ?
  4. 4. CHARACTERISTICS OF LASER  COHERENCE  HIGH INTENSITY  HIGH DIRECTIONALITY  HIGH MONOCHROMATICITY
  5. 5. 1 COHERENCE : The wave trains which are identical in phase and direction are called coherent waves. 2 HigH iNtENsity : Due to the coherent nature of laser, it has the ability to focus over a small area of 10­ 3 HigH diRECtiONality : The angular spread of a laser beam 1mm/meter.
  6. 6. 4 HigH mONOCHROmatiCity : The light from a normal monochromaticity source spread over a range of wavelength of the order 100nm.but, the spread is of the order of 1nm for laser.
  7. 7. stimulatEd aNd spONtaNEOus  Stimulated  It is not a random process.  The photon get multiplied through chain reaction.  t is a controllable process.  More intense.  Monochromatic radiation.  Spontaneous  It is random process.  The photon do not get multiplied through chain reaction.  It is a not controllable process.  Less intense.  Polychromatic radiation.
  8. 8. 9 LASER
  9. 9. Nd: yag lasER
  10. 10. CONSTRUCTION :  Nd yag rod and krypton flash lamp are enclosed inside in ellipsoidal reflector.  In order to make the entire flash radiation to focus on the laser rod.  The nd yag rod is placed t one focal axis and the flash lamp at the other focal axis of the ellipsoidal reflector.
  11. 11. Energy level Diagram E0 Non-radiative transition Ground State Metastable state E2 E3 E1 E4 1.064 µm 0.73µm 0.80µm laser Non-radiative transition
  12. 12. wORkINg  The flash lamp switched on.  The optical pumping excites the ions from the ground energy state E0 to the higher energy level E3 and E4 by absorbing radiation .80µm and .73µm,respectively.  The energy level E4 to E2 is the non radiative transition.  The E2 state is meta stable state.  Any of the spontaneously emitted photon will make the excited ion to undergo a transition between E2 E1 state.
  13. 13.  The transitions E2 E1 yields an intense and coherent laser beam of wavelength 1.064µm.  These laser give beam continuously.  The ions then make a transition between E1 E0.  The flash lamp is used to excite the ions, while the rest heats up the crystal.  Thus, the system can be cooled by either air or water circulation.
  14. 14. APPLICATION OF LASER A) IN INdUSTRy : 1) For welding and melting. 2) For cutting and drilling holes. 3) To test the quality of the material. B) IN mEdICINE : 1) Used for treatment of detached retinas. 2) Used in performing micro and bloodless surgery
  15. 15. C) Military appliCations : 1) The laser beam can serve as war weapon, i.e. A power full laser beam can be used to destroy in few second, the big size object like aeroplanes, missiles etc. D) sCienCe anD engineering appliCation : 1)Fiber optic communication. 2)It is used to holography. 3)Communication between planets is possible with laser.
  16. 16. 4) It is used to accelerate some chemical reaction. 5) It is used to drill minute holes in cell walls without damaging the cell itself.
  17. 17. Laser Output Continuous Output (CW) Pulsed Output (P)                         watt (W) - Unit of power or radiant flux (1 watt = 1 joule per second). Joule (J) - A unit of energy  Energy (Q) The capacity for doing work. Energy content is commonly used to characterize the output  from pulsed lasers and is generally expressed in Joules (J). Irradiance (E) - Power per unit area, expressed in watts per square centimeter. Energy(Watts) Time Energy(Joules) Time
  18. 18. Common Laser Signs and Labels
  19. 19. Thank you

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