1. LASER PRINCIPLES
Dr. Prathyusha PG ENT
Narayana Medical College, Nellore

2. DEFINITION
It is an intense beam of coherent
monochromatic light (or other
electromagnetic radiation) by stimulated
emission of photons from excited atoms or
molecules
light amplification by stimulated emission of
radiation.
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3. CONFUSION????!!!!!!

4. BEFORE WE GO DEEPEEER

7. KNOW THESE TERMS…..
• Absorption
• Emission
• Population inversion
• Stimulated emission

8. ABSORPTION AND
EMISSION

9. VIDEO

11. DIFFERENCE BETWEEN
SPONTANEOUS AND STIMULATED
EMISSIONS
Spontaneous emission Stimulated emission
Spontaneous process and
automatically produced
Induced by external radiation
No need of population inversion Requires population inversion
Photons produced are of different
energy levels hence incoherent
Same energy levels hence coherent
Photons emitted travel randomly in
any direction
Travels in the same direction as the
incident photon

12. SPECTRUM OF
ELECTROMAGNETIC RADIATION

14. CHARACTERISTICS OF
LASER

15. EFFECT OF LASER BEAM ON THE
TISSUES

16. ZONES OF TISSUE
DESTRUCTION

17. EFFECTS OF LASER
• Photo thermal
• Photo acoustic
• Photochemical
• Photodissociation

18. INVISIBLE LASERS
• UV zone
• Infrared
• Micro infrared

19. VISIBLE LASERS
• Different colours
• Argon blue
• KTP laser blue-green color

21. OPERATIONAL PARAMETERS
• Wave length of the laser
• Power
• Exposure time
• Spot size
• Power density

22. MODES OF DELIVERY
• Continous mode
• Pulsed mode
• Q switched mode

23. DISADVANTAGES OF LASER
• High cost
• Special training
• Hazards
• Special anaesthesia

24. THANK YOU