how laser work
DESCRIPTION
This will explain the basic principles of laser. This will help the students in GCE A/L studentsTRANSCRIPT
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LASER
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LASER• Light • Amplification by • Stimulated • Emission of • Radiation
• Proposed by Einstein in 1917
• First LASER was built in 1960
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Excite / Stimulate
e e
hf
eE2
E1
E2
E1
E2
E1
1 2 3
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Population Inversion(Excite / Stimulate (More))
e
eE2
E1
E2
E1
E2
E1
Hf = E2-E1
e e e
e e ehfhfhfhf
ee e e
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Spontaneous Emission(A random process)
hf
e e e e
hf
E2
E1
E2
E1
hf = E2-E1
ehf
A Random Process
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Stimulated Emission
hf
LASER
E2
E1
hf = E2-E1
hf
hf
hf
e e
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e e e e
e e e e
Three State Laser System
hf
hf
hf
hf
e e e e
E3
E2
E1
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hf
LASER
E2
E1hf = E2-E1
hf
hf
hf
e e
E3
Three State Laser System (Contd..)
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Ruby Laser
Visual
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He-Ne Laser
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Virtual Keyboard
LASER Applications
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Laser Printer
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Laser Treatment for Skin