2. LASER
LASER is an acronym for ,
Light Amplification by Stimulated
Emission of Radiation
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3. History of LASER
In 1917, Albert Einstein first theorized the
possibility of Lasers.
The first working laser was created by
Theodore Maiman on May 16th, 1960 at the
Hughes Research Laboratory in California.
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4. Spontaneous Emission
Excited atoms normally drop to Lower
Energy Level Spontaneously
Photons are uncorrelated and unidentical
Incoherent light
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5. Stimulated Emission
Excited atoms
are forced to
emit by another
matching
photon
Photons are
correlated and
identical
Coherent light
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6. Principle of Laser
Population Inversion.
The phenomenon of exciting the atoms, so
that, there are more number of atoms in the
Higher Energy Level than in the Lower
Energy Level
Optical Pumping
The method of achieving Population
Inversion is known as Pumping. And, one
of the types of pumping in known as
Optical Pumping. 6
7. Lasing Action Diagram
Excited State
Spontaneous
Energy
Emission
Metastable State
Optical
Pumping Stimulated
Emission of
Radiation
Ground State
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9. Properties of Laser
Laser light is highly monochromatic.
Laser light is extremely directional.
Laser light is spatially coherent.
Laser light is extremely intense and bright.
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10. Applications of Lasers
Laser are used,
In optical communication.
In guiding missiles to desired destinations.
To scan information on bar codes.
To make holograms.
In making Integrated Circuits.
In CD players
In surgery.
In industries to cut and weld strong metals.
To measure distances very accurately.
To store and view 3D informations. 10
