laser.... Light amplification by stimulated emission of radiation... is a device which is produced the highly coherent and monochromatic beam of light. In this power point i upload the basic introduction of laser, in which i discuss three radiation process on which laser light work, also discuss the basic principle of laser light and properties of laser.

1. 27 February 2019 asghar.jarwar@gmail.com

2. Definition:-
A kind of device that produced the
highly directional, coherent and monochromatic
light beam is called a Laser.
 LASER STAND FOR:-
L LIGHT
A AMPLIFICATION
S STIMULATED
E EMISSION
R RADIATION
LIGHT AMPLIFICATION BY STIMULATED EMISSION OF
RADIATION
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3. THREE RADIATION PROCESS OF LASER LIGHT
PROCESS BEFORE AFTER
INDUCED ABSORPTION
(Stimulated)
E2
e
hf E1
e E2
E1
No emission
SPONTANEOUS
EMISSION
10^-8 sec E2
E1
No incident of Photon
E1
hf
E2
STIMULATED
EMISSION
e E2
hf
E1
E2
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4.  THE LASER PRINCIPLE:-
The Laser principle are given
below, on which this device is work.
 ABSORPTION
 SPONTANEOUS EMISSION
 STIMULATED EMISSION
 PROPERTIES OF LASER:-
 Monochromatic Light Source
 Coherence
 Collimated ( parallel rays of Light )
27 February 2019 asghar.jarwar@gmail.com

5. OPERATION OF LASER:-
 METASTABLE STATE
The energy state of an electron on
which the electron is present ,having much longer life time than
10^-8 sec is called metastable state .
POPULATION INVERSION
To increases the number of electrons
STIMULATED EMISSION
 AMPLIFICATION Using Mirrors
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6. 10^-8 sec
E3
hf
10^-3 sec
E2
hf
electron E1
hf
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7.  The first successful operation of ruby laser was achieved by
T.H Maiman in the year 1960.
 RUBY is a crystal (highly arranged atoms in well define patterns are called crystals) of
aluminum oxide.
Al2O3
In which small numbers of aluminum atoms are replaced by
chromium atoms, that have lost three electrons.
Al2O3 : Cr +3
Q. Why we added the chromium atoms in ruby crystal????
Ans: Because chromium atoms absorbs green and yellow light
but emit red and blue light.
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8.  Ruby Laser Rod ( 5 cm long ) ( Filled with Xenon gas )
 Helical flash lamp ( Provides the pumping yellow and green light )
 High voltage supplier
 Two concave mirrors (fully reflected and partially reflected)
 Key
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9. Fully reflected
mirror M1
Partially
reflected
mirror M2
Colorless
gas
Output
power is
20 kW
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11. Uses of Ruby Laser
1. Range finding
2. Welding
3. Drilling
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12.  Different types of laser are used according to wavelength and power level which range from mile
watts to MW.
1. Solid Laser:-
it is made from crystals, eg Ruby laser, semiconductor laser (size of a pin head ) ( they are used in
optical fiber communication system )
2. Liquid Laser :-
It is made from alcohol or methanol operated at room temperatrue
3. Gas Laser:-
Helium, neon and carbon di- oxide gas lasers are widely used
Used in printing and holography ( 3D image in Space ) also used in an accurate measurement of
length
Laser also used for medicine and surgery purposes
Industry
Computer (Laser printer )
Communications
Space (range )
Environment ( Pollutants detector )
LASER is also know as MASER (Mico-wave amplification)
27 February 2019 asghar.jarwar@gmail.com