-: Pumping Process :-
The process of supplying energy to the medium to transfer it into the state of population inversion is known as Pumping Process .
or
The process in which atoms in the ground state get exited to the exited state with the help of external energy is known as pumping process . Through pumping process the condition of population inversion is achieved.
There are different types of pumping process -
1- Optical Pumping
2- Electrical Pumping
3- Elastic Collision Pumping
1- Optical Pumping :- In this process atoms of the material are exposed by light and atoms absorbs particular wavelength of photon resulting atom get exited . Ruby ( Al2O3 ) laser based on optical pumping .
2- Electrical Pumping :- In this type of pumping electron energized by electric field these energetic electrons collide with the atoms and transfer energy to atoms , resulting atoms get exited .
3- Elastic Collision Pumping :- In this type of pumping one species of atom collide with another species of atom in collision energy transfer take place one atom achieve metastable state and other atom decay to the ground state . He- Ne laser based on this type of pumping .
-: Population Inversion :-
It is the state in which number of atoms in exited state are extremely larger than the atom in ground state .
-: Necessary Conditions of Laser :-
or
Necessary Condition to Achieve Laser Action
1- There must be population inversion i.e. the number of atoms in higher energy state must be greater than that in lower energy state so that the rate of emission become greater than the rate of absorption .
2- The excited states must be metastable state . The states whose lifetime may be 10^-(03) second or more instead of the usual 10^-(08) second are called metastable state .
3- In the end of the laser there are two reflecting mirrors one is fully reflector and other is partly reflector . These mirrors constitute laser cavity . The distance between the reflecting mirrors is integral multiple of n𝝀/2 .
The process of supplying energy to the medium to transfer it into the state of population inversion is known as Pumping Process .
or
The process in which atoms in the ground state get exited to the exited state with the help of external energy is known as pumping process . Through pumping process the condition of population inversion is achieved.
There are different types of pumping process -
1- Optical Pumping
2- Electrical Pumping
3- Elastic Collision Pumping
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1- Optical Pumping :- In this process atoms of the material are exposed by light and atoms absorbs particular wavelength of photon resulting atom get exited . Ruby ( Al2O3 ) laser based on optical pumping .
2- Electrical Pumping :- In this type of pumping electron energized by electric field these energetic electrons collide with the atoms and transfer energy to atoms , resulting atoms get exited .
3- Elastic Collision Pumping :- In this type of pumping one species of atom collide with another species of atom in collision energy transfer take place one atom achieve metastable state and other atom decay to the ground state . He- Ne laser based on this type of pumping .
-: Population Inversion :-
It is the state in which number of atoms in exited state are extremely larger than the atom in ground state .
-: Necessary Conditions of Laser :-
or
Necessary Condition to Achieve Laser Action
1- There must be population inversion i.e. the number of atoms in higher energy state must be greater than that in lower energy state so that the rate of emission become greater than the rate of absorption .
2- The excited states must be metastable state . The states whose lifetime may be 10^-(03) second or more instead of the usual 10^-(08) second are called metastable state .
3- In the end of the laser there are two reflecting mirrors one is fully reflector and other is partly reflector . These mirrors constitute laser cavity . The distance between the reflecting mirrors is integral multiple of n𝝀/2 .
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