In a 3-level laser, more than half of the population of ground level must be excited to the higher energy state to achieve population inversion. So, it will require very high pumping. So efficiency will be low. Also it is very difficult to maintain the population inversion in 3 - level lasers. So, it can not operate in continuous mode. It will operate only in pulse mode. In comparison with four level laser, it is less efficient. The power out put of the pulse may be high but it can not be obtained continuously and a large input power is required for pumping.
In this discussion ground state of an atom is considered to be E1. When electrons are excited from one shell to the other, energy of atom as a whole will change to E2, E3 and so on.. Depending on which electrons are making transition from a particular shell to a particular shell, atom will be in a energy level E2, or E3 or E4 ...
Atoms of all elements do not have a metastable state. It can not be created artificially. If it exists naturally, it can be utilised. Whether it exist or not, that can be found by series of experiments..
Sir ! What are the advantage of a three level population system?
In a 3-level laser, more than half of the population of ground level must be excited to the higher energy state to achieve population inversion. So, it will require very high pumping. So efficiency will be low. Also it is very difficult to maintain the population inversion in 3 - level lasers. So, it can not operate in continuous mode. It will operate only in pulse mode. In comparison with four level laser, it is less efficient.
The power out put of the pulse may be high but it can not be obtained continuously and a large input power is required for pumping.
hi please how do we foun the evoultion equation of each state in this ?
If in a atom electrons r excited from k shell to L shell when they return to K shell releasing a photon then where is the E2 shell in between ??
In this discussion ground state of an atom is considered to be E1. When electrons are excited from one shell to the other, energy of atom as a whole will change to E2, E3 and so on.. Depending on which electrons are making transition from a particular shell to a particular shell, atom will be in a energy level E2, or E3 or E4 ...
@@EngineeringPhysicsbySanjiv does evry atom have metastable state or only some ?? & r they constructed or its already present ??
Atoms of all elements do not have a metastable state. It can not be created artificially. If it exists naturally, it can be utilised. Whether it exist or not, that can be found by series of experiments..
what is the use of this, sir? do we even require 3 level laser system when we can directly have 2???
That’s e really helpful video. Thank you alottt❤❤❤❤😊
Shi bta diya aap nai , aacha kam hai aap ka 😊
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Nice video
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Thankyou sir !
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Tq sir
You are welcome..
Tq sir.
You are welcome.. keep watching..
Thank You Sir
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