laser Archives - Page 2 of 2

I start this topic with the concept of absorption and emission first of all where one uses the Atomic Excitation or Electronic Excitation. What do you think when a photon strike on the electron? Does this result give of transfer of electron in a higher energy state that is represented by either electronic transition (ET) or the atomic transition (AT)? No doubt, which one is correct (ET or AT)? Yes, both are true. Now, in reference to the atomic process perspective, there are two different states, one is ground and the second is the excited state. These states are a reflection of existed electrons, orientation in different states which are filled according to the Pauli exclusion rule, distributed in orbitals through Hands and Aufbau rules and principles, respectively. Any change, in electronic configuration, means a change in atomic states, here the ground state means electrons are in defined states and distributed as per the above-mentioned rules. When an electron absorbs the energy and goes into the higher state electronic configuration changes that you can see and this transition of an electron from a lower state to the higher state is known as electronic transition. On the other hand, the same process in the atom perspective is represented by the excited state of the atom (jumps of the electron in the higher state). So both electronic and atomic transitions are a compliment to each other. In last, the atomic transition represents the change in the states of the atom i.e., from the ground state to the excited state and then after the ground state. In real, electrons absorb/emits the energy and stay in a particular state of the atom (not a solid quantity, as per the Bohr’s and Somerfield’s atomic model, electron revolves around the nucleus with definite energy) for the defined time that is known as the lifetime of the atomic state. Hence ground and excited states of the atom are the results of electronic distributions in various states of the atom. Whether you use atomic transition or electronic transitions the concept behind it should be clear and both are true for LASER explanation.