STIMULATED EMISSION Meaning and
Definition
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Stimulated emission is a phenomenon in physics that occurs when an atom or molecule in an excited state interacts with an external electromagnetic field. It is a process by which an atom or molecule transitions from a higher energy state to a lower energy state by emitting a photon of the same frequency and phase as the incident electromagnetic field.
In stimulated emission, the presence of the external radiation field induces the excited particle to emit a photon that matches its energy state. This emission is stimulated by the incident photon, which provides additional energy to the system, hence the name "stimulated" emission. The emitted photon has the same energy, frequency, and direction as the stimulating photon.
Stimulated emission is a key process in the operation of lasers and other light amplification devices. It is responsible for the amplification and coherent emission of light in these systems. By introducing a population inversion, where there are more particles in an excited state than in a lower energy state, and by stimulating the emission of photons, the output of a laser can be significantly increased, resulting in intense and coherent light output.
The concept of stimulated emission was first proposed by Albert Einstein in 1917, as part of his theoretical work on the nature of light and the quantum theory of radiation. His work laid the foundation for the development of laser technology, which relies on the principles of stimulated emission for its operation.
Etymology of STIMULATED EMISSION
The word "stimulated emission" is a scientific term used in the field of physics, particularly in quantum mechanics and the theory of lasers. The etymology of this word can be analyzed as follows:
1. Stimulated: The term "stimulate" comes from the Latin word "stimulare", meaning "to goad, rouse, or incite". It refers to the process of exciting or encouraging something to happen.
2. Emission: The term "emission" comes from the Latin word "emissio", meaning "a sending out". It generally refers to the act of releasing or producing something, often in the form of energy or particles.
When combined, "stimulated emission" refers to the phenomenon where the emission of radiant energy, such as light, is triggered or encouraged by an external source of energy or a similar particle.
