Is light amplification possible without stimulated emission?
Errorless Physics NEET/AIIMS Yes and no. It depends on what you mean. If you’re being very strict with the definition, then the name “laser” or “Light Amplification by Stimulated Emission of Radiation” precludes laser light coming from any other source.
Is light amplification by stimulated emission of radiation?
Light Amplification by Stimulated Emission of Radiation (laser) is a coherent, convergent, and monochromatic beam of electromagnetic radiation. Various laser sources have been applied in LAM to preheat the workpiece including CO2 lasers, solid state lasers, and excimer lasers. The excimer laser is a gas laser.
Why do we need stimulated emission for light amplification?
Stimulated emission can provide a physical mechanism for optical amplification. If an external source of energy stimulates more than 50\% of the atoms in the ground state to transition into the excited state, then what is called a population inversion is created.
What are conditions for light amplification?
In order to make N1 and N2 constant, number of upward transition must be equal to number of downward transitions. From equation (1) and (2) it is observed that to achieve stimulated emission exclusively, radiation density should be high and N2>N1. That means more atoms should be present in higher energy state.
Which of the following is responsible for amplification of light in laser?
Light Amplification by Stimulated Emission of Radiations
Explanation: LASER is a short form of Light Amplification by Stimulated Emission of Radiations. Stimulated Emission is the process by which amplification of radiations takes place. Hence the meaning of LASER that the light is amplified by stimulating the emission of radiations.
What is amplification in physics?
Amplification means increasing the amplitude (voltage or current) of a time-varying signal by a given factor, as shown here. The graph shows the input (blue) and output voltage (red) of an ideal linear amplifier with an arbitrary signal applied as input.
What is meant by stimulated emission of radiation?
Stimulated emission of radiation: When an electron is in a different energy level of the fundamental level and returns to the ground state through an incident photon, a new photon is generated with exactly the same frequency, direction and phase to the incident photon.
What is stimulated emission of radiation is necessary for the laser production?
In laser action the stimulating emission triggers a chain reaction in which the radiation from one atom stimulates another in succession until all the excited atoms in the system have returned to normalcy. In doing so, coherent monochromatic light (light of a single wavelength) is emitted.
What is amplification in laser?
Light amplification is the process of intensifying the amplitude of an electromagnetic light wave. Laser amplification is associated with the linear polarization which occurs due to first-order atomic susceptibility in an optical medium.
How light amplification occurs in lasers?
In other words, the two photons are coherent. Some of these photons are absorbed by the atoms in the ground state and the photons are lost to the laser process. However, some photons cause stimulated emission in excited-state atoms, releasing another coherent photon. In effect, this results in optical amplification.
What is amplification of light?
What are the applications of laser light amplification?
Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years.
What is electromagnetic radiation?
Electromagnetic radiation electromagnetic radiation, energy radiated in the form of a wave as a result of the motion of electric charges. A moving charge gives rise to a magnetic field, and if the motion is changing (accelerated), then the magnetic field varies and in turn produces an electric field. …..
How does laser light differ from ordinary light?
The coherent light produced by a laser differs from ordinary light in that it is made up of waves all of the same wavelength and all in phase (i.e., in step with each other); ordinary light contains many different wavelengths and phase relations. Both the laser and the maser find theoretical basis for their operation in the quantum theory.
What happens when a photon hits an excited atom?
If a photon whose frequency corresponds to the energy difference between the excited state and the ground state strikes an excited atom, the atom is stimulated to emit a second photon of the same frequency, in phase with and in the same direction as the bombarding photon.