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A coherent state is a monochromatic sinusoidal field. The electric field pulse is inherently not monochromatic, but instead has a spectrum of frequencies which are superimposed on top of one another so as to all add constructively once every pulse repetition time. Therefore, to represent the field pulse in quantum optics you actually need to bring in more ...


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If the wall is made of a perfectly reflective material (such as a mirror) no, you won't see the dot. However, most walls are covered with paint or made of a diffusive material : when the laser beam hits the wall, its light gets diffused in all directions. Thus you are able to see the laser spot on the wall. To summarize : reflection depends on the ...


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A coherent state is actually a mathematical idealization of a monochromatic laser. Strictly speaking, any continuous wave laser in the laboratory would be a statistical mixture of phase-randomized coherent states. Furthermore, it would also have a finite linewidth, and different frequency components in that linewidth would have no definite phase relationship ...


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A properly collimated laser beam is called a Gaussian Beam whose transverse magnetic and electric field amplitude profiles are given by the Gaussian function. The Gaussian beam is a transverse electromagnetic (TEM) mode. The mathematical expression for the electric field amplitude is a solution to the paraxial Helmholtz equation: The width of such laser ...


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Just as Jon Custer wrote in his comment, even a perfectly collimated laser beam with a planar wavefront will diverge. The way it happens is determined by the Huygens principle, and depends on the beam profile: When the light intensity is abruptly cut by a sharp flat obstacle, the light will indeed diffract in almost all angles. A razor blade cutting a laser ...


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It's depend what you call "visible" and "invisible" and "air". :-) In air with a little bit of mist, one laser could just be dim, while the crossing superimposition of several could make the added value more visible in the intersecting region: this is a question of contrast rather than on-off. Also, there exist a technology where this principle is used to ...


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Energy cannot be stored in this way. Optical fibre will lose all the light energy in few seconds. Optical fibre do not have 100% efficiency. In case of 100% efficiency , No effect would be there due light energy in optical fibre outside.


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Relevant link - not exact duplicate . It discusses the need for population inversion, and how to achieve it. A system with fewer than three (four if you want to limit power loss) energy levels is unlikely to be able to sustain population inversion, so while you could get "stimulated emission" it's unlikely that the output of such a medium would be coherent ...


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i think PIConGPU is the best choice for simulation of laser plasma interaction especially for large scale plasma. the VLPL code has been written by Prof. Pukhov's group and isn't open source. you have to contact to him or his coworkers to get the code. if you have enough time like two or three years for your simulations, you can write your own code by ...


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Although the initial meaning of laser came from Light Amplification by Stimulated Emission of Radiation, the current "common" meaning of laser comes from coherent light being laser light and therefore, anything that produces coherent light, is a laser. So, do FEL lase? No, are they lasers? Yes.


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Short answer: You don't choose the modulation frequency, you choose the modulation index, and you choose it depending on your problem and/or on the number of contributing sidebands that you can afford. When studying frequency modulation you may have read about the modulation index, $\beta$, that is defined as the ratio of the modulation amplitude to the ...


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Physically such phenomena happen because of the oscillations inside the laser cavity; a Fabry-Perot cavity, which imposes the criterion that the spacing between the frequencies that are allowed to oscillate inside the cavity has to be 1/T. This is a consequence of Electromagnetic theory and interference of EM waves inside the cavity. On the other hand if you ...


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I am no expert on this but after reading about the technique I would offer a couple of suggestions. The mixing frequency creates side bands at $f+-\Omega$; these have to be "far from" the resonance of the FP resonator, which sets a minimum frequency; but since the frequency is also needed when you mix down for the detection of the error signal I suspect ...



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