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Even weirder...I have 3 laser pointers. One is UV, the other two are visible red. I don't know the wavelengths of any of them. Obviously, the UV laser charges the glow-in-dark paint quickly and brilliantly. Here's the kicker. One of the red lasers makes the glowing paint turn dark, where the other red laser recharges activated lines made by the UV ...

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A free-electron laser (FEL) is a parametric amplifier, which operates by transferring energy to the output signal (photon pulse) from an oscillator (electron bunch running down a long undulator magnet). An electron bunch is accelerated to relativistic energies and sent through a periodic magnetic structure (undulator) where transverse oscillations and ...

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The general notions, to wit, recirculation and highly frequency-selective amplification of noise, carry over almost exactly from electronic oscillators to lasers. From 30 year old memory of electronic oscillators, though, I think some of the details of the dynamical equations are a little different. Also, recirculating a light beam is much more complicated ...

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It's a back-and-forth process where the irises, laser, and external references are aligned to each other. For example, after setting up a laser, you want the laser to be level with the optical table. To do this, take a single iris on a post and adjust the post until the laser hits the center. Then, slide the iris towards and away from the laser. If the spot ...

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In optics a "ray" is the direction of propagation of the classical electromagnetic wave. The term "ray' used for particles, as "cosmic rays" , and "gamma rays" are associated with this directional definition, from the times when it was clear that the phenomena followed straight lines like optical rays, before the differentiation into the particles we know ...

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Lasers are termed as beam. Maybe the reason behind this terminology is the finite and easily characterizable size of the laser. Laser can propagate in a in a defined direction without diverging appreciably, on the other hand the term ray refer to something that propagate in a straight line. However, the parallelism is not necessary property.

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Light is an electromagnetic wave. And for example gamma rays are electromagnetic waves. So the visible and near-visible light produced by most laser is like gamma rays but with a different frequency (wavelength). Thus saying ray and beam is roughly the same. Scientific convention is to say laser beam when the emitted electromagnetic waves are strongly ...

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I will briefly explain the lasers and pulsed lasers. Lasers: As you know lasers are coherent source of radiation. When light is passed from a normal medium it get absorbed due to the fact that most of the atoms are in ground state, if by some means we can place most of the atoms in excited state (known as population inversion) then the passage of light ...

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It is not a matter of being superior. The pulsed laser and the CW laser have different applications. The reason for using pulsed lasers is that if the time interval is very small you can probe events in nature on very small time scales. You can also examine aspects of quantum mechanics, for if the time interval of a laser pulse is very small the Heisenberg ...

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"does the shift directly depend on being above or below resonance?" Phase of reflected light will depend on which side of resonance laser is(check out cavity phase response). "I would have expected you to mix the output signal with the initial laser signal, such that the shift in phase could be determined and hence accounted for." You could in theory do ...

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In many cases, you can see laser cooled atoms in a MOT with the naked eye. They look like a little fuzzy glowing dot at about the same color as the trapping laser. So there are indeed lots of photons leaving the system. This spontaneously emitted light is what ultimately carries away the entropy and make cooling possible. You could try to capture this ...

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Laser cooling works by irradiating a e.g. an ensemble of gas atoms with light that has slightly less energy than a excitable transition in the atom. If the frequency is chosen right, the transition is only addressable by a 2nd order process which will consume kinetic energy from the atom. If I understood your question right, you are asking what is happening ...

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As for "I would like to know how the physics": that question is too broad to answer; I'd suggest that you get a book on Fourier optics and work through it by solving the exercise problems - you can ask for hints to solve the exercises here on Physics SE. I'll answer the more specific questions and address some misconceptions. As for "coherent light": ...

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The lower level of laser transition is above the ground state,this means that the fast non-radiative transfer from the lower laser level to ground state keeps a reasonable population in the upper laser level(3rd) which is fundamental for lasing.Hence its more effective than 3-level system

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quantum experiments are probabilistic (weird non-classical thing): they take a mixture of states the result of the experiment is one of the states each result occurs with a probability proportional to the amplitude of the states after the experiment, the system assumes the state that was observed well known example: probability that an electron hits a ...

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Note I am the OP. The first and foremost thing to note about this equation is that it is not exact and is based on approximations. For the situation described above, once the light has entered the filter it splits into two, one that experiences the ordinary refractive index $n_0$ and the other that experiences the refractive index $n_e$ (which may be ...

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Slow movements in the beam profile of a laser are usually the result of temperature variations inside the laser - it tends to warm up gradually. Temperature changes lead to two effects: The laser cavity gets slightly misaligned, causing the divergence of the laser beam to change and possibly the mode as well. Usually, an ideal laser beam has a smooth ...

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The laser leveler is using a pulsing technology, which is most often associated with distance measurements. The halo is due to scattering of the laser light off of dust particles. The motion you are seeing is that of the dust particles. Video of laser scattering off chalk dust If it is laser speckle, as Peter Shor mentioned, the pattern will randomly ...

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