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6

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 ...


4

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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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 ...


2

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 ...


2

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 ...


2

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 ...


1

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 ...


1

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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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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