# Tag Info

## New answers tagged laser

2

From MIT Museum Collections: Mini Kiss II This hologram was made in 1975 of a person blowing a kiss and is made from multiple exposures (at least 16) on the film so that it appears the person is moving.

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There is nothing wrong with working in a completely enclosed box which has an electric safety switch that turns the power off as soon as it is opened. That is exactly how a professional engineer/physicist will solve this safety problem: with deadlocks like this and measures that prevent the beam intersecting your eye under all circumstances of "normal" use. ...

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When working with any laser above class 1, you should seek appropriate qualification for dealing with your specific laser system (which includes both its wavelength and its power), and you should inquire with your institution as to any formal safety requirements. Specifically, you should not take laser safety advice from what are essentially random ...

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Here's an idea. Maybe it's kind of cheating, I don't know, you decide. Take a small diameter clear tube, fill with ordinary, unfiltered tap water and line the laser up to fire down the length of the tube. Seal the far end water tight. If you're firing the beam at a downward angle, you can leave the end closest to the laser open. The impurities in the water ...

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Is it really obvious that modulating the pumping diode won't work? It's not obvious to me. You say that the fluorescence lifetime of Nd:YAG is slow, but you are thinking of the lifetime when there is no stimulated emission. If there is stimulated emission, excited atoms can be de-excited very very quickly. Think a little harder about laser dynamics, ...

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(This is only a partial answer to one-third of your question.) I'm sure you already know this but ... Inhomogeneous broadening is what you're talking about where different Nd atoms are in different microscopic environments and therefore emit at different wavelengths. Homogeneous broadening is where even a single Nd atom can emit at some range of different ...

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This is typically because of optical selection rules which forbid certain types of transitions. The most usual case is where the states are, in order of energy, $S$, $D$ and $P$ states, driven by a reasonably-intense laser. In this case, the coupling to the EM field is usually a dipole coupling, which means that the atomic operator that does the transitions ...

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Correlation functions, such as $g^{(2)}(\tau)$ (or $g^{(1)}(\tau)$, as also mentioned in glance's answer) in quantum optics are employed to evaluate the quantum degree of coherence of an optical source. Frequently discussed examples of sources are lasers (that generally produce coherent light), thermal lamps (that generally produce chaotic light), or an ...

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What is it? (wordy definition) From Mark Fox's Quantum Optics, an introduction, p.111: The second-order correlation function $g^{(2)}(\tau)$ is the intensity analogue of the first-order correlation function $g^{(1)}(\tau)$ that determines the visibility of interference fringes. (...) $g^{(1)}(\tau)$ quantifies the way in which the electric field ...

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To follow the information in Chris White's answer - essentially, you would want a medium that allows you to see the spectra. There are several online resources that could help you in this experiment, in particular, the CD spectrometer, which can be constructed simply and on that website, it shows several examples of how everyday light sources can be ...

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Lasers by definition only emit a single wavelength of light. You use one if you want that wavelength or if you want your photons to be in phase. You don't care about the photon phases, and you want to sample all wavelengths, so a laser is very much the wrong tool. If you just want collimation of the light, mirrors, lenses, or even just well-separated ...

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Generally "vector" and "scalar" are models for the same kind of thing, the former can be more accurate than the latter. Generally, "vector" models of the electromagnetic field tend to be needed for "fast" fields: i.e. those of high numerical aperture and which contain a wide angular spread of wave directions. "Vector" models are also needed for fields whose ...

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