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The human eye is close to being fully diffraction-limited, at least for photopic (cone-based) vision at the center of the visual field (i.e. for images wholly within the fovea), though it's not quite there for most people. According to Yanoff and Duker (Ophthalmology, 3rd ed. (Mosby, 2009), p. 57): The 20/20 (6/6) Snellen line represents the ability to ...


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Assuming that the source is coherent in nature, the intensity of the interference pattern will be same as that of a ' only ' double slit interference and ' a single slit and then double slit ' interference. This is so because the single slit acts again as a new source of light with same intensity, hence producing same intensity fringes as that of the 'only' ...


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Have in mind that for an interference pattern to show on the screen during a double-slit experiment, you need a coherent source of light. If you use a high coherence laser, you can directly illuminate the double-slit; but if you lack a coherent source of light you first need to make one. That's when the first slit becomes useful as it makes light spatially ...


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A photon is a wave in the EM field that has defined electric and magnetic components. Photons can also be scattered (direction change) by an interaction with electrons in matter and this is the main reason for diffraction. (Also photons are only created by electrons (mostly in atoms) and are only absorbed by electrons in atoms). The interaction of photons ...


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The best way to imagine it without getting too deep into mathematics is as Solomon's comment suggests. Imagine a pond with a wall through the middle, and imagine that the wall has a slit in the middle. If there are waves with wavefronts parallel to the wall hitting the wall from one side, some of the wave will get through and form a more circular wave. In ...


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The interference pattern depends on the wavelength: maxima and minima will be more closely spaced at shorter wavelengths. The peak intensity of the interference pattern depends on the intensity of the light you shine on the slits, which is different from the wavelength of the light.


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You are correct ─ this is an approximation. Unless you introduce some kind of focusing optics to view the fringes, for the rays to interfere they need to reach the same point on the screen, and for this to happen, as you have noted, they need to be at slightly different angles. However, it is important to keep in mind just what the differences are here: ...


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From f and the distance between the lens and the detector, you can calculate the distance to where things will be sharply focused onto the detector. Things a little in front or behind that place will be a little out of focus, perhaps so little that you can't tell the difference. The depth of the region where things are acceptably in focus is called depth of ...


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