Recent content by Claude Bile

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    B How to calculate measurement error by using other quantities?

    The recommended procedure is outlined in the BIPM (International Bureau of Weights and Measures) "Guide to Uncertainty and Measurement". In very general terms, one would typically linearise the function about the expectation and compute the uncertainty/variance using the appropriate linear...
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    I Laser and hair - scattering or destructive interference?

    Both. What you are seeing is interference between the (planar) incident and (cylindrical) scattered wave.
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    I Issues collimating my laser with 4f system

    The beam was probably astigmatic prior to shrinking using the 4f telescope - it would have been less noticeable with the larger beam. I'd check the upstream optics.
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    I Mirror rotates any polarisation by 90°?

    This is a really cool experiment! The "handedness" of circular polarisation is conventionally defined from the perspective of the receiver. Simply put, the mirror reverses the direction of propagation, thus the "sender" becomes the "receiver" and vice versa, hence reversing the handedness of...
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    I Emission of light from incandescence of metals

    You asked about metals giving off light when they are heated. That's black body radiation. If it's not the answer you want, perhaps you should rephrase your question instead of being condescending.
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    I Emission of light from incandescence of metals

    The first stop is black body radiation. It can be understood as the radiated energy from random kinetic motion of charged particles as per b). Metals are excellent absorbers of EM radiation, and so tend to make very good black bodies, however the band structure of some metals e.g. gold can give...
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    I Understanding Light Polarization: An Intuitive Explanation

    Two insights I have personally found helpful; 1. The Jones matrix of a polariser includes "cross-terms". This means that a field component in x can generate a field component in y or vice versa. Polarisers don't simply attenuate the x or y component of the field, the behaviour is much richer...
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    I I'm confused on which equation gives percentage uncertainty

    Hint: Think about the units. What units would you expect a percentage uncertainty to have versus an absolute uncertainty?
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    Understanding Fraunhofer Diffraction Patterns of Circles and Slots

    "If the same method is used in calculating the slot diffraction as you use in the circle then then slot diffraction should also be radial (but stretched to account for the slot height)" Not so. It makes sense for a circular aperture to have a diffraction pattern with circular symmetry and a...
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    Does light reflect if incident exactly at critical angle ?

    It's a good question, but one that classical optics has covered I think. Ray approximations are useful, but don't forget that light is ultimately a wave; and in the wave picture, the plane-wave components are completely non-localized. In other words, light incident upon a surface with some...
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    How to calculate refractive index from reflectance values

    Not possible using only intensity measurements to my knowledge - you need to know the phase change upon reflection as amplitude to calculate the complex (i.e. refraction + absorption) refractive index. Extinction and absorption coefficient are basically the same thing, transparency additionally...
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    Shortest distance light wave can travel?

    I think the simple answer is - there is no minimum distance. If I have a beam of light at some point z = 0, then I can propagate it forward an arbitrarily small distance. Of course, there are details regarding classical vs quantum fields, but the OPs use of the term "beam" would suggest the...
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    Effective refractive index when two transparent medium are joined in s

    Yes, but the calculation is not straightforward, because it depends on the mode profile - which is generally found by solving wave-equations. Once you know the mode profile, the calculation becomes relatively straightforward, essentially it is just an average of the two indices, weighted by the...
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    Light converging inside the eye

    I think the key point is that plane waves traveling in different directions will focus on different points in the focal plane of a lens (or the retina of an eye). This is the fundamental Fourier-transforming characteristic of lenses and the basis of Fourier optics. Claude.
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