Show that you obtain Itr = Iin – Iref and Snellius law (sina/sinb = n) from energy and momentum conservation | |||||||||||||||||||||||||||||||||
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Solution: | |||||||||||||||||||||||||||||||||
The intensity I of the beams is given by their power (energy /t) which is given by the nunber of photons/s in the beams: Ein, Ere, Etr. Everythin always per cm2 but that is not important for what follows. | |||||||||||||||||||||||||||||||||
Energy conservation demands | |||||||||||||||||||||||||||||||||
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Looking at the x-component of the momentum p and considering that the wavelength in the material is l/n we have | |||||||||||||||||||||||||||||||||
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Momentum conservation demands that pz, in + pz, tr – pz, re = 0, or | |||||||||||||||||||||||||||||||||
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Substituting Ire = Iin – Itr leads straight ot | |||||||||||||||||||||||||||||||||
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Exercise 5.1.1 Derivation of Snellius Law
Exercise 5.2.3 Attenuation of Light
Exercise 5.2.2 Fresnel Equations and LEDs
Exercise 5.2.4 Fresnel Equations and Polarization
© H. Föll (Advanced Materials B, part 1 - script)