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Fundamental of Optical Engineering Lecture 7
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Boundary conditions:E and T must be continuous. Region 1:
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Region 2: As we know that E is continuous.
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Therefore,
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For I ≥ I c implies “no refracted wave”. This allows light to propagate with no loss. This result does not depend on polarization and the wave. For I < I c I, there will be a reflected wave and the refracted The ratio of E r or E t to E i depends on the polarization (direction of E i ).
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Plane of incidence is defined by the propagation vector of incident wave and normal to the plane of the interface.
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Consider 2 cases: (i) Ei normal to plane of incidence. This is called ‘s-polarization’ or ‘perpendicular polarization’.
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(ii) Ei in plane of incidence. This is called ‘p-polarization’ or ‘perpendicular polarization’.
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For normal incidence
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We can also show from #3 that
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The angle that makes no light reflection for p-polarization. Maximum polarization occurs at this angle for reflected light. Light reflected at any other angle but Brewster’s is partially linearly polarized.
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Note: There is no Brewster’s angle for s- polarization.
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Calculate Brewster’s angle for light traveling from a medium of refractive index 1.81 into a medium of index 1.52.
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What is the angle of incidence for complete polarization to occur on reflection at the boundary between water (n=4/3) and glass (n=1.589) assuming the light comes from (a) water and (b) glass.
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Unpolarized light Linearly polarized light Partially linearly polarized light Circular polarization Elliptical polarization
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Birefringent median can transform polarization. Birefringent media have different refractive indices for orthogonal polarizations.
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Let us consider
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The output polarization is the same as incident one. This is called “Full-wave”.
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This is called “Half-wave”.
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This is called “quarter-wave”.
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After leaving a crystal Consider real part of an electric field by assuming
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Elliptrical polarization
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These are components which transform polarization.
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