Transcript Document
Polarization
Natural Radiation
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Linear Polarizer
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Mallus;s Law
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Producing Linear Polarization
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Dichroism or selective absorption
Scattering
Reflection
Birefringence or double vision
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Dichroism
Wire-mesh polarizer
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Dichroic Crystals
Tourmaline – coloured crystal
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Polaroid H sheet
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Possibly most commonly used polarizer
Inventor E H Land in 1938
Polyvinyl alcohol sheet heated and stretched
Dipped in iodine rich ink
Iodine chains along direction of stretching
Acts like a wire mesh
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Scattering
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Sky light is polarized
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Reflection
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Brewster’s Law
Brewster’s angle
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Birefringence
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Occurs in anisotropic crystals
Refractive Index ne when E along x axis
Refractive Index no when E perp. to x axis
Optic axis along x
Uniaxial Crystal
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Birefringence
positive
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Wollaston Prism
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Quarter Wave Plate
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Linear to Circular
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Partially Polarized Light
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/
Degree of Polarization
Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India
http://www.cts.iitkgp.ernet.in/~phy1/