Polarization of Light- Wave Optics

Linearly polarized or plane polarized and unpolarized waves, polarizer and analyser

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  Education

[Sathi Das]

madam i hv a questn. why i1=1/2 i0 always?

[Leena Gurg]

Unpolarized light is made up of waves that has randomly directed electric fields. Instead of this mess you can think of unpolarized light as the superposition of 2 waves whose planes of oscillation are perp. to each other.( Using vectors each electric field vector can be resolved along lets say x and y directions.).If this light is incid. on a polarizing sheet and we take the polarizing dirn. of the sheet to be parallel to either x or y then components either along x or y get transmitted.

[Leena Gurg]

Polarization is observed for transverse waves. Sound is a longitudinal wave so it does not show polarization. Light is an electromagnetic wave which is a transverse wave so it shows polarization.

[humanhb]

i have been taught that light has E and H components.So a polariser would delete either component E or Component H?,, if so then polarised light cannot travel because it has only 1 component (because light needs 2 components to travel).. am i right??

[Leena Gurg]

An electromagnetic wave contains electric and magnetic fields. One of these is not removed by polarization. When we talk of polarized light we define the direction of vibration of the electric vector E. The magnetic field exists all along. We could have also defined polarization using the magnetic field vector. Its just that its been defined in terms of the electric field vector and not the magnetic field vector.

[Logan Moua]

Knowing that Electric Potential Energy/ Magnetic Potential Energy = C = 3*10e8. This saying that E is much much greater than B( or H) that the ratio of them is the speed of light. Considering only the Energy of Electric Potential Energy is gooe enough. By the way. Maxwell's Law said E creates B and also B creates E. So one will exist as long as the other exist.

[taslima khatoon]

thank u

[Sathi Das]

o that means magnetic field always remains before and after the polarisation of light but we get electric feild in a definite direction after the polarisation. am i right?

[Sathi Das]

but in malus's law we didn't make the first polaroid p1 totally vertical or totally horizontal i.e, the polarizing direction of first polaroid is neither totally along x direction nor along y-direction but it is inclined at an angle. then how can i have i1=!/2 i0?

[Sathi Das]

madam plz upload more videos about polarisation (e,g-nicol prism,) & diffraction.