Polarization of Light from Basics to Instruments

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Beam displacers,

Beam splitters,

Polarizers,

Analyzers, .

Examples: Nicol prism, Glan-Thomson polarizer, Glan or Glan-Foucault prism, Wollaston prism, Thin-film polarizer, .

Part III: Optical components, polarizers

Slide 42

Mueller matrices of polarizers (I)

(Ideal) linear polarizer at angle :

Part III: Optical components, polarizers

Slide 43

Mueller matrices of polarizers (II)

Linear (±Q) polarizer at 0º:

Linear (±U) polarizer at 0º :

Part III: Optical components, polarizers

Circular (±V) polarizer at 0º :

Slide 44

Mueller calculus with a polarizer

Input light: unpolarized --- output light: polarized

Total output intensity: 0.5 I

Part III: Optical components, polarizers

Slide 45

Retarders

In retarders, one polarization gets ‘retarded’, or delayed, with respect to the other one. There is a final phase difference between the 2 components of the polarization. Therefore, the polarization is changed.

Most retarders are based on birefringent materials (quartz, mica, polymers) that have different indices of refraction depending on the polarization of the incoming light.

Part III: Optical components, retarders

Slide 46

Half-Wave plate (I)

Retardation of ½ wave or 180º for one of the polarizations.

Used to flip the linear polarization or change the handedness of circular polarization.

Part III: Optical components, retarders

Slide 47

Half-Wave plate (II)

Part III: Optical components, retarders

Slide 48

Quarter-Wave plate (I)

Retardation of ¼ wave or 90º for one of the polarizations

Used to convert linear polarization to elliptical.

Part III: Optical components, retarders

Slide 49

Special case: incoming light polarized at 45º with respect to the retarder’s axis

Conversion from linear to circular polarization (vice versa)

Quarter-Wave plate (II)

Part III: Optical components, retarders

Slide 50

Mueller matrix of retarders (I)

Retarder of retardance  and position angle :

Part III: Optical components, retarders