Basic electromagnetic wave phenomena

Phenomena - observation of something which exist or happen.

Wave, the magnetic and electric fields oscillation - electromagnetic wave(EM). Light is only part of spectrum, interest in in frequencies from infrared to ultraviolet, with including the visible spectrum.

Wave possible to describe by trigonometric formulas and equation for transverse EM wave, the signals and system theory gives tools for manipulation with waves, formulas.

Physical properties of waves:


 * propagation
 * absorption ( losing energy )
 * reflection ( changing direction )
 * refraction ( changing speed )
 * diffraction ( "rounding" )
 * interference ( "multiplying" )
 * polarization

* also dispersion, Doppler effect

Electromagnetic wave
Radiation, travels with the speed of light, even in vacuum. Maxwell's equation describes behavior of EM fields.

EM(electro-magnetic) waves exhibits wave and particle properties. Single particle - photon.

Polarization
Changing geometrical orientation of the oscillation.

Polarizers:


 * absorptive polarizers - unwanted polarization states are absorbed
 * beam splitting polarizers - beam split into two beams with opposite polarization states

Dichroism
Reflect some wavelengths but not others. Can be used as linear polarizers.

Examples: tourmaline, herapathite. They tend to absorb light which is polarized parallel to the direction of crystal alignment but to transmit light which is perpendicular to it.

Birefringence
Unpolarized light which incident on surface is split by refraction into two rays with different polarization states. Examples: quartz, calcite.

Optical rotation
Polarization rotation, circular birefringence - this activity occurs only in chiral materials. Slow down one component of EM wave - the whole polarization state is rotating.