Conditions for Interference

Conditions for Interference - Conditions for Interference...

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Conditions for Interference Recall that light, which obeys the wave equation, must also obey the principle of superposition. In fact, both the electric and magnetic fields of the light in a region where two light waves overlap must be the vector sums of the individual electric and magnetic fields. Interference is collective name for the effects that occur when two or more light waves overlap to give an irradiance that is different from the sum of the component irradiances. The irradiance is defined as the average energy per area per unit time falling on a surface. It is proportional to the square of the amplitude of the light wave: I = < S > = = ε 0 c < E 2 > = where < F > denotes the time average of F , and E 0 is the amplitude of the electric field vector. The irradiance is a very useful concept to use because it can be easily measured by a range of optical instruments (including our eye--irradiance is a measure of the 'brightness' we perceive). When we have a single light wave the value of <
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Conditions for Interference - Conditions for Interference...

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