Задача 40291.

Calculate the difference between the phase and group velocity of light with a wavelength of 0.768 microns in the glass, it is known that the refractive index for this wavelength is equal to 1,511, and for a wavelength of 0 656 m it is equal to 1.514.

Detailed solution with a short recording conditions, laws and formulas used in the decision, the withdrawal of the calculation formula and the answer.
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