Question

Optics: Interference and Diffraction

1. Why do you think the colors (when light diffracts) appears in different places at all?

2. Why do the colors appear specifically in the order they do?

3. What kind of shape must the diffraction gratings be to produce the diffraction in light? Explain. (answer is rectangular slit grating, but explain why it’s this shape)

Answer 1

1) The visible spectrum consists of different colors with different wavelengths. Because of its wavelengths only we are observing it in different places when it diffracts.

2) These wavelengths are making an order to it.

3) The shape of the diffraction grating is rectangular slit grating. In a simple slit case, we observe far behind the slit number of parallel stripes with different intensities. We will observe wavefronts. At a certain angle, each wavelet of the second half will have partner wavelet in the first half with precisely a half wavelength optical path difference.