Young's Double Slit Experiment
Separation of the fringes and brightness of bright fringes will be affected based on the changes on some particle factors.
Wavelength of visible light is 400-700nm，and different colors of light have different wavelengths, as well as frequency. Wider the wavelengths, lower the frequency. Red lights have the wider wavelengths, then are orange, yellow, green, blue and violet lights.
Plane Transmission Grating
Plane transmission grating is a kind of diffraction grating. In a plane transmission grating, lights go through a piece of glass/plastic with many evenly separated opaque parallel lines that act as slits. Thus, plane transmission grating is actually a large number of slits on a grating. However, it is still a bit different from double-slit grating.
Additionally, y(n) = D·tan (theta).
