Yksireikädiffraktio

Yksireikädiffraktio, also known as single-slit diffraction, is an optical phenomenon that occurs when light waves pass through a narrow aperture, or slit, with a width comparable to the wavelength of the light. Instead of continuing in a straight line as predicted by geometrical optics, the light spreads out and deviates from its original path. This bending and spreading of light is a direct consequence of the wave nature of light.

When light encounters a single slit, each point on the slit acts as a source of secondary spherical wavelets, according to Huygens' principle. These wavelets propagate outwards and interfere with each other. In directions away from the straight-through path, the wavelets travel different distances to reach a distant observation screen, leading to path differences. Constructive interference occurs when these path differences are an integer multiple of the wavelength, resulting in bright fringes. Destructive interference occurs when the path differences are half-integer multiples of the wavelength, creating dark fringes.

The resulting diffraction pattern on a screen placed behind the slit typically consists of a central bright maximum, which is much wider and more intense than the other maxima. On either side of the central maximum, there are a series of alternating dark minima and progressively weaker bright maxima. The angular position of the minima is given by the equation a sin(θ) = mλ, where 'a' is the width of the slit, 'θ' is the angle of deviation from the center, 'm' is an integer (±1, ±2, ±3, ...), and 'λ' is the wavelength of the light. Yksireikädiffraktio is a fundamental demonstration of wave diffraction and is crucial in understanding the behavior of light in optical instruments.