mehrspaltiges

Mehrspaltiges refers to interference and diffraction effects produced by more than two slits arranged in a regular or irregular array. The term is used in optics to describe how coherent light passing through several slits generates a characteristic interference pattern that generalizes the classic Young two-slit experiment. Mehrspaltige Beugung occurs when the slits are closely spaced, equally illuminated, and the light is approximately monochromatic.

In the Fraunhofer (far-field) regime, the intensity pattern of N equally wide and equally spaced slits can be described by the product of the single-slit diffraction envelope and the multi-slit interference factor. A common expression is I(θ) = I0 (sin α/α)^2 (sin(Nβ)/sin β)^2, where α = π a sin θ / λ and β = π d sin θ / λ; here a is the slit width, d is the center-to-center slit spacing, θ is the observation angle, and λ is the light wavelength. The principal maxima occur when d sin θ = m λ (m being an integer), and the N-slit term produces sharp, highly reinforced maxima whose width decreases as N increases. The single-slit envelope (sin α/α)^2 limits intensity between maxima.

Mehrspaltige Anordnungen underpin diffraction gratings and are widely used in spectroscopy, metrology, and optical instrumentation. By increasing N and controlling geometry, these systems achieve high spectral resolution and angular selectivity. The concept extends naturally to various lattice geometries and wavelength ranges, including visible, ultraviolet, and infrared light.