Stråldelare

Stråldelare, in English beam splitter, is an optical component that divides an incident light beam into two or more separate beams. It is designed to transmit part of the light and reflect part, with the exact split depending on design, wavelength, and angle of incidence. Beam splitters can be non-polarizing, preserving the polarization state, or polarized, which separate light by polarization.

Common designs include plate beam splitters, consisting of a partial-reflective coating on a glass plate, and cube beam splitters, formed by cementing two right-angle prisms with a partially reflective coating at their interface. Dichroic beam splitters separate light by wavelength, while polarizing beam splitters, such as Wollaston or Glan–Taylor types, separate based on polarization.

Operation relies on interference and coatings. A dielectric coating creates a specified transmission and reflection for a given wavelength and angle; sometimes two coatings are used to achieve high extinction ratios or broadband performance. The split ratio can be designed for a fixed wavelength or be wavelength-dependent.

Applications include interferometers (Michelson, Mach-Zehnder), laser cavities, spectrometers, fiber-optic systems, and imaging and photography. They are used to route light to detectors, reference arms, or different spectral channels.

Key considerations are losses, polarization sensitivity, wavelength bandwidth, angular sensitivity, and environmental stability. Alignment and coating quality strongly influence performance. Stråldelare are fundamental components in optical laboratories and commercial optics, and their exact configuration is chosen to fit the specific optical system.