Brewster dispersing prisms have an apex angle whereby linearly polarized light of a specific wavelength introduced at the Brewster angle has a minimum deflection angle (prism apex angle when light passes through a prism parallel to the bottom face).
Linearly polarized light parallel to the electric field vector perpendicular to the bottom face of the prism (P polarized light) passes completely through the incident and outgoing faces.
Brewster dispersing prisms with functions similar to Brewster windows are used as elements for low-gain laser cavities that require extremely low loss.
Littrow dispersing prisms are shaped in such a way that the apex angle of Brewster dispersing prism is divided into two halves. Littrow dispersing prisms with dielectric multilayer reflection coatings on one face are used as substitutes for laser resonator flat mirrors employing concave and flat mirrors.
