Dowell prism

The Dowell prism is regarded as a 90 degree prism whose sharp angle is truncated, which can reduce the volume of the prism and the internal refraction of stray light. When used for convergent beams, they introduce astigmatism, so we recommend using them for collimated beams. In addition, these prisms also affect the degree of polarization of the transmitted beam

generally speaking, Dowell prism uses the critical angle theory to achieve internal total refraction, so its field of view is limited. At the same time, it is important to keep the refractive surface clean and use directional light

The reflection in the prism is not caused by complete internal refraction. Since the beam enters at an angle less than the critical angle, the two refracting surfaces are coated with refracting materials to produce specular refraction. The two transmission surfaces are coated with anti refraction coating to reduce refraction. The refraction inside the Dowell prism is not caused by total refraction. Because the angle of incident light during reflection is less than the critical angle, that is, the small angle of total reflection. Therefore, both reflecting surfaces shall be plated as mirrors. In a dowager prism, light usually travels along the longitudinal axis of the prism. The light reflected from the cross section forms an inverted image on the other side of the Dowell prism