An optical unit with this construction always produce disturbance fringes
A prism whoever refracting perspective is extremely almost 180 levels.
A combination of two quick rectangular glass prisms cemented together at their particular diagonal faces to be able to form a cube; -- labeled as also optical cube. It really is utilized in one type of photometer.
A prism with two refractive edges every one of little angle, its cross-section becoming an obtuse-angled isosceles triangle.
an optical device for acquiring disturbance fringes