A high-precision right angle prism can deflect the optical path by 90 ° or 180 °, and the angle of deflection depends on which side of the prism RIGHT-ANGLE-PRISM uses as the incident surface. The size of the prism can be processed according to the needs. The slope or two right angles of a right angle prism can be coated with one of the following three standard broadband antireflection films (A: 350-700 nanometers, B: 650-1050 nanometers, C: 1050-1620 nanometers), which can effectively reduce surface loss.