Prisms » Dove Prisms

Dove Prisms are used as image rotators in a variety of opto-mechanical systems. They are a truncated form of the right angle prism, and use total internal reflection (TIR) to produce an inverted image which emerges from the exit surface without deviation.

As the prism is rotated about its optical axis, the image will rotate at twice the angular rate of the prism. Since the length of the prism is approximately four times the height, the incident light must be parallel or collimated.

For applications in which the hypotenuse cannot be kept sufficiently clean for TIR, a metal or dielectric coating can be applied to the hypotenuse.