Abstract
Aspherical mirrors are being widely used in modern optoelectronic instruments. Hence measurement of optical aspherical surfaces is necessary. Phase shifting interferometry is the current method for measuring aspherical mirror and has many advantages, but it is marred by a few inaccuracies due to the vibration and mechanical movement of the phase shifter itself. This paper presents a novel aspherical optical surface measurement instrument based on the fringe projection. In this system, phase shifting is done electronically and thus errors due to the vibration and mechanical movement of the phase shifter itself are eliminated. The shifting operation is easy and rapid, and can be controlled precisely. A practical example confirms the predictions of the proposed method.
