Evaluation of anti-vibration capability of the wavefront testing method in time- and spatial-domain

The proposed wavefront testing method in time- and spatial-domain takes advantage of both active and passive phaseshifting. It obtains stable wavefront with random noises removed after processing of large amount of serially collected interforograms. Since the environmental vibration and air turbulence are adopted as the passive phase-shifting source, this method performs well in normal laboratory environment without special vibration isolation or air flow control. This method has application prospect in large-aperture optical surface test because it can help simplify the system and reduce the cost and difficulty in fabrication. In order to quantitatively evaluate the anti-vibration capability of this method, the influence of vibration on the measurement accuracy is simulated and analyzed. It is confirmed that corresponding to certain accuracy tolerance, the product of maximum tolerant vibration amplitude and frequency is invariable. This very product is adopted as the threshold indicating anti-vibration capability. More conclusions can be drawn after analysis about the influence of active phase-shifting velocity, sampling frame frequency and relative sampling frame number on the measurement accuracy: when the relative sampling frame number is fixed, the anti-vibration capability of the method is increased with active phase-sifting velocity.