Study on the phase detecting laser interferometric system with computer generated hologram

A description was made on a recently-built phase detecting interferometric system with computer generated hologram (CGH), whose optical system and CGH interference field were discussed here. Based on the phase detecting technique and fitting processing method of digital wavefront, the system can realize the measurement of high accuracy. The experimental results show that a precision of ��/20 can be obtained in measuring the aspheric surface.