Research On Fizeau Synchronous Phase Shifting Interference Testing Technology

Simultaneous phase shifting interferometry is the best measure method in anti-vibration field.At present,most of the simultaneous phase-shifting schemes use the Twyman-type structure,and Fizeau-type interferometer is suitable for detecting plane component.There are several Fizeau-type structures are not suitable for long-cavity interferometry.For the purpose of long-cavity interferometry,a new method of simultaneous phase shifting interferometry is proposed in this paper.The system based on the Fizeau phase-shifting interferometer measurement system and using a quarter wave plate as a reference mirror,a pair of orthogonal polarized light are acquired.After crossing the Ronchi phase grating,diffracted beams of(±1,±1)orders are formed in the same diffracting efficiency which selected by a special aperture.The four diffracted beams obtain 4 phase-shifting of ?/2 through a phase delay array and a polarizing plate.The principle of fizeau simultaneous phase shift interferometer based on the quarter-wave plate is analyzed by Jones matrix.The key devices of this system are designed and constructed from the aspects of interference system,splitting system,phase-shifting system and data acquisition system.A plane is measured and the results are agreed with the measurement results of the ZYGO interferometer.The difference of peak and valley is 0.004? and the root mean square error of the plane system is 0.001?.The error of each component is analyzed,especially the phase shift error of the quarter-wave plate,the position error of the fast axis,the azimuth error of the polarizer and the phase-shifting error of the phase delay array.The overall error of the device is ?/10.It can simplify the structure of the system,reduce the system error,suitable for the measurement of the plane and easier to installation comparing to the Twyman simultaneous phase shifting interferometry.It is suitable for the measurement of long-cavity interferometry,and can effectively reduce the influence of vibration in interferometric measurement.