Study about deflection wavefront measurement approach of liquid-crystal grating phased array

In order to test deflection wavefront of liquid-crystal grating phased array,a key component in phased array laser radar,and monitor and evaluate the quality of radar scanning beams,a radial shearing interference measurement technology with direction changing function was adopted and theoretical analysis and experimental verification about this method were carried out.Test data were obtained with a 10mm×10mm aperture deflection wavefront tester and a commercial WYKO interferometer respectively.The difference of test results is less than λ/20 for peak-valley value and less than λ/200 for root mean square(RMS)value for the same plane optical element.Deflection wavefront of liquid-crystal grating phased array was measured.The experimental results show that this method can measure deflection wavefront of the liquid-crystal grating phased array with high precision.