The Correction of Hartmann-Shack Sensor Measured Datum in Non-Normal Incidence Method

In this paper, a deformable mirror is used to simulate mirror thermal distortion induced by laser, which deforms by different drive voltages loaded on it. The deformation is measured by a Hartmann-Shack sensor in the method of normal incidence and non-normal incidence respectively. In contrast to the true peak to valley value (PV value )of wavefront aberration which is measured in normal incidence method, the PV value of wavefront aberration measured in non-normal incidence method is less , the relative deviation between them increases with the increasing of the deformation, and closely relates with the incident angle. With the increasing of incident angle, the relative deviation increases significantly. In order to correct the deviation, the datum which is the PV value of wavefront aberration measured in non-normal incidence method divided by the cosine of the incident angle are analyzed, found to be good agreement with the true PV value of wavefront aberration , and the maximum relative deviation is less than 2%.