Optimization of the dwell time point sampling step length for ion beam polishing

In order to the dwell time function can be solved quickly and accurately, the sampling step length of the dwell point in the solution process of ion beam polishing dwell time has been optimized. Taking the PV value for per unit of uniform material removal and dwell time as the analysis object, the fluctuation caused of uniform removal and the total dwell time under different dwell time sampling step length are analyzed. The optimal dwell time sampling step length of ion beam polishing is 1.5σ。Using the determined sampling step length, the optical element with a diameter of 50mm is simulated polishing, and the surface PV value of the element decreases from 110.81nm to 20.06 nm. The optical element was polished by ion beam according to the simulation results, the PV value of the element surface decreased from 110.81nm to 46.46nm. The experimental results verify the effectiveness of the simulation results. Using the determined dwell point sampling step length, the dwell time can be solved quickly, and the PV value of the optical elements converges well.