纳米光栅间距测量系统的主要误差分析与仿真OA

A theoretical analysis and simulation study on the main error sources of a grating pitch measurement system are conducted based on a direct-tracing grating interferometer.The focus is placed on the influences of pitch error,yaw error,and roll error of the grating under test on the measurement results of grating pitch.Through theoretical analysis,experimental measurement,and uncertainty evaluation,the main error sources of the system are identified.A system model is established using optical simulation software to simulate the displacement of the grating along the vector direction,extract the coherent phase at the detector,and perform phase unwrapping and grating pitch calculation.By varying the rotation angles of the grating under test around the X-,Y-,and Z-axes,the effects on measurement accuracy are systematically analyzed.Simulation results show that when the grating under test has a pitch angle of 0.01°～0.10°,the relative error of the measured grating pitch is 0.12%;when a roll angle of 0.01°～0.10° exists,the relative error reaches 0.41%;and when a yaw angle of 0.01°～0.10° is present,the range of the measured grating pitch is up to 6.9 nm.