基于相对调制度的非方形干涉图处理方法

以相对调制度作为判据 ,划分干涉图中的有效点和无效点 ,并据此进行加权 ,采用加权最小二乘算法进行去包裹处理。采用这种方法可以有效减小包裹位相中坏点或无信息点对有效点去包裹位相的影响。以移相式干涉仪为例 ,给出了相对调制度的计算方法 ,简述了加权最小二乘去包裹算法的原理 ,并通过光学盘片的处理结果验证方法的正确性。

Phase unwrapping algorithm in the least-squares sense by relative modulation

Phase unwrapping is one of key segments in phase-stepping technique. The paper uses relative modulation as the base to mark off the valid and invalid areas, by which the wrapping phase is weighted. Then, the phase unwrapping algorithm in the least-squares sense is applied to process the weighted wrapping phase and get unwrapped phase. By this method, the effect of the points of bad or non-phase information to the unwrapping phase of valid points can be reduced greatly. The paper presents the principle of relative modulation to mark of the valid and invalid areas. Using a phase-stepping interferometer as example, the paper presents the calculating steps of relative modulation. The paper also describes the principle of the weighted phase unwrapping in the least-squares sense. Finally, the processing result of a ringy optical flat verifies the correctness.