用于光热反射显微热成像的位置漂移修正方法

Position Drift Compensation Method for Thermoreflectance Microscopy

光热反射显微热成像测试过程中需要采集若干被测图像,整个过程中图像各像素与被测表面位置的对应关系应保持不变,但是被测表面不可避免地会发生位置漂移,从而引起测量误差。结合光热反射显微热成像的具体应用场景和位置漂移的特性,设计了有针对性的亚像素图像配准算法,结合PID控制驱动三轴纳米位移台实现实时的位置漂移修正。实验验证了算法性能以及漂移修正效果,位移修正残差在5 nm以内,与未补偿测量相比,位置漂移引入的误差得到了较好的抑制,提高了光热反射显微热成像测试的准确性。

Multiple images are acquired during the procedure of thermoreflectance microscopy,each pixel of the image should be bound to a fixed position of the object's surface throughout the procedure.Nevertheless,drifting of the object is inevitable,thus jeopardizing accuracy of the measurement.A sub-pixel image registration algorithm is put forward to estimate the drift,and the result is feed into a PID algorithm controlling a piezo nanopositioner to compensate for the position drift,so the real-time position drift correction is carried out.Experiments verify the performance of the algorithm and the effect of drift correction,the residual error of displacement correction is within 5 nm,and errors introduced by position drift are well suppressed compared to uncompensated measurement,the test accuracy of thermoreflectance microscopy is improved.