A first review of optical edge-diffraction technology for precision dimensional metrology

Abstract

A comprehensive study relevant to displacement sensing techniques based on optical edge-diffraction has been first introduced in academic society. Dimensional sensors with nanometer resolution are key components of many precision imaging, positioning, and fabrication machines. Knife-edge techniques are commonly used for optical beam profiling of laser beams, but edge-diffraction sensing techniques for dimensional metrology was first introduced in 2006 and have been used for many dimensional metrology applications. This review paper outlines the computational approaches for optical edge-diffraction analysis and the case study for various displacement measurement applications. This review is the first report that summarizes literature relevant to displacement sensors based on optical edge-diffraction and discusses how optical edge-diffraction techniques enhance dimensional metrology in terms of accuracy, precision, sensitivity, bandwidth, and uncertainty. In addition, future applications for employing edge-diffraction techniques will be further discussed and highlighted.