A calibration method of CMOS-based autocollimator using reflected diffraction pattern of strip reflector

Abstract

We propose a new calibration standard for a CMOS-based autocollimator using an optical angle generator with a submillimeter strip reflector (OAG-SSR). The OAG-SSR combines the advantages of existing standards while minimizing their limitations by generating reference angles in the form of a reflected diffraction pattern from the strip reflector. This method provides angular values along the measuring range of the autocollimator without any mechanical movement, enabling a faster calibration process. This feature is suitable for the autocollimator integrated with production lines. In this work, we applied the propagation of uncertainty method and the Monte Carlo simulation for uncertainty evaluations. The expanded uncertainty of the reference angle from the OAG-SSR is 2.5″ with an approximately 95% confidence level for the calibration range of 1270".