Experimental demonstration of the sine condition test plus, part 1: development of an alignment method using deflectometry and the sine condition test

The sine condition test plus (SCT+) is a novel alignment technique, to our knowledge, that integrates two metrology concepts, deflectometry and the sine condition test. This paper presents an experimental validation of the SCT+, demonstrating its ability to measure the five aberrations that indicate misalignment and comparing these measurements with predictions. The experimental results of the SCT+ show a strong correlation with predicted values within expected uncertainties, confirming the accuracy and reliability of the method. Additionally, the efficacy of the SCT+ is evaluated with a cross-check using interferometry. These findings strongly support that the SCT+ can provide accurate and efficient optical alignment, which will be presented in a subsequent paper.