A measurement system for determining the thickness of an optical wave plate

This study proposes a non-destructive measurement method for determining the thickness of an optical wave plate. The measurement system comprises a laser interferometer to conduct optical path length measurement, a stepping motor to adjust the angle of the incident light on the wave plate, and a computer to perform data calculations. The optical path difference is obtained by adjusting the angle of rotation of the wave plate using the stepping motor. The thickness of the optical wave plate can be obtained accurately and rapidly from the mathematical relations describing the optical path length difference. The proposed measurement method is capable of measuring large thicknesses (i.e., at the cm scale) with nano-scale precision. As such, the method provides a valuable contribution to the field of precision thickness measurement.