Abstract

Recently, the demand for complex optical parts is on the increase in industry and science; therefore, high-accuracy dimension measurements of the parts have gained much importance. In particular, dimensions of a comer cube prism, which is important in interferometric length metrology, is required with high accuracy, because knowledge of the accurate dimensions of its optical center and alignment of the spatial position of an optical system are necessary for eliminating error in length measurement.^1,2 However, such measurements by conventional methods using continuous waves are difficult because many beams reflected from the surfaces of the parts exist coaxially and are inseparable. If a short optical pulse is used as a light source, the overlapping beams can be resolved by time gating.

© 1995 IEEE