曲率半径是球面光学元件中的重要参数之一，曲率半径的高精度测量已经成为光学元件使用与加工中的一个关键问题。提出了基于差动共焦法的曲率半径测量方法，研制了1套激光差动共焦曲率半径测量系统，并对2组曲率半径测量结果进行不确定度评定。结果表明，2组曲率半径的测量值均与标称值吻合，其相对误差为0001 15%，两组测量数据的标准不确定度均优于3211 11×10-4 mm。

Radius of curvature is one of the primary parameters of optical elements, and radius-of -curvature measurement is critical for precision optics manufacturing. A laser differential confocal radius-of-curvature measurement system was constructed and uncertainties of two groups of curvature radius measurement results were evaluated. It is demonstrated that the measurement results of two groups of curvature radius have a difference of 0001 15% with each other, which are all consistent with the nominal value, moreover the uncertainties of two groups are both superior to 3211 11×10-4 mm.