加工制作了一种液芯变焦柱透镜，并利用这种柱透镜精确测量液体的折射率。在空心的柱透镜内注入待测液体，通过测量液芯透镜的焦距，根据焦距和折射率之间的关系，计算出液芯介质的折射率。此方法有效地提高了折射率测量的灵敏度，减小了测量系统的景深。选取20×显微物镜可实现液体折射率在1.3~1.642范围内的精确测量，单次测量误差小于0.0002。对透镜折射率灵敏度曲线以及测量系统景深曲线的分析表明，增加折射率灵敏度和测量系统的有效数值孔径，可以进一步提高测量的准确度。

A liquid-core-zoom cylindrical lens has been fabricated, which is used to measure accurately the refractive index of liquid filled into the core region of the cylindrical lens. The focal length of such a cylindrical lens varies with the refractive index of core liquid, which can be known by measuring experimentally the related focal length. Due to a high sensitivity in measuring refractive index and a short depth of field, a high accuracy in measurement of refractive index is ensured. The accuracy of refractive index for one single measurement is better than 0.0002 in the range of 1.3~1.642, when a 20× objective is used in a reading microscope. By either enhancing sensitivity of refractive index of the cylindrical lens or enlarging effective numerical aperture of the measurement system, the accuracy of refractive index can be further improved.