Method of measuring the refractive index distribution and composition ratio distributions of the optical crystal wafer

摘要

PROBLEM TO BE SOLVED: To measure a refractive-index distribution of a sample by a higher- accuracy and quick method without being influenced by a distribution of a wafer thickness in view of a problem of a conventional technique.;SOLUTION: An apparatus for measuring the refractive-index distribution by using a z-cut 5-inch LiNbO₃ wafer is arranged as shown in the figure. In order to measure a transmitted-wave-front strain (an optical path length), an interferometer made by ZYGO Company is used. A polarization state in a measurement is changed over. A reflecting mirror 3 is mounted on a mirror mount 4 to which a tilt adjustment is attached, and a tilt is adjusted by tilt adjusting screws 5, 6, 7. The optical systems are arranged on a vibration-proof optical surface plate, and the whole is arranged inside a clean bench controlled at 0.1°C.;COPYRIGHT: (C)2004,JPO