以激光回馈干涉技术提高砷化镓和蓝宝石晶体的折射率测量精度

砷化镓和蓝宝石晶体已经广泛应用于红外领域、光电领域和军事设备，因此两种材料的折射率测量对光学设计、计量检测和工业应用具有重要意义。为提高两种材料折射率的测量精度，采用微片激光回馈干涉技术同时测量折射率和厚度。此系统结合外差调制和准公共路径对空气气流和振动进行补偿，因此具有高灵敏度、高精度和高稳定性的特点，特别是同时测量性以及仅需将样品加工成薄片状而非棱柱形。实验结果表明，砷化镓和蓝宝石晶体（在寻常光下）的折射率测量精度提高到10?3和10?4，且厚度的精度均为10?4 mm。

Improving the measurement accuracy of refractive index of GaAs and Sapphire Crystal by laser feedback interferometry

GaAs and Sapphire Crystal has been widely used in infrared region, optoelectronics field and military equipment, so the measurement of refractive index of two materials is of great significance to optical design, metrological inspection and industrial application. To improve the measurement accuracy of refractive index of two materials, microchip laser feedback interferometer technology was used to simultaneously measure refractive index and thickness. The system combined heterodyne modulation and quasi-common path to compensate for airflow and vibration, so it has the characteristics of high sensitivity, high precision and high stability, especially the simultaneous measurement and only the material needs to be processed into flake rather than prism shape. The experimental results demonstrate that the measurement accuracy of refractive index of GaAs and Sapphire Crystal (under ordinary light) has been enhanced to 10?3 and 10?4 respectively and thickness is 10?4 mm.