Retroreflective projection gratings

A retroreflective projection grating technique has been investigated to inspect quasi flat and specular surfaces. The method introduces the flexibility to adjust the properties of the grating to a specific application or to move it as a whole, in order to use phase shifting technology. Three types of optical configuration have been demonstrated. The method has been tested with a quantified artifact. The experiment shows that it can successfully recover the contour and amplitude of the surface waviness on the artifact. The method can be developed for industrial application in nondestructive testing and evaluation (NDTE).     

高折射率玻璃微珠色散特性及影响

基于二次彩虹法用三种不同波长(632.8 nm、532 nm、404 nm)的激光测量了玻璃微珠的折射率,并由柯西色散公式拟合得到三种典型高折射率玻璃微珠1.90、1.93和2.2的色散方程,得出现行的玻璃微珠具有正常色散但色散较大的结论.通过分析在不同入射角情况下,色散对玻璃微珠回归反射性能的影响,得出折射率1.90和1.93的玻璃微珠具有优良的回归反射性能.此外,用光线追迹模拟了色散对回归反射后光能量在近轴区域分布的影响,折射率1.90和1.93的玻璃微珠回归反射光线的能量主要集中在5°范围内.