Multiple mode resonance shifts in tilted fiber Bragg gratings (TFBGs) are used to simultaneously measure the thickness and the refractive index of TiO₂ thin films formed by Atomic Layer Deposition (ALD) on optical fibers. This is achieved by comparing the experimental wavelength shifts of 8 TFBG resonances during the deposition process with simulated shifts from a range of thicknesses (T) and values of the real part of the refractive index (n). The minimization of an error function computed for each (n, T) pair then provides a solution for the thickness and refractive index of the deposited film and, a posteriori, to verify the deposition rate throughout the process from the time evolution of the wavelength shift data. Validations of the results were carried out with a conventional ellipsometer on flat witness samples deposited simultaneously with the fiber and with scanning electron measurements on cut pieces of the fiber itself. The final values obtained by the TFBG (n = 2.25, final thickness of 185 nm) were both within 4% of the validation measurements. This approach provides a method to measure the formation of nanoscale dielectric coatings on fibers in situ for applications that require precise thicknesses and refractive indices, such as the optical fiber sensor field. Furthermore, the TFBG can also be used as a process monitor for deposition on other substrates for deposition methods that produce uniform coatings on dissimilar shaped substrates, such as ALD.

针对目前常见广义椭偏仪变角结构多采用双电机驱动，且存在结构复杂、变角后光路存在偏离等问题，论文提出一种单电机驱动广义椭偏仪新的变角结构。该结构采用固定起偏臂，利用同步齿轮传动单电机驱动方式使载物台和检偏臂同步旋转，实现椭偏仪多角度测量。在传统卧式结构广义椭偏仪变角结构基础上，设置样品载物台和检偏臂1∶2同步传动，并通过Inventor运动仿真验证了本结构的可行性。论文提出的单电机驱动变角结构变角后不仅维持了变角前后的准直，而且其整体结构简单，极大地优化了椭偏仪变角的复杂度，在广义椭偏仪工程化进程中有比较重要的应用价值。