基于光纤多波长激光器的相位延迟高精密测量系统设计

Design of high precision phase delay measurement system based on fiber multiwavelength laser

摘要:

针对当前相位延迟测量系统，缺少对入射光源的分析，导致不同波长光源对应平移量误差大，造成相位延迟测量精度低的问题，设计了基于光纤多波长激光器的相位延迟高精密测量系统。通过分析光纤散射原因，选取532nm半导体激光作为系统光源，采用伺服电机为系统供电，使用SGX5528光电探测器实现光转换为电，从而获得不同位置间的电位差。利用聚乙烯醇薄膜拉伸型人造偏振片，使入射的纵光或横光具有起偏特性，并测量偏振片的透振方向和横轴夹角，完成系统硬件设计。设置两束激光光源，调整偏振棱镜，使光强输出达到最大值，并利用直接测量法，计算待测波片的相位延迟，通过调整电光调制器晶轴方位，保证光束垂直入射到器件表面，完成系统软件设计，实现相位延迟高精密测量。实验结果表明，该系统在L0、L1、L2位置下的平移量误差分别为0.008mm、0.0071mm、0.002mm，均小于理想允许误差，能够有效提高相位延迟测量精度。

Abstract:

Due to the lack of analysis of the incident light source in the current phase delay measurement system, the corresponding translation error of different wavelength light sources is large, resulting in low phase delay measurement accuracy. A high-precision phase delay measurement system based on fiber multi wavelength laser is designed. By analyzing the cause of fiber scattering, 532nm semiconductor laser is selected as the system light source, servo motor is used to supply power for the system, and SGX5528 photodetector is used to realize the conversion of light into electricity, so as to obtain the potential difference between different positions. The polarizer is made of polyvinyl alcohol (PVA) film to make the incident longitudinal light or transverse light have polarization characteristics. The transmission direction and transverse axis angle of the polarizer are measured to complete the hardware design of the system. Set two laser light sources, adjust the polarizing prism to make the light intensity output reach the maximum value, and use the direct measurement method to calculate the phase delay of the wave plate to be measured. By adjusting the crystal axis orientation of the electro-optic modulator, ensure that the beam is perpendicular to the surface of the device, complete the system software design, and realize the high-precision measurement of the phase delay. The experimental results show that the translation errors of the system at L0, L1 and L2 are 0.008 mm, 0.0071 mm and 0.002 mm respectively, which are less than the ideal allowable error, and can effectively improve the phase delay measurement accuracy.