SBIR Phase I: Low-Cost Laser Ultrasonic Receiver for Industrial Inspection Based on Pseudo Phase Conjugation

这个小型企业创新研究（SBIR）第一阶段项目提出了使用无源干涉接收机的可行性，该接收机使用伪相位共轭作为低成本激光超声检测系统的一部分，用于工业检测和过程控制。在许多工业应用中，传统的无损检测技术不能用于实时过程控制，因为零件是热的，振动或快速平移。激光超声波是一种远程，非接触式检测技术，克服了这些限制，可以在最苛刻的工业环境中发挥作用。新的接收器将展示高检测灵敏度和带宽，以及对粗糙表面斑点的静态和动态补偿。该设计改编自经典概念，但不需要路径长度稳定，也不使用光折变晶体。使用为电信应用开发的光纤组件，接收器可以在人眼安全波长下工作。激光超声可用于无缝钢管和玻璃容器的在线壁厚测量，用于激光焊接的在线检测，以及用于航空航天工业的大型复合材料板的扫描检测。在每种情况下都记录了大量的成本节约。

This Small Business Innovative Research (SBIR)Phase I project proposes to demonstrate the feasibility of using a passive, interferometric receiver using pseudo phase conjugation as part of a low-cost laser ultrasonic inspection system for industrial inspection and process control. In many industrial applications, conventional nondestructive inspection techniques cannot be applied for real-time process control, because parts are hot, vibrating or translating rapidly. Laser ultrasonics is a remote, non-contact inspection technique that overcomes these limitations and can function in the most demanding industrialenvironments. The new receiver will demonstrate high detection sensitivity and bandwidth, as well as static and dynamic compensation for speckles from rough surfaces. The design is adapted from classical concepts but requires no path-length stabilization and uses no photo-refractive crystal. The receiver can operate at an eye-safe wavelength using fiber optic components developed for telecomm applications.Laser ultrasonics can be used for in-line wall thickness measurement of seamless steel tubes and glass containers, for in-line inspection of laser welds, and scanning inspection of large composite panels used in the aerospace industry. Substantial cost savings have been documented in each case.