Development of defect investigation technique using multi channel detector

从混凝土表面散射出来的光变成了斑点状。虽然利用光折光型干涉仪可以解决相位分布的无序性，但仍然存在空间强度分布，信噪比存在空间差异。然后，利用多通道光检测器对信号光进行空间分割，并对去除低灵敏度通道等进行处理，以提高信噪比为目标。在此检测中，信噪比提高1.9倍。进行了混凝土表面二维测量和弹性波在混凝土表面传播可视化的基本实验。利用多通道光学探测器成功地测量了压电致动器表面的振动。

The scattered light from the concrete surface has become speckle-like. Although the disorder of the phase distribution could be solvable by using a photo refractive type interferometer, spatial intensity distribution still exists and the signal noise ratio differs spatially. Then, signal light was spatially divided using the multi-channel optical detector, and it processed removing a channel with low sensitivity etc., and aimed at improvement in S/N ratio. In this detection, there was improvement in 1.9 times of S/N ratio.The basic experiment which measures the concrete surface by two dimensions and the elastic wave propagation on the surface of concrete visualizes was conducted. It was successful that vibration of the piezo actuator surface was measured by multi-channel optical detector.