光纤检测中数据处理方法研究

随着光纤的应用日趋广泛，在一些领域(例如军事)对光纤的质量提出了更高的要求。光纤生产过程中产生的微小气泡等缺陷，因影响光纤的强度和光纤中信号的传输质量而使精密系统受到影响，有时这种影响甚至是致命的。因此寻求一种有效的、非接触的、在线的和快速的光纤微小缺陷检测方法非常重要。光电混合联合变换相关器是方法之一。该方法的关键是如何提高系统的识别能力。文中通过对用该方法得到的数字化功率谱特性的研究，提出用减小功率谱直流项和二值化两种方法进行数字化处理。实验结果表明，两种方法都能提高系统相关输出的信噪比，减小中间峰的强度，从而使系统的识别能力得到很大程度的提高。

Investigation on data processing methods in the detection system of optical fiber

As the application of optical fiber is boasting, higher quality optical fibers are required in some application fields. Some pinhole defects such as air bubbles, caused during the manufacture of optical fiber, may have severe (or fatal) impacts on precision instruments because of affecting the optical fiber's toughness and signal propagating along the fiber. Therefore, it is very important to detecting the defects in optical fiber using an effective, non-touched, on-line and fast method. A hybrid opto-electronic joint transform correlator (JTC) is competent to do it. The key using the JTC is how to improve discrimination of the detection system. In this paper, through investigating the characteristics of digital joint power spectrum of optical fiber, two data processing methods to improve discrimination of the system are proposed, which are reducing joint-power-spectrum DC item method and binarizing joint power spectrum method. The experimental results show that both methods can greatly increase SNR and reduce the intensity of central peak of the correlation output, and largely improve discrimination probability of the detection system.