光反馈自混合干涉技术是一种新出现的有别于传统双光束干涉的测试技术。文章基于此技术对半导体激光器进行线宽展宽因数的测量，以激光器HL7851G为对象进行了大量的实验，实验结果与线宽测量法基本一致，相对误差只有3.22%。相比线宽测量法，光反馈自混合法具有成本低、精度高的优点，是一种更加简洁有效的测量方法。

Dynamics of a semiconductor laser subject to moderate optical feedback operating in the low-frequency fluctuation regime is numerically investigated. Multimode Lang-Kobayashi (LK) equations show that the low-frequency intensity dropout including the total intensity and sub-modes intensity is accompanied by sudden dropout simultaneously, which is in good agreement with experimental observation. The power fluctuation is quite annoying in practical applications, therefore it becomes important to study the mechanism of power fluctuation. It is also shown that many factors, such as spontaneous emission noise and feedback parameter, may influence power fluctuation larger than previously expected.