为了研究激光切割过程光信号与切割质量的关系，搭建了以切割前沿光辐射作为检测参量的实时检测系统，对切割前沿光辐射的时、频域信号进行了试验研究，得到了不同参数下光信号的变化规律。时域分析表明，无缺陷式样对应的标准方差较低；与无缺陷切割相比，过烧缺陷对应的光信号具有较低的强度和较高的标准方差；挂渣缺陷具有较高的强度和标准方差。频域分析表明，低速切割，光信号主频与切缝表面波纹频率一致；高速无缺陷切割无明显主频；挂渣缺陷具有明显的低频波动。结果表明，燃烧循环理论不仅是切割面波纹形成的主要因素，也是光信号主频产生的主要原因。

In order to study the relationship between optical signal and cutting quality,an on-line monitoring system with cut front radiation as the criterion for laser cutting was built up. The signal was studied in time-domain and frequency-domain. The analysis in time-domain shows that there is little fluctuation for free defect,while the reverse for the defects. The analysis in frequency-domain shows that when the cutting speed is slower than that of combustion reaction,the dominant frequency relates to the waviness frequency of cut front. The combustion cycle is the main reason of both cutting waviness and main frequency of optical signal.