引入复自相干度来度量同一脉冲产生的超连续谱的相干性,并对其进行了实验研究.采用Mach-Zehnder干涉仪,测量700 ps脉冲抽运光予晶体光纤产生的超连续谱的相干性.实验测得超连续谱不同波长成分的相干长度均大于40μm,在长波区可达225μm.超连续谱的整个光谱区域各谱成分的相干度有差异,但复自相干度的模平均值为0.461,相干性较好,可以满足如光测量、光学传感等很多应用.
The complex degree of self-coherence is introduced to quantify the coherence of supercontinuum generated by the same long pulse,and experiments are performed.The coherence properties of supercontinuum generated in the photonic crystal fiber pumped by 700 ps pulse are measured using the Mach-Zehnder interferometer.The experimental results show that the coherence lengths of different wavelength parts of the supercontinuum are all longer than 40μm,and can reach 225μm in the long wavelength region.The coherence degrees of different parts of supercontinuum are not the same;however,the mean coherence degree over the supercontinuum is 0.461 which manifests good coherence property of the whole spectrum of supercontinuum.Consequently,requirements of many applications such as optical measurement and optical sensing can be satisfied.