色散对法布里－珀罗干涉仪纵模间隔的影响

摘要

In order to study effect of material dispersion on transmission characteristics of a Fabry -Perot interferometer ( F-PI) , transmission spectrum of the F-PI was calculated based on the Lorentz oscillator mode and the effect of dispersion intensityχ0 , attenuation coefficient γand resonant frequency ω0 on longitudinal mode interval was investigated .The results show that the interval between longitudinal modes at low and high frequency band decreases with the increasing of χ0 and increases with the increase of γ.For the longitudinal modes near ω0 , the interval between longitudinal modes increases with the increase of χ0 at first and then decreases .Whenχ0 is small, the interval between longitudinal modes decreases with the increase of γand increases with the increase of ω0 at first and then decreases when χ0 is big, the interval between longitudinal modes increases with the increase ofγat first and then decreases , and decreases with the increase of ω0 .The results are helpful for design and research of lasers.%为了分析材料色散对法布里－珀罗干涉仪透射特性的影响，采用洛伦兹振子模型计算了法布里－珀罗干涉仪的透射谱，研究了色散强度、衰减系数和谐振频率对纵模间隔的影响。结果表明，高、低频段的纵模间隔随色散强度的增大而减小，随衰减系数的增大而增大；对于谐振频率附近的纵模，纵模间隔随着色散强度的增大先增大后减小；色散强度很小时，纵模间隔随衰减系数的增大而减小，随谐振频率的增大先增大后减小；当色散强度较大时，纵模间隔随衰减系数的增大先增大后减小，随谐振频率的增大而减小。这一结果对激光器的设计和研究有一定的帮助。