白光光源光谱对白光干涉信号的影响

Influence of white light source spectrum on interference signal

传统白光光源一般由一个纯高斯函数来进行模拟,通过改变中心波长和带宽来调节干涉信号.本文分别利用高斯模型和洛伦兹模型来讨论白光干涉信号,得出中心波长与相干长度的比值越大,零级条纹可见性越高,以及高斯模型的可靠范围.鉴于现代白光光源与传统光源不同,以发光二极管(LED)为例,模拟研究现代白光光源对白光干涉信号的影响.利用洛伦兹模型模拟白色LED光源时干涉信号存在凹陷,通过合理调整LED拟合光峰值间的距离降低凹陷对零级条纹的影响,以期得到在实际应用中干涉特性较优的白光光源光谱.

Traditional white light sources are typically modeled by a pure Gaussian function,which adjust theinterference signal by changing the center wavelength and bandwidth. In this paper,the Gaussian model and theLorentzian model are used to discuss the white light interference signals,respectively. The larger the ratio of thecentral wavelength to the coherence length is,the higher the visibility of the zero-order fringes. The reliable rangeof the Gaussian model is also obtained. In view of the difference between modern white light source and traditionallight source,the white LED is used as an example to simulate the influence of modern white light source on whitelight interference signal. When the Lorentz model is used,the interference signal has a depression. Furthermore,byadjusting the distance between the peaks of the LED fitting light properly,the influence of the depression on the zero order fringes is reduced in order to acquire a better white light source spectrum with interference properties inpractical application.