色散补偿啁啾光纤光栅耦合模方程理论探讨

Theoretical discussion of couple mode using chirped fiber grating in compensation

对色散补偿啁啾光纤光栅耦合模方程进行了理论研究，提出了耦合模方程的一种解法。讨论了光纤光栅的透射率和反射率是位置函数的问题，进一步研究了啁啾光栅色散补偿器的耦合系数和色散系数。研究结果表明：啁啾光纤光栅的反射率不仅与光栅的模式耦合系数有关，同时也与变周期有关；减小光栅的模式耦合系数可以增大耦合效率和提高光栅反射率。对于色散补偿器来说，它的带宽必须大于光脉冲的带宽，啁啾光栅的带宽越窄，它的色散系数就越大。

After theoretical study of the couple mode equation of chirped fiber grating for compeusating dispersion,a solution to the equation is presented,meanwhile the problem that transmitting and reflecting rates are a sitting function is discussed,the dispersion coefficient and coupled coefficient of compensator in chirped fiber grating are further studied.The research shows that the reflecting rate of the fiber grating is associated not only with its mode couple coefficient but also its varying peorid. The couple efficiency and the reflecting rate increase with the decrease of the mode couple coefficient.The bandwidth of the compensator should be greater than that of laser pulse,and the greater the dispersion cofficient is,the narrower the bandwidth of chirped fiber grating.