《光纤光栅频谱》ppt课件

1、光纤光栅的光谱特性-典型光纤光栅构造及其光谱特性1 均匀周期光纤光栅2( )(1cos()coren znnz 典型折射率分布函数: 设光栅参数为:包层折射率nclad=1.45,纤芯折射率ncore=1.45+0.006,纤芯直径d=5 ,光栅长3.0mm,45 10n 00.5m 光谱特性分析m折射率分布图Contour Map of Index Profile at Y=0X (m)30-20-10-0102030Z (m)0123456789101.451.4565折射率分布截面图Cut of Index Profile at X=-0.5Z (m)012345678910 x10-4

2、Refractive Index145561455814560145621456422 1.451 0.51.451 mBeffn 22 1.4512 0.51.4512 mBeffn 不考虑扰动考虑扰动计算结果光栅长度L增大至10mmGrating Spectral Responsex10-4Wavelength (m)14508 14509 14510 14511 14512 14513 14514 14515 14516Relative Power (a.u.)0.00.10.20.30.40.50.60.70.80.91.0光纤Bragg光栅的反射谱根本特性N表示光栅周期数( )cos

3、(/ ),/2:/2v zz L zLL 2 Taper型光栅切趾其它参数同前折射率分布曲线频谱响应2( )cos (/ ),/2:/2v zz L zLL Grating Spectral Responsex10-4Wavelength (m)14502145051450814511145141451714520Relative Power (a.u.)0.00.10.20.30.40.5频谱响应 典型应用: 作为激光器外腔反射镜,与其它器件组成波分复用器,窄带滤波器等3 线性啁啾光栅( )(/2)0.001 (/0.5)zzLZ L (0, )ZL频谱响应光栅长度L=40mmGrating

4、 Spectral ResponseWavelength (m)1.421.431.441.451.461.471.48Relative Power (a.u.)0.00.10.20.30.40.50.6( )(/2)0.005 (/0.5)zzLZ L 增大周期变化频谱优化同时应用Taper和啁啾Grating Spectral ResponseWavelength (m)1.421.431.441.451.461.471.48Relative Power (a.u.)0.00.10.20.30.40.5典型应用 宽带滤波器 色散补偿器4. Moire相移光栅由前述的两段光纤光栅组成，初始相位相差180度光谱特性由两段均匀周期光纤光栅组成Grating Spectral ResponseWavelength (m)1.4501.4511.452Relative Power (a.u.)0.00.10.20.30.40.50.60.70.80.91.0典型应用 窄带通滤波