《光纖光柵頻譜》ppt課件

1、光纖光柵的光譜特性-典型光纖光柵構(gòu)造及其光譜特性1 均勻周期光纖光柵2( )(1cos()coren znnz 典型折射率分布函數(shù): 設(shè)光柵參數(shù)為:包層折射率nclad=1.45,纖芯折射率ncore=1.45+0.006,纖芯直徑d=5 ,光柵長3.0mm,45 10n 00.5m 光譜特性分析m折射率分布圖Contour Map of Index Profile at Y=0X (m)30-20-10-0102030Z (m)0123456789101.451.4565折射率分布截面圖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 不考慮擾動考慮擾動計算結(jié)果光柵長度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光纖Bragg光柵的反射譜根本特性N表示光柵周期數(shù)( )cos

3、(/ ),/2:/2v zz L zLL 2 Taper型光柵切趾其它參數(shù)同前折射率分布曲線頻譜響應(yīng)2( )cos (/ ),/2:/2v zz L zLL Grating Spectral Responsex10-4Wavelength (m)14502145051450814511145141451714520Relative Power (a.u.)0.00.10.20.30.40.5頻譜響應(yīng) 典型應(yīng)用: 作為激光器外腔反射鏡,與其它器件組成波分復(fù)用器,窄帶濾波器等3 線性啁啾光柵( )(/2)0.001 (/0.5)zzLZ L (0, )ZL頻譜響應(yīng)光柵長度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 增大周期變化頻譜優(yōu)化同時應(yīng)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典型應(yīng)用 寬帶濾波器 色散補(bǔ)償器4. Moire相移光柵由前述的兩段光纖光柵組成，初始相位相差180度光譜特性由兩段均勻周期光纖光柵組成Grating Spectral ResponseWavelength (m)1.4501.4511.452Relative Power (a.u.)0.00.10.20.30.40.50.60.70.80.91.0典型應(yīng)用 窄帶通濾波