低波长漂移的电吸收调制DFB激光器

Low Wavelength Shift Electroabsorption Modulated DFB Laser

采用端面有效反射率法 ,从理论上计算了单片集成电吸收调制 DFB激光器 (Electroabsorption ModulatedDFB L aser,EML)的腔面反射率、耦合强度 (κL)对其波长漂移的影响 .同时在实验中通过改变腔面的反射率来验证计算结果 .理论与实验的结果表明 :为提高 EML 的模式稳定性 ,必须减小调制器一端的反射率 ,同时增加DFB激光器的 κL.最终我们采用选择区域生长 (Selective Area Growth,SAG)的方法 ,制作了低光反馈出光面的单脊条形 EML,在 2 .5 Gb/ s的非归零 (NRZ)码调制下 ,经过 2 80 km的标准光纤传输后 ,没有发现色散代价 .

Effective facet reflectivity incorporating couple wave theory is adopted to calculate wavelength shift of electroabsorption modulated DFB laser (EML) with different facet reflectivity,facet phase and coupling strength,κL.Wavelength shift of index coupled EML is measured by optical spectrometer when the modulator side facet of the EML is coated with different reflectivity optical thin films.Theoretic and experimental results show that light feedback from the modulator output facet must be minimized and a relatively larger κL is needed to maintain the longitudinal mode stability.Single ridge waveguide EML incorporating InP window and anti-reflection optical film coating is fabricated by selective area growth.No power penalty is observed at a bit-error-ratio of 10 -12 after standard single mode fiber transmission of 280km long when the EML is modulated with 25Gb/s NRZ 2 23-1 PRBS data.