Growth and fabrication of an integrated DFB laser and EA modulator

By using the selective area growth (SAG) technique, the grating over growth technique, and the buried hetero-structure (BH) regrowth technique, we have successful fabricated integrated distributed feedback laser and electro-absorption modulator. A suitable tensile strain is introduced during the multiple quantum well (MQW) growth to compensate the compressive strain caused by the SAG effect. To obtain better control on the growth condition and grating coupling coefficient, a quaternary grating laser is used. The best DFB laser shows a threshold current of around 12 mA and slope efficiency up to 0.13 mW/mA from one facet.