In this work, a novel light source of tandem InGaAsP/InGaAsP multiple quantum well electroabsoption modulator(EAM) monolithically integrated with distributed feedback laser is fabricated by ultra-low-pressure (22×１０２Pa) selective area growth metal-organic chemical vapor diposition technique. Superior device performances have been obtained, such as low threshold current of 19 mA, output light power of 4.5 mW, and over 20 dB extinction ratio at 5 V applied voltage when coupled into a single mode fiber. Over 10 GHz 3dB bandwidth in EAM part is developed with a driving voltage of 2 V. Using this sinusoidal voltage driven integrated device, 10GHz repetition rate pulse with an actual width of 13.7 ps without any compression elements is obtained due to the gate operation effect of tandem EAMs.