2.5 Gb/s electroabsorption modulator integrated with partially gain-coupled distributed feedback laser fabricated using a very simple device structure

An electroabsorption (EA) modulator integrated with a partially gain-couple d distributed feedback (DFB) semiconductor laser is fabricated using a very simple device structure. An identical epitaxtial layer is used for the act ive layer of the laser and the waveguide of the modulator to achieve wavele ngth compatibility between the two components. The fabricated device shows a low threshold current of 27 mA, a large extinction ratio of over 17dB at -3 V, and a fiber coupled power of 2.7 mW. Packaged modules are also fabric ated for 2.5 Gb/s operation. The power penalty at a 10(-10) bit-error rate is less than 0.5 dB after transmission through 240 km of traditional fiber The influence of lasing wavelength detuning on device performance is also d iscussed based on our experimental data.