Monolithic integration of a 1.55-mu m strained multiple-quantum-well distributed feedback laser and quantum-confined Stark-effect modulator by metal organic vapor-phase epitaxy using an InP-buffer-layer incorporated Butt coupling scheme

We present experimental studies on monolithic integration of a 1.55-mu m wa velength InGaAsP/InGaAsP multiple quantum well (MQW) distributed feedback ( DFB) laser with an electroabsorption modulator based on the quantum-confine d Stark-effect (QCSE) by using a InP-buffer-layer incorporated butt-couplin g metalorganic vapor phase epitaxy An electroabsorption change of 46 meV du e to the QCSE was obtained in an applied electric field of 2x10(5) V/cm ove r the 1.55-mu m wavelength region. Using the self-aligned semiconductor fab rication process, we obtained a high-performance electroabsorption modulato r-integrated DFB laser light source having a threshold current of 14 mA, a bandwidth of 3 GHz, and an extinction ratio of 13 dB with -2.5 volts applie d to a 200-mu m-long modulator chip. A Si3Nx film was deposited on the modu lator facet as an anti-reflective coat and gave a lon spectral width of 0.2 nm at 13 dB under a 2.5 Gbps non-return-to-zero pseudo-random modulation.