We report on the design and experimental results of monolithically integrated optoelectronic devices containing distributed feedback (DFB) laser, electroabsorption modulator (EAM), and semiconductor optical amplifier (SOA). Common InGaAlAs multiple quantum well (MQW) layers are used in all device sections. The incorporation of local lateral metal gratings in the DFB section enables device fabrication by single-step epitaxial growth. The emission wavelength is λ=1.3 micrometer. More than 2 mW single-mode fiber-coupled output power as well as 10 dB/2 V static extinction ratio have been achieved. Modulation experiments clearly show 10 Gbit/s capability.
We present experimental results on 40 Gb/s large-signal modulation performance of 1.31μm monolithic integrated laser-modulator in the InGaAlAs/InP material system, exploiting the gain and absorption properties of an identical multiple quantum well (MQW) active layer. In continuous wave operation, at 15°C, the devices achieved threshold currents < 28 mA, fiber coupled optical power levels up to +0.4 dBm. The measured small-signal modulation bandwidth was about 32 GHz. An air-cavity based Fabry-Perot interferometer has been realized to characterize the spectral chirp of the integrated structures in the time domain up to 40 Gb/s.
We present first experimental results of the successful transfer of our monolithic integrated double-stack multi quantum well laser-modulator approach from the traditional InGaAsP/InP to the more promising InGaAlAs/InP material system. In continuous wave operation at room temperature, the devices achieved threshold currents of <21 mA, fiber coupled optical power levels up to 570 μW and static extinction ratios in the range of 15 dB/V. The measured small-signal modulation bandwidth of about 10 GHz is capacitance limited due to a conservative device layout.