Photonic integration technology is a key enabler of high bit-rate coherent optical communication systems. The integration of dissimilar optical elements on a common substrate has led to narrow linewidth widely tunable lasers, high performance I-Q modulators, and integrated coherent receivers. We review the fundamentals and latest developments.
We demonstrate InxAlyGa1-x-yAs based electro-absorption modulated DFB laser at 1.3 μm wavelength based on selective area growth technique. The fabricated device exhibits 5 mW output power, wide E-O bandwidth (>40 GHz), 2V driving-voltage for 10 dB extinction ratio, and clear eye-opening at 32Gbit/sec.
Large p-doping offset layer in a p-i-n heterostructure is proposed for Impurity free vacancy disordering (IFVD) quantum-well-intermixing (QWI) in a SOA-integrated EAM. The P-dopant diffusion during QWI can thus be reduced for performing bandgap engineering, leading to high-speed modulation of 30Gb/s and improving modulation efficiency.