We present principles for tunnel-juhction (TJ) design optimization for use in intracavity contacted long-wavelength vertical-cavity surface-emitting lasers (LW-VCSELs). Using the WKB approximation, we find that layer thicknesses of 10 nm on the n++ side and 10 mn on the p++ side are large enough to maximize quantum tunneling probability and small enough to yield low optical free-carrier absorption loss. We also conjecture that our experimental test structures and actual devices have far lower active acceptor concentration than we expect based on an analytical model. Finally, we calculate the necessary doping levels to enable single-mode operation of LW-VCSELs and incorporate these conditions into a complete optimized model of our VCSELs. Based on optimal I-V curves, we can expect an increase in single-mode output power from 2 to 3.5 mW.

A monolithic integration platform is demonstrated for high functionality photonic circuits that include quantum-well electroalisorption modulators, semiconductor optical amplifiers, and widely tunable lasers. The platform is based on the selective removal of a set of active quantum wells located above an optical waveguide layer. The waveguide layer contains a second set of quantum wells to be used in modulator regions. Fabrication requires only a single blanket InP regrowth.

A method of all-optical synchronisation is proposed and demonstrated at 40 Gbit/s. Based on pre-programmable fibre Bragg grating army and fast-switched widely-tunable wavelength converters. negligible power penalty is achieved up to 1 mu s delay as well as 100% layer 22 throughput.

Tunable photocurrent-driven wavelength converters using widely tunable sampled grating distributed Bragg reflector lasers, electroabsorption modulators, semiconductor optical amplifiers, and an optically preamplified receiver have been fabricated and tested. Dynamic wavelength conversion has been achieved over 40 nm with optical bandwidths up to 10 GHz.