Commercial demand for optical transceivers operating at 14Gbps is now a reality. It is further expected that
communications standards utilizing 850nm VCSELs at speeds up to 28Gbps will be ratified in the near future. We report
on the development and productization of 850nm VCSELs for several applications, including high speed (both 14Gbps
and 28Gbps) operation to support the continued fulfillment of data communication demand.
VCSELs continue to be widely deployed in data communication networks. The total bandwidth requirements continue to
grow, resulting in higher data rates and utilization of both spatial and wavelength multiplexing. This paper will discuss
recent results on VCSELs operating at aggregate speeds up to 1000Gbps as well as the prospects and results on
extending to higher serial data rates.
In this paper we will discuss recent results on high speed VCSELs targeted for the emerging 16GFC (Fibre Channel)
standard as well as the now forming 25Gbps PCI express standard. Significant challenges in designing for reliability and
speed have been overcome to demonstrate VCSELs with bandwidth in excess of 20Gbps.
There has been great technological interest in the use of InAs quantum dots for InP-based lasers which can provide long wavelength emission in the 1.55-2 μm range. The atom-like densities of states of quantum dots provide low threshold current density, high differential gain, temperature insensitive operation and low chirp. However, to take advantage of these aspects, it is important to have dots with uniform size and shape. We report the atomic force microscope (AFM) and photoluminescence (PL) studies of self organized InAs quantum dots grown by molecular beam epitaxy on InGaAs and InAlAs lattice matched to InP. Our experiments confirm prior results that InAs forms quantum wires on InGaAs matrix layer. However, we find that depositing a thin buffer layer of InAlAs helps in the formation of well-shaped quantum dots. We believe that the aluminum in the buffer layer reduces the surface diffusion of indium adatoms and aids the formation of dots with high density. Our results show that formation of quantum dots depends strongly on the strain, surface energy and surface diffusion kinetics that are in turn dependent on the nature of buffer layer and growth conditions. We improve the quality of dots by optimizing the growth parameters such as growth temperature and arsenic overpressure.