High speed nanophotonic devices based on quantum dots

Speaker:

Nikolai Ledentsov Professor, A.F. Ioffe Institute (Russia) / VI-Systems GmbH (Germany)

Co-Author(s):

[1] N.N. Ledentsov, V.M. Ustinov, A.Yu. Egorov, A.E. Zhukov, M.V. Maximov, I.G. Tabatadze, P.S. Kop’ev “Optical properties of heterostructures with InGaAs-GaAs quantum clusters” Semiconductors Vol. 28, pp. 832-834 (1994), submitted December 29th 1993.

[2]N. N. Ledentsov, D. Bimberg, Zh.I.Alferov "Progress in Epitaxial Growth and Performance of Quantum Dot and Quantum Wire Lasers" Journal of Lightwave Technology Vol. 26, Issue: 9-12, pp. 1540-1555 (2008).

Quantum Dot (QD) lasers were first demonstrated in 1993 [1]. Since that time advantages of a complete three-dimensional quantum confinement of carriers in QDs were properly understood allowing several strategic device applications [2].
Presently, due to the serious problems met by the mainstream “quantum well” (QW) technology, the introduction of quantum dot lasers may be accelerated further.
Continuous silicon scaling resulted in a dramatic input-output (I/O) bandwidth demand for the processor chips. Signaling rate of 27Gb/s is required for chip-to-chip interconnects to address memory and peripherals for the 45 nm node. At these speeds, already medium distances suffer from significant power dissipation in the copper links. Furthermore, data transmission at speeds of 17 and 20Gb/s is on the roadmaps of Fibre Channel standard for Storage Area Networks and Infiniband interconnect standard, respectively. The related applications also access optical networks for further data distribution and aggregation at 10-100m distances, particularly in Datacenters.
This bandwidth gap could be potentially bridged by the transceivers based on the QW Vertical Cavity Surface Emitting Lasers (VCSELs), which are traditionally used in these networks. QW VCSEL, representing a micro-resonator device, is characterized by low power dissipation, while being highly reliable and cost effective transmitter for very short reach optical interconnects at signaling speeds of 10Gb/s and below. Low power consumption of VCSEL is a must for applications in datacenters, which already absorb 1.5% of the total electricity produced in the USA in 2006 (the consumption doubles each 5 years).
Surprisingly, QW VCSELs appeared to be not reliable at transmission speeds significantly above 10Gb/s, and there is a quickly evolving bottleneck, which is already taking its tall in numerous key applications and causing delays in the standardization schedules.
We will explain how Quantum Dot nanostructures can provide a solution to this dramatic challenge in modern datacommunication industry.