Silicon photonics evolve into 1.3μm quantum dot lasers
The researchers utilised an engineered germanium silicon substrate and III-V molecular beam epitaxy template growth, both provided by IQE, to grow 1.3μm dots composed of indium (In) and arsenium (As).
The researchers believe the InAs quantum dots mark a milestone in large-scale photonic integration in an ultra low-cost platform, which will lead to the mass adoption of silicon photonics.
An optical micrograph of the fabricated laser devices. Source: Alan Liu, University of California Santa Barbara.
The development is considered to be a step closer to Vertical Cavity Surface Emitting Laser (VCSEL) wafers that have been used to produce communications lasers that achieve error-free operation at speeds up to 40Gb/s with energy dissipation below 100 fJ/bit.
The 980nm VCSELs developed at the Technical University of Berlin also exhibited extreme temperature stability during high-speed operation up to 85°C.
The efficiencies achieved with VCSELs is a critical factor in reducing the overall energy consumption of optical interconnects used in datacentres, and USCB's integrated quantum dot devices are seen as the next step in boosting the efficiency.
Professor Dieter Bimberg, Head of the Centre of NanoPhotonics at TU-Berlin, added:
This is the lowest reported value of dissipated energy at error-free operation for any semiconductor laser diode at any wavelength or bit rate. This result is achieved at a low current density of 10kA/cm2, demonstrating the suitability of our devices for application in reliable and sustainable commercial optical interconnects. At 40Gb/s the TU-Berlin/IQE VCSELs dissipate only 108 fJ per transmitted bit, which is at least four times less than any other published result for semiconductor laser diodes.
The researchers presented their results at the recently held Optical Fiber Communications Conference (OFC).
- Nick Flaherty
|Related Articles||Editor's Choice|