Dilute nitride materials and detectors for next generation optical communications

Optical communications underpin many aspects of modern life and most importantly today's economy. Everyone simply expects to be able to move large amounts of data around the world rapidly and for almost zero cost. Moreover, everyone expects bandwidths and data rates to continue to increase year on year. In the same way that Moore's law for silicon chip technology has had significant economic impact, confidence in increasing communication bandwidths has enabled and even driven economic growth around the world. Also analogous to Moore's law, the research effort required to meet the expected increase is significant and escalates with each technology generation. This PhD project will contribute to developing the next generation of detectors for optical transceivers.
The project will focus on the development and application of dilute nitride semiconductor materials in infrared detectors. In particular InGaAsN, grown lattice matched to GaAs, will be studied. IQE will provide the growth expertise and resource for the project, as well as providing a scalable route to commercial exploitation and impact. Novel unity gain and avalanche detectors will be developed, with the aim of reducing cost and increasing bandwidths. The gain-bandwidth product for avalanche detectors is of great importance as bit rates increase. Current values, typically <200GHz, will limit the magnitude of gain which can be exploited in high bit rate receivers and this threatens to become a roadblock to increases in bitrates. The project will seek to raise the gain-bandwidth product achievable using alternative materials and structural changes.