Background: Photonic Integrated Circuits for high-temperature operation
Operating temperature is a key factor in determining both performance and practicality of laser-diodes. Temperature control tends to improve performance by reducing threshold current, improving efficiency and speed, and stabilizing output wavelength. Yet avoiding the need for cooling and temperature stabilization reduces module power requirements, cuts costs, and allows operation in a wide range of environments. Increasingly importantly, it facilitates denser photonic integration and co-integration with electronics. In the framework of a very large national photonics initiative
, in this project we intend to evaluate the laser active layer design in terms of high-temperature suitability and identify the primary physical processes which are limiting the maximum operating temperatures.Project description
The InGaAsP/InP alloys have relatively low barrier heights in the active layers, impairing charge carrier confinement, leading to a further, rapid degradation in efficiency at high temperature. at a wavelength of 1550nm. The low numbers of quantum wells require higher carrier densities, accelerating these inefficacies. The deployment of photonic integrated circuits within electronic systems will require photonic circuits to operate well beyond 100 degrees Celsius. This will require innovations in predictive methods for accelerated lifetime estimation.
The selected candidate will perform cutting-edge applied research in material science.
Within the PSN group, the expertise in defect analysis provides state-of-the-art tools for identifying recombination centres, their origins and their impacts. Additionally, the PSN has developed an experimental environment tailored for the investigation of optical and electronic structures at the level of individual defects. Besides that, the group's excels in methods beyond the effective mass approximation, enabling band-gap engineering in systems characterized by robust spin-orbit interactions (such as InGaAlAs/InP alloys), particularly for optoelectronic application.
The projects will be supervised by dr. A. Silov at the Department of Applied Physics, in collaboration with prof. K. Wiliams, Electrical Engineering Department and companies active in photonics.