1.55 μm lasers epitaxially grown on silicon for optical interconnects

Achieving high performance, long lifetime, and electrical injection silicon-based lasers will deliver the last missing building block in silicon photonics, a platform that can not only enable optical interconnects, but also serve other growth markets such as cluster computing, light detection and ranging (LIDAR), machine vision and environmental sensing. This project aims to develop high-performance 1.55 µm C-band quantum dot (QD) and nano lasers to benefit from the lowest fibre attenuations. Advanced heteroepitaxy techniques will be explored to yield highly strained nanostructures with superior optical qualities and low dislocation density III-V materials on silicon and silicon-on-insulator substrates. The material and device characteristics and possible light coupling schemes with silicon photonics will be investigated.

The newly established metal-organic chemical vapour deposition (MOCVD) capability at Cardiff University and the availability of molecular beam epitaxy (MBE) provides a complementary experimental setting for the study in this work. The project will concentrate on developing active device structures of 1.55 µm QD lasers with an aim to achieve superior optical properties and improved gain characteristics. Cross-examination using AFM and PL can correlate the growth parameters, morphology and optical quality of the quantum dots. QD development on native InP wafers will be carried out in parallel with the development of InP growth on mismatched Si substrates. Electrically injected lasers with temperature-insensitive and low threshold current operation will be demonstrated to guide material development and optimisation.

Start date: April, July or October 2021. 4 years Full Time.

How to Apply:

Applicants should submit an application for postgraduate study via the Cardiff University webpages (https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/physics-and-astronomy) including:

• an upload of your CV
• a personal statement/covering letter
• two references
• Current academic transcripts

Applicants should select Doctor of Philosophy, with a start date of April, July or October 2021.

In the research proposal section of your application, please specify the project title and supervisors of this project and copy the project description in the text box provided. In the funding section, please select the ’self -funding’ option.

Candidates should hold a good bachelor’s degree (first or upper second-class honours degree) or a MSc degree in Physics or a related subject.

Applicants whose first language is not English will be required to demonstrate proficiency in the English language (IELTS 6.5 or equivalent).