Device and Material Characterisation of Vertical Cavity Surface Emitting Lasers

Vertical Cavity Surface Emitting Lasers (VCSELs) are required for a large number of applications due to low energy usage, superior beam quality and the potential for very large volume manufacturing. The epitaxial layer design and the fabrication methodology are substantially different for the different characteristics required by different applications. This leads to different requirements in the scaling up of manufacturing. The student will gain an overview of the entire VCSEL manufacturing process from the design of suitable structures for particular applications, the growth of the Compound Semiconductor layers, the fabrication of devices and arrays of devices, the on-wafer testing for quality assurance and the measurement of individual characteristics together with an understanding of the underlying physics. The student will address the scientific challenges associated with manufacturing two representative types of VCSELS; the first primarily requiring the efficient conversion of electrical to optical energy and the second focussed on VCSELs with very high beam quality and narrow laser linewidth. The student will also investigate the opportunities for growth and fabrication on different substrates such as Silicon and even amorphous materials.

Industrial CASE award in partnership with IQE plc.
(4 year funded PhD)

Supervisors Prof Peter Smowton and Dr Iwan Davies (IQE)
The PhD will be carried out across the IQE and Cardiff University sites