A Novel Optical Coupler for Nanophotonics

During a previous EPSRC grant we developed a novel means of coupling light from an optical fibre to a very small semiconductor waveguides, of the order on 250nm in height, resulting in numerous publications and a patent. The predicted theoretical efficiency for the best device design was in excess of 90%, but when fabricated at the Southampton Microelectronics facility, the dimensions produced were incorrect due to an equipment failure, reducing the efficiency to a theoretical value of ~60%. Measured efficiency of this device was 55%, which is clearly very encouraging. Southampton University have agreed to provide devices of the correct dimensions that now need to be characterised in terms of coupling efficiency, polarisation and thermal performance. This one year project will characterise the devices, and will potentially demonstrate the highest coupling efficiency in the world into such a small device. This potentially world leading result will have immediate impact as this is a topical subject of research at present, particularly for novel applications such as optical interconnect.