Background of EDISON - GA

The limited dynamic range of most digital cameras is due to the method of operation of the pixel used in these cameras. Such pixels integrate light on a photodiode and readout this integrated light at the end of a reference frame. Often this integration time is either too short for low intensities or too high for bright intensities to generate a faithfully integrated response. In addition, most digital cameras use a rolling shutter mechanism which limits their usability in scenes with high speed motion. Previous research conducted in the group of Dr. Bhaskar Choubey has generated new pixel topologies which can record a large dynamic range of input intensities. Furthermore, this pixel can produce any monotonically changing transduction function between the input light and output of the camera.

However, better colour response requires better and sharper colour filters. Towards this end, previous research in the group of Prof. David Cumming has shown integration of Plasmonic based nanostructures on a CMOS photodetectors. These nanostructures designed using single electron beam lithography and dry etch have shown the potential of application as sharp filters, which can be designed for different pass bands.

In order to use these techniques in commercial or medical imaging, one needs to design large format image sensors with various interface circuits. Particularly, in x-ray applications, one needs to stitch a number of image sensors side-by-side to produce a good quality focal plane array. Such arrays needs complex interface circuits to ensure no gaps in images acquired.

The Industrial partner of the project, Awaiba is a successful small and medium scale enterprise which in the past seven years has introduced a range of CMOS image sensors for various applications. In particular, they have produced a range of biomedical cameras for use in x-ray panels, endoscopy and computed tomography. They have also introduced the smallest camera in the world with a size of 1mm.