18 July 2012
One of the fundamental components used in optics, the semiconductor laser, which powers the internet, laser machining, the defence industry and scientific research, is set to be revolutionised thanks to a grant of over £640,000.
The optical lens has been in use for many hundreds of years and uses refraction to focus light to a point. This project will use a radical new approach based on what are known as nanoantennas or optical antennas.
A conventional radio antenna is used to transmit or receive electromagnetic waves in many different applications such as mobile phones and the size of the antenna is roughly the same size as the electromagnetic wavelength.
In recent years researchers around the world have realised that this same principle can apply to light which is part of the same electromagnetic spectrum as radio waves, but with a wavelength about 100,000 times smaller.
The researchers will use arrays of nanoscale optical antennas to focus and steer light by controlling the time delay at each of the antennas. This is known as a Phased Array antenna and has been in use in radio antennas for many years.
The project will integrate these nanoantenna arrays on to the facets of semiconductor lasers to enable electronically controlled focusing and steering of light beams, which could dramatically reduce the cost of many laser based applications including medical sensors and optical communications systems.
The University of Bristol have been awarded £412,176 by the EPSRC for the three-year project, Integrated Tunable Flat Lenses (TuneFuL). The project started on 17 May 2012 and will end on 16 May 2015.
The University of Exeter have been awarded £233,289 by the EPSRC for the three-year project, Integrated Tunable Flat Lenses.
The team showed preliminary results in a paper published in January 2012 in Applied Physics Letters. G R Nash, J L Stokes, J R Pugh, and S J B Przeslak, P J Heard, J G Rarity and M J Cryan Single Lateral Mode Mid-Infrared Laser Diode using Sub-Wavelength Modulation of the Facet Reflectivity, Applied Physics Letters (Jan 2012).
About the Engineering and Physical Sciences Research Council (EPSRC)
The Engineering and Physical Sciences Research Council (EPSRC) is the UK’s main agency for funding research in engineering and the physical sciences. EPSRC invests around £800 million a year in research and postgraduate training, to help the nation handle the next generation of technological change. The areas covered range from information technology to structural engineering, and mathematics to materials science. This research forms the basis for future economic development in the UK and improvements for everyone’s health, lifestyle and culture. EPSRC works alongside other Research Councils with responsibility for other areas of research. The Research Councils work collectively on issues of common concern via Research Councils UK.
The light emitting facet of a semiconductor laser that has been patterned with an array of aperture antennas in order to control the beamshape of the laser