Ultrafast optical control in semiconductor

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The standard of living that we enjoy today is largely due to our understanding of the natural world and our attempts to apply that understanding in technology. In some cases we strive to surpass what nature has to offer and develop new materials or processes to advance technology for the benefits of society.        Our research program attempts to further the use of light in information and photonic technologies. Canada is one of the leaders in this area with large and small companies proposing and marketing new ways to increase the capacity of the internet or enhance communication and other information services. Besides helping to satisfy demands for trained manpower in the broad photonics industrial sector, university-based groups such as ours investigate new ideas for the next generation of optical technology.       We focus on two thrusts related to gaining control of how light and semiconductors interact. In the first thrust, we use the coherence or phase property of laser radiation to directly control the amplitude and direction of charge and spin currents, placing these currents where we want them and when we want them, on time scales as short as femtoseconds, i.e. thousands of millionths of millionths of a second. These techniques might allow for the possible development of new types of information cryptography and quantum information processing.       The other thrust employs nanostructed semiconductors to control light.  By varying the architecture of materials that transmit light one can control how pulses propagate, how light can be used to switch or rout other light pulses, and, also control how fast light pulses move on a chip.  For example, with respect to how fast light moves, while it is known that nothing travels faster than light in some cases light based information, can overload a communications system. "Slow" light is required for optical buffers or storage devices to control the flow of  information.  The problem is to do so in a manner that allows the short optical pulses that underpin high speed communications systems to be delayed by adjustable amounts without the pulses breaking up.