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Reza Maram Qartavol (PhD)

Preventing the computation energy crisis through sustainable optics

Current information and communications technology (ICT), including smartphones, computers, networks account for ~5-10% of the total global electricity consumption. This share is rapidly increasing with serious consequences for the economy and the environment if no changes are made to how we deliver and consume information. The problem is particularly compounded by our desire for high-speed computation since energy consumption significantly increases with speed in present electronic-based signal processors. Therefore the need for low-energy, high-speed computation is not just a technological issue, but one that has real ethical implications of opening access to affordable ICT without accelerating global pollution and climate change. Unless new technologies are found, it is predicted that growth in computational processing power will come to a halt within the next two decades using only present electronics technology. Among other alternative technologies, the use of light has been extensively explored to provide a way to overcome the limitations of computational speed inherent in electronics because processing speeds can be 1000 times faster than electronics. However, many in the optical research community have largely ignored energy consumption of optical processors, typically exploiting a variety of nonlinear optical effects, which typically scales to be at least 1000 times higher than electronics. As it is, proposed solutions to date are much more unsustainable for energy consumption than current electronics.

My research is a novel attempt towards developing a technological solution to the problem of energy consumption in optical processors, particularly, logic gates which are the fundamental building blocks of digital computing devices and at the core of energy consumption problem. The operation of our proposed logic gates looks nothing like any previous logic gate – electronic or optical and it represents a new paradigm shift in gate design. Rather than throwing away the unwanted part of the input energy like other methods, instead, we reuse the energy in the logic gate to build the output signal, similar to how noise-cancelling head-phones use waves from the noise in the room to destroy background noise. The proposed techniques may provide not only ‘orders of magnitude improvements in signal-processing speed’ but ‘with a fraction of the power consumption’ required by present electronic technologies. Such sustainable green solutions to a fundamental problem in computing and engineering, information consumption, will be needed to prevent an impending global data/energy crisis.