Photonic Devices for Sensing and Communication

Electrical Engineering Professor Adam Mock, from the School of Engineering and Technology at Central Michigan University, performs computational electromagnetic modeling of micrometer and nanometer scale photonic devices. While these devices are microscopic in size, the similarly microscopic optical wavelength must be sufficiently resolved in simulations. For devices with sub-wavelength features in all three dimensions, computational demands are significant. Mock comments, "Fortunately, the state-of-the-art HPCC resources at MSU make multi-parameter optimizations tractable." Professor Mock's photonic device research targets three primary applications: (1) chip-scale optical data communication, (2) optical sensing, and (3) solar energy. In each application, device goals resolve around controlling or measuring the direction, speed and/or intensity of light.

1. Chip-scale optical data communication: The world's communication infrastructure is made up of thousands of kilometers of glass optical fibers that connect people on opposite sides of the earth. While this technology is excellent at transporting data over long distances, routing and switching the data to ensure that it reaches its intended recipient often requires signal processing in the electrical domain. Current research seeks to perform switching, routing and other signal processing in the optical domain to improve speed, cost and power consumption. The goal of this work is to produce photonic integrated circuits in which hundreds of data channels can be processed simultaneously. These technologies are beginning to be deployed in highly connected data centers. Professor Mock is primarily interested in small footprint microresonators for light generation, filtering and switching.
2. Optical sensing: Optical sensors use light to measure the quantity of a particular gas or liquid. This is done by measuring how much light is absorbed by a sample or by a change in the sample's refractive index. Careful design of the sub-wavelength geometries and use of specialized materials can enhance the sensitivity, the response time or both. Continued engineering of sensor technologies will make them even more ubiquitous in industrial, military and controlled environment settings. Professor Mock's work is investigating microstructured optical fibers as highly sensitive optical sensors with fast response time that can be easily deployed for continuous monitoring in large areas.
3. Solar energy: As humans' energy needs continue to grow, the conversion of light energy from the sun into electrical energy is going to play an increasing role in our energy portfolio. Photovoltaic technologies involve two important engineerable processes: trapping light and converting the trapped light into electrical current. Both processes continue to be studied and optimized, and highly accurate device modeling plays a crucial role. Professor Mock is investigating improved light-trapping and absorption via highly scattering nanocomposites.