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Dr. Byoung Ham

Gwangju Institute of Science and Techbology, Gwangju, Korea


Talk Title
Direct frequency conveverion between optical and microwave fields for 5G technologies

Talk Abstract

In this talk, I present a novel wavelength conversion technique between optical and microwave fields for a direct data conversion process, for example, in a base station of wireless communications. As the data conversion rate increases, its power consumption in the base station increases too, where the energy control in the wireless communication networks has already become a major issue. Conventional frequency conversion process between optical and microwave fields has been performed via optical wave-mixing process between two coherent lasers, where the frequency conversion process is quite inefficient due to low nonlinearity and thus energy consuming. As the microwave frequency increases for example in  5G wireless communications by an order of magnitude, the inefficiency in the conversion process becomes severe. Here, I propose a simple quantum technology to resolve the indirect, complex and inefficient wavelength conversion process in the base station, whereas the proposed optical to microwave conversion process and vice versa is direct, simple, and energy efficient. In conventional nonlinear optics, phase mismatching between optical and microwave fields has prohibited the direct coupling between them for any applications. According to a simple electromagnetic theory, however, the energy density of a propagating field increases as its propagation speed gets slow down inside a medium. Thus, the limited nonlinear efficiency resulting from the phase mismatching can be resolved via slowing down the the light speed. Moreover, both absorption and dispersion of the fields at the absorption line center becomes zero if EIT or CPT is involved. Thus, the phase mismatch between optical and microwave fields can also be minimized and coupled each other. Finally, the spatial envelops of both optical and microwave fields can be perfectly matched inside a medium due to the coherent conversion process in a slow light regime. As a result, the proposed direct frequency conversion between optical and microwave fields can be near perfect and thus pave a road to the 5G wireless communication networks, where the inefficient and power consuming conventional rf technologies in the base station can be replaced by quantum technologies. By the way, the ultraslow light has already been observed in atomic media, rare-earth doped solids, semiconductors, metamaterials, and even Si-based optical ring resonators over the last two decades and has also been applied to quantum nonlinear optics such as single photon switching and Schrodinger’s cat.

Short Biography

Dr. Byoung Ham is a full professor of EECS department and concurrently a director of the Center for Photon Information Processing, GIST, S. Korea. He got a Ph.D. in 1995 under the subject of lasers without inversion in solids. He joined MIT as a postdoc and specialized in quantum nonlinear optics such as nondegenerate four-wave mixing and ultraslow light. In 2000s, he demonstrated the stop light in solids for the first time and expanded the basic concept of light-matter interactions to quantum switching, quantum memories, and all-optical logic gates. His recent research focuses on light-matter interactions for ultrafast all-optical information processing, quantum machine learning, quantum memories, and secured quantum communciations. One of his recent research interests is direct coupling between lights and sounds for supervision, unverwater target tracking, and real-time medical imaging. The idea of direct wavelength conversion between optical and microwave fields should open a door to a new relem of 5G wireless communications in terms of high speed, direct data processing, cost effectiveness, and energy saving. Dr. Ham was awarded “This Month Scientist” by the Korean government in 2010 and “Best Scholar Award” by the Optical Society of Korea in 2013. He has served for the international optics community as a topical editor of Applied Optics in Optical Society of America, the USA, and an Advisory Board member of Optics Communications in Elsevier, UK.

Talk Keywords
optical-microwave conversion, frequency conversion, base station optoelectronics, quantum nonlinear optics, ultraslow light, dark resonance.
Target Audience
Researchers, Government policy makers, Industrail leaders, Students, General publics
Speaker-intro video

The International Conference on Innovative Applied Energy (IAPE’18)